Skip to main content

GMAB 6-K

Genmab A/S (GMAB)

6-K 2025-04-14 For: 2025-04-14
View Original
Added on April 08, 2026

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549


FORM 6-K


REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16

OF THE SECURITIES EXCHANGE ACT OF 1934

FOR THE MONTH OF APRIL 2025


COMMISSION FILE NUMBER 001-38976

Genmab A/S
(Exact name of Registrant as specified in its charter)

Carl Jacobsens Vej 30

2500 Valby

Denmark

+45 70 20 27 28
(Address of principal executive offices)


Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F ⌧ Form 40-F ◻

This report on Form 6-K shall be deemed to be incorporated by reference in Genmab A/S’s registration statements on Form S-8 (File No. 333-232693, 333-253519, 333-262970, 333-277273 and 333-284876) and to be a part thereof from the date on which this report is filed, to the extent not superseded by documents or reports subsequently filed or furnished.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

nthony
GENMAB A/S
BY: /s/ Anthony Pagano
Name: Anthony Pagano
Title: Executive Vice President & Chief Financial Officer

DATE: APRIL 14, 2025

EXHIBIT INDEX

O
Exhibit Description of Exhibit
99.1 Company Announcement Dated April 14, 2025: Transactions in Connection with Share Buy-back Program
99.1(a) Appendix Share buyback program – Specification for April 7 – April 9, 2025
99.1(b) Appendix Share buyback program – Specification for April 10 – April 11, 2025

Exhibit 99.1

Graphic

Transactions in Connection with Share Buy-back Program

Company Announcement

COPENHAGEN, Denmark; April 14, 2025 – Genmab A/S (Nasdaq: GMAB). On March 25, 2025, Genmab announced the initiation of a share buy-back program to repurchase up to 2.2 million shares to reduce capital and to honor our commitments under the Restricted Stock Unit program. The share buy-back program is expected to be completed no later than July 10, 2025.

The following transactions were executed under the program from April 7 to April 11, 2025:

Trading Platform No. of shares Average price (DKK) Total value (DKK)
Accumulated through last announcement 636,089 842,761,475.78
April 7, 2025 XCSE 57,453 1,220.89
BCXE 28,000 1,220.60
AQEU 4,700 1,218.75
TQEX 5,500 1,218.54
Total 95,653 116,750,732.64
April 8, 2025 XCSE 54,200 1,269.18
BCXE 26,400 1,269.08
AQEU 4,400 1,269.80
TQEX 5,000 1,268.78
Total 90,000 114,224,256.00
April 9, 2025 XCSE 51,000 1,189.42
BCXE 26,000 1,189.36
AQEU 3,752 1,187.35
TQEX 5,000 1,190.17
Total 85,752 101,989,587.11
April 10, 2025 XCSE 51,010 1,250.98
BCXE 26,579 1,250.91
AQEU 4,800 1,250.99
TQEX 5,100 1,251.84
Total 87,489 109,449,263.93
April 11, 2025 XCSE 52,840 1,222.93
BCXE 27,400 1,222.90
AQEU 3,579 1,222.79
TQEX 5,100 1,222.09
Total 88,919 108,735,915.15
Total 447,813 551,149,754.83
Accumulated under the program 1,083,902 1,393,911,230.61

Genmab A/S Tel: +45 7020 2728 Company Announcement no. 19
Carl Jacobsens Vej 30 Fax: +45 7020 2729 Page 1/2
2500 Valby, Denmark www.genmab.com CVR no. 2102 3884
LEI Code 529900MTJPDPE4MHJ122

Graphic

Transactions in Connection with Share Buy-back Program

Details of each transaction are included as an appendix to this announcement.

Following these transactions, Genmab holds 1,536,655 shares as treasury shares, corresponding to 2.40% of the total share capital and voting rights.

The share buy-back program is undertaken in accordance with Regulation (EU) No. 596/2014 (‘MAR’) and the Commission Delegated Regulation (EU) 2016/1052, also referred to as the “Safe Harbour Regulation.” Further details on the terms of the share buy-back program can be found in our company announcement no. 14 dated March 25, 2025.

About Genmab

Genmab is an international biotechnology company with a core purpose of guiding its unstoppable team to strive toward improving the lives of patients with innovative and differentiated antibody therapeutics. For more than 25 years, its passionate, innovative and collaborative team has invented next-generation antibody technology platforms and leveraged translational, quantitative and data sciences, resulting in a proprietary pipeline including bispecific T-cell engagers, antibody-drug conjugates, next-generation immune checkpoint modulators and effector function-enhanced antibodies. By 2030, Genmab’s vision is to transform the lives of people with cancer and other serious diseases with knock-your-socks-off (KYSO) antibody medicines^®^.

Established in 1999, Genmab is headquartered in Copenhagen, Denmark, with international presence across North America, Europe and Asia Pacific. For more information, please visit Genmab.com and follow us on LinkedIn and X.

Contact:
Marisol Peron, Senior Vice President, Global Communications & Corporate Affairs

T: +1 609 524 0065; E: [email protected]

Andrew Carlsen, Vice President, Head of Investor Relations

T: +45 3377 9558; E: [email protected]


This Company Announcement contains forward looking statements. The words “believe,” “expect,” “anticipate,” “intend” and “plan” and similar expressions identify forward looking statements. Actual results or performance may differ materially from any future results or performance expressed or implied by such statements. The important factors that could cause our actual results or performance to differ materially include, among others, risks associated with pre-clinical and clinical development of products, uncertainties related to the outcome and conduct of clinical trials including unforeseen safety issues, uncertainties related to product manufacturing, the lack of market acceptance of our products, our inability to manage growth, the competitive environment in relation to our business area and markets, our inability to attract and retain suitably qualified personnel, the unenforceability or lack of protection of our patents and proprietary rights, our relationships with affiliated entities, changes and developments in technology which may render our products or technologies obsolete, and other factors. For a further discussion of these risks, please refer to the risk management sections in Genmab’s most recent financial reports, which are available on www.genmab.com and the risk factors included in Genmab’s most recent Annual Report on Form 20-F and other filings with the U.S. Securities and Exchange Commission (SEC), which are available at www.sec.gov. Genmab does not undertake any obligation to update or revise forward looking statements in this Company Announcement nor to confirm such statements to reflect subsequent events or circumstances after the date made or in relation to actual results, unless required by law.


Genmab A/S and/or its subsidiaries own the following trademarks: Genmab^®^; the Y-shaped Genmab logo^®^; Genmab in combination with the Y-shaped Genmab logo^®^; HuMax^®^; DuoBody^®^; HexaBody^®^; DuoHexaBody^®^, HexElect^®^ and KYSO^®^.

Genmab A/S Tel: +45 7020 2728 Company Announcement no. 19
Carl Jacobsens Vej 30 Fax: +45 7020 2729 Page 2/2
2500 Valby, Denmark www.genmab.com CVR no. 2102 3884
LEI Code 529900MTJPDPE4MHJ122

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

Issuer Date Time CET Quantity Price (DKK) Venue
GENMAB A/S 07-Apr-2025 09:35:27 AM 42 1177.00 XCSE
GENMAB A/S 07-Apr-2025 09:35:27 AM 32 1177.00 XCSE
GENMAB A/S 07-Apr-2025 09:35:27 AM 80 1177.00 AQEU
GENMAB A/S 07-Apr-2025 09:35:27 AM 73 1177.00 CEUX
GENMAB A/S 07-Apr-2025 09:35:33 AM 54 1177.00 XCSE
GENMAB A/S 07-Apr-2025 09:35:33 AM 49 1177.00 CEUX
GENMAB A/S 07-Apr-2025 09:35:34 AM 54 1177.00 AQEU
GENMAB A/S 07-Apr-2025 09:36:09 AM 26 1178.00 XCSE
GENMAB A/S 07-Apr-2025 09:36:09 AM 28 1178.00 CEUX
GENMAB A/S 07-Apr-2025 09:36:36 AM 33 1177.50 AQEU
GENMAB A/S 07-Apr-2025 09:36:36 AM 76 1177.50 TQEX
GENMAB A/S 07-Apr-2025 09:36:39 AM 26 1177.00 XCSE
GENMAB A/S 07-Apr-2025 09:36:39 AM 31 1176.50 AQEU
GENMAB A/S 07-Apr-2025 09:36:39 AM 71 1176.50 TQEX
GENMAB A/S 07-Apr-2025 09:36:39 AM 28 1177.00 CEUX
GENMAB A/S 07-Apr-2025 09:37:32 AM 28 1179.00 XCSE
GENMAB A/S 07-Apr-2025 09:37:32 AM 55 1179.00 XCSE
GENMAB A/S 07-Apr-2025 09:37:35 AM 87 1178.00 XCSE
GENMAB A/S 07-Apr-2025 09:37:35 AM 27 1178.50 TQEX
GENMAB A/S 07-Apr-2025 09:37:35 AM 51 1178.00 CEUX
GENMAB A/S 07-Apr-2025 09:37:39 AM 25 1177.50 TQEX
GENMAB A/S 07-Apr-2025 09:37:40 AM 86 1177.00 XCSE
GENMAB A/S 07-Apr-2025 09:37:40 AM 9 1177.00 CEUX
GENMAB A/S 07-Apr-2025 09:37:40 AM 46 1177.00 CEUX
GENMAB A/S 07-Apr-2025 09:37:48 AM 64 1176.00 XCSE
GENMAB A/S 07-Apr-2025 09:37:48 AM 75 1176.00 CEUX
GENMAB A/S 07-Apr-2025 09:38:01 AM 24 1174.50 XCSE
GENMAB A/S 07-Apr-2025 09:38:31 AM 28 1173.00 XCSE
GENMAB A/S 07-Apr-2025 09:38:31 AM 12 1173.00 TQEX
GENMAB A/S 07-Apr-2025 09:38:31 AM 18 1173.00 TQEX
GENMAB A/S 07-Apr-2025 09:38:36 AM 24 1172.00 XCSE
GENMAB A/S 07-Apr-2025 09:40:29 AM 84 1180.00 XCSE
GENMAB A/S 07-Apr-2025 09:40:29 AM 24 1180.00 TQEX
GENMAB A/S 07-Apr-2025 09:40:29 AM 22 1180.00 CEUX
GENMAB A/S 07-Apr-2025 09:40:49 AM 63 1180.50 XCSE
GENMAB A/S 07-Apr-2025 09:41:20 AM 40 1180.00 CEUX
GENMAB A/S 07-Apr-2025 09:41:39 AM 5 1180.50 CEUX
GENMAB A/S 07-Apr-2025 09:42:22 AM 46 1183.00 XCSE
GENMAB A/S 07-Apr-2025 09:42:22 AM 44 1183.00 XCSE
GENMAB A/S 07-Apr-2025 09:42:52 AM 24 1182.50 TQEX
GENMAB A/S 07-Apr-2025 09:42:52 AM 64 1182.50 CEUX

1

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 09:44:20 AM 87 1185.50 XCSE
GENMAB A/S 07-Apr-2025 09:44:20 AM 56 1185.50 CEUX
GENMAB A/S 07-Apr-2025 09:44:32 AM 45 1185.00 TQEX
GENMAB A/S 07-Apr-2025 09:44:37 AM 87 1184.00 XCSE
GENMAB A/S 07-Apr-2025 09:44:37 AM 58 1184.50 CEUX
GENMAB A/S 07-Apr-2025 09:44:54 AM 7 1185.50 CEUX
GENMAB A/S 07-Apr-2025 09:45:12 AM 25 1188.00 XCSE
GENMAB A/S 07-Apr-2025 09:45:12 AM 20 1188.00 XCSE
GENMAB A/S 07-Apr-2025 09:45:12 AM 38 1188.00 XCSE
GENMAB A/S 07-Apr-2025 09:47:05 AM 86 1192.00 XCSE
GENMAB A/S 07-Apr-2025 09:47:05 AM 10 1191.00 XCSE
GENMAB A/S 07-Apr-2025 09:47:05 AM 79 1191.00 XCSE
GENMAB A/S 07-Apr-2025 09:47:05 AM 86 1192.50 CEUX
GENMAB A/S 07-Apr-2025 09:47:05 AM 79 1191.50 CEUX
GENMAB A/S 07-Apr-2025 09:47:15 AM 26 1191.50 CEUX
GENMAB A/S 07-Apr-2025 09:47:21 AM 31 1190.50 CEUX
GENMAB A/S 07-Apr-2025 09:47:48 AM 84 1191.00 XCSE
GENMAB A/S 07-Apr-2025 09:48:04 AM 11 1192.00 CEUX
GENMAB A/S 07-Apr-2025 09:48:04 AM 21 1192.00 CEUX
GENMAB A/S 07-Apr-2025 09:48:05 AM 88 1191.50 XCSE
GENMAB A/S 07-Apr-2025 09:48:15 AM 4 1190.50 CEUX
GENMAB A/S 07-Apr-2025 09:48:34 AM 84 1192.00 XCSE
GENMAB A/S 07-Apr-2025 09:48:34 AM 27 1192.00 AQEU
GENMAB A/S 07-Apr-2025 09:48:48 AM 66 1192.00 XCSE
GENMAB A/S 07-Apr-2025 09:48:48 AM 31 1192.00 AQEU
GENMAB A/S 07-Apr-2025 09:48:49 AM 32 1191.50 CEUX
GENMAB A/S 07-Apr-2025 09:48:53 AM 85 1191.00 XCSE
GENMAB A/S 07-Apr-2025 09:48:53 AM 25 1191.00 TQEX
GENMAB A/S 07-Apr-2025 09:48:53 AM 26 1191.00 AQEU
GENMAB A/S 07-Apr-2025 09:48:58 AM 21 1190.50 CEUX
GENMAB A/S 07-Apr-2025 09:49:00 AM 90 1190.00 XCSE
GENMAB A/S 07-Apr-2025 09:49:00 AM 24 1190.00 AQEU
GENMAB A/S 07-Apr-2025 09:51:02 AM 66 1194.00 XCSE
GENMAB A/S 07-Apr-2025 09:51:02 AM 25 1194.00 AQEU
GENMAB A/S 07-Apr-2025 09:51:02 AM 47 1194.00 CEUX
GENMAB A/S 07-Apr-2025 09:51:20 AM 24 1194.00 TQEX
GENMAB A/S 07-Apr-2025 09:51:20 AM 40 1194.50 CEUX
GENMAB A/S 07-Apr-2025 09:51:36 AM 27 1193.00 XCSE
GENMAB A/S 07-Apr-2025 09:51:36 AM 2 1193.00 XCSE
GENMAB A/S 07-Apr-2025 09:51:36 AM 28 1193.00 XCSE
GENMAB A/S 07-Apr-2025 09:51:36 AM 36 1193.00 CEUX
GENMAB A/S 07-Apr-2025 09:51:37 AM 54 1192.00 XCSE
GENMAB A/S 07-Apr-2025 09:51:37 AM 41 1192.00 CEUX

2

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 09:52:07 AM 24 1191.00 CEUX
GENMAB A/S 07-Apr-2025 09:52:51 AM 86 1191.50 XCSE
GENMAB A/S 07-Apr-2025 09:52:51 AM 12 1191.50 CEUX
GENMAB A/S 07-Apr-2025 09:52:51 AM 14 1191.50 CEUX
GENMAB A/S 07-Apr-2025 09:53:19 AM 45 1192.50 TQEX
GENMAB A/S 07-Apr-2025 09:53:19 AM 2 1192.50 TQEX
GENMAB A/S 07-Apr-2025 09:53:19 AM 12 1192.50 CEUX
GENMAB A/S 07-Apr-2025 09:53:19 AM 13 1192.50 CEUX
GENMAB A/S 07-Apr-2025 09:53:21 AM 11 1192.00 AQEU
GENMAB A/S 07-Apr-2025 09:53:56 AM 62 1191.50 XCSE
GENMAB A/S 07-Apr-2025 09:53:56 AM 51 1190.50 XCSE
GENMAB A/S 07-Apr-2025 09:53:59 AM 19 1190.00 CEUX
GENMAB A/S 07-Apr-2025 09:53:59 AM 5 1190.00 CEUX
GENMAB A/S 07-Apr-2025 09:54:03 AM 27 1189.50 CEUX
GENMAB A/S 07-Apr-2025 09:55:58 AM 85 1193.50 XCSE
GENMAB A/S 07-Apr-2025 09:55:58 AM 29 1193.50 AQEU
GENMAB A/S 07-Apr-2025 09:55:58 AM 35 1193.50 CEUX
GENMAB A/S 07-Apr-2025 09:56:05 AM 52 1195.00 XCSE
GENMAB A/S 07-Apr-2025 09:56:05 AM 36 1195.00 XCSE
GENMAB A/S 07-Apr-2025 09:56:05 AM 24 1195.50 CEUX
GENMAB A/S 07-Apr-2025 09:56:57 AM 85 1195.00 XCSE
GENMAB A/S 07-Apr-2025 09:56:58 AM 85 1194.00 XCSE
GENMAB A/S 07-Apr-2025 09:56:58 AM 34 1194.50 CEUX
GENMAB A/S 07-Apr-2025 09:58:00 AM 61 1195.50 XCSE
GENMAB A/S 07-Apr-2025 09:58:00 AM 26 1195.50 CEUX
GENMAB A/S 07-Apr-2025 09:58:21 AM 44 1194.50 XCSE
GENMAB A/S 07-Apr-2025 09:58:21 AM 24 1194.50 CEUX
GENMAB A/S 07-Apr-2025 09:58:31 AM 27 1194.00 AQEU
GENMAB A/S 07-Apr-2025 09:58:33 AM 3 1193.50 CEUX
GENMAB A/S 07-Apr-2025 09:58:33 AM 30 1193.50 CEUX
GENMAB A/S 07-Apr-2025 09:58:41 AM 1 1193.00 XCSE
GENMAB A/S 07-Apr-2025 09:58:41 AM 83 1193.00 XCSE
GENMAB A/S 07-Apr-2025 09:58:45 AM 2 1192.50 CEUX
GENMAB A/S 07-Apr-2025 09:58:45 AM 24 1192.50 CEUX
GENMAB A/S 07-Apr-2025 09:59:09 AM 24 1195.00 CEUX
GENMAB A/S 07-Apr-2025 09:59:23 AM 13 1196.00 XCSE
GENMAB A/S 07-Apr-2025 09:59:23 AM 54 1196.00 XCSE
GENMAB A/S 07-Apr-2025 09:59:23 AM 27 1196.00 CEUX
GENMAB A/S 07-Apr-2025 10:00:10 AM 35 1196.50 TQEX
GENMAB A/S 07-Apr-2025 10:00:12 AM 72 1196.50 XCSE
GENMAB A/S 07-Apr-2025 10:00:32 AM 10 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:00:32 AM 30 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:00:34 AM 31 1196.00 CEUX

3

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 10:00:38 AM 63 1195.00 XCSE
GENMAB A/S 07-Apr-2025 10:00:38 AM 24 1195.00 CEUX
GENMAB A/S 07-Apr-2025 10:00:43 AM 20 1195.00 XCSE
GENMAB A/S 07-Apr-2025 10:00:43 AM 7 1195.00 XCSE
GENMAB A/S 07-Apr-2025 10:00:43 AM 27 1195.00 AQEU
GENMAB A/S 07-Apr-2025 10:00:43 AM 25 1195.00 CEUX
GENMAB A/S 07-Apr-2025 10:00:46 AM 54 1194.00 XCSE
GENMAB A/S 07-Apr-2025 10:01:04 AM 24 1194.50 CEUX
GENMAB A/S 07-Apr-2025 10:01:28 AM 34 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:03:02 AM 75 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:05:04 AM 87 1205.00 XCSE
GENMAB A/S 07-Apr-2025 10:05:04 AM 87 1203.50 XCSE
GENMAB A/S 07-Apr-2025 10:05:04 AM 13 1202.50 XCSE
GENMAB A/S 07-Apr-2025 10:05:04 AM 71 1202.50 XCSE
GENMAB A/S 07-Apr-2025 10:05:04 AM 33 1205.00 TQEX
GENMAB A/S 07-Apr-2025 10:05:04 AM 26 1204.00 TQEX
GENMAB A/S 07-Apr-2025 10:05:04 AM 24 1205.00 AQEU
GENMAB A/S 07-Apr-2025 10:05:04 AM 62 1205.00 CEUX
GENMAB A/S 07-Apr-2025 10:05:04 AM 56 1203.50 CEUX
GENMAB A/S 07-Apr-2025 10:05:04 AM 54 1202.50 CEUX
GENMAB A/S 07-Apr-2025 10:05:05 AM 89 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:05:05 AM 56 1201.50 CEUX
GENMAB A/S 07-Apr-2025 10:05:37 AM 24 1202.50 XCSE
GENMAB A/S 07-Apr-2025 10:05:45 AM 26 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:08:07 AM 27 1205.50 TQEX
GENMAB A/S 07-Apr-2025 10:08:07 AM 20 1205.50 TQEX
GENMAB A/S 07-Apr-2025 10:08:48 AM 90 1204.50 XCSE
GENMAB A/S 07-Apr-2025 10:08:48 AM 25 1204.50 AQEU
GENMAB A/S 07-Apr-2025 10:08:48 AM 51 1205.00 CEUX
GENMAB A/S 07-Apr-2025 10:09:14 AM 35 1204.00 CEUX
GENMAB A/S 07-Apr-2025 10:09:31 AM 62 1203.50 XCSE
GENMAB A/S 07-Apr-2025 10:09:31 AM 26 1203.50 AQEU
GENMAB A/S 07-Apr-2025 10:09:31 AM 3 1203.00 CEUX
GENMAB A/S 07-Apr-2025 10:09:31 AM 21 1203.00 CEUX
GENMAB A/S 07-Apr-2025 10:10:02 AM 3 1202.50 XCSE
GENMAB A/S 07-Apr-2025 10:10:02 AM 40 1202.50 XCSE
GENMAB A/S 07-Apr-2025 10:10:21 AM 85 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:10:21 AM 48 1201.50 CEUX
GENMAB A/S 07-Apr-2025 10:11:05 AM 52 1201.00 CEUX
GENMAB A/S 07-Apr-2025 10:11:29 AM 7 1202.00 CEUX
GENMAB A/S 07-Apr-2025 10:11:29 AM 33 1202.00 CEUX
GENMAB A/S 07-Apr-2025 10:11:31 AM 45 1202.00 AQEU
GENMAB A/S 07-Apr-2025 10:11:42 AM 85 1201.50 XCSE

4

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 10:11:51 AM 25 1201.00 CEUX
GENMAB A/S 07-Apr-2025 10:11:58 AM 88 1200.50 XCSE
GENMAB A/S 07-Apr-2025 10:12:11 AM 87 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:12:11 AM 25 1200.00 CEUX
GENMAB A/S 07-Apr-2025 10:12:11 AM 30 1200.00 CEUX
GENMAB A/S 07-Apr-2025 10:12:31 AM 29 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:13:07 AM 33 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:13:37 AM 24 1201.00 CEUX
GENMAB A/S 07-Apr-2025 10:13:54 AM 29 1200.00 TQEX
GENMAB A/S 07-Apr-2025 10:13:59 AM 11 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:13:59 AM 16 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:13:59 AM 56 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:15:01 AM 6 1200.50 XCSE
GENMAB A/S 07-Apr-2025 10:15:06 AM 83 1200.50 XCSE
GENMAB A/S 07-Apr-2025 10:15:06 AM 28 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:15:33 AM 33 1201.50 CEUX
GENMAB A/S 07-Apr-2025 10:15:45 AM 31 1201.50 CEUX
GENMAB A/S 07-Apr-2025 10:15:48 AM 7 1201.00 XCSE
GENMAB A/S 07-Apr-2025 10:15:48 AM 78 1201.00 XCSE
GENMAB A/S 07-Apr-2025 10:16:15 AM 36 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:17:03 AM 42 1202.00 XCSE
GENMAB A/S 07-Apr-2025 10:17:03 AM 30 1202.00 XCSE
GENMAB A/S 07-Apr-2025 10:17:03 AM 10 1202.00 XCSE
GENMAB A/S 07-Apr-2025 10:17:03 AM 12 1202.00 XCSE
GENMAB A/S 07-Apr-2025 10:18:14 AM 41 1202.00 CEUX
GENMAB A/S 07-Apr-2025 10:18:20 AM 83 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:18:20 AM 32 1201.50 TQEX
GENMAB A/S 07-Apr-2025 10:18:20 AM 24 1201.50 AQEU
GENMAB A/S 07-Apr-2025 10:18:33 AM 32 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:18:33 AM 15 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:18:33 AM 11 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:18:33 AM 55 1201.50 XCSE
GENMAB A/S 07-Apr-2025 10:18:46 AM 24 1200.50 TQEX
GENMAB A/S 07-Apr-2025 10:18:46 AM 30 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:18:53 AM 89 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:18:53 AM 11 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:18:53 AM 14 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:19:01 AM 77 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:19:01 AM 85 1197.50 XCSE
GENMAB A/S 07-Apr-2025 10:19:01 AM 15 1197.50 AQEU
GENMAB A/S 07-Apr-2025 10:19:01 AM 39 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:19:01 AM 37 1197.50 CEUX
GENMAB A/S 07-Apr-2025 10:20:33 AM 20 1202.00 TQEX

5

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 10:20:41 AM 35 1201.50 CEUX
GENMAB A/S 07-Apr-2025 10:20:45 AM 1 1201.50 CEUX
GENMAB A/S 07-Apr-2025 10:20:46 AM 87 1201.00 XCSE
GENMAB A/S 07-Apr-2025 10:20:46 AM 5 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:22:25 AM 83 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:22:25 AM 1 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:22:25 AM 31 1200.50 CEUX
GENMAB A/S 07-Apr-2025 10:22:37 AM 31 1201.50 AQEU
GENMAB A/S 07-Apr-2025 10:22:37 AM 4 1201.00 CEUX
GENMAB A/S 07-Apr-2025 10:22:37 AM 34 1201.00 CEUX
GENMAB A/S 07-Apr-2025 10:22:42 AM 89 1200.50 XCSE
GENMAB A/S 07-Apr-2025 10:22:55 AM 13 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:22:55 AM 11 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:22:55 AM 45 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:22:55 AM 11 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:22:55 AM 22 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:23:27 AM 83 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:25:07 AM 4 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:25:07 AM 79 1200.00 XCSE
GENMAB A/S 07-Apr-2025 10:25:07 AM 24 1200.00 TQEX
GENMAB A/S 07-Apr-2025 10:25:10 AM 19 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:25:10 AM 55 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:25:10 AM 8 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:25:10 AM 35 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:25:24 AM 13 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:25:24 AM 46 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:25:24 AM 24 1198.50 AQEU
GENMAB A/S 07-Apr-2025 10:25:24 AM 33 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:26:24 AM 58 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:26:24 AM 4 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:26:24 AM 34 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:27:59 AM 85 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:27:59 AM 84 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:27:59 AM 24 1199.00 TQEX
GENMAB A/S 07-Apr-2025 10:27:59 AM 24 1199.00 AQEU
GENMAB A/S 07-Apr-2025 10:27:59 AM 63 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:27:59 AM 44 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:28:28 AM 67 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:28:28 AM 44 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:28:41 AM 10 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:28:41 AM 14 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:28:41 AM 1 1198.00 TQEX
GENMAB A/S 07-Apr-2025 10:28:41 AM 28 1198.00 TQEX

6

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 10:28:41 AM 29 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:29:23 AM 24 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:29:44 AM 85 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:29:44 AM 27 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:29:44 AM 7 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:29:55 AM 30 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:29:55 AM 34 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:29:55 AM 27 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:30:05 AM 86 1197.50 XCSE
GENMAB A/S 07-Apr-2025 10:30:05 AM 29 1197.50 CEUX
GENMAB A/S 07-Apr-2025 10:30:29 AM 28 1196.50 XCSE
GENMAB A/S 07-Apr-2025 10:30:56 AM 34 1197.50 AQEU
GENMAB A/S 07-Apr-2025 10:31:09 AM 26 1197.50 CEUX
GENMAB A/S 07-Apr-2025 10:31:10 AM 34 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:31:10 AM 26 1197.00 TQEX
GENMAB A/S 07-Apr-2025 10:31:11 AM 28 1196.50 CEUX
GENMAB A/S 07-Apr-2025 10:31:17 AM 25 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:31:56 AM 35 1195.00 XCSE
GENMAB A/S 07-Apr-2025 10:33:22 AM 8 1195.00 XCSE
GENMAB A/S 07-Apr-2025 10:35:06 AM 25 1198.00 TQEX
GENMAB A/S 07-Apr-2025 10:35:06 AM 65 1198.00 CEUX
GENMAB A/S 07-Apr-2025 10:35:09 AM 1 1198.00 CEUX
GENMAB A/S 07-Apr-2025 10:35:23 AM 88 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:35:23 AM 47 1197.00 CEUX
GENMAB A/S 07-Apr-2025 10:35:25 AM 75 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:35:27 AM 4 1196.00 CEUX
GENMAB A/S 07-Apr-2025 10:35:30 AM 33 1196.00 CEUX
GENMAB A/S 07-Apr-2025 10:35:40 AM 21 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:35:41 AM 61 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:35:41 AM 24 1196.00 CEUX
GENMAB A/S 07-Apr-2025 10:37:44 AM 12 1199.00 CEUX
GENMAB A/S 07-Apr-2025 10:37:44 AM 31 1199.00 CEUX
GENMAB A/S 07-Apr-2025 10:37:46 AM 70 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:37:46 AM 14 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:38:03 AM 85 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:38:22 AM 24 1198.00 TQEX
GENMAB A/S 07-Apr-2025 10:38:22 AM 4 1198.00 AQEU
GENMAB A/S 07-Apr-2025 10:38:22 AM 29 1198.00 CEUX
GENMAB A/S 07-Apr-2025 10:39:24 AM 31 1197.50 XCSE
GENMAB A/S 07-Apr-2025 10:39:32 AM 23 1198.00 AQEU
GENMAB A/S 07-Apr-2025 10:39:35 AM 40 1197.50 XCSE
GENMAB A/S 07-Apr-2025 10:39:56 AM 6 1197.00 CEUX
GENMAB A/S 07-Apr-2025 10:39:56 AM 19 1197.00 CEUX

7

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 10:40:00 AM 13 1196.50 XCSE
GENMAB A/S 07-Apr-2025 10:40:00 AM 24 1196.50 XCSE
GENMAB A/S 07-Apr-2025 10:40:00 AM 25 1196.50 TQEX
GENMAB A/S 07-Apr-2025 10:40:07 AM 21 1195.50 XCSE
GENMAB A/S 07-Apr-2025 10:40:28 AM 88 1196.50 XCSE
GENMAB A/S 07-Apr-2025 10:40:28 AM 15 1196.50 CEUX
GENMAB A/S 07-Apr-2025 10:40:28 AM 23 1196.50 CEUX
GENMAB A/S 07-Apr-2025 10:40:52 AM 75 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:40:52 AM 25 1197.00 AQEU
GENMAB A/S 07-Apr-2025 10:40:52 AM 43 1197.00 CEUX
GENMAB A/S 07-Apr-2025 10:40:52 AM 1 1197.00 CEUX
GENMAB A/S 07-Apr-2025 10:41:00 AM 64 1195.50 XCSE
GENMAB A/S 07-Apr-2025 10:41:00 AM 24 1195.50 CEUX
GENMAB A/S 07-Apr-2025 10:41:26 AM 87 1194.50 XCSE
GENMAB A/S 07-Apr-2025 10:41:26 AM 26 1194.50 CEUX
GENMAB A/S 07-Apr-2025 10:42:09 AM 15 1196.00 TQEX
GENMAB A/S 07-Apr-2025 10:43:53 AM 28 1197.50 XCSE
GENMAB A/S 07-Apr-2025 10:43:53 AM 39 1197.50 XCSE
GENMAB A/S 07-Apr-2025 10:44:00 AM 56 1196.50 XCSE
GENMAB A/S 07-Apr-2025 10:44:00 AM 35 1196.50 CEUX
GENMAB A/S 07-Apr-2025 10:44:33 AM 37 1195.50 XCSE
GENMAB A/S 07-Apr-2025 10:44:33 AM 29 1196.50 AQEU
GENMAB A/S 07-Apr-2025 10:44:33 AM 25 1195.50 CEUX
GENMAB A/S 07-Apr-2025 10:45:28 AM 60 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:45:28 AM 20 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:45:50 AM 63 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:45:50 AM 26 1196.50 TQEX
GENMAB A/S 07-Apr-2025 10:45:50 AM 53 1196.50 CEUX
GENMAB A/S 07-Apr-2025 10:45:50 AM 44 1195.50 CEUX
GENMAB A/S 07-Apr-2025 10:46:00 AM 62 1195.00 XCSE
GENMAB A/S 07-Apr-2025 10:46:00 AM 27 1194.50 CEUX
GENMAB A/S 07-Apr-2025 10:46:35 AM 24 1195.50 CEUX
GENMAB A/S 07-Apr-2025 10:47:34 AM 53 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:47:42 AM 11 1196.00 XCSE
GENMAB A/S 07-Apr-2025 10:48:00 AM 1 1195.50 CEUX
GENMAB A/S 07-Apr-2025 10:48:00 AM 25 1195.50 CEUX
GENMAB A/S 07-Apr-2025 10:48:18 AM 45 1195.00 AQEU
GENMAB A/S 07-Apr-2025 10:49:46 AM 28 1196.50 TQEX
GENMAB A/S 07-Apr-2025 10:49:46 AM 49 1197.00 CEUX
GENMAB A/S 07-Apr-2025 10:52:02 AM 113 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:52:28 AM 16 1199.50 TQEX
GENMAB A/S 07-Apr-2025 10:53:14 AM 25 1201.00 XCSE
GENMAB A/S 07-Apr-2025 10:53:14 AM 42 1201.00 XCSE

8

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 10:53:14 AM 30 1201.00 XCSE
GENMAB A/S 07-Apr-2025 10:54:50 AM 50 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:54:50 AM 20 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:54:50 AM 1 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:54:50 AM 73 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:54:53 AM 32 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:54:53 AM 16 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:55:13 AM 5 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:55:13 AM 11 1199.50 XCSE
GENMAB A/S 07-Apr-2025 10:55:26 AM 71 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:55:50 AM 19 1199.50 CEUX
GENMAB A/S 07-Apr-2025 10:55:55 AM 80 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:55:55 AM 3 1199.00 XCSE
GENMAB A/S 07-Apr-2025 10:55:55 AM 24 1199.00 AQEU
GENMAB A/S 07-Apr-2025 10:56:09 AM 24 1198.50 TQEX
GENMAB A/S 07-Apr-2025 10:56:09 AM 3 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:56:09 AM 78 1198.50 CEUX
GENMAB A/S 07-Apr-2025 10:56:33 AM 90 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:56:33 AM 39 1198.50 XCSE
GENMAB A/S 07-Apr-2025 10:56:38 AM 33 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:56:52 AM 51 1198.00 XCSE
GENMAB A/S 07-Apr-2025 10:56:54 AM 47 1197.50 CEUX
GENMAB A/S 07-Apr-2025 10:56:54 AM 20 1197.50 CEUX
GENMAB A/S 07-Apr-2025 10:58:21 AM 56 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:58:21 AM 34 1197.00 XCSE
GENMAB A/S 07-Apr-2025 10:58:21 AM 26 1197.00 TQEX
GENMAB A/S 07-Apr-2025 10:58:26 AM 44 1196.50 AQEU
GENMAB A/S 07-Apr-2025 11:00:08 AM 87 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:00:45 AM 83 1198.00 CEUX
GENMAB A/S 07-Apr-2025 11:00:48 AM 85 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:00:48 AM 24 1197.50 TQEX
GENMAB A/S 07-Apr-2025 11:01:27 AM 14 1197.00 CEUX
GENMAB A/S 07-Apr-2025 11:01:59 AM 90 1196.50 XCSE
GENMAB A/S 07-Apr-2025 11:01:59 AM 27 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:01:59 AM 57 1197.00 CEUX
GENMAB A/S 07-Apr-2025 11:02:30 AM 17 1195.50 XCSE
GENMAB A/S 07-Apr-2025 11:02:30 AM 66 1195.50 XCSE
GENMAB A/S 07-Apr-2025 11:02:30 AM 33 1196.00 CEUX
GENMAB A/S 07-Apr-2025 11:02:43 AM 24 1195.50 TQEX
GENMAB A/S 07-Apr-2025 11:04:31 AM 13 1195.50 XCSE
GENMAB A/S 07-Apr-2025 11:04:31 AM 75 1195.50 XCSE
GENMAB A/S 07-Apr-2025 11:04:31 AM 24 1195.50 AQEU
GENMAB A/S 07-Apr-2025 11:04:34 AM 42 1195.00 CEUX

9

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 11:04:37 AM 76 1194.50 XCSE
GENMAB A/S 07-Apr-2025 11:04:37 AM 9 1194.50 XCSE
GENMAB A/S 07-Apr-2025 11:04:51 AM 4 1194.00 CEUX
GENMAB A/S 07-Apr-2025 11:04:51 AM 1 1194.00 CEUX
GENMAB A/S 07-Apr-2025 11:05:03 AM 4 1193.00 XCSE
GENMAB A/S 07-Apr-2025 11:05:03 AM 43 1194.00 CEUX
GENMAB A/S 07-Apr-2025 11:05:11 AM 1 1193.00 XCSE
GENMAB A/S 07-Apr-2025 11:06:00 AM 84 1193.00 XCSE
GENMAB A/S 07-Apr-2025 11:06:00 AM 49 1193.00 CEUX
GENMAB A/S 07-Apr-2025 11:06:15 AM 25 1192.50 TQEX
GENMAB A/S 07-Apr-2025 11:06:45 AM 85 1192.00 XCSE
GENMAB A/S 07-Apr-2025 11:06:45 AM 1 1191.50 CEUX
GENMAB A/S 07-Apr-2025 11:06:45 AM 56 1191.50 CEUX
GENMAB A/S 07-Apr-2025 11:06:59 AM 84 1194.50 XCSE
GENMAB A/S 07-Apr-2025 11:06:59 AM 10 1194.00 AQEU
GENMAB A/S 07-Apr-2025 11:06:59 AM 10 1194.50 CEUX
GENMAB A/S 07-Apr-2025 11:06:59 AM 31 1194.50 CEUX
GENMAB A/S 07-Apr-2025 11:06:59 AM 30 1194.50 CEUX
GENMAB A/S 07-Apr-2025 11:07:27 AM 89 1194.50 XCSE
GENMAB A/S 07-Apr-2025 11:07:27 AM 25 1194.50 CEUX
GENMAB A/S 07-Apr-2025 11:09:47 AM 83 1194.50 XCSE
GENMAB A/S 07-Apr-2025 11:09:48 AM 16 1195.50 TQEX
GENMAB A/S 07-Apr-2025 11:10:37 AM 6 1196.00 CEUX
GENMAB A/S 07-Apr-2025 11:10:37 AM 49 1196.00 CEUX
GENMAB A/S 07-Apr-2025 11:11:44 AM 55 1198.50 CEUX
GENMAB A/S 07-Apr-2025 11:11:57 AM 40 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:11:57 AM 21 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:11:57 AM 7 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:12:57 AM 21 1198.50 CEUX
GENMAB A/S 07-Apr-2025 11:12:57 AM 23 1198.50 CEUX
GENMAB A/S 07-Apr-2025 11:13:10 AM 1 1198.00 XCSE
GENMAB A/S 07-Apr-2025 11:13:25 AM 87 1198.00 XCSE
GENMAB A/S 07-Apr-2025 11:13:25 AM 25 1198.00 TQEX
GENMAB A/S 07-Apr-2025 11:13:29 AM 4 1198.00 AQEU
GENMAB A/S 07-Apr-2025 11:13:31 AM 25 1198.00 AQEU
GENMAB A/S 07-Apr-2025 11:13:38 AM 53 1197.50 CEUX
GENMAB A/S 07-Apr-2025 11:14:54 AM 20 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:15:01 AM 88 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:15:01 AM 5 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:15:01 AM 12 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:15:27 AM 40 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:15:27 AM 30 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:15:27 AM 12 1197.00 XCSE

10

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 11:16:31 AM 26 1196.50 XCSE
GENMAB A/S 07-Apr-2025 11:16:31 AM 24 1196.00 TQEX
GENMAB A/S 07-Apr-2025 11:16:31 AM 26 1196.00 AQEU
GENMAB A/S 07-Apr-2025 11:16:31 AM 28 1196.00 CEUX
GENMAB A/S 07-Apr-2025 11:16:45 AM 85 1195.50 XCSE
GENMAB A/S 07-Apr-2025 11:17:21 AM 83 1197.00 XCSE
GENMAB A/S 07-Apr-2025 11:17:32 AM 16 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:17:56 AM 74 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:18:11 AM 35 1197.00 CEUX
GENMAB A/S 07-Apr-2025 11:18:26 AM 26 1198.00 TQEX
GENMAB A/S 07-Apr-2025 11:18:26 AM 39 1198.00 CEUX
GENMAB A/S 07-Apr-2025 11:18:26 AM 26 1198.00 CEUX
GENMAB A/S 07-Apr-2025 11:18:50 AM 10 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:18:50 AM 75 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:19:15 AM 12 1197.00 AQEU
GENMAB A/S 07-Apr-2025 11:19:15 AM 35 1197.00 CEUX
GENMAB A/S 07-Apr-2025 11:20:26 AM 89 1196.00 XCSE
GENMAB A/S 07-Apr-2025 11:20:26 AM 68 1196.00 CEUX
GENMAB A/S 07-Apr-2025 11:21:28 AM 21 1196.00 TQEX
GENMAB A/S 07-Apr-2025 11:21:28 AM 5 1196.00 TQEX
GENMAB A/S 07-Apr-2025 11:21:28 AM 30 1196.00 AQEU
GENMAB A/S 07-Apr-2025 11:22:28 AM 32 1196.50 XCSE
GENMAB A/S 07-Apr-2025 11:22:28 AM 16 1196.50 XCSE
GENMAB A/S 07-Apr-2025 11:23:57 AM 70 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:23:57 AM 18 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:23:57 AM 24 1197.50 TQEX
GENMAB A/S 07-Apr-2025 11:23:57 AM 75 1197.50 CEUX
GENMAB A/S 07-Apr-2025 11:24:28 AM 10 1198.00 XCSE
GENMAB A/S 07-Apr-2025 11:24:28 AM 74 1198.00 XCSE
GENMAB A/S 07-Apr-2025 11:25:44 AM 12 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:26:46 AM 40 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:26:46 AM 65 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:26:46 AM 8 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:26:59 AM 7 1198.50 CEUX
GENMAB A/S 07-Apr-2025 11:27:23 AM 16 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:27:27 AM 70 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:27:27 AM 83 1198.50 CEUX
GENMAB A/S 07-Apr-2025 11:27:46 AM 75 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:27:46 AM 24 1198.00 TQEX
GENMAB A/S 07-Apr-2025 11:27:46 AM 27 1197.50 AQEU
GENMAB A/S 07-Apr-2025 11:27:46 AM 63 1197.50 CEUX
GENMAB A/S 07-Apr-2025 11:30:05 AM 5 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:31:38 AM 25 1198.00 AQEU

11

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 11:31:41 AM 89 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:32:00 AM 44 1197.50 TQEX
GENMAB A/S 07-Apr-2025 11:32:28 AM 34 1199.00 CEUX
GENMAB A/S 07-Apr-2025 11:32:28 AM 36 1199.00 CEUX
GENMAB A/S 07-Apr-2025 11:33:27 AM 83 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:33:27 AM 43 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:33:27 AM 11 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:33:27 AM 24 1199.50 AQEU
GENMAB A/S 07-Apr-2025 11:35:26 AM 28 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:35:26 AM 16 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:35:26 AM 40 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:35:26 AM 11 1199.50 XCSE
GENMAB A/S 07-Apr-2025 11:35:26 AM 18 1199.00 CEUX
GENMAB A/S 07-Apr-2025 11:35:36 AM 89 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:35:36 AM 85 1197.50 XCSE
GENMAB A/S 07-Apr-2025 11:35:36 AM 25 1199.00 AQEU
GENMAB A/S 07-Apr-2025 11:35:36 AM 48 1199.00 CEUX
GENMAB A/S 07-Apr-2025 11:35:36 AM 38 1199.00 CEUX
GENMAB A/S 07-Apr-2025 11:37:41 AM 12 1199.00 TQEX
GENMAB A/S 07-Apr-2025 11:37:41 AM 19 1199.50 CEUX
GENMAB A/S 07-Apr-2025 11:37:41 AM 69 1199.50 CEUX
GENMAB A/S 07-Apr-2025 11:38:09 AM 26 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:09 AM 30 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:09 AM 16 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:09 AM 40 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 81 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 9 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 40 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 4 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 10 1198.50 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 26 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 30 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 3 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:38:12 AM 90 1198.50 CEUX
GENMAB A/S 07-Apr-2025 11:38:45 AM 85 1197.50 CEUX
GENMAB A/S 07-Apr-2025 11:40:31 AM 34 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:40:32 AM 5 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:40:32 AM 46 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:40:32 AM 27 1199.00 TQEX
GENMAB A/S 07-Apr-2025 11:40:55 AM 46 1199.00 AQEU
GENMAB A/S 07-Apr-2025 11:41:08 AM 40 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:41:08 AM 30 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:41:08 AM 16 1199.00 XCSE

12

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 11:41:08 AM 15 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:41:47 AM 16 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:41:47 AM 47 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:41:59 AM 10 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:42:00 AM 2 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:42:00 AM 15 1199.00 XCSE
GENMAB A/S 07-Apr-2025 11:42:08 AM 43 1199.50 CEUX
GENMAB A/S 07-Apr-2025 11:42:08 AM 37 1199.50 CEUX
GENMAB A/S 07-Apr-2025 11:43:21 AM 36 1200.00 XCSE
GENMAB A/S 07-Apr-2025 11:44:00 AM 71 1199.50 CEUX
GENMAB A/S 07-Apr-2025 11:45:30 AM 40 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:45:30 AM 11 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:45:30 AM 76 1200.50 CEUX
GENMAB A/S 07-Apr-2025 11:46:16 AM 87 1202.00 XCSE
GENMAB A/S 07-Apr-2025 11:46:16 AM 26 1202.00 XCSE
GENMAB A/S 07-Apr-2025 11:46:18 AM 83 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:46:18 AM 29 1201.00 TQEX
GENMAB A/S 07-Apr-2025 11:46:50 AM 47 1200.50 CEUX
GENMAB A/S 07-Apr-2025 11:47:01 AM 84 1200.00 XCSE
GENMAB A/S 07-Apr-2025 11:47:01 AM 28 1200.00 TQEX
GENMAB A/S 07-Apr-2025 11:48:27 AM 83 1201.50 XCSE
GENMAB A/S 07-Apr-2025 11:48:27 AM 62 1201.50 CEUX
GENMAB A/S 07-Apr-2025 11:48:27 AM 26 1202.00 CEUX
GENMAB A/S 07-Apr-2025 11:49:27 AM 24 1202.50 CEUX
GENMAB A/S 07-Apr-2025 11:49:37 AM 40 1203.00 XCSE
GENMAB A/S 07-Apr-2025 11:49:37 AM 4 1203.00 XCSE
GENMAB A/S 07-Apr-2025 11:50:02 AM 83 1202.00 XCSE
GENMAB A/S 07-Apr-2025 11:50:02 AM 34 1202.00 AQEU
GENMAB A/S 07-Apr-2025 11:50:02 AM 13 1202.00 AQEU
GENMAB A/S 07-Apr-2025 11:50:37 AM 23 1202.00 XCSE
GENMAB A/S 07-Apr-2025 11:50:54 AM 66 1202.00 XCSE
GENMAB A/S 07-Apr-2025 11:51:35 AM 47 1201.50 CEUX
GENMAB A/S 07-Apr-2025 11:51:39 AM 87 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:52:06 AM 50 1200.50 CEUX
GENMAB A/S 07-Apr-2025 11:53:27 AM 87 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:53:51 AM 1 1201.00 TQEX
GENMAB A/S 07-Apr-2025 11:53:51 AM 32 1201.00 TQEX
GENMAB A/S 07-Apr-2025 11:53:52 AM 1 1200.50 CEUX
GENMAB A/S 07-Apr-2025 11:53:52 AM 41 1200.50 CEUX
GENMAB A/S 07-Apr-2025 11:55:08 AM 86 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:55:28 AM 83 1201.00 XCSE
GENMAB A/S 07-Apr-2025 11:55:32 AM 3 1206.50 XCSE
GENMAB A/S 07-Apr-2025 11:55:32 AM 34 1206.50 XCSE

13

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 11:55:32 AM 1 1206.50 XCSE
GENMAB A/S 07-Apr-2025 11:55:32 AM 22 1206.50 XCSE
GENMAB A/S 07-Apr-2025 11:55:32 AM 27 1206.50 XCSE
GENMAB A/S 07-Apr-2025 11:55:32 AM 1 1206.00 CEUX
GENMAB A/S 07-Apr-2025 11:55:32 AM 18 1206.00 CEUX
GENMAB A/S 07-Apr-2025 11:55:34 AM 89 1205.50 XCSE
GENMAB A/S 07-Apr-2025 11:55:34 AM 38 1206.00 CEUX
GENMAB A/S 07-Apr-2025 11:56:02 AM 54 1208.00 XCSE
GENMAB A/S 07-Apr-2025 11:56:02 AM 43 1208.00 CEUX
GENMAB A/S 07-Apr-2025 11:56:22 AM 54 1207.00 XCSE
GENMAB A/S 07-Apr-2025 11:56:22 AM 44 1207.00 CEUX
GENMAB A/S 07-Apr-2025 11:56:48 AM 24 1206.50 TQEX
GENMAB A/S 07-Apr-2025 11:57:31 AM 24 1206.00 XCSE
GENMAB A/S 07-Apr-2025 11:57:31 AM 24 1206.00 CEUX
GENMAB A/S 07-Apr-2025 11:57:48 AM 49 1205.50 XCSE
GENMAB A/S 07-Apr-2025 11:57:54 AM 40 1206.00 XCSE
GENMAB A/S 07-Apr-2025 11:58:43 AM 42 1204.50 XCSE
GENMAB A/S 07-Apr-2025 11:58:43 AM 27 1204.50 CEUX
GENMAB A/S 07-Apr-2025 11:59:49 AM 37 1205.00 XCSE
GENMAB A/S 07-Apr-2025 12:00:21 PM 20 1205.50 TQEX
GENMAB A/S 07-Apr-2025 12:00:21 PM 30 1205.50 AQEU
GENMAB A/S 07-Apr-2025 12:00:23 PM 1 1205.00 CEUX
GENMAB A/S 07-Apr-2025 12:00:25 PM 2 1205.00 CEUX
GENMAB A/S 07-Apr-2025 12:01:22 PM 11 1205.00 XCSE
GENMAB A/S 07-Apr-2025 12:01:30 PM 22 1205.00 CEUX
GENMAB A/S 07-Apr-2025 12:01:30 PM 18 1205.00 CEUX
GENMAB A/S 07-Apr-2025 12:03:28 PM 88 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:03:28 PM 24 1217.00 TQEX
GENMAB A/S 07-Apr-2025 12:03:28 PM 68 1216.50 CEUX
GENMAB A/S 07-Apr-2025 12:03:28 PM 31 1217.00 AQEU
GENMAB A/S 07-Apr-2025 12:03:43 PM 88 1216.00 XCSE
GENMAB A/S 07-Apr-2025 12:03:55 PM 44 1216.00 XCSE
GENMAB A/S 07-Apr-2025 12:03:55 PM 15 1216.00 XCSE
GENMAB A/S 07-Apr-2025 12:04:24 PM 78 1221.50 XCSE
GENMAB A/S 07-Apr-2025 12:04:24 PM 64 1221.00 CEUX
GENMAB A/S 07-Apr-2025 12:04:27 PM 7 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:04:27 PM 11 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:04:27 PM 50 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:04:27 PM 66 1220.00 CEUX
GENMAB A/S 07-Apr-2025 12:04:36 PM 27 1220.00 XCSE
GENMAB A/S 07-Apr-2025 12:04:46 PM 31 1220.00 CEUX
GENMAB A/S 07-Apr-2025 12:04:52 PM 24 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:05:00 PM 24 1217.50 XCSE

14

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 12:05:02 PM 24 1216.50 XCSE
GENMAB A/S 07-Apr-2025 12:05:29 PM 24 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:05:29 PM 29 1218.50 CEUX
GENMAB A/S 07-Apr-2025 12:06:06 PM 24 1220.00 XCSE
GENMAB A/S 07-Apr-2025 12:06:20 PM 27 1220.00 CEUX
GENMAB A/S 07-Apr-2025 12:06:24 PM 25 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:06:58 PM 28 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:06:58 PM 29 1218.00 TQEX
GENMAB A/S 07-Apr-2025 12:06:58 PM 24 1218.50 CEUX
GENMAB A/S 07-Apr-2025 12:07:16 PM 29 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:07:47 PM 26 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:07:48 PM 46 1220.00 CEUX
GENMAB A/S 07-Apr-2025 12:07:49 PM 24 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:07:49 PM 24 1219.50 AQEU
GENMAB A/S 07-Apr-2025 12:08:57 PM 31 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:10:01 PM 27 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:10:06 PM 24 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:10:06 PM 24 1218.50 CEUX
GENMAB A/S 07-Apr-2025 12:11:32 PM 55 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:11:32 PM 24 1219.50 TQEX
GENMAB A/S 07-Apr-2025 12:11:32 PM 24 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:11:35 PM 60 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:11:35 PM 28 1218.50 CEUX
GENMAB A/S 07-Apr-2025 12:12:14 PM 24 1220.00 AQEU
GENMAB A/S 07-Apr-2025 12:12:37 PM 40 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:12:37 PM 11 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:12:37 PM 24 1220.50 CEUX
GENMAB A/S 07-Apr-2025 12:12:52 PM 5 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:12:52 PM 41 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:12:52 PM 26 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:12:56 PM 36 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:13:32 PM 28 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:13:32 PM 8 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:14:22 PM 28 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:14:22 PM 24 1219.00 TQEX
GENMAB A/S 07-Apr-2025 12:14:22 PM 4 1219.00 TQEX
GENMAB A/S 07-Apr-2025 12:15:28 PM 55 1220.00 XCSE
GENMAB A/S 07-Apr-2025 12:15:39 PM 56 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:15:39 PM 36 1219.00 CEUX
GENMAB A/S 07-Apr-2025 12:16:49 PM 27 1220.50 CEUX
GENMAB A/S 07-Apr-2025 12:17:06 PM 24 1220.00 AQEU
GENMAB A/S 07-Apr-2025 12:17:26 PM 69 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:18:40 PM 48 1220.50 CEUX

15

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 12:19:00 PM 33 1220.50 CEUX
GENMAB A/S 07-Apr-2025 12:19:22 PM 1 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:19:22 PM 24 1220.00 TQEX
GENMAB A/S 07-Apr-2025 12:19:49 PM 43 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:19:49 PM 32 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:20:05 PM 9 1220.50 CEUX
GENMAB A/S 07-Apr-2025 12:20:05 PM 15 1220.50 CEUX
GENMAB A/S 07-Apr-2025 12:20:52 PM 1 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:20:52 PM 80 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:20:52 PM 26 1221.00 CEUX
GENMAB A/S 07-Apr-2025 12:20:52 PM 24 1220.50 AQEU
GENMAB A/S 07-Apr-2025 12:22:33 PM 46 1220.00 TQEX
GENMAB A/S 07-Apr-2025 12:22:34 PM 75 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:22:34 PM 27 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:22:36 PM 29 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:24:00 PM 75 1220.00 XCSE
GENMAB A/S 07-Apr-2025 12:24:00 PM 24 1220.00 CEUX
GENMAB A/S 07-Apr-2025 12:24:26 PM 31 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:25:13 PM 33 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:25:13 PM 12 1220.50 XCSE
GENMAB A/S 07-Apr-2025 12:25:13 PM 34 1220.00 CEUX
GENMAB A/S 07-Apr-2025 12:25:15 PM 82 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:25:40 PM 26 1219.00 CEUX
GENMAB A/S 07-Apr-2025 12:25:40 PM 24 1219.00 AQEU
GENMAB A/S 07-Apr-2025 12:26:17 PM 80 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:26:17 PM 25 1218.00 CEUX
GENMAB A/S 07-Apr-2025 12:26:26 PM 58 1217.50 XCSE
GENMAB A/S 07-Apr-2025 12:26:36 PM 30 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:27:10 PM 10 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:27:10 PM 10 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:27:10 PM 20 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:27:10 PM 32 1219.00 CEUX
GENMAB A/S 07-Apr-2025 12:27:20 PM 25 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:27:48 PM 34 1220.00 XCSE
GENMAB A/S 07-Apr-2025 12:28:03 PM 25 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:29:28 PM 26 1219.50 CEUX
GENMAB A/S 07-Apr-2025 12:30:00 PM 45 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:30:00 PM 45 1218.50 TQEX
GENMAB A/S 07-Apr-2025 12:30:00 PM 24 1218.50 CEUX
GENMAB A/S 07-Apr-2025 12:30:00 PM 24 1218.50 AQEU
GENMAB A/S 07-Apr-2025 12:31:00 PM 10 1218.00 XCSE
GENMAB A/S 07-Apr-2025 12:31:00 PM 29 1218.00 XCSE
GENMAB A/S 07-Apr-2025 12:31:00 PM 25 1218.00 CEUX

16

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 12:31:01 PM 27 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:31:26 PM 33 1216.50 XCSE
GENMAB A/S 07-Apr-2025 12:33:40 PM 65 1216.50 XCSE
GENMAB A/S 07-Apr-2025 12:33:40 PM 20 1215.50 XCSE
GENMAB A/S 07-Apr-2025 12:33:40 PM 6 1215.50 XCSE
GENMAB A/S 07-Apr-2025 12:33:40 PM 24 1216.50 CEUX
GENMAB A/S 07-Apr-2025 12:33:42 PM 20 1215.50 XCSE
GENMAB A/S 07-Apr-2025 12:34:54 PM 88 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:35:00 PM 16 1217.50 XCSE
GENMAB A/S 07-Apr-2025 12:35:00 PM 53 1217.50 XCSE
GENMAB A/S 07-Apr-2025 12:35:00 PM 30 1218.00 CEUX
GENMAB A/S 07-Apr-2025 12:35:00 PM 24 1218.00 AQEU
GENMAB A/S 07-Apr-2025 12:35:23 PM 30 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:35:24 PM 67 1216.50 XCSE
GENMAB A/S 07-Apr-2025 12:35:24 PM 1 1216.50 XCSE
GENMAB A/S 07-Apr-2025 12:35:30 PM 30 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:35:35 PM 28 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:35:56 PM 25 1216.50 CEUX
GENMAB A/S 07-Apr-2025 12:36:44 PM 7 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:36:44 PM 24 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:36:44 PM 24 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:39:16 PM 81 1219.00 XCSE
GENMAB A/S 07-Apr-2025 12:39:16 PM 32 1219.00 CEUX
GENMAB A/S 07-Apr-2025 12:39:16 PM 46 1219.00 AQEU
GENMAB A/S 07-Apr-2025 12:39:34 PM 24 1219.50 XCSE
GENMAB A/S 07-Apr-2025 12:39:34 PM 24 1219.50 TQEX
GENMAB A/S 07-Apr-2025 12:40:29 PM 34 1219.00 CEUX
GENMAB A/S 07-Apr-2025 12:40:46 PM 75 1218.00 XCSE
GENMAB A/S 07-Apr-2025 12:40:46 PM 25 1218.00 CEUX
GENMAB A/S 07-Apr-2025 12:41:51 PM 59 1218.00 XCSE
GENMAB A/S 07-Apr-2025 12:41:51 PM 1 1218.00 CEUX
GENMAB A/S 07-Apr-2025 12:41:51 PM 23 1218.00 CEUX
GENMAB A/S 07-Apr-2025 12:42:07 PM 44 1218.00 TQEX
GENMAB A/S 07-Apr-2025 12:44:32 PM 88 1218.00 XCSE
GENMAB A/S 07-Apr-2025 12:45:03 PM 56 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:45:03 PM 31 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:45:23 PM 24 1216.00 XCSE
GENMAB A/S 07-Apr-2025 12:45:23 PM 26 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:46:58 PM 39 1217.50 CEUX
GENMAB A/S 07-Apr-2025 12:47:02 PM 61 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:47:02 PM 13 1217.00 XCSE
GENMAB A/S 07-Apr-2025 12:47:02 PM 40 1216.50 CEUX
GENMAB A/S 07-Apr-2025 12:48:26 PM 78 1217.00 XCSE

17

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 12:48:26 PM 25 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:48:45 PM 64 1216.00 XCSE
GENMAB A/S 07-Apr-2025 12:48:45 PM 24 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:49:39 PM 46 1216.50 AQEU
GENMAB A/S 07-Apr-2025 12:49:46 PM 5 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:50:50 PM 70 1216.00 XCSE
GENMAB A/S 07-Apr-2025 12:50:50 PM 24 1216.00 TQEX
GENMAB A/S 07-Apr-2025 12:50:50 PM 33 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:52:33 PM 32 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:52:33 PM 55 1218.50 XCSE
GENMAB A/S 07-Apr-2025 12:52:55 PM 46 1218.00 CEUX
GENMAB A/S 07-Apr-2025 12:53:11 PM 2 1217.50 XCSE
GENMAB A/S 07-Apr-2025 12:53:11 PM 83 1217.50 XCSE
GENMAB A/S 07-Apr-2025 12:53:26 PM 35 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:54:05 PM 28 1217.00 CEUX
GENMAB A/S 07-Apr-2025 12:54:08 PM 83 1216.50 XCSE
GENMAB A/S 07-Apr-2025 12:55:14 PM 24 1216.00 TQEX
GENMAB A/S 07-Apr-2025 12:55:14 PM 1 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:55:14 PM 27 1216.00 CEUX
GENMAB A/S 07-Apr-2025 12:56:19 PM 32 1216.50 CEUX
GENMAB A/S 07-Apr-2025 12:57:04 PM 57 1215.50 XCSE
GENMAB A/S 07-Apr-2025 12:57:09 PM 24 1215.00 CEUX
GENMAB A/S 07-Apr-2025 12:57:42 PM 89 1215.50 XCSE
GENMAB A/S 07-Apr-2025 12:57:42 PM 35 1215.50 CEUX
GENMAB A/S 07-Apr-2025 12:58:07 PM 31 1214.50 XCSE
GENMAB A/S 07-Apr-2025 12:58:07 PM 32 1214.50 CEUX
GENMAB A/S 07-Apr-2025 12:58:45 PM 28 1214.50 CEUX
GENMAB A/S 07-Apr-2025 13:00:06 PM 10 1216.00 XCSE
GENMAB A/S 07-Apr-2025 13:00:06 PM 1 1216.00 XCSE
GENMAB A/S 07-Apr-2025 13:00:06 PM 78 1216.00 XCSE
GENMAB A/S 07-Apr-2025 13:00:07 PM 47 1215.50 TQEX
GENMAB A/S 07-Apr-2025 13:00:07 PM 25 1215.50 CEUX
GENMAB A/S 07-Apr-2025 13:00:07 PM 46 1215.50 AQEU
GENMAB A/S 07-Apr-2025 13:00:27 PM 4 1215.00 XCSE
GENMAB A/S 07-Apr-2025 13:00:27 PM 83 1215.00 XCSE
GENMAB A/S 07-Apr-2025 13:01:33 PM 89 1214.00 XCSE
GENMAB A/S 07-Apr-2025 13:01:33 PM 25 1214.50 CEUX
GENMAB A/S 07-Apr-2025 13:03:28 PM 40 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:03:28 PM 12 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:03:28 PM 23 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:03:28 PM 11 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:03:56 PM 70 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:06:21 PM 70 1217.50 CEUX

18

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 13:06:34 PM 13 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:07:29 PM 58 1217.50 CEUX
GENMAB A/S 07-Apr-2025 13:07:57 PM 10 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:09:27 PM 39 1220.00 XCSE
GENMAB A/S 07-Apr-2025 13:09:27 PM 23 1220.00 XCSE
GENMAB A/S 07-Apr-2025 13:09:27 PM 30 1220.00 XCSE
GENMAB A/S 07-Apr-2025 13:09:54 PM 83 1219.00 XCSE
GENMAB A/S 07-Apr-2025 13:09:54 PM 35 1219.50 TQEX
GENMAB A/S 07-Apr-2025 13:09:54 PM 57 1219.00 CEUX
GENMAB A/S 07-Apr-2025 13:09:54 PM 44 1219.50 AQEU
GENMAB A/S 07-Apr-2025 13:10:56 PM 89 1218.00 XCSE
GENMAB A/S 07-Apr-2025 13:10:56 PM 61 1218.00 CEUX
GENMAB A/S 07-Apr-2025 13:11:01 PM 25 1217.50 CEUX
GENMAB A/S 07-Apr-2025 13:11:11 PM 60 1217.00 XCSE
GENMAB A/S 07-Apr-2025 13:11:11 PM 41 1216.50 XCSE
GENMAB A/S 07-Apr-2025 13:11:11 PM 42 1216.50 XCSE
GENMAB A/S 07-Apr-2025 13:11:11 PM 43 1216.50 CEUX
GENMAB A/S 07-Apr-2025 13:11:15 PM 87 1215.50 XCSE
GENMAB A/S 07-Apr-2025 13:11:15 PM 46 1215.50 CEUX
GENMAB A/S 07-Apr-2025 13:11:56 PM 43 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:11:56 PM 46 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:12:05 PM 46 1213.00 XCSE
GENMAB A/S 07-Apr-2025 13:13:18 PM 9 1213.50 XCSE
GENMAB A/S 07-Apr-2025 13:13:18 PM 31 1213.50 XCSE
GENMAB A/S 07-Apr-2025 13:13:18 PM 9 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:13:18 PM 16 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:14:50 PM 34 1213.50 XCSE
GENMAB A/S 07-Apr-2025 13:14:50 PM 30 1213.50 TQEX
GENMAB A/S 07-Apr-2025 13:14:50 PM 14 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:14:50 PM 13 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:15:54 PM 30 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:15:54 PM 25 1213.50 AQEU
GENMAB A/S 07-Apr-2025 13:19:04 PM 90 1213.50 XCSE
GENMAB A/S 07-Apr-2025 13:19:04 PM 25 1214.00 TQEX
GENMAB A/S 07-Apr-2025 13:19:04 PM 19 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:20:12 PM 63 1214.50 CEUX
GENMAB A/S 07-Apr-2025 13:20:20 PM 24 1215.00 TQEX
GENMAB A/S 07-Apr-2025 13:20:20 PM 21 1215.00 CEUX
GENMAB A/S 07-Apr-2025 13:20:21 PM 25 1215.00 CEUX
GENMAB A/S 07-Apr-2025 13:20:34 PM 88 1215.00 XCSE
GENMAB A/S 07-Apr-2025 13:20:34 PM 4 1215.00 CEUX
GENMAB A/S 07-Apr-2025 13:20:34 PM 47 1215.00 AQEU
GENMAB A/S 07-Apr-2025 13:20:42 PM 12 1214.00 XCSE

19

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 13:20:42 PM 58 1214.00 XCSE
GENMAB A/S 07-Apr-2025 13:20:42 PM 15 1214.00 XCSE
GENMAB A/S 07-Apr-2025 13:20:43 PM 34 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:20:43 PM 11 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:21:03 PM 4 1213.50 XCSE
GENMAB A/S 07-Apr-2025 13:22:54 PM 33 1214.00 CEUX
GENMAB A/S 07-Apr-2025 13:23:12 PM 31 1214.00 CEUX
GENMAB A/S 07-Apr-2025 13:24:09 PM 26 1214.00 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 40 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 30 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 26 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 4 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 13 1214.50 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 79 1213.50 XCSE
GENMAB A/S 07-Apr-2025 13:25:05 PM 44 1214.00 TQEX
GENMAB A/S 07-Apr-2025 13:25:05 PM 46 1214.00 CEUX
GENMAB A/S 07-Apr-2025 13:25:07 PM 33 1213.50 CEUX
GENMAB A/S 07-Apr-2025 13:25:34 PM 25 1212.50 CEUX
GENMAB A/S 07-Apr-2025 13:25:46 PM 34 1212.50 XCSE
GENMAB A/S 07-Apr-2025 13:26:45 PM 2 1212.50 XCSE
GENMAB A/S 07-Apr-2025 13:26:45 PM 84 1212.50 XCSE
GENMAB A/S 07-Apr-2025 13:26:45 PM 27 1212.50 CEUX
GENMAB A/S 07-Apr-2025 13:28:57 PM 39 1212.50 CEUX
GENMAB A/S 07-Apr-2025 13:29:00 PM 86 1212.00 XCSE
GENMAB A/S 07-Apr-2025 13:29:00 PM 25 1211.50 CEUX
GENMAB A/S 07-Apr-2025 13:29:41 PM 88 1211.00 XCSE
GENMAB A/S 07-Apr-2025 13:29:44 PM 3 1210.50 CEUX
GENMAB A/S 07-Apr-2025 13:29:44 PM 21 1210.50 CEUX
GENMAB A/S 07-Apr-2025 13:29:44 PM 2 1210.50 CEUX
GENMAB A/S 07-Apr-2025 13:30:01 PM 90 1210.00 XCSE
GENMAB A/S 07-Apr-2025 13:30:01 PM 8 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:30:02 PM 28 1209.00 CEUX
GENMAB A/S 07-Apr-2025 13:30:03 PM 1 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:30:03 PM 1 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:30:03 PM 80 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:32:09 PM 25 1209.00 TQEX
GENMAB A/S 07-Apr-2025 13:33:42 PM 21 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:33:42 PM 68 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:35:14 PM 84 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:35:14 PM 42 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:35:14 PM 10 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:35:14 PM 28 1208.50 AQEU
GENMAB A/S 07-Apr-2025 13:35:37 PM 20 1208.50 CEUX

20

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 13:35:37 PM 40 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:36:02 PM 87 1210.00 XCSE
GENMAB A/S 07-Apr-2025 13:36:02 PM 24 1210.00 TQEX
GENMAB A/S 07-Apr-2025 13:36:52 PM 34 1209.50 CEUX
GENMAB A/S 07-Apr-2025 13:37:17 PM 23 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:37:17 PM 23 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:37:17 PM 37 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:37:28 PM 37 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:38:09 PM 85 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:38:09 PM 30 1207.50 CEUX
GENMAB A/S 07-Apr-2025 13:38:09 PM 31 1207.50 AQEU
GENMAB A/S 07-Apr-2025 13:38:13 PM 83 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:41:20 PM 83 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:41:20 PM 44 1209.50 TQEX
GENMAB A/S 07-Apr-2025 13:41:20 PM 58 1209.50 CEUX
GENMAB A/S 07-Apr-2025 13:41:21 PM 51 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:41:41 PM 3 1208.00 AQEU
GENMAB A/S 07-Apr-2025 13:41:44 PM 50 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:41:44 PM 35 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:41:44 PM 27 1208.00 AQEU
GENMAB A/S 07-Apr-2025 13:43:21 PM 9 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:43:59 PM 83 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:44:08 PM 14 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:44:52 PM 40 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:45:00 PM 21 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:45:00 PM 53 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:45:17 PM 22 1207.50 CEUX
GENMAB A/S 07-Apr-2025 13:45:17 PM 16 1207.50 CEUX
GENMAB A/S 07-Apr-2025 13:45:48 PM 28 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:46:10 PM 45 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:46:13 PM 11 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:46:24 PM 20 1206.50 AQEU
GENMAB A/S 07-Apr-2025 13:49:06 PM 24 1209.50 XCSE
GENMAB A/S 07-Apr-2025 13:49:06 PM 54 1209.50 XCSE
GENMAB A/S 07-Apr-2025 13:49:06 PM 11 1209.50 XCSE
GENMAB A/S 07-Apr-2025 13:49:06 PM 70 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:49:06 PM 27 1209.00 XCSE
GENMAB A/S 07-Apr-2025 13:49:06 PM 24 1209.00 TQEX
GENMAB A/S 07-Apr-2025 13:49:06 PM 63 1208.50 CEUX
GENMAB A/S 07-Apr-2025 13:49:06 PM 24 1209.00 AQEU
GENMAB A/S 07-Apr-2025 13:49:14 PM 7 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:49:14 PM 79 1208.00 XCSE
GENMAB A/S 07-Apr-2025 13:49:22 PM 24 1207.50 TQEX

21

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 13:49:22 PM 53 1207.50 CEUX
GENMAB A/S 07-Apr-2025 13:50:27 PM 55 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:50:47 PM 34 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:51:21 PM 44 1206.50 CEUX
GENMAB A/S 07-Apr-2025 13:51:52 PM 88 1206.50 XCSE
GENMAB A/S 07-Apr-2025 13:51:52 PM 24 1206.50 TQEX
GENMAB A/S 07-Apr-2025 13:52:32 PM 84 1205.50 XCSE
GENMAB A/S 07-Apr-2025 13:52:32 PM 53 1205.50 CEUX
GENMAB A/S 07-Apr-2025 13:52:32 PM 25 1205.00 AQEU
GENMAB A/S 07-Apr-2025 13:52:39 PM 45 1204.50 CEUX
GENMAB A/S 07-Apr-2025 13:52:39 PM 1 1204.50 CEUX
GENMAB A/S 07-Apr-2025 13:52:53 PM 10 1204.50 CEUX
GENMAB A/S 07-Apr-2025 13:53:25 PM 85 1204.00 XCSE
GENMAB A/S 07-Apr-2025 13:54:30 PM 89 1205.00 XCSE
GENMAB A/S 07-Apr-2025 13:54:30 PM 47 1205.00 TQEX
GENMAB A/S 07-Apr-2025 13:56:44 PM 83 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:56:44 PM 63 1207.00 XCSE
GENMAB A/S 07-Apr-2025 13:57:35 PM 86 1207.50 CEUX
GENMAB A/S 07-Apr-2025 14:01:29 PM 12 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:29 PM 11 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:29 PM 7 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:29 PM 37 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:46 PM 60 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:46 PM 11 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:46 PM 87 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:01:46 PM 86 1210.50 CEUX
GENMAB A/S 07-Apr-2025 14:01:46 PM 26 1210.50 AQEU
GENMAB A/S 07-Apr-2025 14:01:53 PM 83 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 2 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 11 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 12 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 30 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 10 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 17 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 11 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:53 PM 35 1210.00 AQEU
GENMAB A/S 07-Apr-2025 14:01:54 PM 12 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:01:54 PM 12 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:02:07 PM 11 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:02:07 PM 11 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:02:07 PM 16 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:02:07 PM 40 1210.50 XCSE
GENMAB A/S 07-Apr-2025 14:02:07 PM 19 1210.50 XCSE

22

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 14:02:22 PM 89 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:02:22 PM 87 1209.50 CEUX
GENMAB A/S 07-Apr-2025 14:03:45 PM 84 1211.00 XCSE
GENMAB A/S 07-Apr-2025 14:03:45 PM 33 1211.00 TQEX
GENMAB A/S 07-Apr-2025 14:04:21 PM 83 1210.50 CEUX
GENMAB A/S 07-Apr-2025 14:05:11 PM 1 1209.50 XCSE
GENMAB A/S 07-Apr-2025 14:05:11 PM 79 1209.50 XCSE
GENMAB A/S 07-Apr-2025 14:05:11 PM 10 1209.50 XCSE
GENMAB A/S 07-Apr-2025 14:05:11 PM 83 1209.50 CEUX
GENMAB A/S 07-Apr-2025 14:05:11 PM 26 1209.50 AQEU
GENMAB A/S 07-Apr-2025 14:07:32 PM 30 1210.50 TQEX
GENMAB A/S 07-Apr-2025 14:07:32 PM 85 1210.50 CEUX
GENMAB A/S 07-Apr-2025 14:07:46 PM 29 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:07:46 PM 57 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:08:05 PM 47 1209.50 XCSE
GENMAB A/S 07-Apr-2025 14:08:05 PM 22 1209.50 XCSE
GENMAB A/S 07-Apr-2025 14:08:05 PM 10 1209.50 XCSE
GENMAB A/S 07-Apr-2025 14:08:05 PM 26 1209.50 TQEX
GENMAB A/S 07-Apr-2025 14:08:05 PM 82 1209.50 CEUX
GENMAB A/S 07-Apr-2025 14:08:05 PM 7 1209.50 CEUX
GENMAB A/S 07-Apr-2025 14:08:05 PM 28 1209.50 AQEU
GENMAB A/S 07-Apr-2025 14:08:08 PM 16 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:08:19 PM 67 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:08:21 PM 36 1208.50 CEUX
GENMAB A/S 07-Apr-2025 14:08:21 PM 49 1208.50 CEUX
GENMAB A/S 07-Apr-2025 14:08:30 PM 12 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:08:30 PM 23 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:08:38 PM 25 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:08:38 PM 28 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:09:37 PM 1 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:09:44 PM 30 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:09:44 PM 2 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:10:14 PM 24 1209.00 AQEU
GENMAB A/S 07-Apr-2025 14:10:38 PM 27 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:10:38 PM 7 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:11:18 PM 24 1208.50 TQEX
GENMAB A/S 07-Apr-2025 14:11:18 PM 72 1208.50 CEUX
GENMAB A/S 07-Apr-2025 14:11:56 PM 20 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:11:56 PM 67 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:11:56 PM 2 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:11:56 PM 53 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:13:15 PM 17 1207.50 XCSE
GENMAB A/S 07-Apr-2025 14:13:15 PM 9 1207.50 XCSE

23

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 14:13:56 PM 2 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:13:56 PM 4 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:13:56 PM 20 1207.50 AQEU
GENMAB A/S 07-Apr-2025 14:13:57 PM 17 1208.00 XCSE
GENMAB A/S 07-Apr-2025 14:16:00 PM 25 1210.50 TQEX
GENMAB A/S 07-Apr-2025 14:16:46 PM 89 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:16:47 PM 12 1210.00 CEUX
GENMAB A/S 07-Apr-2025 14:16:47 PM 73 1210.00 CEUX
GENMAB A/S 07-Apr-2025 14:17:08 PM 24 1209.50 TQEX
GENMAB A/S 07-Apr-2025 14:17:43 PM 34 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:02 PM 50 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:02 PM 89 1209.00 CEUX
GENMAB A/S 07-Apr-2025 14:18:42 PM 26 1209.50 AQEU
GENMAB A/S 07-Apr-2025 14:18:43 PM 10 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 30 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 10 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 23 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 12 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 10 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 11 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 12 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 12 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:43 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:44 PM 10 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:44 PM 12 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:44 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:18:44 PM 40 1210.00 XCSE
GENMAB A/S 07-Apr-2025 14:19:04 PM 27 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:19:04 PM 62 1209.00 XCSE
GENMAB A/S 07-Apr-2025 14:19:04 PM 25 1209.00 TQEX
GENMAB A/S 07-Apr-2025 14:19:04 PM 83 1209.00 CEUX
GENMAB A/S 07-Apr-2025 14:19:31 PM 6 1211.00 XCSE
GENMAB A/S 07-Apr-2025 14:20:29 PM 63 1211.50 CEUX
GENMAB A/S 07-Apr-2025 14:20:29 PM 25 1211.50 CEUX
GENMAB A/S 07-Apr-2025 14:20:32 PM 85 1211.00 XCSE
GENMAB A/S 07-Apr-2025 14:20:32 PM 24 1211.50 TQEX
GENMAB A/S 07-Apr-2025 14:20:32 PM 86 1211.50 CEUX
GENMAB A/S 07-Apr-2025 14:20:32 PM 24 1211.00 AQEU
GENMAB A/S 07-Apr-2025 14:20:33 PM 3 1210.50 CEUX

24

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 14:21:22 PM 10 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:21:22 PM 40 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:21:22 PM 11 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:21:22 PM 11 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:21:23 PM 40 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:21:57 PM 17 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:21:57 PM 11 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:22:25 PM 88 1213.00 XCSE
GENMAB A/S 07-Apr-2025 14:22:25 PM 90 1212.50 CEUX
GENMAB A/S 07-Apr-2025 14:22:25 PM 46 1212.50 AQEU
GENMAB A/S 07-Apr-2025 14:23:22 PM 40 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:23:22 PM 11 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:23:22 PM 10 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:23:22 PM 45 1214.50 TQEX
GENMAB A/S 07-Apr-2025 14:23:24 PM 90 1213.50 XCSE
GENMAB A/S 07-Apr-2025 14:23:24 PM 3 1214.50 CEUX
GENMAB A/S 07-Apr-2025 14:23:24 PM 86 1214.50 CEUX
GENMAB A/S 07-Apr-2025 14:23:24 PM 72 1213.50 CEUX
GENMAB A/S 07-Apr-2025 14:24:00 PM 3 1213.50 CEUX
GENMAB A/S 07-Apr-2025 14:24:00 PM 22 1213.50 CEUX
GENMAB A/S 07-Apr-2025 14:24:37 PM 88 1212.50 XCSE
GENMAB A/S 07-Apr-2025 14:24:37 PM 57 1212.50 CEUX
GENMAB A/S 07-Apr-2025 14:24:38 PM 90 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:24:40 PM 37 1211.00 CEUX
GENMAB A/S 07-Apr-2025 14:25:39 PM 27 1211.00 CEUX
GENMAB A/S 07-Apr-2025 14:27:29 PM 84 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:27:35 PM 30 1211.00 CEUX
GENMAB A/S 07-Apr-2025 14:27:37 PM 40 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:27:37 PM 28 1211.50 XCSE
GENMAB A/S 07-Apr-2025 14:28:31 PM 25 1212.50 TQEX
GENMAB A/S 07-Apr-2025 14:29:01 PM 12 1214.50 XCSE
GENMAB A/S 07-Apr-2025 14:29:01 PM 11 1214.50 XCSE
GENMAB A/S 07-Apr-2025 14:29:01 PM 10 1214.50 XCSE
GENMAB A/S 07-Apr-2025 14:29:01 PM 12 1214.50 XCSE
GENMAB A/S 07-Apr-2025 14:31:23 PM 44 1219.00 TQEX
GENMAB A/S 07-Apr-2025 14:31:34 PM 81 1218.50 CEUX
GENMAB A/S 07-Apr-2025 14:31:34 PM 24 1219.00 AQEU
GENMAB A/S 07-Apr-2025 14:31:44 PM 85 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:31:44 PM 40 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:31:44 PM 32 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:31:44 PM 40 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:31:44 PM 46 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:31:44 PM 1 1218.00 XCSE

25

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 14:31:44 PM 85 1217.50 CEUX
GENMAB A/S 07-Apr-2025 14:32:06 PM 86 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:32:06 PM 40 1217.50 XCSE
GENMAB A/S 07-Apr-2025 14:32:06 PM 10 1217.50 XCSE
GENMAB A/S 07-Apr-2025 14:32:06 PM 40 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:32:06 PM 11 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:32:06 PM 1 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:32:06 PM 24 1217.50 CEUX
GENMAB A/S 07-Apr-2025 14:32:22 PM 18 1216.50 CEUX
GENMAB A/S 07-Apr-2025 14:32:22 PM 51 1216.50 CEUX
GENMAB A/S 07-Apr-2025 14:32:31 PM 84 1216.00 XCSE
GENMAB A/S 07-Apr-2025 14:33:41 PM 85 1215.50 XCSE
GENMAB A/S 07-Apr-2025 14:35:04 PM 18 1215.00 CEUX
GENMAB A/S 07-Apr-2025 14:35:05 PM 88 1214.50 XCSE
GENMAB A/S 07-Apr-2025 14:35:05 PM 39 1215.00 CEUX
GENMAB A/S 07-Apr-2025 14:35:30 PM 1 1216.00 AQEU
GENMAB A/S 07-Apr-2025 14:36:17 PM 28 1216.00 AQEU
GENMAB A/S 07-Apr-2025 14:36:23 PM 64 1215.50 XCSE
GENMAB A/S 07-Apr-2025 14:36:23 PM 1 1215.50 XCSE
GENMAB A/S 07-Apr-2025 14:36:23 PM 19 1215.50 XCSE
GENMAB A/S 07-Apr-2025 14:36:59 PM 25 1215.50 TQEX
GENMAB A/S 07-Apr-2025 14:37:56 PM 84 1215.50 XCSE
GENMAB A/S 07-Apr-2025 14:37:59 PM 50 1215.00 CEUX
GENMAB A/S 07-Apr-2025 14:38:17 PM 4 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:38:41 PM 86 1214.50 XCSE
GENMAB A/S 07-Apr-2025 14:38:41 PM 31 1214.50 AQEU
GENMAB A/S 07-Apr-2025 14:38:57 PM 26 1214.00 CEUX
GENMAB A/S 07-Apr-2025 14:39:34 PM 87 1213.50 XCSE
GENMAB A/S 07-Apr-2025 14:39:50 PM 3 1213.00 CEUX
GENMAB A/S 07-Apr-2025 14:39:50 PM 21 1213.00 CEUX
GENMAB A/S 07-Apr-2025 14:40:28 PM 40 1214.00 XCSE
GENMAB A/S 07-Apr-2025 14:40:28 PM 19 1214.00 XCSE
GENMAB A/S 07-Apr-2025 14:40:28 PM 10 1214.00 XCSE
GENMAB A/S 07-Apr-2025 14:40:28 PM 11 1214.00 XCSE
GENMAB A/S 07-Apr-2025 14:40:28 PM 24 1213.50 TQEX
GENMAB A/S 07-Apr-2025 14:40:28 PM 84 1213.50 CEUX
GENMAB A/S 07-Apr-2025 14:40:28 PM 43 1213.50 CEUX
GENMAB A/S 07-Apr-2025 14:41:47 PM 11 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:41:47 PM 14 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:41:49 PM 42 1215.00 XCSE
GENMAB A/S 07-Apr-2025 14:42:00 PM 37 1216.00 XCSE
GENMAB A/S 07-Apr-2025 14:42:00 PM 2 1216.00 TQEX
GENMAB A/S 07-Apr-2025 14:42:00 PM 75 1216.00 CEUX

26

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 14:42:00 PM 1 1216.00 AQEU
GENMAB A/S 07-Apr-2025 14:42:01 PM 24 1216.00 AQEU
GENMAB A/S 07-Apr-2025 14:42:21 PM 27 1216.00 XCSE
GENMAB A/S 07-Apr-2025 14:42:21 PM 44 1216.00 CEUX
GENMAB A/S 07-Apr-2025 14:43:23 PM 88 1216.50 XCSE
GENMAB A/S 07-Apr-2025 14:43:23 PM 42 1216.50 XCSE
GENMAB A/S 07-Apr-2025 14:44:25 PM 3 1216.00 AQEU
GENMAB A/S 07-Apr-2025 14:44:29 PM 10 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:44:29 PM 11 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:44:29 PM 11 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:44:31 PM 23 1218.50 XCSE
GENMAB A/S 07-Apr-2025 14:44:31 PM 11 1218.50 XCSE
GENMAB A/S 07-Apr-2025 14:44:31 PM 12 1218.50 XCSE
GENMAB A/S 07-Apr-2025 14:44:35 PM 41 1217.50 XCSE
GENMAB A/S 07-Apr-2025 14:44:35 PM 66 1217.50 CEUX
GENMAB A/S 07-Apr-2025 14:44:43 PM 25 1217.00 AQEU
GENMAB A/S 07-Apr-2025 14:44:46 PM 32 1216.50 TQEX
GENMAB A/S 07-Apr-2025 14:44:46 PM 20 1216.00 CEUX
GENMAB A/S 07-Apr-2025 14:45:35 PM 40 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:45:35 PM 12 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:45:35 PM 11 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:45:37 PM 31 1216.00 CEUX
GENMAB A/S 07-Apr-2025 14:45:48 PM 28 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:45:48 PM 11 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:45:48 PM 40 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:45:48 PM 16 1217.00 XCSE
GENMAB A/S 07-Apr-2025 14:46:12 PM 90 1216.00 XCSE
GENMAB A/S 07-Apr-2025 14:46:12 PM 49 1216.50 CEUX
GENMAB A/S 07-Apr-2025 14:47:57 PM 35 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:47:57 PM 11 1218.00 XCSE
GENMAB A/S 07-Apr-2025 14:48:29 PM 50 1219.00 XCSE
GENMAB A/S 07-Apr-2025 14:48:29 PM 27 1219.00 XCSE
GENMAB A/S 07-Apr-2025 14:48:36 PM 1 1219.00 AQEU
GENMAB A/S 07-Apr-2025 14:48:36 PM 1 1219.00 AQEU
GENMAB A/S 07-Apr-2025 14:48:50 PM 28 1218.50 TQEX
GENMAB A/S 07-Apr-2025 14:48:50 PM 23 1219.00 AQEU
GENMAB A/S 07-Apr-2025 14:49:13 PM 84 1223.50 XCSE
GENMAB A/S 07-Apr-2025 14:49:13 PM 84 1223.50 CEUX
GENMAB A/S 07-Apr-2025 14:49:19 PM 7 1224.50 XCSE
GENMAB A/S 07-Apr-2025 14:49:19 PM 83 1224.50 XCSE
GENMAB A/S 07-Apr-2025 14:50:33 PM 25 1226.50 TQEX
GENMAB A/S 07-Apr-2025 14:50:33 PM 74 1226.50 CEUX
GENMAB A/S 07-Apr-2025 14:50:37 PM 86 1226.00 XCSE

27

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 14:50:37 PM 85 1225.00 XCSE
GENMAB A/S 07-Apr-2025 14:50:37 PM 76 1225.50 CEUX
GENMAB A/S 07-Apr-2025 14:50:37 PM 46 1225.50 AQEU
GENMAB A/S 07-Apr-2025 14:51:35 PM 86 1227.50 XCSE
GENMAB A/S 07-Apr-2025 14:51:50 PM 90 1226.50 XCSE
GENMAB A/S 07-Apr-2025 14:51:50 PM 24 1226.50 CEUX
GENMAB A/S 07-Apr-2025 14:52:02 PM 42 1225.00 XCSE
GENMAB A/S 07-Apr-2025 14:52:02 PM 43 1225.00 XCSE
GENMAB A/S 07-Apr-2025 14:52:02 PM 16 1226.00 TQEX
GENMAB A/S 07-Apr-2025 14:52:02 PM 9 1226.00 TQEX
GENMAB A/S 07-Apr-2025 14:52:02 PM 39 1225.50 CEUX
GENMAB A/S 07-Apr-2025 14:52:24 PM 30 1227.00 XCSE
GENMAB A/S 07-Apr-2025 14:52:24 PM 23 1227.00 XCSE
GENMAB A/S 07-Apr-2025 14:52:24 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 14:52:24 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 14:52:57 PM 48 1227.50 CEUX
GENMAB A/S 07-Apr-2025 14:53:46 PM 71 1228.00 XCSE
GENMAB A/S 07-Apr-2025 14:55:18 PM 85 1229.00 XCSE
GENMAB A/S 07-Apr-2025 14:55:18 PM 25 1229.00 TQEX
GENMAB A/S 07-Apr-2025 14:55:18 PM 16 1229.50 CEUX
GENMAB A/S 07-Apr-2025 14:55:18 PM 33 1229.50 CEUX
GENMAB A/S 07-Apr-2025 14:55:18 PM 25 1229.50 CEUX
GENMAB A/S 07-Apr-2025 14:55:38 PM 47 1229.00 AQEU
GENMAB A/S 07-Apr-2025 14:56:21 PM 53 1229.50 CEUX
GENMAB A/S 07-Apr-2025 14:56:21 PM 13 1229.50 CEUX
GENMAB A/S 07-Apr-2025 14:56:24 PM 90 1229.00 XCSE
GENMAB A/S 07-Apr-2025 14:56:30 PM 59 1228.50 CEUX
GENMAB A/S 07-Apr-2025 14:56:49 PM 10 1228.00 XCSE
GENMAB A/S 07-Apr-2025 14:56:49 PM 77 1228.00 XCSE
GENMAB A/S 07-Apr-2025 14:57:22 PM 40 1229.50 XCSE
GENMAB A/S 07-Apr-2025 14:57:22 PM 16 1229.50 XCSE
GENMAB A/S 07-Apr-2025 14:57:22 PM 11 1229.50 XCSE
GENMAB A/S 07-Apr-2025 14:57:22 PM 10 1229.50 XCSE
GENMAB A/S 07-Apr-2025 14:57:22 PM 8 1229.50 XCSE
GENMAB A/S 07-Apr-2025 14:57:22 PM 24 1230.00 TQEX
GENMAB A/S 07-Apr-2025 14:57:22 PM 32 1229.50 CEUX
GENMAB A/S 07-Apr-2025 14:58:44 PM 89 1229.00 XCSE
GENMAB A/S 07-Apr-2025 14:59:30 PM 1 1229.00 XCSE
GENMAB A/S 07-Apr-2025 14:59:30 PM 88 1229.00 XCSE
GENMAB A/S 07-Apr-2025 14:59:30 PM 24 1229.00 TQEX
GENMAB A/S 07-Apr-2025 14:59:38 PM 25 1228.50 CEUX
GENMAB A/S 07-Apr-2025 14:59:38 PM 12 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:00:01 PM 17 1229.00 XCSE

28

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:00:02 PM 10 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:00:02 PM 1 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:00:50 PM 57 1229.50 CEUX
GENMAB A/S 07-Apr-2025 15:01:03 PM 62 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:01:03 PM 86 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:01:03 PM 55 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:02:32 PM 85 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:02:32 PM 24 1229.00 TQEX
GENMAB A/S 07-Apr-2025 15:02:32 PM 30 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:03:11 PM 90 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:04:56 PM 12 1228.00 TQEX
GENMAB A/S 07-Apr-2025 15:04:56 PM 33 1228.00 AQEU
GENMAB A/S 07-Apr-2025 15:06:08 PM 89 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:06:08 PM 40 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:06:08 PM 17 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:06:08 PM 24 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:06:08 PM 32 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:06:08 PM 1 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:06:08 PM 83 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:06:09 PM 2 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:07:09 PM 85 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:07:09 PM 38 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:07:43 PM 54 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:08:49 PM 22 1227.50 TQEX
GENMAB A/S 07-Apr-2025 15:09:23 PM 89 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:09:23 PM 54 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:09:23 PM 30 1227.50 TQEX
GENMAB A/S 07-Apr-2025 15:09:23 PM 85 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:10:23 PM 30 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:10:23 PM 16 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:12:49 PM 85 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:12:49 PM 34 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:12:49 PM 26 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:12:49 PM 24 1229.00 TQEX
GENMAB A/S 07-Apr-2025 15:12:49 PM 20 1229.50 CEUX
GENMAB A/S 07-Apr-2025 15:12:49 PM 66 1229.50 CEUX
GENMAB A/S 07-Apr-2025 15:12:49 PM 33 1229.50 AQEU
GENMAB A/S 07-Apr-2025 15:12:50 PM 34 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:13:21 PM 83 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:13:21 PM 24 1229.00 TQEX
GENMAB A/S 07-Apr-2025 15:14:23 PM 45 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 26 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 40 1229.00 XCSE

29

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:14:23 PM 2 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 27 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 23 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 11 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 40 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 12 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:23 PM 32 1229.00 CEUX
GENMAB A/S 07-Apr-2025 15:14:23 PM 89 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:14:23 PM 33 1228.50 AQEU
GENMAB A/S 07-Apr-2025 15:14:47 PM 26 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:14:47 PM 12 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:15:48 PM 83 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:15:48 PM 58 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:15:48 PM 27 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:15:48 PM 31 1228.50 AQEU
GENMAB A/S 07-Apr-2025 15:16:16 PM 23 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:16 PM 7 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:16 PM 59 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:16 PM 24 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:16 PM 24 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:16 PM 9 1228.00 TQEX
GENMAB A/S 07-Apr-2025 15:16:16 PM 15 1228.00 TQEX
GENMAB A/S 07-Apr-2025 15:16:17 PM 28 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:16:27 PM 5 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:50 PM 29 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:50 PM 40 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:50 PM 18 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:16:50 PM 58 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:17:32 PM 4 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:17:32 PM 11 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:17:32 PM 40 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:17:33 PM 11 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:17:38 PM 90 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:17:38 PM 17 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:17:38 PM 7 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:17:38 PM 64 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:17:38 PM 28 1228.00 AQEU
GENMAB A/S 07-Apr-2025 15:18:55 PM 85 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:18:55 PM 25 1229.00 TQEX
GENMAB A/S 07-Apr-2025 15:18:55 PM 90 1229.00 CEUX
GENMAB A/S 07-Apr-2025 15:19:07 PM 87 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:19:10 PM 24 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:19:28 PM 16 1228.50 XCSE

30

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:19:28 PM 1 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:19:36 PM 71 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:20:01 PM 26 1228.00 TQEX
GENMAB A/S 07-Apr-2025 15:20:01 PM 59 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:20:01 PM 24 1228.00 AQEU
GENMAB A/S 07-Apr-2025 15:20:07 PM 40 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:20:07 PM 26 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:20:07 PM 39 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:20:22 PM 84 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:20:22 PM 90 1227.00 CEUX
GENMAB A/S 07-Apr-2025 15:21:39 PM 24 1228.50 AQEU
GENMAB A/S 07-Apr-2025 15:23:16 PM 28 1230.00 CEUX
GENMAB A/S 07-Apr-2025 15:23:27 PM 16 1230.50 TQEX
GENMAB A/S 07-Apr-2025 15:23:27 PM 6 1230.50 TQEX
GENMAB A/S 07-Apr-2025 15:23:27 PM 3 1230.50 TQEX
GENMAB A/S 07-Apr-2025 15:23:27 PM 88 1230.50 CEUX
GENMAB A/S 07-Apr-2025 15:23:42 PM 87 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:42 PM 43 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:42 PM 40 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:42 PM 30 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:42 PM 12 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:42 PM 11 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:42 PM 6 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:45 PM 10 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:45 PM 10 1230.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:49 PM 26 1230.00 TQEX
GENMAB A/S 07-Apr-2025 15:23:50 PM 11 1230.00 XCSE
GENMAB A/S 07-Apr-2025 15:23:50 PM 16 1230.00 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 89 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 40 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 30 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 6 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 11 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 12 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:23:56 PM 87 1229.50 CEUX
GENMAB A/S 07-Apr-2025 15:23:56 PM 24 1229.50 AQEU
GENMAB A/S 07-Apr-2025 15:24:07 PM 40 1229.50 XCSE
GENMAB A/S 07-Apr-2025 15:24:12 PM 87 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:24:12 PM 7 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:24:12 PM 78 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:24:12 PM 24 1228.50 AQEU
GENMAB A/S 07-Apr-2025 15:24:57 PM 40 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:24:57 PM 10 1228.50 XCSE

31

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:24:57 PM 11 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:24:57 PM 21 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:24:57 PM 20 1228.50 XCSE
GENMAB A/S 07-Apr-2025 15:25:00 PM 89 1227.00 CEUX
GENMAB A/S 07-Apr-2025 15:25:06 PM 30 1227.50 TQEX
GENMAB A/S 07-Apr-2025 15:25:06 PM 28 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:25:06 PM 56 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:25:34 PM 89 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:25:34 PM 63 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:25:34 PM 23 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:25:47 PM 22 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:25:47 PM 3 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:26:07 PM 89 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:26:07 PM 40 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:26:07 PM 24 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:26:07 PM 35 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:26:07 PM 24 1226.00 AQEU
GENMAB A/S 07-Apr-2025 15:26:49 PM 32 1226.50 TQEX
GENMAB A/S 07-Apr-2025 15:27:18 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:18 PM 40 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:18 PM 27 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:18 PM 1 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:18 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:19 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:19 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:19 PM 40 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:19 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:19 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:30 PM 85 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:30 PM 60 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:30 PM 2 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:30 PM 27 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:30 PM 11 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:30 PM 26 1227.50 TQEX
GENMAB A/S 07-Apr-2025 15:27:30 PM 84 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:27:30 PM 46 1227.50 AQEU
GENMAB A/S 07-Apr-2025 15:27:30 PM 1 1227.50 AQEU
GENMAB A/S 07-Apr-2025 15:27:40 PM 25 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:40 PM 64 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:27:40 PM 55 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:27:40 PM 30 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:28:10 PM 89 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:28:10 PM 87 1225.50 XCSE

32

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:28:10 PM 85 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:29:06 PM 20 1225.00 CEUX
GENMAB A/S 07-Apr-2025 15:29:06 PM 42 1225.00 CEUX
GENMAB A/S 07-Apr-2025 15:29:07 PM 26 1225.00 TQEX
GENMAB A/S 07-Apr-2025 15:29:07 PM 7 1225.00 CEUX
GENMAB A/S 07-Apr-2025 15:29:26 PM 1 1224.50 XCSE
GENMAB A/S 07-Apr-2025 15:29:26 PM 84 1224.50 XCSE
GENMAB A/S 07-Apr-2025 15:29:32 PM 46 1223.50 XCSE
GENMAB A/S 07-Apr-2025 15:29:32 PM 41 1223.50 XCSE
GENMAB A/S 07-Apr-2025 15:29:32 PM 47 1224.00 CEUX
GENMAB A/S 07-Apr-2025 15:30:00 PM 30 1223.00 CEUX
GENMAB A/S 07-Apr-2025 15:30:00 PM 26 1223.00 AQEU
GENMAB A/S 07-Apr-2025 15:30:00 PM 18 1223.00 AQEU
GENMAB A/S 07-Apr-2025 15:30:04 PM 34 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:04 PM 24 1222.50 TQEX
GENMAB A/S 07-Apr-2025 15:30:14 PM 8 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:14 PM 17 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:14 PM 51 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:14 PM 8 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:14 PM 58 1222.50 CEUX
GENMAB A/S 07-Apr-2025 15:30:22 PM 11 1221.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:27 PM 74 1221.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:27 PM 50 1221.50 CEUX
GENMAB A/S 07-Apr-2025 15:30:31 PM 15 1220.50 TQEX
GENMAB A/S 07-Apr-2025 15:30:44 PM 10 1221.00 CEUX
GENMAB A/S 07-Apr-2025 15:30:44 PM 26 1221.00 CEUX
GENMAB A/S 07-Apr-2025 15:30:44 PM 16 1221.00 CEUX
GENMAB A/S 07-Apr-2025 15:30:44 PM 15 1221.00 CEUX
GENMAB A/S 07-Apr-2025 15:30:46 PM 89 1221.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:46 PM 94 1221.50 XCSE
GENMAB A/S 07-Apr-2025 15:30:46 PM 9 1221.00 CEUX
GENMAB A/S 07-Apr-2025 15:31:44 PM 25 1224.50 TQEX
GENMAB A/S 07-Apr-2025 15:31:44 PM 43 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:31:45 PM 40 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:31:56 PM 100 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 90 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 34 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 12 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 30 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 37 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 12 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 11 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 10 1225.50 XCSE

33

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:32:06 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 34 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 27 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 10 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 17 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 10 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 9 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:06 PM 31 1225.00 TQEX
GENMAB A/S 07-Apr-2025 15:32:07 PM 12 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:07 PM 11 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:07 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:11 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:11 PM 27 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:14 PM 88 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:32:14 PM 27 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:32:14 PM 27 1225.00 TQEX
GENMAB A/S 07-Apr-2025 15:32:14 PM 20 1225.00 CEUX
GENMAB A/S 07-Apr-2025 15:32:20 PM 2 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:32:20 PM 11 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:32:37 PM 8 1226.00 TQEX
GENMAB A/S 07-Apr-2025 15:32:37 PM 6 1226.00 TQEX
GENMAB A/S 07-Apr-2025 15:32:45 PM 85 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:32:45 PM 89 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:32:45 PM 15 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:32:45 PM 8 1225.50 AQEU
GENMAB A/S 07-Apr-2025 15:33:03 PM 22 1225.50 AQEU
GENMAB A/S 07-Apr-2025 15:33:08 PM 5 1225.50 AQEU
GENMAB A/S 07-Apr-2025 15:33:14 PM 25 1225.50 TQEX
GENMAB A/S 07-Apr-2025 15:33:22 PM 36 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:33:34 PM 36 1225.00 CEUX
GENMAB A/S 07-Apr-2025 15:33:34 PM 25 1224.50 AQEU
GENMAB A/S 07-Apr-2025 15:33:42 PM 43 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:33:42 PM 42 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:33:42 PM 36 1225.00 CEUX
GENMAB A/S 07-Apr-2025 15:33:42 PM 2 1224.50 AQEU
GENMAB A/S 07-Apr-2025 15:33:56 PM 100 1224.50 XCSE
GENMAB A/S 07-Apr-2025 15:34:02 PM 60 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:08 PM 40 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:08 PM 26 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:08 PM 10 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:08 PM 24 1224.50 TQEX
GENMAB A/S 07-Apr-2025 15:34:08 PM 87 1224.50 CEUX

34

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:34:08 PM 40 1224.50 AQEU
GENMAB A/S 07-Apr-2025 15:34:30 PM 40 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:30 PM 11 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:30 PM 26 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:30 PM 24 1224.50 TQEX
GENMAB A/S 07-Apr-2025 15:34:30 PM 68 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:30 PM 18 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:30 PM 28 1224.50 AQEU
GENMAB A/S 07-Apr-2025 15:34:30 PM 2 1224.50 AQEU
GENMAB A/S 07-Apr-2025 15:34:35 PM 20 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:35 PM 22 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:41 PM 36 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:41 PM 15 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:45 PM 34 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:48 PM 20 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:49 PM 24 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:49 PM 16 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:49 PM 10 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:49 PM 12 1229.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:49 PM 86 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:50 PM 16 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:50 PM 36 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:52 PM 33 1229.00 CEUX
GENMAB A/S 07-Apr-2025 15:34:53 PM 85 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:53 PM 79 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:34:53 PM 15 1227.50 TQEX
GENMAB A/S 07-Apr-2025 15:34:53 PM 17 1227.50 TQEX
GENMAB A/S 07-Apr-2025 15:34:53 PM 32 1228.00 CEUX
GENMAB A/S 07-Apr-2025 15:34:53 PM 90 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:34:53 PM 33 1227.50 AQEU
GENMAB A/S 07-Apr-2025 15:35:03 PM 8 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:03 PM 60 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:03 PM 22 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 87 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 40 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 23 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 27 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 10 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 13 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 10 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 23 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 11 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 47 1227.00 XCSE

35

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:35:11 PM 22 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 1 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 40 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:11 PM 29 1226.50 TQEX
GENMAB A/S 07-Apr-2025 15:35:11 PM 84 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:11 PM 27 1226.50 AQEU
GENMAB A/S 07-Apr-2025 15:35:12 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 40 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 40 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 75 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:12 PM 14 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:16 PM 11 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:16 PM 23 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:16 PM 10 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:16 PM 40 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:16 PM 29 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:16 PM 27 1225.50 TQEX
GENMAB A/S 07-Apr-2025 15:35:16 PM 86 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:17 PM 13 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:17 PM 11 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:17 PM 10 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:17 PM 26 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:19 PM 87 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:19 PM 29 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:19 PM 55 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:20 PM 70 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:20 PM 11 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:20 PM 11 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:20 PM 21 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:26 PM 86 1224.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:26 PM 90 1224.00 CEUX
GENMAB A/S 07-Apr-2025 15:35:31 PM 27 1223.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:46 PM 85 1223.00 XCSE
GENMAB A/S 07-Apr-2025 15:35:46 PM 33 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:46 PM 50 1222.50 XCSE
GENMAB A/S 07-Apr-2025 15:35:46 PM 78 1222.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:46 PM 10 1222.50 CEUX
GENMAB A/S 07-Apr-2025 15:35:46 PM 27 1223.00 AQEU

36

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:36:25 PM 38 1221.50 XCSE
GENMAB A/S 07-Apr-2025 15:36:25 PM 50 1221.50 XCSE
GENMAB A/S 07-Apr-2025 15:36:25 PM 27 1221.50 CEUX
GENMAB A/S 07-Apr-2025 15:36:27 PM 89 1220.50 XCSE
GENMAB A/S 07-Apr-2025 15:36:27 PM 78 1219.50 XCSE
GENMAB A/S 07-Apr-2025 15:36:27 PM 5 1219.50 XCSE
GENMAB A/S 07-Apr-2025 15:36:27 PM 85 1218.00 XCSE
GENMAB A/S 07-Apr-2025 15:36:27 PM 26 1221.00 TQEX
GENMAB A/S 07-Apr-2025 15:36:27 PM 25 1220.50 CEUX
GENMAB A/S 07-Apr-2025 15:36:27 PM 30 1219.00 CEUX
GENMAB A/S 07-Apr-2025 15:36:27 PM 9 1220.00 AQEU
GENMAB A/S 07-Apr-2025 15:36:27 PM 16 1220.00 AQEU
GENMAB A/S 07-Apr-2025 15:36:28 PM 41 1219.00 XCSE
GENMAB A/S 07-Apr-2025 15:36:32 PM 25 1218.00 XCSE
GENMAB A/S 07-Apr-2025 15:36:44 PM 27 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:36:44 PM 24 1216.00 XCSE
GENMAB A/S 07-Apr-2025 15:36:44 PM 30 1217.50 CEUX
GENMAB A/S 07-Apr-2025 15:36:44 PM 24 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:36:44 PM 13 1215.50 CEUX
GENMAB A/S 07-Apr-2025 15:36:45 PM 24 1215.50 XCSE
GENMAB A/S 07-Apr-2025 15:36:45 PM 25 1215.50 TQEX
GENMAB A/S 07-Apr-2025 15:36:58 PM 31 1214.50 XCSE
GENMAB A/S 07-Apr-2025 15:37:27 PM 25 1216.00 XCSE
GENMAB A/S 07-Apr-2025 15:37:27 PM 44 1216.00 XCSE
GENMAB A/S 07-Apr-2025 15:37:27 PM 39 1215.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:02 PM 90 1219.00 XCSE
GENMAB A/S 07-Apr-2025 15:38:02 PM 90 1218.00 XCSE
GENMAB A/S 07-Apr-2025 15:38:02 PM 24 1219.00 TQEX
GENMAB A/S 07-Apr-2025 15:38:02 PM 19 1218.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:02 PM 31 1218.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:02 PM 24 1219.00 AQEU
GENMAB A/S 07-Apr-2025 15:38:11 PM 32 1217.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:11 PM 15 1217.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:12 PM 27 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:38:15 PM 56 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:38:15 PM 23 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:15 PM 16 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:38:25 PM 32 1215.50 XCSE
GENMAB A/S 07-Apr-2025 15:38:25 PM 6 1215.50 XCSE
GENMAB A/S 07-Apr-2025 15:38:29 PM 42 1215.00 CEUX
GENMAB A/S 07-Apr-2025 15:38:30 PM 25 1214.00 XCSE
GENMAB A/S 07-Apr-2025 15:38:30 PM 27 1214.00 CEUX
GENMAB A/S 07-Apr-2025 15:38:30 PM 27 1214.00 AQEU

37

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:38:31 PM 14 1214.50 TQEX
GENMAB A/S 07-Apr-2025 15:39:57 PM 40 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:39:57 PM 22 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:39:57 PM 25 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:39:57 PM 26 1218.00 XCSE
GENMAB A/S 07-Apr-2025 15:40:17 PM 27 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:17 PM 30 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:17 PM 9 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 41 1216.00 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 16 1216.00 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 29 1216.00 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 86 1215.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 37 1214.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 52 1214.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:19 PM 29 1216.00 TQEX
GENMAB A/S 07-Apr-2025 15:40:19 PM 70 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:40:19 PM 52 1215.50 CEUX
GENMAB A/S 07-Apr-2025 15:40:19 PM 49 1214.50 CEUX
GENMAB A/S 07-Apr-2025 15:40:19 PM 1 1216.00 AQEU
GENMAB A/S 07-Apr-2025 15:40:19 PM 23 1216.00 AQEU
GENMAB A/S 07-Apr-2025 15:40:29 PM 1 1214.50 CEUX
GENMAB A/S 07-Apr-2025 15:40:29 PM 30 1214.50 CEUX
GENMAB A/S 07-Apr-2025 15:40:31 PM 1 1214.50 AQEU
GENMAB A/S 07-Apr-2025 15:40:31 PM 45 1214.50 AQEU
GENMAB A/S 07-Apr-2025 15:40:35 PM 6 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:35 PM 77 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:40:35 PM 31 1214.00 TQEX
GENMAB A/S 07-Apr-2025 15:40:42 PM 45 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:40:58 PM 2 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:40:58 PM 16 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:41:20 PM 24 1214.00 TQEX
GENMAB A/S 07-Apr-2025 15:41:20 PM 36 1214.00 CEUX
GENMAB A/S 07-Apr-2025 15:41:20 PM 13 1214.00 CEUX
GENMAB A/S 07-Apr-2025 15:41:23 PM 24 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:41:23 PM 36 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:41:23 PM 24 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:41:23 PM 46 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:41:34 PM 85 1214.00 XCSE
GENMAB A/S 07-Apr-2025 15:41:34 PM 35 1214.00 CEUX
GENMAB A/S 07-Apr-2025 15:41:47 PM 24 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:41:51 PM 57 1212.50 XCSE
GENMAB A/S 07-Apr-2025 15:41:51 PM 27 1212.50 XCSE
GENMAB A/S 07-Apr-2025 15:41:51 PM 1 1213.00 CEUX

38

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:42:01 PM 15 1212.50 CEUX
GENMAB A/S 07-Apr-2025 15:42:01 PM 9 1212.50 CEUX
GENMAB A/S 07-Apr-2025 15:42:19 PM 34 1211.50 XCSE
GENMAB A/S 07-Apr-2025 15:42:19 PM 42 1211.50 XCSE
GENMAB A/S 07-Apr-2025 15:42:19 PM 46 1211.50 TQEX
GENMAB A/S 07-Apr-2025 15:42:19 PM 29 1211.50 CEUX
GENMAB A/S 07-Apr-2025 15:42:35 PM 24 1214.00 AQEU
GENMAB A/S 07-Apr-2025 15:42:47 PM 2 1215.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:47 PM 12 1215.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:47 PM 23 1215.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:47 PM 33 1215.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:47 PM 11 1215.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:52 PM 84 1214.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:52 PM 85 1213.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:52 PM 27 1212.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:52 PM 30 1212.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:52 PM 29 1212.00 XCSE
GENMAB A/S 07-Apr-2025 15:42:52 PM 51 1214.00 CEUX
GENMAB A/S 07-Apr-2025 15:42:52 PM 22 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:42:52 PM 27 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:42:52 PM 11 1211.50 CEUX
GENMAB A/S 07-Apr-2025 15:42:52 PM 20 1211.50 CEUX
GENMAB A/S 07-Apr-2025 15:42:52 PM 16 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:42:52 PM 6 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:42:59 PM 66 1213.00 XCSE
GENMAB A/S 07-Apr-2025 15:43:21 PM 3 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:43:21 PM 31 1213.00 CEUX
GENMAB A/S 07-Apr-2025 15:44:09 PM 60 1213.00 XCSE
GENMAB A/S 07-Apr-2025 15:44:09 PM 40 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:44:09 PM 11 1213.50 XCSE
GENMAB A/S 07-Apr-2025 15:44:09 PM 50 1213.50 CEUX
GENMAB A/S 07-Apr-2025 15:44:11 PM 24 1213.00 XCSE
GENMAB A/S 07-Apr-2025 15:44:16 PM 25 1213.50 TQEX
GENMAB A/S 07-Apr-2025 15:44:16 PM 50 1213.50 CEUX
GENMAB A/S 07-Apr-2025 15:44:16 PM 24 1213.50 AQEU
GENMAB A/S 07-Apr-2025 15:45:05 PM 85 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:45:05 PM 40 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:45:05 PM 12 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:45:33 PM 45 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:45:33 PM 38 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:45:33 PM 40 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:33 PM 24 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:33 PM 12 1217.50 XCSE

39

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:45:33 PM 24 1216.50 TQEX
GENMAB A/S 07-Apr-2025 15:45:33 PM 19 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:45:34 PM 40 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:34 PM 16 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:34 PM 10 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:34 PM 10 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:34 PM 6 1217.50 XCSE
GENMAB A/S 07-Apr-2025 15:45:36 PM 30 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:45:36 PM 8 1216.50 CEUX
GENMAB A/S 07-Apr-2025 15:45:38 PM 20 1216.50 AQEU
GENMAB A/S 07-Apr-2025 15:45:48 PM 36 1217.00 XCSE
GENMAB A/S 07-Apr-2025 15:45:48 PM 82 1217.00 CEUX
GENMAB A/S 07-Apr-2025 15:46:33 PM 8 1220.00 TQEX
GENMAB A/S 07-Apr-2025 15:46:33 PM 4 1220.00 TQEX
GENMAB A/S 07-Apr-2025 15:46:33 PM 12 1220.00 TQEX
GENMAB A/S 07-Apr-2025 15:46:38 PM 44 1219.50 CEUX
GENMAB A/S 07-Apr-2025 15:46:38 PM 30 1219.50 CEUX
GENMAB A/S 07-Apr-2025 15:47:08 PM 24 1221.00 TQEX
GENMAB A/S 07-Apr-2025 15:47:09 PM 6 1220.50 CEUX
GENMAB A/S 07-Apr-2025 15:47:11 PM 34 1220.50 XCSE
GENMAB A/S 07-Apr-2025 15:47:11 PM 50 1220.50 XCSE
GENMAB A/S 07-Apr-2025 15:47:11 PM 40 1220.50 XCSE
GENMAB A/S 07-Apr-2025 15:47:11 PM 10 1220.50 XCSE
GENMAB A/S 07-Apr-2025 15:47:11 PM 59 1220.50 CEUX
GENMAB A/S 07-Apr-2025 15:47:11 PM 13 1220.50 CEUX
GENMAB A/S 07-Apr-2025 15:47:11 PM 25 1220.50 AQEU
GENMAB A/S 07-Apr-2025 15:47:12 PM 17 1220.00 TQEX
GENMAB A/S 07-Apr-2025 15:47:13 PM 23 1220.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:22 PM 23 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:48:28 PM 10 1224.00 TQEX
GENMAB A/S 07-Apr-2025 15:48:36 PM 19 1225.50 AQEU
GENMAB A/S 07-Apr-2025 15:48:38 PM 10 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 25 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 10 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 14 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 14 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 30 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 56 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:48:38 PM 33 1225.50 TQEX
GENMAB A/S 07-Apr-2025 15:48:38 PM 13 1225.50 AQEU
GENMAB A/S 07-Apr-2025 15:48:38 PM 26 1225.00 AQEU
GENMAB A/S 07-Apr-2025 15:48:50 PM 86 1225.50 XCSE

40

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:48:50 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:50 PM 12 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:50 PM 24 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:48:50 PM 83 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:49:01 PM 84 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:49:06 PM 90 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:49:46 PM 3 1225.00 AQEU
GENMAB A/S 07-Apr-2025 15:49:46 PM 30 1225.00 AQEU
GENMAB A/S 07-Apr-2025 15:49:55 PM 18 1224.50 XCSE
GENMAB A/S 07-Apr-2025 15:49:55 PM 10 1224.50 XCSE
GENMAB A/S 07-Apr-2025 15:49:55 PM 33 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:49:55 PM 10 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:49:55 PM 40 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:49:55 PM 2 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:49:55 PM 90 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:49:56 PM 40 1225.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:12 PM 89 1224.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:12 PM 32 1224.00 TQEX
GENMAB A/S 07-Apr-2025 15:50:12 PM 60 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:50:12 PM 24 1224.50 CEUX
GENMAB A/S 07-Apr-2025 15:50:17 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:50:17 PM 23 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:50:17 PM 21 1225.50 XCSE
GENMAB A/S 07-Apr-2025 15:50:39 PM 43 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:50:39 PM 45 1225.50 CEUX
GENMAB A/S 07-Apr-2025 15:50:45 PM 45 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:45 PM 10 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 45 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 30 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 3 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 12 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 23 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 92 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 11 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:50:48 PM 10 1226.00 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 30 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 40 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 34 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 9 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 12 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 2 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 40 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:02 PM 10 1227.50 XCSE

41

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:51:03 PM 12 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 40 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 10 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 10 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 12 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 29 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 11 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 11 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 34 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 10 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 10 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:03 PM 32 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:34 PM 86 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:34 PM 83 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:51:34 PM 6 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:51:46 PM 17 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:51:56 PM 26 1227.00 TQEX
GENMAB A/S 07-Apr-2025 15:51:58 PM 34 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:51:58 PM 34 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:51:58 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:51:58 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:03 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:03 PM 40 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:03 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:15 PM 13 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 83 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 40 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 1 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 30 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 10 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 10 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:19 PM 84 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:52:37 PM 40 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:37 PM 13 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:52:37 PM 53 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:52:37 PM 23 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:52:40 PM 87 1227.50 XCSE
GENMAB A/S 07-Apr-2025 15:52:40 PM 24 1227.00 TQEX
GENMAB A/S 07-Apr-2025 15:52:40 PM 12 1227.50 CEUX
GENMAB A/S 07-Apr-2025 15:52:46 PM 88 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:52:46 PM 87 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:52:46 PM 31 1227.00 AQEU
GENMAB A/S 07-Apr-2025 15:53:23 PM 24 1226.50 TQEX

42

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:53:24 PM 3 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:53:24 PM 29 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:53:24 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:53:51 PM 89 1226.50 XCSE
GENMAB A/S 07-Apr-2025 15:53:51 PM 25 1226.50 TQEX
GENMAB A/S 07-Apr-2025 15:53:51 PM 87 1226.50 CEUX
GENMAB A/S 07-Apr-2025 15:53:51 PM 28 1226.00 AQEU
GENMAB A/S 07-Apr-2025 15:54:01 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:01 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:01 PM 61 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:01 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:01 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:01 PM 24 1227.00 AQEU
GENMAB A/S 07-Apr-2025 15:54:09 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:12 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:12 PM 11 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:13 PM 12 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:13 PM 10 1227.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:30 PM 11 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:54:32 PM 65 1228.00 XCSE
GENMAB A/S 07-Apr-2025 15:55:02 PM 44 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:55:02 PM 42 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:55:02 PM 27 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:55:22 PM 56 1228.50 CEUX
GENMAB A/S 07-Apr-2025 15:56:08 PM 7 1230.50 TQEX
GENMAB A/S 07-Apr-2025 15:56:08 PM 36 1230.50 TQEX
GENMAB A/S 07-Apr-2025 15:56:41 PM 26 1231.50 TQEX
GENMAB A/S 07-Apr-2025 15:57:01 PM 86 1231.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 76 1231.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 17 1231.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 76 1231.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 12 1231.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 1 1231.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 24 1231.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:01 PM 90 1231.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:01 PM 36 1231.50 CEUX
GENMAB A/S 07-Apr-2025 15:57:01 PM 6 1231.50 CEUX
GENMAB A/S 07-Apr-2025 15:57:01 PM 7 1231.50 CEUX
GENMAB A/S 07-Apr-2025 15:57:01 PM 36 1231.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:01 PM 7 1231.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:21 PM 83 1232.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:34 PM 12 1232.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:34 PM 11 1232.00 XCSE

43

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:57:34 PM 40 1232.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:34 PM 2 1232.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:34 PM 10 1232.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:34 PM 10 1232.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:34 PM 41 1232.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:34 PM 48 1232.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:34 PM 36 1232.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:34 PM 6 1232.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:34 PM 6 1232.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:34 PM 45 1232.00 AQEU
GENMAB A/S 07-Apr-2025 15:57:41 PM 10 1233.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:41 PM 11 1233.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:41 PM 40 1233.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:41 PM 40 1233.50 XCSE
GENMAB A/S 07-Apr-2025 15:57:41 PM 83 1233.00 XCSE
GENMAB A/S 07-Apr-2025 15:57:41 PM 66 1233.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:42 PM 21 1233.00 CEUX
GENMAB A/S 07-Apr-2025 15:57:54 PM 14 1233.00 AQEU
GENMAB A/S 07-Apr-2025 15:58:32 PM 40 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:32 PM 2 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:32 PM 10 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:32 PM 33 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:32 PM 12 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:32 PM 11 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:41 PM 36 1233.50 TQEX
GENMAB A/S 07-Apr-2025 15:58:41 PM 87 1233.50 CEUX
GENMAB A/S 07-Apr-2025 15:58:45 PM 11 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:45 PM 10 1234.00 XCSE
GENMAB A/S 07-Apr-2025 15:58:58 PM 5 1233.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:14 PM 56 1234.50 CEUX
GENMAB A/S 07-Apr-2025 15:59:14 PM 31 1234.50 CEUX
GENMAB A/S 07-Apr-2025 15:59:20 PM 37 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 21 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 40 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 11 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 4 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 75 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 3 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 10 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 12 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 10 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 10 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 40 1234.50 XCSE

44

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 15:59:20 PM 53 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:20 PM 33 1234.00 TQEX
GENMAB A/S 07-Apr-2025 15:59:21 PM 10 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 12 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 12 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 40 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 11 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 28 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 12 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 12 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 40 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 37 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:21 PM 11 1234.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:33 PM 6 1234.50 TQEX
GENMAB A/S 07-Apr-2025 15:59:35 PM 18 1234.50 TQEX
GENMAB A/S 07-Apr-2025 15:59:37 PM 6 1235.00 CEUX
GENMAB A/S 07-Apr-2025 15:59:37 PM 75 1235.00 CEUX
GENMAB A/S 07-Apr-2025 15:59:39 PM 40 1238.00 XCSE
GENMAB A/S 07-Apr-2025 15:59:39 PM 26 1237.50 CEUX
GENMAB A/S 07-Apr-2025 15:59:39 PM 30 1237.50 CEUX
GENMAB A/S 07-Apr-2025 15:59:43 PM 92 1238.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:43 PM 12 1238.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:43 PM 9 1238.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:43 PM 40 1238.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:49 PM 40 1239.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:53 PM 6 1240.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:53 PM 12 1240.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:53 PM 15 1240.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:53 PM 75 1240.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:53 PM 5 1240.50 XCSE
GENMAB A/S 07-Apr-2025 15:59:53 PM 85 1240.00 CEUX
GENMAB A/S 07-Apr-2025 15:59:57 PM 24 1241.00 XCSE
GENMAB A/S 07-Apr-2025 15:59:57 PM 25 1240.50 TQEX
GENMAB A/S 07-Apr-2025 15:59:57 PM 89 1240.50 CEUX
GENMAB A/S 07-Apr-2025 15:59:58 PM 41 1240.00 AQEU
GENMAB A/S 07-Apr-2025 16:00:03 PM 19 1240.50 CEUX
GENMAB A/S 07-Apr-2025 16:00:03 PM 25 1240.50 AQEU
GENMAB A/S 07-Apr-2025 16:00:15 PM 84 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:00:15 PM 84 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:00:15 PM 16 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:00:15 PM 13 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:15 PM 85 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:15 PM 22 1240.50 CEUX

45

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:00:15 PM 6 1240.50 CEUX
GENMAB A/S 07-Apr-2025 16:00:15 PM 10 1240.50 CEUX
GENMAB A/S 07-Apr-2025 16:00:15 PM 85 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:15 PM 26 1241.00 AQEU
GENMAB A/S 07-Apr-2025 16:00:15 PM 12 1240.00 AQEU
GENMAB A/S 07-Apr-2025 16:00:15 PM 18 1240.00 AQEU
GENMAB A/S 07-Apr-2025 16:00:45 PM 85 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:45 PM 89 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:45 PM 10 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:45 PM 76 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:45 PM 45 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:45 PM 51 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:45 PM 5 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:45 PM 20 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:47 PM 40 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:47 PM 8 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:00:47 PM 2 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:48 PM 22 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:00:55 PM 29 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:01:04 PM 45 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:01:04 PM 25 1238.00 TQEX
GENMAB A/S 07-Apr-2025 16:01:04 PM 24 1238.00 CEUX
GENMAB A/S 07-Apr-2025 16:01:15 PM 24 1237.00 CEUX
GENMAB A/S 07-Apr-2025 16:01:25 PM 10 1236.50 XCSE
GENMAB A/S 07-Apr-2025 16:01:25 PM 23 1236.50 XCSE
GENMAB A/S 07-Apr-2025 16:01:27 PM 20 1236.00 CEUX
GENMAB A/S 07-Apr-2025 16:01:27 PM 4 1236.00 CEUX
GENMAB A/S 07-Apr-2025 16:01:56 PM 60 1236.50 XCSE
GENMAB A/S 07-Apr-2025 16:01:56 PM 45 1236.50 CEUX
GENMAB A/S 07-Apr-2025 16:02:25 PM 83 1236.50 XCSE
GENMAB A/S 07-Apr-2025 16:02:25 PM 3 1236.50 XCSE
GENMAB A/S 07-Apr-2025 16:02:25 PM 41 1236.50 TQEX
GENMAB A/S 07-Apr-2025 16:02:25 PM 22 1236.50 CEUX
GENMAB A/S 07-Apr-2025 16:02:25 PM 10 1236.50 CEUX
GENMAB A/S 07-Apr-2025 16:02:25 PM 33 1236.50 AQEU
GENMAB A/S 07-Apr-2025 16:03:29 PM 35 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:29 PM 12 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:29 PM 40 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:41 PM 40 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:41 PM 22 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:41 PM 11 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:41 PM 40 1237.50 CEUX
GENMAB A/S 07-Apr-2025 16:03:41 PM 14 1237.50 CEUX

46

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:03:41 PM 34 1237.50 AQEU
GENMAB A/S 07-Apr-2025 16:03:42 PM 40 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:42 PM 15 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:43 PM 40 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:43 PM 12 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:47 PM 80 1237.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:47 PM 5 1237.00 XCSE
GENMAB A/S 07-Apr-2025 16:03:47 PM 6 1237.00 TQEX
GENMAB A/S 07-Apr-2025 16:03:48 PM 18 1237.00 TQEX
GENMAB A/S 07-Apr-2025 16:03:49 PM 18 1236.50 CEUX
GENMAB A/S 07-Apr-2025 16:03:49 PM 5 1236.50 CEUX
GENMAB A/S 07-Apr-2025 16:04:47 PM 90 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:04:47 PM 81 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:04:47 PM 9 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:04:49 PM 87 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:04:49 PM 30 1242.00 TQEX
GENMAB A/S 07-Apr-2025 16:04:49 PM 86 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:04:56 PM 36 1242.00 AQEU
GENMAB A/S 07-Apr-2025 16:04:58 PM 40 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:04:58 PM 73 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:05:07 PM 89 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:05:07 PM 12 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:05:07 PM 75 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:05:08 PM 26 1240.50 TQEX
GENMAB A/S 07-Apr-2025 16:05:19 PM 83 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:05:19 PM 84 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:05:37 PM 39 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:05:39 PM 5 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:05:48 PM 78 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:05:48 PM 27 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:06:07 PM 10 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:07 PM 40 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:07 PM 23 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:07 PM 10 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:17 PM 37 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:17 PM 10 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:17 PM 10 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:17 PM 11 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:06:17 PM 12 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:02 PM 35 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:02 PM 51 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:02 PM 44 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:07:19 PM 31 1241.00 TQEX

47

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:07:19 PM 82 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:07:25 PM 6 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:25 PM 79 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:25 PM 29 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:07:25 PM 38 1240.00 AQEU
GENMAB A/S 07-Apr-2025 16:07:26 PM 40 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:26 PM 11 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:26 PM 11 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:26 PM 11 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:07:29 PM 73 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:07:29 PM 10 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:07:29 PM 41 1240.50 CEUX
GENMAB A/S 07-Apr-2025 16:07:47 PM 40 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:07:47 PM 22 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:07:47 PM 10 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:07:48 PM 87 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:07:48 PM 32 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:07:48 PM 14 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:08:11 PM 38 1238.50 XCSE
GENMAB A/S 07-Apr-2025 16:08:11 PM 45 1238.50 XCSE
GENMAB A/S 07-Apr-2025 16:08:11 PM 14 1238.50 CEUX
GENMAB A/S 07-Apr-2025 16:08:11 PM 13 1238.50 CEUX
GENMAB A/S 07-Apr-2025 16:09:05 PM 40 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:09:05 PM 19 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:09:05 PM 30 1240.00 TQEX
GENMAB A/S 07-Apr-2025 16:09:05 PM 58 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:09:05 PM 37 1240.00 AQEU
GENMAB A/S 07-Apr-2025 16:09:13 PM 83 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:28 PM 29 1241.00 TQEX
GENMAB A/S 07-Apr-2025 16:09:28 PM 68 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:09:28 PM 2 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:09:31 PM 39 1241.00 AQEU
GENMAB A/S 07-Apr-2025 16:09:32 PM 83 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:09:32 PM 69 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:09:47 PM 4 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:47 PM 11 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:47 PM 40 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:47 PM 11 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:47 PM 30 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:48 PM 11 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:48 PM 40 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:48 PM 11 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:48 PM 11 1240.50 XCSE

48

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:09:57 PM 12 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:57 PM 40 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:57 PM 20 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:57 PM 12 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:57 PM 14 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:09:57 PM 4 1240.00 TQEX
GENMAB A/S 07-Apr-2025 16:09:58 PM 24 1240.00 TQEX
GENMAB A/S 07-Apr-2025 16:10:29 PM 76 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:10:34 PM 88 1242.50 XCSE
GENMAB A/S 07-Apr-2025 16:10:34 PM 55 1243.00 CEUX
GENMAB A/S 07-Apr-2025 16:10:42 PM 105 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:10:48 PM 47 1243.50 CEUX
GENMAB A/S 07-Apr-2025 16:10:59 PM 86 1244.50 XCSE
GENMAB A/S 07-Apr-2025 16:11:12 PM 86 1246.50 XCSE
GENMAB A/S 07-Apr-2025 16:11:12 PM 37 1246.50 CEUX
GENMAB A/S 07-Apr-2025 16:11:15 PM 28 1247.00 CEUX
GENMAB A/S 07-Apr-2025 16:11:19 PM 40 1249.00 XCSE
GENMAB A/S 07-Apr-2025 16:11:19 PM 21 1249.00 XCSE
GENMAB A/S 07-Apr-2025 16:11:19 PM 23 1249.00 XCSE
GENMAB A/S 07-Apr-2025 16:11:19 PM 34 1249.00 CEUX
GENMAB A/S 07-Apr-2025 16:11:21 PM 23 1249.00 CEUX
GENMAB A/S 07-Apr-2025 16:11:23 PM 71 1249.50 XCSE
GENMAB A/S 07-Apr-2025 16:11:23 PM 31 1250.00 CEUX
GENMAB A/S 07-Apr-2025 16:11:31 PM 22 1249.50 CEUX
GENMAB A/S 07-Apr-2025 16:11:43 PM 19 1250.50 TQEX
GENMAB A/S 07-Apr-2025 16:11:46 PM 83 1249.50 XCSE
GENMAB A/S 07-Apr-2025 16:11:46 PM 43 1249.50 CEUX
GENMAB A/S 07-Apr-2025 16:11:51 PM 69 1249.50 XCSE
GENMAB A/S 07-Apr-2025 16:11:54 PM 55 1248.50 XCSE
GENMAB A/S 07-Apr-2025 16:12:16 PM 44 1248.50 XCSE
GENMAB A/S 07-Apr-2025 16:12:16 PM 25 1248.50 CEUX
GENMAB A/S 07-Apr-2025 16:12:21 PM 40 1250.00 XCSE
GENMAB A/S 07-Apr-2025 16:12:21 PM 30 1250.00 CEUX
GENMAB A/S 07-Apr-2025 16:12:34 PM 24 1250.50 XCSE
GENMAB A/S 07-Apr-2025 16:12:36 PM 30 1251.00 XCSE
GENMAB A/S 07-Apr-2025 16:12:40 PM 25 1252.00 CEUX
GENMAB A/S 07-Apr-2025 16:12:48 PM 28 1251.50 AQEU
GENMAB A/S 07-Apr-2025 16:13:16 PM 86 1252.00 XCSE
GENMAB A/S 07-Apr-2025 16:13:21 PM 34 1251.50 TQEX
GENMAB A/S 07-Apr-2025 16:13:21 PM 34 1251.50 CEUX
GENMAB A/S 07-Apr-2025 16:13:30 PM 43 1254.00 CEUX
GENMAB A/S 07-Apr-2025 16:13:30 PM 28 1254.00 AQEU
GENMAB A/S 07-Apr-2025 16:13:55 PM 6 1257.50 XCSE

49

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:13:55 PM 12 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:13:55 PM 40 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:13:55 PM 16 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:15 PM 83 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:16 PM 89 1258.00 XCSE
GENMAB A/S 07-Apr-2025 16:14:16 PM 10 1258.00 TQEX
GENMAB A/S 07-Apr-2025 16:14:16 PM 24 1258.00 TQEX
GENMAB A/S 07-Apr-2025 16:14:19 PM 90 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:19 PM 29 1256.50 CEUX
GENMAB A/S 07-Apr-2025 16:14:20 PM 17 1256.50 CEUX
GENMAB A/S 07-Apr-2025 16:14:29 PM 44 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:31 PM 4 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:34 PM 70 1258.00 XCSE
GENMAB A/S 07-Apr-2025 16:14:42 PM 28 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:42 PM 51 1256.50 CEUX
GENMAB A/S 07-Apr-2025 16:14:47 PM 42 1255.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:47 PM 45 1255.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:47 PM 36 1255.50 CEUX
GENMAB A/S 07-Apr-2025 16:14:50 PM 36 1254.50 XCSE
GENMAB A/S 07-Apr-2025 16:14:52 PM 24 1256.00 XCSE
GENMAB A/S 07-Apr-2025 16:14:52 PM 38 1256.00 CEUX
GENMAB A/S 07-Apr-2025 16:15:02 PM 28 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:15:02 PM 24 1256.00 CEUX
GENMAB A/S 07-Apr-2025 16:15:04 PM 18 1255.50 TQEX
GENMAB A/S 07-Apr-2025 16:15:11 PM 7 1256.00 XCSE
GENMAB A/S 07-Apr-2025 16:15:14 PM 14 1256.00 XCSE
GENMAB A/S 07-Apr-2025 16:15:28 PM 19 1257.50 CEUX
GENMAB A/S 07-Apr-2025 16:15:38 PM 37 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:15:44 PM 13 1259.50 CEUX
GENMAB A/S 07-Apr-2025 16:15:44 PM 28 1259.50 CEUX
GENMAB A/S 07-Apr-2025 16:15:49 PM 42 1259.50 XCSE
GENMAB A/S 07-Apr-2025 16:15:49 PM 24 1259.50 CEUX
GENMAB A/S 07-Apr-2025 16:16:12 PM 14 1263.00 XCSE
GENMAB A/S 07-Apr-2025 16:16:12 PM 4 1263.00 TQEX
GENMAB A/S 07-Apr-2025 16:16:12 PM 20 1263.00 TQEX
GENMAB A/S 07-Apr-2025 16:16:12 PM 32 1263.00 CEUX
GENMAB A/S 07-Apr-2025 16:16:29 PM 24 1264.50 AQEU
GENMAB A/S 07-Apr-2025 16:16:36 PM 87 1265.50 XCSE
GENMAB A/S 07-Apr-2025 16:16:36 PM 47 1265.00 CEUX
GENMAB A/S 07-Apr-2025 16:16:36 PM 28 1265.00 AQEU
GENMAB A/S 07-Apr-2025 16:16:38 PM 85 1264.50 XCSE
GENMAB A/S 07-Apr-2025 16:16:38 PM 42 1264.00 CEUX
GENMAB A/S 07-Apr-2025 16:16:38 PM 2 1264.00 CEUX

50

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:16:39 PM 41 1263.00 XCSE
GENMAB A/S 07-Apr-2025 16:16:39 PM 11 1263.00 XCSE
GENMAB A/S 07-Apr-2025 16:16:41 PM 45 1263.00 CEUX
GENMAB A/S 07-Apr-2025 16:16:59 PM 34 1265.00 XCSE
GENMAB A/S 07-Apr-2025 16:16:59 PM 16 1265.00 XCSE
GENMAB A/S 07-Apr-2025 16:17:12 PM 46 1266.50 XCSE
GENMAB A/S 07-Apr-2025 16:17:12 PM 29 1266.00 CEUX
GENMAB A/S 07-Apr-2025 16:17:18 PM 30 1265.50 XCSE
GENMAB A/S 07-Apr-2025 16:17:21 PM 16 1265.50 XCSE
GENMAB A/S 07-Apr-2025 16:17:46 PM 70 1268.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:06 PM 75 1268.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:06 PM 7 1267.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:06 PM 4 1267.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:06 PM 59 1267.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:06 PM 30 1268.00 TQEX
GENMAB A/S 07-Apr-2025 16:18:06 PM 42 1268.50 CEUX
GENMAB A/S 07-Apr-2025 16:18:06 PM 8 1267.50 CEUX
GENMAB A/S 07-Apr-2025 16:18:06 PM 32 1267.50 CEUX
GENMAB A/S 07-Apr-2025 16:18:11 PM 42 1266.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:11 PM 32 1267.00 TQEX
GENMAB A/S 07-Apr-2025 16:18:11 PM 25 1266.00 CEUX
GENMAB A/S 07-Apr-2025 16:18:11 PM 37 1267.00 AQEU
GENMAB A/S 07-Apr-2025 16:18:12 PM 46 1265.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:12 PM 7 1266.00 CEUX
GENMAB A/S 07-Apr-2025 16:18:14 PM 27 1265.00 CEUX
GENMAB A/S 07-Apr-2025 16:18:28 PM 20 1266.50 CEUX
GENMAB A/S 07-Apr-2025 16:18:28 PM 9 1266.50 CEUX
GENMAB A/S 07-Apr-2025 16:18:47 PM 58 1267.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:56 PM 43 1266.50 XCSE
GENMAB A/S 07-Apr-2025 16:18:56 PM 26 1266.00 CEUX
GENMAB A/S 07-Apr-2025 16:19:00 PM 24 1265.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:11 PM 22 1264.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:11 PM 19 1264.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:11 PM 27 1265.00 CEUX
GENMAB A/S 07-Apr-2025 16:19:12 PM 24 1264.00 CEUX
GENMAB A/S 07-Apr-2025 16:19:35 PM 20 1264.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:35 PM 60 1264.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:35 PM 2 1263.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:45 PM 24 1264.00 CEUX
GENMAB A/S 07-Apr-2025 16:19:46 PM 32 1263.50 XCSE
GENMAB A/S 07-Apr-2025 16:19:48 PM 36 1263.50 AQEU
GENMAB A/S 07-Apr-2025 16:19:49 PM 27 1263.00 CEUX
GENMAB A/S 07-Apr-2025 16:20:00 PM 55 1262.00 XCSE

51

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:20:00 PM 40 1262.00 TQEX
GENMAB A/S 07-Apr-2025 16:20:00 PM 24 1262.00 CEUX
GENMAB A/S 07-Apr-2025 16:20:53 PM 50 1260.50 XCSE
GENMAB A/S 07-Apr-2025 16:20:53 PM 40 1260.50 XCSE
GENMAB A/S 07-Apr-2025 16:20:53 PM 30 1260.50 XCSE
GENMAB A/S 07-Apr-2025 16:20:53 PM 24 1260.50 CEUX
GENMAB A/S 07-Apr-2025 16:21:05 PM 27 1259.50 XCSE
GENMAB A/S 07-Apr-2025 16:21:05 PM 25 1259.50 CEUX
GENMAB A/S 07-Apr-2025 16:21:23 PM 58 1259.00 XCSE
GENMAB A/S 07-Apr-2025 16:21:25 PM 55 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:21:25 PM 32 1258.50 CEUX
GENMAB A/S 07-Apr-2025 16:21:25 PM 33 1258.00 AQEU
GENMAB A/S 07-Apr-2025 16:21:37 PM 47 1257.00 CEUX
GENMAB A/S 07-Apr-2025 16:21:48 PM 23 1258.00 XCSE
GENMAB A/S 07-Apr-2025 16:21:48 PM 30 1258.00 XCSE
GENMAB A/S 07-Apr-2025 16:21:48 PM 7 1258.00 XCSE
GENMAB A/S 07-Apr-2025 16:21:48 PM 42 1258.00 CEUX
GENMAB A/S 07-Apr-2025 16:22:02 PM 86 1258.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:06 PM 31 1258.00 CEUX
GENMAB A/S 07-Apr-2025 16:22:07 PM 2 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:07 PM 17 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:07 PM 70 1257.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:08 PM 80 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:08 PM 5 1256.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:08 PM 24 1256.00 XCSE
GENMAB A/S 07-Apr-2025 16:22:08 PM 46 1257.00 CEUX
GENMAB A/S 07-Apr-2025 16:22:10 PM 29 1255.50 CEUX
GENMAB A/S 07-Apr-2025 16:22:14 PM 37 1256.00 XCSE
GENMAB A/S 07-Apr-2025 16:22:16 PM 1 1255.00 XCSE
GENMAB A/S 07-Apr-2025 16:22:16 PM 32 1255.00 XCSE
GENMAB A/S 07-Apr-2025 16:22:16 PM 28 1254.00 XCSE
GENMAB A/S 07-Apr-2025 16:22:16 PM 25 1254.00 CEUX
GENMAB A/S 07-Apr-2025 16:22:52 PM 45 1257.00 XCSE
GENMAB A/S 07-Apr-2025 16:22:52 PM 30 1257.50 TQEX
GENMAB A/S 07-Apr-2025 16:22:53 PM 33 1256.50 CEUX
GENMAB A/S 07-Apr-2025 16:22:54 PM 39 1255.50 XCSE
GENMAB A/S 07-Apr-2025 16:22:54 PM 24 1255.50 CEUX
GENMAB A/S 07-Apr-2025 16:23:02 PM 24 1254.50 CEUX
GENMAB A/S 07-Apr-2025 16:23:24 PM 26 1254.00 XCSE
GENMAB A/S 07-Apr-2025 16:23:24 PM 27 1253.00 XCSE
GENMAB A/S 07-Apr-2025 16:23:24 PM 12 1253.00 XCSE
GENMAB A/S 07-Apr-2025 16:23:24 PM 24 1253.00 CEUX
GENMAB A/S 07-Apr-2025 16:23:24 PM 34 1253.00 AQEU

52

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:23:33 PM 25 1252.50 TQEX
GENMAB A/S 07-Apr-2025 16:23:33 PM 19 1252.00 CEUX
GENMAB A/S 07-Apr-2025 16:23:44 PM 69 1252.50 XCSE
GENMAB A/S 07-Apr-2025 16:23:49 PM 16 1251.50 XCSE
GENMAB A/S 07-Apr-2025 16:23:49 PM 10 1251.50 XCSE
GENMAB A/S 07-Apr-2025 16:23:49 PM 15 1252.00 CEUX
GENMAB A/S 07-Apr-2025 16:23:59 PM 26 1251.00 CEUX
GENMAB A/S 07-Apr-2025 16:24:07 PM 24 1250.50 CEUX
GENMAB A/S 07-Apr-2025 16:24:24 PM 36 1250.50 TQEX
GENMAB A/S 07-Apr-2025 16:24:24 PM 24 1250.50 CEUX
GENMAB A/S 07-Apr-2025 16:24:56 PM 50 1250.00 XCSE
GENMAB A/S 07-Apr-2025 16:24:56 PM 40 1250.00 XCSE
GENMAB A/S 07-Apr-2025 16:24:56 PM 15 1250.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:07 PM 40 1250.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:07 PM 11 1250.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:08 PM 40 1249.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:08 PM 36 1249.50 XCSE
GENMAB A/S 07-Apr-2025 16:25:08 PM 27 1249.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:08 PM 24 1248.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:19 PM 59 1247.50 XCSE
GENMAB A/S 07-Apr-2025 16:25:19 PM 25 1247.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:19 PM 31 1247.00 AQEU
GENMAB A/S 07-Apr-2025 16:25:24 PM 88 1246.50 XCSE
GENMAB A/S 07-Apr-2025 16:25:24 PM 30 1245.50 XCSE
GENMAB A/S 07-Apr-2025 16:25:24 PM 56 1245.50 XCSE
GENMAB A/S 07-Apr-2025 16:25:24 PM 26 1246.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:24 PM 30 1245.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:24 PM 4 1245.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:56 PM 50 1247.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:56 PM 24 1246.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:59 PM 16 1246.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:59 PM 11 1246.00 XCSE
GENMAB A/S 07-Apr-2025 16:25:59 PM 21 1245.50 CEUX
GENMAB A/S 07-Apr-2025 16:25:59 PM 3 1245.50 CEUX
GENMAB A/S 07-Apr-2025 16:26:06 PM 20 1246.00 XCSE
GENMAB A/S 07-Apr-2025 16:26:14 PM 35 1246.00 XCSE
GENMAB A/S 07-Apr-2025 16:26:14 PM 29 1245.50 CEUX
GENMAB A/S 07-Apr-2025 16:26:15 PM 49 1245.00 XCSE
GENMAB A/S 07-Apr-2025 16:26:45 PM 61 1247.50 XCSE
GENMAB A/S 07-Apr-2025 16:26:45 PM 1 1247.50 XCSE
GENMAB A/S 07-Apr-2025 16:27:03 PM 66 1247.50 XCSE
GENMAB A/S 07-Apr-2025 16:27:04 PM 41 1247.00 CEUX
GENMAB A/S 07-Apr-2025 16:27:18 PM 51 1246.50 XCSE

53

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:27:18 PM 44 1246.50 TQEX
GENMAB A/S 07-Apr-2025 16:27:24 PM 31 1246.00 CEUX
GENMAB A/S 07-Apr-2025 16:27:24 PM 41 1246.00 AQEU
GENMAB A/S 07-Apr-2025 16:27:36 PM 90 1247.50 XCSE
GENMAB A/S 07-Apr-2025 16:27:38 PM 32 1247.00 CEUX
GENMAB A/S 07-Apr-2025 16:27:38 PM 26 1247.00 CEUX
GENMAB A/S 07-Apr-2025 16:27:55 PM 78 1246.50 XCSE
GENMAB A/S 07-Apr-2025 16:28:00 PM 54 1246.00 CEUX
GENMAB A/S 07-Apr-2025 16:28:07 PM 59 1245.50 XCSE
GENMAB A/S 07-Apr-2025 16:28:07 PM 29 1245.00 CEUX
GENMAB A/S 07-Apr-2025 16:28:15 PM 8 1244.00 XCSE
GENMAB A/S 07-Apr-2025 16:28:15 PM 33 1244.00 XCSE
GENMAB A/S 07-Apr-2025 16:28:22 PM 52 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:28:22 PM 44 1243.50 CEUX
GENMAB A/S 07-Apr-2025 16:28:24 PM 58 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:28:24 PM 21 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:28:24 PM 7 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:28:43 PM 45 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:28:43 PM 24 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:28:48 PM 29 1240.50 CEUX
GENMAB A/S 07-Apr-2025 16:28:50 PM 29 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:29:04 PM 24 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:29:14 PM 16 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:29:14 PM 8 1239.00 XCSE
GENMAB A/S 07-Apr-2025 16:29:17 PM 24 1238.50 CEUX
GENMAB A/S 07-Apr-2025 16:29:23 PM 8 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:29:23 PM 30 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:29:23 PM 24 1237.50 CEUX
GENMAB A/S 07-Apr-2025 16:29:51 PM 40 1237.00 XCSE
GENMAB A/S 07-Apr-2025 16:30:01 PM 11 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:30:03 PM 40 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:30:03 PM 19 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:30:03 PM 15 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:30:08 PM 2 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:30:08 PM 56 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:30:08 PM 2 1238.50 TQEX
GENMAB A/S 07-Apr-2025 16:30:08 PM 17 1238.50 TQEX
GENMAB A/S 07-Apr-2025 16:30:08 PM 3 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:30:08 PM 14 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:30:08 PM 13 1238.00 CEUX
GENMAB A/S 07-Apr-2025 16:30:12 PM 11 1238.50 TQEX
GENMAB A/S 07-Apr-2025 16:30:12 PM 10 1238.00 CEUX
GENMAB A/S 07-Apr-2025 16:30:12 PM 2 1238.00 CEUX

54

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:30:28 PM 90 1238.00 XCSE
GENMAB A/S 07-Apr-2025 16:30:28 PM 27 1238.50 TQEX
GENMAB A/S 07-Apr-2025 16:30:28 PM 3 1238.50 TQEX
GENMAB A/S 07-Apr-2025 16:30:28 PM 5 1238.00 CEUX
GENMAB A/S 07-Apr-2025 16:30:28 PM 25 1238.50 AQEU
GENMAB A/S 07-Apr-2025 16:30:57 PM 15 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:30:57 PM 20 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:30:57 PM 40 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:31:07 PM 17 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:31:07 PM 40 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:31:07 PM 20 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:31:07 PM 86 1240.00 XCSE
GENMAB A/S 07-Apr-2025 16:31:07 PM 59 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:31:07 PM 10 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:31:08 PM 24 1239.50 AQEU
GENMAB A/S 07-Apr-2025 16:31:30 PM 77 1238.50 XCSE
GENMAB A/S 07-Apr-2025 16:31:30 PM 38 1238.50 TQEX
GENMAB A/S 07-Apr-2025 16:31:30 PM 37 1239.00 CEUX
GENMAB A/S 07-Apr-2025 16:31:31 PM 15 1238.00 CEUX
GENMAB A/S 07-Apr-2025 16:31:31 PM 19 1238.00 CEUX
GENMAB A/S 07-Apr-2025 16:31:43 PM 75 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:31:52 PM 25 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:08 PM 8 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:32:10 PM 8 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:32:10 PM 58 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:32:10 PM 29 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:11 PM 24 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:12 PM 8 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:32:12 PM 47 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:32:12 PM 12 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:32:13 PM 19 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:14 PM 2 1240.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:33 PM 26 1243.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:38 PM 16 1243.00 CEUX
GENMAB A/S 07-Apr-2025 16:32:47 PM 20 1243.50 XCSE
GENMAB A/S 07-Apr-2025 16:32:47 PM 40 1244.00 XCSE
GENMAB A/S 07-Apr-2025 16:32:47 PM 20 1244.00 XCSE
GENMAB A/S 07-Apr-2025 16:32:47 PM 88 1243.50 XCSE
GENMAB A/S 07-Apr-2025 16:32:47 PM 37 1244.00 TQEX
GENMAB A/S 07-Apr-2025 16:32:47 PM 9 1243.50 AQEU
GENMAB A/S 07-Apr-2025 16:32:47 PM 1 1243.50 AQEU
GENMAB A/S 07-Apr-2025 16:32:47 PM 29 1243.50 AQEU
GENMAB A/S 07-Apr-2025 16:32:49 PM 39 1243.00 CEUX

55

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:32:51 PM 67 1242.50 XCSE
GENMAB A/S 07-Apr-2025 16:33:05 PM 30 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:33:05 PM 38 1243.00 CEUX
GENMAB A/S 07-Apr-2025 16:33:06 PM 46 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:33:15 PM 33 1241.50 XCSE
GENMAB A/S 07-Apr-2025 16:33:15 PM 26 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:33:33 PM 2 1243.50 CEUX
GENMAB A/S 07-Apr-2025 16:33:33 PM 19 1243.50 CEUX
GENMAB A/S 07-Apr-2025 16:33:33 PM 14 1243.50 CEUX
GENMAB A/S 07-Apr-2025 16:33:46 PM 23 1244.00 XCSE
GENMAB A/S 07-Apr-2025 16:33:52 PM 40 1244.00 XCSE
GENMAB A/S 07-Apr-2025 16:33:52 PM 36 1243.50 CEUX
GENMAB A/S 07-Apr-2025 16:33:54 PM 58 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:04 PM 10 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:04 PM 43 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:37 PM 21 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:37 PM 24 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:37 PM 40 1243.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:37 PM 26 1242.50 CEUX
GENMAB A/S 07-Apr-2025 16:34:45 PM 23 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:45 PM 18 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:45 PM 1 1242.50 XCSE
GENMAB A/S 07-Apr-2025 16:34:45 PM 2 1242.50 XCSE
GENMAB A/S 07-Apr-2025 16:34:45 PM 40 1242.50 XCSE
GENMAB A/S 07-Apr-2025 16:34:45 PM 5 1242.50 XCSE
GENMAB A/S 07-Apr-2025 16:34:54 PM 63 1242.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:54 PM 33 1242.00 CEUX
GENMAB A/S 07-Apr-2025 16:34:59 PM 62 1241.00 XCSE
GENMAB A/S 07-Apr-2025 16:34:59 PM 26 1241.00 CEUX
GENMAB A/S 07-Apr-2025 16:35:10 PM 24 1241.00 AQEU
GENMAB A/S 07-Apr-2025 16:35:12 PM 41 1240.50 XCSE
GENMAB A/S 07-Apr-2025 16:35:12 PM 36 1240.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:13 PM 48 1239.50 XCSE
GENMAB A/S 07-Apr-2025 16:35:13 PM 3 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:13 PM 2 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:13 PM 5 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:13 PM 28 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:13 PM 3 1239.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:13 PM 24 1240.00 AQEU
GENMAB A/S 07-Apr-2025 16:35:16 PM 25 1239.50 TQEX
GENMAB A/S 07-Apr-2025 16:35:26 PM 24 1239.00 TQEX
GENMAB A/S 07-Apr-2025 16:35:36 PM 24 1238.50 XCSE
GENMAB A/S 07-Apr-2025 16:35:36 PM 31 1238.00 CEUX

56

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:35:48 PM 39 1237.00 XCSE
GENMAB A/S 07-Apr-2025 16:35:48 PM 34 1236.00 XCSE
GENMAB A/S 07-Apr-2025 16:35:48 PM 25 1236.50 CEUX
GENMAB A/S 07-Apr-2025 16:35:49 PM 49 1236.50 XCSE
GENMAB A/S 07-Apr-2025 16:36:03 PM 28 1236.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:07 PM 34 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:07 PM 31 1235.00 CEUX
GENMAB A/S 07-Apr-2025 16:36:36 PM 40 1235.50 XCSE
GENMAB A/S 07-Apr-2025 16:36:36 PM 43 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:40 PM 29 1236.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:40 PM 27 1236.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:43 PM 17 1235.50 CEUX
GENMAB A/S 07-Apr-2025 16:36:49 PM 31 1235.50 CEUX
GENMAB A/S 07-Apr-2025 16:36:52 PM 45 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:57 PM 1 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:36:57 PM 28 1234.00 CEUX
GENMAB A/S 07-Apr-2025 16:37:22 PM 60 1234.50 XCSE
GENMAB A/S 07-Apr-2025 16:37:22 PM 40 1234.50 XCSE
GENMAB A/S 07-Apr-2025 16:37:22 PM 1 1234.50 TQEX
GENMAB A/S 07-Apr-2025 16:37:22 PM 23 1234.50 TQEX
GENMAB A/S 07-Apr-2025 16:37:22 PM 39 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:37:22 PM 4 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:37:22 PM 19 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:37:41 PM 15 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:37:41 PM 40 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:37:42 PM 13 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:37:51 PM 24 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:37:51 PM 63 1233.50 XCSE
GENMAB A/S 07-Apr-2025 16:37:51 PM 24 1234.50 TQEX
GENMAB A/S 07-Apr-2025 16:37:51 PM 48 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:37:51 PM 61 1233.50 CEUX
GENMAB A/S 07-Apr-2025 16:37:51 PM 38 1234.00 AQEU
GENMAB A/S 07-Apr-2025 16:38:02 PM 53 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:02 PM 15 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:38:03 PM 12 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:38:31 PM 88 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 40 1233.50 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 10 1233.50 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 11 1233.50 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 40 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 10 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 2 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:31 PM 20 1233.50 CEUX

57

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:38:31 PM 21 1233.50 CEUX
GENMAB A/S 07-Apr-2025 16:38:36 PM 42 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:38:36 PM 35 1233.00 AQEU
GENMAB A/S 07-Apr-2025 16:38:57 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:57 PM 11 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:57 PM 30 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:38:57 PM 58 1232.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:03 PM 37 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:04 PM 34 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:04 PM 48 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:39:32 PM 36 1232.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:33 PM 27 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:39:34 PM 24 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:34 PM 18 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:39:35 PM 38 1231.00 CEUX
GENMAB A/S 07-Apr-2025 16:39:36 PM 71 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:36 PM 7 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:39:36 PM 30 1230.50 TQEX
GENMAB A/S 07-Apr-2025 16:39:37 PM 27 1229.50 TQEX
GENMAB A/S 07-Apr-2025 16:39:37 PM 34 1230.00 CEUX
GENMAB A/S 07-Apr-2025 16:39:46 PM 43 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:39:46 PM 24 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:39:58 PM 30 1228.50 XCSE
GENMAB A/S 07-Apr-2025 16:40:13 PM 11 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:40:13 PM 40 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:40:13 PM 10 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:40:13 PM 9 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:40:13 PM 36 1230.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:13 PM 35 1229.50 AQEU
GENMAB A/S 07-Apr-2025 16:40:22 PM 55 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:40:22 PM 2 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:22 PM 40 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:22 PM 2 1228.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:22 PM 10 1228.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:23 PM 5 1228.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:23 PM 7 1228.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:28 PM 39 1227.50 XCSE
GENMAB A/S 07-Apr-2025 16:40:30 PM 2 1227.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:30 PM 32 1227.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:39 PM 40 1227.00 CEUX
GENMAB A/S 07-Apr-2025 16:40:40 PM 44 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:33 PM 58 1226.00 XCSE
GENMAB A/S 07-Apr-2025 16:41:33 PM 30 1226.50 XCSE

58

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:41:33 PM 12 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:33 PM 11 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:33 PM 42 1225.50 TQEX
GENMAB A/S 07-Apr-2025 16:41:33 PM 24 1225.50 CEUX
GENMAB A/S 07-Apr-2025 16:41:50 PM 87 1226.00 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 40 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 22 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 12 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 2 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 12 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 12 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 40 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 11 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 38 1227.00 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 3 1227.00 XCSE
GENMAB A/S 07-Apr-2025 16:41:50 PM 44 1225.50 CEUX
GENMAB A/S 07-Apr-2025 16:41:50 PM 36 1226.00 AQEU
GENMAB A/S 07-Apr-2025 16:41:59 PM 37 1225.50 CEUX
GENMAB A/S 07-Apr-2025 16:41:59 PM 3 1225.50 CEUX
GENMAB A/S 07-Apr-2025 16:42:04 PM 15 1225.50 CEUX
GENMAB A/S 07-Apr-2025 16:42:04 PM 13 1225.50 CEUX
GENMAB A/S 07-Apr-2025 16:42:07 PM 14 1226.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:07 PM 40 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:42:07 PM 22 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:42:07 PM 16 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:42:14 PM 19 1226.50 XCSE
GENMAB A/S 07-Apr-2025 16:42:17 PM 45 1226.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:17 PM 40 1225.50 XCSE
GENMAB A/S 07-Apr-2025 16:42:17 PM 2 1226.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:17 PM 39 1225.50 TQEX
GENMAB A/S 07-Apr-2025 16:42:17 PM 46 1226.00 CEUX
GENMAB A/S 07-Apr-2025 16:42:29 PM 36 1227.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:29 PM 11 1227.00 CEUX
GENMAB A/S 07-Apr-2025 16:42:29 PM 26 1227.00 CEUX
GENMAB A/S 07-Apr-2025 16:42:44 PM 45 1228.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:45 PM 19 1228.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:46 PM 11 1228.00 XCSE
GENMAB A/S 07-Apr-2025 16:42:57 PM 40 1228.00 XCSE
GENMAB A/S 07-Apr-2025 16:43:08 PM 36 1228.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:08 PM 27 1228.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:08 PM 43 1227.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:09 PM 53 1227.00 XCSE
GENMAB A/S 07-Apr-2025 16:43:09 PM 14 1227.00 XCSE

59

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:43:16 PM 66 1227.00 XCSE
GENMAB A/S 07-Apr-2025 16:43:16 PM 70 1227.50 XCSE
GENMAB A/S 07-Apr-2025 16:43:16 PM 37 1227.50 XCSE
GENMAB A/S 07-Apr-2025 16:43:16 PM 28 1227.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:29 PM 39 1227.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:34 PM 37 1227.00 XCSE
GENMAB A/S 07-Apr-2025 16:43:34 PM 33 1226.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:37 PM 35 1228.50 CEUX
GENMAB A/S 07-Apr-2025 16:43:38 PM 20 1228.50 XCSE
GENMAB A/S 07-Apr-2025 16:43:38 PM 16 1228.50 XCSE
GENMAB A/S 07-Apr-2025 16:43:38 PM 22 1228.00 TQEX
GENMAB A/S 07-Apr-2025 16:43:38 PM 16 1228.00 TQEX
GENMAB A/S 07-Apr-2025 16:43:38 PM 35 1228.50 CEUX
GENMAB A/S 07-Apr-2025 16:44:00 PM 39 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:44:04 PM 15 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:44:10 PM 81 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:44:10 PM 5 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:44:10 PM 31 1229.50 AQEU
GENMAB A/S 07-Apr-2025 16:44:11 PM 42 1228.50 XCSE
GENMAB A/S 07-Apr-2025 16:44:11 PM 24 1228.50 AQEU
GENMAB A/S 07-Apr-2025 16:44:15 PM 20 1228.00 CEUX
GENMAB A/S 07-Apr-2025 16:44:16 PM 53 1228.00 XCSE
GENMAB A/S 07-Apr-2025 16:44:16 PM 16 1228.00 CEUX
GENMAB A/S 07-Apr-2025 16:44:26 PM 1 1228.00 XCSE
GENMAB A/S 07-Apr-2025 16:44:47 PM 88 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:44:53 PM 67 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:44:53 PM 5 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:44:53 PM 40 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:00 PM 7 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:45:00 PM 18 1229.00 CEUX
GENMAB A/S 07-Apr-2025 16:45:14 PM 40 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:14 PM 20 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:14 PM 40 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:14 PM 44 1228.50 CEUX
GENMAB A/S 07-Apr-2025 16:45:26 PM 20 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:45:26 PM 20 1230.00 TQEX
GENMAB A/S 07-Apr-2025 16:45:26 PM 9 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:45:26 PM 36 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:45:49 PM 89 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:49 PM 24 1231.00 CEUX
GENMAB A/S 07-Apr-2025 16:45:53 PM 81 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:53 PM 6 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:53 PM 32 1232.00 CEUX

60

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:45:54 PM 12 1232.50 XCSE
GENMAB A/S 07-Apr-2025 16:45:54 PM 40 1232.50 XCSE
GENMAB A/S 07-Apr-2025 16:45:55 PM 32 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:45:55 PM 16 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:12 PM 52 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:12 PM 32 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:14 PM 88 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:14 PM 36 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:15 PM 31 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:15 PM 13 1230.00 TQEX
GENMAB A/S 07-Apr-2025 16:46:15 PM 18 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:15 PM 22 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:15 PM 35 1230.50 AQEU
GENMAB A/S 07-Apr-2025 16:46:16 PM 3 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:33 PM 2 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:38 PM 40 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:38 PM 39 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:38 PM 11 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:38 PM 4 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:46:44 PM 12 1231.00 TQEX
GENMAB A/S 07-Apr-2025 16:46:45 PM 10 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 11 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 40 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 12 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 12 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 40 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 11 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 9 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:46:45 PM 28 1231.00 TQEX
GENMAB A/S 07-Apr-2025 16:46:52 PM 38 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:46:52 PM 24 1231.00 TQEX
GENMAB A/S 07-Apr-2025 16:46:52 PM 35 1231.00 AQEU
GENMAB A/S 07-Apr-2025 16:47:04 PM 50 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:04 PM 36 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 6 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 14 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 5 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 7 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 8 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 7 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 3 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 2 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:04 PM 1 1230.50 CEUX

61

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:47:06 PM 42 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:07 PM 31 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:07 PM 7 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:09 PM 24 1229.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:16 PM 10 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:16 PM 21 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:30 PM 40 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:47:30 PM 32 1229.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:30 PM 24 1228.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:31 PM 72 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:39 PM 29 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:39 PM 32 1229.50 CEUX
GENMAB A/S 07-Apr-2025 16:47:47 PM 40 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:47:47 PM 20 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:47:47 PM 12 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:47:57 PM 28 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:47:57 PM 28 1229.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:02 PM 4 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:02 PM 34 1229.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:19 PM 36 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:20 PM 32 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:25 PM 40 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 10 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 11 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 12 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 12 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 40 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 11 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 40 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:25 PM 6 1230.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:30 PM 3 1229.50 TQEX
GENMAB A/S 07-Apr-2025 16:48:30 PM 61 1229.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:30 PM 39 1230.00 AQEU
GENMAB A/S 07-Apr-2025 16:48:31 PM 22 1229.50 TQEX
GENMAB A/S 07-Apr-2025 16:48:31 PM 2 1229.50 TQEX
GENMAB A/S 07-Apr-2025 16:48:31 PM 16 1229.50 TQEX
GENMAB A/S 07-Apr-2025 16:48:37 PM 12 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:37 PM 12 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:37 PM 20 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:37 PM 10 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:37 PM 10 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:37 PM 4 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:48 PM 51 1229.00 XCSE

62

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:48:48 PM 11 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:48 PM 11 1229.50 XCSE
GENMAB A/S 07-Apr-2025 16:48:48 PM 32 1229.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:54 PM 31 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:55 PM 10 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:55 PM 40 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:55 PM 11 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:55 PM 14 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:56 PM 4 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:48:59 PM 23 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:48:59 PM 19 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:49:17 PM 41 1230.00 TQEX
GENMAB A/S 07-Apr-2025 16:49:17 PM 36 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:49:17 PM 11 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:49:29 PM 54 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:49:29 PM 40 1230.00 XCSE
GENMAB A/S 07-Apr-2025 16:49:29 PM 36 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:49:29 PM 9 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:49:41 PM 34 1230.00 AQEU
GENMAB A/S 07-Apr-2025 16:49:42 PM 18 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:49:42 PM 40 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:49:42 PM 1 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:49:43 PM 36 1231.00 CEUX
GENMAB A/S 07-Apr-2025 16:49:45 PM 32 1231.00 CEUX
GENMAB A/S 07-Apr-2025 16:49:54 PM 29 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:49:54 PM 18 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:49:56 PM 25 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:50:03 PM 55 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:03 PM 17 1231.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:03 PM 45 1230.50 CEUX
GENMAB A/S 07-Apr-2025 16:50:21 PM 15 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:21 PM 17 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:50:24 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:24 PM 39 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:24 PM 7 1233.50 XCSE
GENMAB A/S 07-Apr-2025 16:50:24 PM 27 1233.50 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 30 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 20 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 12 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 39 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:50:27 PM 16 1233.00 CEUX

63

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:50:33 PM 24 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:50:35 PM 14 1233.00 TQEX
GENMAB A/S 07-Apr-2025 16:50:37 PM 32 1233.50 CEUX
GENMAB A/S 07-Apr-2025 16:50:38 PM 27 1233.00 TQEX
GENMAB A/S 07-Apr-2025 16:51:02 PM 16 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:02 PM 16 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:11 PM 28 1232.50 XCSE
GENMAB A/S 07-Apr-2025 16:51:11 PM 85 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:11 PM 29 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:11 PM 29 1232.00 AQEU
GENMAB A/S 07-Apr-2025 16:51:23 PM 16 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:23 PM 6 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:25 PM 26 1233.50 CEUX
GENMAB A/S 07-Apr-2025 16:51:25 PM 11 1233.50 CEUX
GENMAB A/S 07-Apr-2025 16:51:26 PM 47 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:26 PM 39 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:31 PM 5 1232.50 TQEX
GENMAB A/S 07-Apr-2025 16:51:31 PM 26 1232.50 TQEX
GENMAB A/S 07-Apr-2025 16:51:31 PM 36 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:31 PM 6 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 27 1235.50 XCSE
GENMAB A/S 07-Apr-2025 16:51:41 PM 40 1235.50 XCSE
GENMAB A/S 07-Apr-2025 16:51:41 PM 86 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:41 PM 36 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 7 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 7 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 36 1235.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 7 1235.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 7 1235.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 13 1235.00 CEUX
GENMAB A/S 07-Apr-2025 16:51:41 PM 24 1234.50 AQEU
GENMAB A/S 07-Apr-2025 16:51:47 PM 40 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:47 PM 12 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:47 PM 11 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:47 PM 40 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 85 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 40 1234.50 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 40 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 33 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 18 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 12 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 10 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:49 PM 36 1235.00 XCSE

64

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:51:58 PM 24 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:51:58 PM 36 1235.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:02 PM 32 1235.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:03 PM 29 1235.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:09 PM 40 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:09 PM 11 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:09 PM 10 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:09 PM 20 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:09 PM 21 1234.50 TQEX
GENMAB A/S 07-Apr-2025 16:52:09 PM 15 1234.50 TQEX
GENMAB A/S 07-Apr-2025 16:52:09 PM 26 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:13 PM 40 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:13 PM 11 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:13 PM 10 1235.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:13 PM 18 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:14 PM 6 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:16 PM 42 1234.50 CEUX
GENMAB A/S 07-Apr-2025 16:52:20 PM 33 1234.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:20 PM 36 1234.50 XCSE
GENMAB A/S 07-Apr-2025 16:52:20 PM 27 1234.00 AQEU
GENMAB A/S 07-Apr-2025 16:52:22 PM 33 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:22 PM 8 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:52:23 PM 18 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:52:24 PM 9 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:24 PM 28 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:24 PM 24 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:52:48 PM 37 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:52:50 PM 32 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:52:52 PM 26 1231.50 TQEX
GENMAB A/S 07-Apr-2025 16:52:52 PM 41 1231.50 CEUX
GENMAB A/S 07-Apr-2025 16:53:09 PM 32 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:53:09 PM 24 1232.00 AQEU
GENMAB A/S 07-Apr-2025 16:53:16 PM 24 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:53:19 PM 88 1231.50 XCSE
GENMAB A/S 07-Apr-2025 16:53:19 PM 27 1232.00 CEUX
GENMAB A/S 07-Apr-2025 16:53:28 PM 10 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:53:28 PM 12 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:53:29 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:53:29 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:53:29 PM 10 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:53:30 PM 4 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:53:30 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:53:33 PM 30 1233.00 CEUX

65

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 07-Apr-2025 16:53:41 PM 5 1232.50 CEUX
GENMAB A/S 07-Apr-2025 16:53:41 PM 17 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:53:41 PM 19 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:53:49 PM 3 1232.00 AQEU
GENMAB A/S 07-Apr-2025 16:53:51 PM 40 1232.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:07 PM 47 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:54:11 PM 37 1233.00 TQEX
GENMAB A/S 07-Apr-2025 16:54:11 PM 7 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:54:11 PM 19 1233.00 AQEU
GENMAB A/S 07-Apr-2025 16:54:11 PM 10 1233.00 AQEU
GENMAB A/S 07-Apr-2025 16:54:12 PM 33 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:54:13 PM 7 1233.00 CEUX
GENMAB A/S 07-Apr-2025 16:54:15 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:15 PM 11 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:15 PM 12 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:16 PM 40 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:16 PM 73 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:16 PM 113 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:17 PM 113 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:19 PM 36 1233.00 XCSE
GENMAB A/S 07-Apr-2025 16:54:34 PM 1 1233.50 XCSE
GENMAB A/S 08-Apr-2025 09:59:10 AM 72 1241.00 XCSE
GENMAB A/S 08-Apr-2025 09:59:10 AM 76 1241.00 CEUX
GENMAB A/S 08-Apr-2025 10:00:02 AM 82 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:00:02 AM 71 1240.00 CEUX
GENMAB A/S 08-Apr-2025 10:00:02 AM 79 1240.00 AQEU
GENMAB A/S 08-Apr-2025 10:00:07 AM 27 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:00:11 AM 24 1239.00 XCSE
GENMAB A/S 08-Apr-2025 10:00:11 AM 65 1239.50 TQEX
GENMAB A/S 08-Apr-2025 10:00:11 AM 17 1239.50 TQEX
GENMAB A/S 08-Apr-2025 10:00:11 AM 72 1239.00 AQEU
GENMAB A/S 08-Apr-2025 10:00:13 AM 13 1238.50 TQEX
GENMAB A/S 08-Apr-2025 10:00:13 AM 58 1238.50 TQEX
GENMAB A/S 08-Apr-2025 10:00:13 AM 53 1238.50 CEUX
GENMAB A/S 08-Apr-2025 10:00:18 AM 24 1238.00 XCSE
GENMAB A/S 08-Apr-2025 10:00:18 AM 50 1238.00 AQEU
GENMAB A/S 08-Apr-2025 10:00:23 AM 16 1237.50 TQEX
GENMAB A/S 08-Apr-2025 10:00:24 AM 14 1237.50 TQEX
GENMAB A/S 08-Apr-2025 10:00:24 AM 5 1237.50 TQEX
GENMAB A/S 08-Apr-2025 10:01:00 AM 25 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:01:03 AM 28 1239.00 CEUX
GENMAB A/S 08-Apr-2025 10:01:12 AM 28 1238.50 XCSE
GENMAB A/S 08-Apr-2025 10:01:12 AM 32 1238.00 CEUX

66

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 10:01:22 AM 26 1237.50 XCSE
GENMAB A/S 08-Apr-2025 10:01:57 AM 31 1236.50 CEUX
GENMAB A/S 08-Apr-2025 10:02:52 AM 33 1237.00 XCSE
GENMAB A/S 08-Apr-2025 10:02:52 AM 42 1237.50 CEUX
GENMAB A/S 08-Apr-2025 10:03:21 AM 34 1236.50 CEUX
GENMAB A/S 08-Apr-2025 10:04:38 AM 49 1238.50 CEUX
GENMAB A/S 08-Apr-2025 10:04:49 AM 69 1238.00 XCSE
GENMAB A/S 08-Apr-2025 10:04:49 AM 35 1237.50 CEUX
GENMAB A/S 08-Apr-2025 10:04:53 AM 80 1237.00 XCSE
GENMAB A/S 08-Apr-2025 10:05:18 AM 27 1236.00 XCSE
GENMAB A/S 08-Apr-2025 10:05:18 AM 8 1236.50 CEUX
GENMAB A/S 08-Apr-2025 10:05:18 AM 28 1236.50 CEUX
GENMAB A/S 08-Apr-2025 10:05:22 AM 3 1235.50 CEUX
GENMAB A/S 08-Apr-2025 10:05:22 AM 22 1235.50 CEUX
GENMAB A/S 08-Apr-2025 10:06:37 AM 33 1237.50 CEUX
GENMAB A/S 08-Apr-2025 10:06:46 AM 4 1237.00 XCSE
GENMAB A/S 08-Apr-2025 10:09:44 AM 2 1239.50 TQEX
GENMAB A/S 08-Apr-2025 10:09:44 AM 4 1239.50 CEUX
GENMAB A/S 08-Apr-2025 10:09:44 AM 47 1239.50 CEUX
GENMAB A/S 08-Apr-2025 10:09:45 AM 26 1239.50 TQEX
GENMAB A/S 08-Apr-2025 10:10:18 AM 22 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:10:18 AM 23 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:10:18 AM 1 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:10:18 AM 47 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:10:18 AM 16 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:10:18 AM 4 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:10:27 AM 82 1240.50 CEUX
GENMAB A/S 08-Apr-2025 10:10:32 AM 50 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:10:32 AM 35 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:10:34 AM 82 1239.50 CEUX
GENMAB A/S 08-Apr-2025 10:10:37 AM 83 1239.00 XCSE
GENMAB A/S 08-Apr-2025 10:10:42 AM 53 1238.50 CEUX
GENMAB A/S 08-Apr-2025 10:10:44 AM 84 1238.00 XCSE
GENMAB A/S 08-Apr-2025 10:12:19 AM 33 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:12:20 AM 53 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:12:20 AM 29 1240.50 CEUX
GENMAB A/S 08-Apr-2025 10:12:43 AM 84 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:12:58 AM 25 1239.50 CEUX
GENMAB A/S 08-Apr-2025 10:13:01 AM 2 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:14:07 AM 1 1241.00 CEUX
GENMAB A/S 08-Apr-2025 10:14:07 AM 40 1241.00 CEUX
GENMAB A/S 08-Apr-2025 10:14:58 AM 85 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:14:58 AM 42 1241.00 CEUX

67

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 10:15:08 AM 36 1240.00 CEUX
GENMAB A/S 08-Apr-2025 10:15:26 AM 15 1240.00 CEUX
GENMAB A/S 08-Apr-2025 10:15:26 AM 11 1240.00 CEUX
GENMAB A/S 08-Apr-2025 10:15:37 AM 84 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:15:39 AM 45 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:15:39 AM 16 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:16:16 AM 27 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:16:16 AM 3 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:16:16 AM 15 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:18:01 AM 26 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:18:01 AM 5 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:18:01 AM 29 1240.50 AQEU
GENMAB A/S 08-Apr-2025 10:18:02 AM 55 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:24 AM 84 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:24 AM 39 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:24 AM 30 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:24 AM 39 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:24 AM 5 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:24 AM 87 1240.50 CEUX
GENMAB A/S 08-Apr-2025 10:19:25 AM 15 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:19:25 AM 9 1240.50 XCSE
GENMAB A/S 08-Apr-2025 10:20:16 AM 22 1241.00 XCSE
GENMAB A/S 08-Apr-2025 10:20:16 AM 67 1241.00 XCSE
GENMAB A/S 08-Apr-2025 10:21:23 AM 86 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:21:23 AM 44 1239.50 CEUX
GENMAB A/S 08-Apr-2025 10:21:24 AM 64 1238.50 XCSE
GENMAB A/S 08-Apr-2025 10:21:24 AM 22 1238.50 XCSE
GENMAB A/S 08-Apr-2025 10:21:24 AM 24 1238.50 CEUX
GENMAB A/S 08-Apr-2025 10:22:06 AM 88 1238.50 XCSE
GENMAB A/S 08-Apr-2025 10:22:06 AM 75 1238.50 CEUX
GENMAB A/S 08-Apr-2025 10:23:01 AM 74 1239.00 CEUX
GENMAB A/S 08-Apr-2025 10:23:25 AM 14 1238.50 XCSE
GENMAB A/S 08-Apr-2025 10:23:46 AM 40 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:23:46 AM 16 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:23:46 AM 39 1239.50 XCSE
GENMAB A/S 08-Apr-2025 10:24:04 AM 35 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:04 AM 36 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:04 AM 39 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 16 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 39 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 16 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 16 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 26 1240.00 XCSE

68

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 10:24:05 AM 15 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 39 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 16 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 40 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:05 AM 3 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:18 AM 54 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:18 AM 40 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:18 AM 10 1240.00 XCSE
GENMAB A/S 08-Apr-2025 10:24:31 AM 46 1239.00 CEUX
GENMAB A/S 08-Apr-2025 10:25:58 AM 85 1241.50 XCSE
GENMAB A/S 08-Apr-2025 10:26:11 AM 34 1241.50 XCSE
GENMAB A/S 08-Apr-2025 10:26:11 AM 16 1241.50 XCSE
GENMAB A/S 08-Apr-2025 10:26:31 AM 99 1242.00 XCSE
GENMAB A/S 08-Apr-2025 10:26:47 AM 86 1241.50 XCSE
GENMAB A/S 08-Apr-2025 10:27:23 AM 86 1242.50 XCSE
GENMAB A/S 08-Apr-2025 10:29:05 AM 87 1243.50 XCSE
GENMAB A/S 08-Apr-2025 10:29:05 AM 85 1243.50 CEUX
GENMAB A/S 08-Apr-2025 10:30:11 AM 86 1242.50 XCSE
GENMAB A/S 08-Apr-2025 10:30:11 AM 88 1242.50 CEUX
GENMAB A/S 08-Apr-2025 10:30:26 AM 86 1241.50 XCSE
GENMAB A/S 08-Apr-2025 10:30:26 AM 43 1241.50 CEUX
GENMAB A/S 08-Apr-2025 10:30:26 AM 43 1241.50 CEUX
GENMAB A/S 08-Apr-2025 10:30:30 AM 24 1241.00 TQEX
GENMAB A/S 08-Apr-2025 10:30:50 AM 25 1242.00 TQEX
GENMAB A/S 08-Apr-2025 10:32:01 AM 31 1241.00 XCSE
GENMAB A/S 08-Apr-2025 10:32:01 AM 57 1241.00 XCSE
GENMAB A/S 08-Apr-2025 10:32:01 AM 27 1241.00 AQEU
GENMAB A/S 08-Apr-2025 10:32:01 AM 61 1241.00 CEUX
GENMAB A/S 08-Apr-2025 10:33:42 AM 83 1245.50 XCSE
GENMAB A/S 08-Apr-2025 10:34:05 AM 36 1245.00 CEUX
GENMAB A/S 08-Apr-2025 10:34:05 AM 46 1245.00 CEUX
GENMAB A/S 08-Apr-2025 10:35:00 AM 41 1246.00 XCSE
GENMAB A/S 08-Apr-2025 10:35:00 AM 39 1246.00 XCSE
GENMAB A/S 08-Apr-2025 10:35:00 AM 10 1246.00 XCSE
GENMAB A/S 08-Apr-2025 10:35:16 AM 90 1245.00 XCSE
GENMAB A/S 08-Apr-2025 10:35:16 AM 23 1244.50 TQEX
GENMAB A/S 08-Apr-2025 10:36:15 AM 88 1245.00 XCSE
GENMAB A/S 08-Apr-2025 10:36:15 AM 5 1245.00 CEUX
GENMAB A/S 08-Apr-2025 10:36:57 AM 21 1245.00 CEUX
GENMAB A/S 08-Apr-2025 10:37:36 AM 24 1245.50 XCSE
GENMAB A/S 08-Apr-2025 10:37:36 AM 17 1245.50 XCSE
GENMAB A/S 08-Apr-2025 10:39:50 AM 84 1247.50 XCSE
GENMAB A/S 08-Apr-2025 10:39:50 AM 24 1248.00 XCSE

69

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 10:39:50 AM 62 1248.00 XCSE
GENMAB A/S 08-Apr-2025 10:39:50 AM 27 1248.00 XCSE
GENMAB A/S 08-Apr-2025 10:39:50 AM 84 1247.50 CEUX
GENMAB A/S 08-Apr-2025 10:39:50 AM 2 1247.50 CEUX
GENMAB A/S 08-Apr-2025 10:40:37 AM 27 1249.00 TQEX
GENMAB A/S 08-Apr-2025 10:40:40 AM 31 1248.50 XCSE
GENMAB A/S 08-Apr-2025 10:41:25 AM 25 1249.50 XCSE
GENMAB A/S 08-Apr-2025 10:41:25 AM 30 1249.50 XCSE
GENMAB A/S 08-Apr-2025 10:41:26 AM 58 1249.50 XCSE
GENMAB A/S 08-Apr-2025 10:41:58 AM 28 1249.50 XCSE
GENMAB A/S 08-Apr-2025 10:41:58 AM 28 1249.50 XCSE
GENMAB A/S 08-Apr-2025 10:43:21 AM 50 1251.50 XCSE
GENMAB A/S 08-Apr-2025 10:43:21 AM 40 1251.50 XCSE
GENMAB A/S 08-Apr-2025 10:43:21 AM 36 1251.50 CEUX
GENMAB A/S 08-Apr-2025 10:43:21 AM 49 1251.50 CEUX
GENMAB A/S 08-Apr-2025 10:43:38 AM 89 1250.50 XCSE
GENMAB A/S 08-Apr-2025 10:43:38 AM 29 1251.00 TQEX
GENMAB A/S 08-Apr-2025 10:43:38 AM 1 1250.50 CEUX
GENMAB A/S 08-Apr-2025 10:43:38 AM 63 1250.50 CEUX
GENMAB A/S 08-Apr-2025 10:43:38 AM 11 1250.50 CEUX
GENMAB A/S 08-Apr-2025 10:43:38 AM 1 1250.50 CEUX
GENMAB A/S 08-Apr-2025 10:43:40 AM 7 1250.50 CEUX
GENMAB A/S 08-Apr-2025 10:44:48 AM 11 1253.00 TQEX
GENMAB A/S 08-Apr-2025 10:45:29 AM 14 1253.00 TQEX
GENMAB A/S 08-Apr-2025 10:45:29 AM 39 1253.00 AQEU
GENMAB A/S 08-Apr-2025 10:45:30 AM 46 1253.00 XCSE
GENMAB A/S 08-Apr-2025 10:45:30 AM 21 1253.00 XCSE
GENMAB A/S 08-Apr-2025 10:45:54 AM 30 1253.00 XCSE
GENMAB A/S 08-Apr-2025 10:45:54 AM 16 1253.00 XCSE
GENMAB A/S 08-Apr-2025 10:45:54 AM 15 1253.00 XCSE
GENMAB A/S 08-Apr-2025 10:45:54 AM 83 1252.50 CEUX
GENMAB A/S 08-Apr-2025 10:45:58 AM 86 1252.50 XCSE
GENMAB A/S 08-Apr-2025 10:47:07 AM 88 1254.00 XCSE
GENMAB A/S 08-Apr-2025 10:48:34 AM 13 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:48:34 AM 30 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:48:34 AM 45 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:48:34 AM 25 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:49:11 AM 26 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:49:11 AM 61 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:49:11 AM 49 1254.50 CEUX
GENMAB A/S 08-Apr-2025 10:49:11 AM 38 1254.50 CEUX
GENMAB A/S 08-Apr-2025 10:49:45 AM 6 1253.50 XCSE
GENMAB A/S 08-Apr-2025 10:49:45 AM 1 1253.50 TQEX

70

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 10:49:45 AM 55 1253.50 CEUX
GENMAB A/S 08-Apr-2025 10:49:45 AM 21 1253.50 CEUX
GENMAB A/S 08-Apr-2025 10:49:49 AM 77 1253.50 XCSE
GENMAB A/S 08-Apr-2025 10:49:49 AM 23 1253.50 TQEX
GENMAB A/S 08-Apr-2025 10:49:49 AM 14 1253.50 CEUX
GENMAB A/S 08-Apr-2025 10:49:53 AM 15 1252.50 CEUX
GENMAB A/S 08-Apr-2025 10:50:00 AM 35 1252.50 XCSE
GENMAB A/S 08-Apr-2025 10:50:00 AM 54 1252.50 XCSE
GENMAB A/S 08-Apr-2025 10:50:00 AM 1 1252.50 CEUX
GENMAB A/S 08-Apr-2025 10:50:00 AM 71 1252.50 CEUX
GENMAB A/S 08-Apr-2025 10:52:37 AM 87 1254.00 XCSE
GENMAB A/S 08-Apr-2025 10:52:37 AM 40 1254.00 TQEX
GENMAB A/S 08-Apr-2025 10:52:37 AM 28 1253.50 AQEU
GENMAB A/S 08-Apr-2025 10:52:37 AM 88 1254.00 CEUX
GENMAB A/S 08-Apr-2025 10:53:38 AM 22 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:53:38 AM 25 1254.50 XCSE
GENMAB A/S 08-Apr-2025 10:53:38 AM 44 1254.50 TQEX
GENMAB A/S 08-Apr-2025 10:54:32 AM 85 1256.00 XCSE
GENMAB A/S 08-Apr-2025 10:54:32 AM 39 1256.00 CEUX
GENMAB A/S 08-Apr-2025 10:54:32 AM 43 1256.00 CEUX
GENMAB A/S 08-Apr-2025 10:55:12 AM 29 1256.50 XCSE
GENMAB A/S 08-Apr-2025 10:55:12 AM 10 1256.50 XCSE
GENMAB A/S 08-Apr-2025 10:55:12 AM 39 1256.50 TQEX
GENMAB A/S 08-Apr-2025 10:58:04 AM 53 1260.00 CEUX
GENMAB A/S 08-Apr-2025 10:59:28 AM 30 1260.50 XCSE
GENMAB A/S 08-Apr-2025 10:59:28 AM 16 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:03 AM 90 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:03 AM 45 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:03 AM 16 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:03 AM 44 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:03 AM 32 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:00:11 AM 30 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:11 AM 45 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:11 AM 14 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:11 AM 24 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:12 AM 27 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:13 AM 3 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:13 AM 4 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:13 AM 2 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:33 AM 33 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:37 AM 69 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:00:45 AM 29 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:00:45 AM 38 1260.00 TQEX

71

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 11:00:45 AM 18 1260.00 AQEU
GENMAB A/S 08-Apr-2025 11:00:45 AM 8 1260.00 AQEU
GENMAB A/S 08-Apr-2025 11:00:45 AM 17 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:00:58 AM 33 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:00:58 AM 13 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:00:58 AM 47 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:00:59 AM 2 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:00:59 AM 85 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:02:18 AM 39 1259.00 TQEX
GENMAB A/S 08-Apr-2025 11:02:18 AM 24 1259.00 AQEU
GENMAB A/S 08-Apr-2025 11:02:18 AM 1 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:02:18 AM 86 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:02:32 AM 88 1258.50 XCSE
GENMAB A/S 08-Apr-2025 11:04:02 AM 24 1259.50 TQEX
GENMAB A/S 08-Apr-2025 11:04:02 AM 24 1259.50 AQEU
GENMAB A/S 08-Apr-2025 11:04:15 AM 15 1259.00 XCSE
GENMAB A/S 08-Apr-2025 11:04:15 AM 72 1259.00 XCSE
GENMAB A/S 08-Apr-2025 11:04:15 AM 89 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:05:36 AM 5 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:05:36 AM 3 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:05:36 AM 1 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:05:36 AM 12 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:06:42 AM 10 1259.00 XCSE
GENMAB A/S 08-Apr-2025 11:07:34 AM 45 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:08:51 AM 7 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:09:09 AM 46 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:09:09 AM 40 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:09:09 AM 27 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:09:09 AM 14 1260.00 TQEX
GENMAB A/S 08-Apr-2025 11:09:09 AM 24 1260.00 TQEX
GENMAB A/S 08-Apr-2025 11:09:09 AM 46 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:09:09 AM 36 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:10:06 AM 24 1260.00 AQEU
GENMAB A/S 08-Apr-2025 11:10:51 AM 34 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:08 AM 32 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:08 AM 30 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:08 AM 13 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:08 AM 38 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:12 AM 29 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:12 AM 30 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:12 AM 39 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:12 AM 15 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:23 AM 30 1260.00 XCSE

72

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 11:11:23 AM 31 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:41 AM 35 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:11:41 AM 1 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:11:44 AM 80 1259.00 XCSE
GENMAB A/S 08-Apr-2025 11:11:44 AM 30 1259.00 TQEX
GENMAB A/S 08-Apr-2025 11:11:44 AM 40 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:11:44 AM 8 1259.00 CEUX
GENMAB A/S 08-Apr-2025 11:11:57 AM 34 1258.50 AQEU
GENMAB A/S 08-Apr-2025 11:12:28 AM 13 1258.00 TQEX
GENMAB A/S 08-Apr-2025 11:12:28 AM 32 1258.00 CEUX
GENMAB A/S 08-Apr-2025 11:12:28 AM 57 1258.00 CEUX
GENMAB A/S 08-Apr-2025 11:12:30 AM 1 1258.00 TQEX
GENMAB A/S 08-Apr-2025 11:12:30 AM 1 1258.00 TQEX
GENMAB A/S 08-Apr-2025 11:12:31 AM 20 1258.00 TQEX
GENMAB A/S 08-Apr-2025 11:12:34 AM 87 1257.50 XCSE
GENMAB A/S 08-Apr-2025 11:13:58 AM 35 1258.50 XCSE
GENMAB A/S 08-Apr-2025 11:13:58 AM 15 1258.50 XCSE
GENMAB A/S 08-Apr-2025 11:15:01 AM 83 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:15:01 AM 24 1260.00 AQEU
GENMAB A/S 08-Apr-2025 11:15:07 AM 50 1259.50 TQEX
GENMAB A/S 08-Apr-2025 11:15:12 AM 86 1259.00 XCSE
GENMAB A/S 08-Apr-2025 11:15:14 AM 24 1259.00 AQEU
GENMAB A/S 08-Apr-2025 11:18:08 AM 45 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:18:11 AM 35 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:18:11 AM 65 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:19:08 AM 45 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:19:14 AM 36 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:19:14 AM 20 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:19:25 AM 7 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:25 AM 5 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:25 AM 6 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:25 AM 3 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:25 AM 36 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:25 AM 56 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:34 AM 29 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:19:51 AM 45 1260.50 TQEX
GENMAB A/S 08-Apr-2025 11:19:51 AM 12 1260.50 AQEU
GENMAB A/S 08-Apr-2025 11:19:51 AM 12 1260.50 AQEU
GENMAB A/S 08-Apr-2025 11:20:33 AM 43 1261.00 CEUX
GENMAB A/S 08-Apr-2025 11:20:38 AM 41 1261.00 CEUX
GENMAB A/S 08-Apr-2025 11:21:24 AM 74 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:21:24 AM 16 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:21:24 AM 39 1260.50 XCSE

73

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 11:21:24 AM 13 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:21:24 AM 28 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:21:24 AM 30 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:21:24 AM 3 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:21:24 AM 31 1260.50 TQEX
GENMAB A/S 08-Apr-2025 11:21:24 AM 24 1260.50 AQEU
GENMAB A/S 08-Apr-2025 11:21:36 AM 87 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:21:58 AM 17 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:21:58 AM 15 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:24:38 AM 87 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:24:38 AM 44 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:24:38 AM 66 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:24:38 AM 3 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:24:38 AM 24 1260.00 AQEU
GENMAB A/S 08-Apr-2025 11:24:38 AM 83 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:24:42 AM 27 1261.00 CEUX
GENMAB A/S 08-Apr-2025 11:25:10 AM 59 1261.00 CEUX
GENMAB A/S 08-Apr-2025 11:25:14 AM 5 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:25:14 AM 80 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:25:14 AM 26 1260.50 TQEX
GENMAB A/S 08-Apr-2025 11:25:18 AM 83 1260.00 CEUX
GENMAB A/S 08-Apr-2025 11:25:47 AM 82 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:25:47 AM 2 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:25:47 AM 37 1259.50 TQEX
GENMAB A/S 08-Apr-2025 11:25:59 AM 1 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:26:00 AM 65 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:27:45 AM 36 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:27:45 AM 1 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:27:45 AM 39 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:27:45 AM 37 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:28:18 AM 35 1258.50 CEUX
GENMAB A/S 08-Apr-2025 11:28:38 AM 4 1259.00 XCSE
GENMAB A/S 08-Apr-2025 11:32:00 AM 79 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:32:00 AM 9 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:32:38 AM 36 1261.00 CEUX
GENMAB A/S 08-Apr-2025 11:32:40 AM 51 1261.00 CEUX
GENMAB A/S 08-Apr-2025 11:32:43 AM 30 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:32:43 AM 14 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:32:43 AM 39 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:00 AM 29 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:00 AM 39 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:00 AM 16 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:00 AM 29 1261.00 XCSE

74

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 11:33:00 AM 28 1260.50 TQEX
GENMAB A/S 08-Apr-2025 11:33:01 AM 13 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:01 AM 16 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:01 AM 39 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:33:01 AM 39 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:35:11 AM 39 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:35:11 AM 35 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:35:45 AM 85 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:35:50 AM 8 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:36:00 AM 20 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:36:00 AM 39 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:36:00 AM 27 1260.50 TQEX
GENMAB A/S 08-Apr-2025 11:36:00 AM 39 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:36:04 AM 54 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:36:04 AM 29 1259.50 XCSE
GENMAB A/S 08-Apr-2025 11:36:04 AM 39 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:36:04 AM 39 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:36:04 AM 14 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:36:04 AM 13 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:36:04 AM 18 1259.50 TQEX
GENMAB A/S 08-Apr-2025 11:36:04 AM 1 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:36:04 AM 3 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:36:04 AM 1 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:36:04 AM 81 1259.50 CEUX
GENMAB A/S 08-Apr-2025 11:38:29 AM 39 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:38:29 AM 30 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:38:29 AM 1 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:38:38 AM 59 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:39:28 AM 3 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:39:28 AM 4 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:39:28 AM 3 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:39:28 AM 3 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:39:28 AM 33 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:44:36 AM 26 1261.00 TQEX
GENMAB A/S 08-Apr-2025 11:44:36 AM 28 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:44:36 AM 5 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:44:36 AM 2 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:44:36 AM 27 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:44:40 AM 3 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:44:45 AM 83 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:44:45 AM 15 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:44:45 AM 39 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:44:45 AM 16 1261.50 XCSE

75

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 11:44:45 AM 15 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:45:00 AM 15 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:45:00 AM 39 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:45:00 AM 13 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:45:30 AM 13 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:00 AM 14 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:24 AM 13 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:24 AM 39 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:24 AM 1 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:24 AM 39 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:26 AM 12 1261.50 CEUX
GENMAB A/S 08-Apr-2025 11:46:26 AM 28 1261.50 CEUX
GENMAB A/S 08-Apr-2025 11:46:29 AM 14 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:29 AM 39 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:29 AM 39 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:30 AM 15 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:30 AM 33 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:46:48 AM 87 1261.00 XCSE
GENMAB A/S 08-Apr-2025 11:46:48 AM 28 1261.00 TQEX
GENMAB A/S 08-Apr-2025 11:46:49 AM 3 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:46:49 AM 7 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:47:57 AM 24 1260.50 AQEU
GENMAB A/S 08-Apr-2025 11:47:57 AM 74 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:48:28 AM 31 1260.00 XCSE
GENMAB A/S 08-Apr-2025 11:48:28 AM 25 1260.00 TQEX
GENMAB A/S 08-Apr-2025 11:50:34 AM 3 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:50:34 AM 58 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:50:34 AM 23 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:50:34 AM 14 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:50:34 AM 25 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:50:34 AM 85 1260.50 CEUX
GENMAB A/S 08-Apr-2025 11:52:15 AM 16 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:52:26 AM 71 1260.50 XCSE
GENMAB A/S 08-Apr-2025 11:53:03 AM 7 1264.00 XCSE
GENMAB A/S 08-Apr-2025 11:53:03 AM 89 1264.00 CEUX
GENMAB A/S 08-Apr-2025 11:53:04 AM 27 1264.00 XCSE
GENMAB A/S 08-Apr-2025 11:53:04 AM 29 1264.00 AQEU
GENMAB A/S 08-Apr-2025 11:53:08 AM 54 1264.00 XCSE
GENMAB A/S 08-Apr-2025 11:53:08 AM 30 1264.00 XCSE
GENMAB A/S 08-Apr-2025 11:53:08 AM 15 1264.00 XCSE
GENMAB A/S 08-Apr-2025 11:53:34 AM 25 1263.50 TQEX
GENMAB A/S 08-Apr-2025 11:53:43 AM 62 1263.00 XCSE
GENMAB A/S 08-Apr-2025 11:53:43 AM 28 1263.00 XCSE

76

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 11:53:43 AM 84 1263.00 CEUX
GENMAB A/S 08-Apr-2025 11:53:49 AM 27 1262.50 TQEX
GENMAB A/S 08-Apr-2025 11:53:49 AM 39 1262.50 AQEU
GENMAB A/S 08-Apr-2025 11:53:54 AM 55 1262.00 CEUX
GENMAB A/S 08-Apr-2025 11:53:54 AM 34 1262.00 CEUX
GENMAB A/S 08-Apr-2025 11:54:01 AM 89 1263.50 XCSE
GENMAB A/S 08-Apr-2025 11:54:01 AM 32 1263.50 AQEU
GENMAB A/S 08-Apr-2025 11:54:14 AM 90 1262.50 XCSE
GENMAB A/S 08-Apr-2025 11:54:14 AM 86 1262.50 CEUX
GENMAB A/S 08-Apr-2025 11:54:17 AM 62 1262.50 CEUX
GENMAB A/S 08-Apr-2025 11:55:25 AM 84 1261.50 XCSE
GENMAB A/S 08-Apr-2025 11:55:25 AM 6 1261.50 CEUX
GENMAB A/S 08-Apr-2025 11:55:25 AM 76 1261.50 CEUX
GENMAB A/S 08-Apr-2025 11:58:00 AM 85 1263.50 XCSE
GENMAB A/S 08-Apr-2025 11:58:00 AM 33 1263.50 AQEU
GENMAB A/S 08-Apr-2025 11:58:00 AM 7 1263.00 CEUX
GENMAB A/S 08-Apr-2025 11:58:00 AM 2 1263.00 CEUX
GENMAB A/S 08-Apr-2025 11:58:03 AM 44 1263.00 CEUX
GENMAB A/S 08-Apr-2025 11:58:09 AM 4 1262.50 XCSE
GENMAB A/S 08-Apr-2025 11:58:09 AM 1 1262.50 XCSE
GENMAB A/S 08-Apr-2025 11:58:26 AM 3 1262.50 XCSE
GENMAB A/S 08-Apr-2025 11:58:33 AM 75 1262.50 XCSE
GENMAB A/S 08-Apr-2025 12:00:04 PM 54 1262.00 CEUX
GENMAB A/S 08-Apr-2025 12:00:22 PM 71 1261.50 XCSE
GENMAB A/S 08-Apr-2025 12:01:01 PM 33 1261.50 XCSE
GENMAB A/S 08-Apr-2025 12:01:01 PM 54 1261.50 XCSE
GENMAB A/S 08-Apr-2025 12:01:01 PM 35 1261.50 TQEX
GENMAB A/S 08-Apr-2025 12:01:01 PM 7 1261.50 CEUX
GENMAB A/S 08-Apr-2025 12:01:01 PM 36 1261.50 CEUX
GENMAB A/S 08-Apr-2025 12:01:09 PM 90 1260.50 XCSE
GENMAB A/S 08-Apr-2025 12:02:46 PM 23 1261.50 CEUX
GENMAB A/S 08-Apr-2025 12:02:46 PM 32 1261.50 CEUX
GENMAB A/S 08-Apr-2025 12:05:46 PM 3 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:05:46 PM 6 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:05:46 PM 15 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:05:46 PM 39 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:05:46 PM 49 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:06:21 PM 22 1266.50 CEUX
GENMAB A/S 08-Apr-2025 12:06:21 PM 52 1266.50 CEUX
GENMAB A/S 08-Apr-2025 12:08:08 PM 31 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:14 PM 43 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:14 PM 43 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:14 PM 27 1267.00 XCSE

77

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 12:10:14 PM 13 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:14 PM 64 1266.50 CEUX
GENMAB A/S 08-Apr-2025 12:10:18 PM 13 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:18 PM 16 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:19 PM 13 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:20 PM 15 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:20 PM 14 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:22 PM 13 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:22 PM 23 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:48 PM 39 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:48 PM 39 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:48 PM 32 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:10:48 PM 3 1267.00 XCSE
GENMAB A/S 08-Apr-2025 12:11:40 PM 19 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:11:40 PM 6 1266.00 TQEX
GENMAB A/S 08-Apr-2025 12:12:13 PM 67 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:12:13 PM 19 1266.00 TQEX
GENMAB A/S 08-Apr-2025 12:12:13 PM 4 1265.50 CEUX
GENMAB A/S 08-Apr-2025 12:12:13 PM 67 1265.50 CEUX
GENMAB A/S 08-Apr-2025 12:12:19 PM 84 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:12:19 PM 25 1266.00 TQEX
GENMAB A/S 08-Apr-2025 12:12:28 PM 20 1265.50 AQEU
GENMAB A/S 08-Apr-2025 12:13:05 PM 83 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:13:05 PM 32 1265.00 TQEX
GENMAB A/S 08-Apr-2025 12:13:05 PM 6 1265.50 AQEU
GENMAB A/S 08-Apr-2025 12:13:05 PM 26 1265.50 CEUX
GENMAB A/S 08-Apr-2025 12:13:05 PM 49 1265.50 CEUX
GENMAB A/S 08-Apr-2025 12:13:07 PM 37 1264.50 CEUX
GENMAB A/S 08-Apr-2025 12:14:26 PM 23 1264.50 CEUX
GENMAB A/S 08-Apr-2025 12:14:31 PM 36 1264.00 XCSE
GENMAB A/S 08-Apr-2025 12:14:31 PM 50 1264.00 XCSE
GENMAB A/S 08-Apr-2025 12:14:49 PM 12 1263.50 AQEU
GENMAB A/S 08-Apr-2025 12:15:06 PM 15 1263.50 AQEU
GENMAB A/S 08-Apr-2025 12:15:22 PM 4 1263.50 XCSE
GENMAB A/S 08-Apr-2025 12:15:30 PM 80 1263.50 XCSE
GENMAB A/S 08-Apr-2025 12:16:23 PM 24 1263.50 AQEU
GENMAB A/S 08-Apr-2025 12:18:43 PM 3 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:22:31 PM 31 1268.50 XCSE
GENMAB A/S 08-Apr-2025 12:22:31 PM 4 1268.50 XCSE
GENMAB A/S 08-Apr-2025 12:22:31 PM 26 1268.50 XCSE
GENMAB A/S 08-Apr-2025 12:22:31 PM 27 1268.50 XCSE
GENMAB A/S 08-Apr-2025 12:22:31 PM 86 1268.00 CEUX
GENMAB A/S 08-Apr-2025 12:22:34 PM 1 1269.00 XCSE

78

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 12:22:34 PM 38 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 15 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 16 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 39 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 4 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 22 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 60 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:22:34 PM 31 1269.00 XCSE
GENMAB A/S 08-Apr-2025 12:23:46 PM 84 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:24:10 PM 11 1267.00 TQEX
GENMAB A/S 08-Apr-2025 12:24:10 PM 22 1267.00 TQEX
GENMAB A/S 08-Apr-2025 12:24:10 PM 36 1267.00 AQEU
GENMAB A/S 08-Apr-2025 12:24:10 PM 89 1267.00 CEUX
GENMAB A/S 08-Apr-2025 12:25:47 PM 72 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:25:47 PM 14 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:26:28 PM 1 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:26:30 PM 28 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:26:58 PM 4 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 21 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 4 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 3 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 37 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 19 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 1 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:43 PM 28 1268.00 XCSE
GENMAB A/S 08-Apr-2025 12:28:52 PM 89 1267.50 XCSE
GENMAB A/S 08-Apr-2025 12:28:52 PM 83 1266.50 XCSE
GENMAB A/S 08-Apr-2025 12:28:52 PM 24 1267.00 TQEX
GENMAB A/S 08-Apr-2025 12:28:52 PM 32 1266.00 TQEX
GENMAB A/S 08-Apr-2025 12:28:52 PM 34 1267.00 AQEU
GENMAB A/S 08-Apr-2025 12:28:52 PM 86 1267.00 CEUX
GENMAB A/S 08-Apr-2025 12:28:52 PM 46 1266.00 CEUX
GENMAB A/S 08-Apr-2025 12:28:52 PM 10 1266.00 CEUX
GENMAB A/S 08-Apr-2025 12:28:52 PM 34 1266.00 CEUX
GENMAB A/S 08-Apr-2025 12:28:53 PM 50 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:28:53 PM 35 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:28:53 PM 61 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:28:53 PM 38 1265.50 AQEU
GENMAB A/S 08-Apr-2025 12:28:53 PM 77 1265.50 CEUX
GENMAB A/S 08-Apr-2025 12:29:51 PM 22 1264.50 CEUX
GENMAB A/S 08-Apr-2025 12:30:38 PM 46 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:30:38 PM 36 1264.50 CEUX
GENMAB A/S 08-Apr-2025 12:30:38 PM 29 1264.50 CEUX

79

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 12:31:21 PM 8 1265.00 AQEU
GENMAB A/S 08-Apr-2025 12:31:46 PM 17 1265.00 AQEU
GENMAB A/S 08-Apr-2025 12:31:46 PM 11 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:31:46 PM 13 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:32:20 PM 40 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:32:30 PM 1 1264.00 TQEX
GENMAB A/S 08-Apr-2025 12:32:30 PM 1 1264.00 TQEX
GENMAB A/S 08-Apr-2025 12:32:30 PM 24 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:32:35 PM 30 1263.50 XCSE
GENMAB A/S 08-Apr-2025 12:32:35 PM 53 1263.50 XCSE
GENMAB A/S 08-Apr-2025 12:34:30 PM 17 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:34:30 PM 7 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:35:01 PM 25 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:35:01 PM 39 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:35:10 PM 31 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:35:10 PM 1 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:35:12 PM 16 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:38:37 PM 1 1264.00 TQEX
GENMAB A/S 08-Apr-2025 12:38:37 PM 33 1264.00 TQEX
GENMAB A/S 08-Apr-2025 12:38:37 PM 25 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:41:11 PM 29 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:41:45 PM 2 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:41:45 PM 3 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:42:03 PM 1 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:42:03 PM 54 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:42:03 PM 18 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:42:03 PM 30 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:43:13 PM 8 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:44:45 PM 87 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:44:45 PM 69 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:44:45 PM 42 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:44:45 PM 2 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:44:45 PM 21 1265.00 TQEX
GENMAB A/S 08-Apr-2025 12:44:45 PM 12 1265.00 TQEX
GENMAB A/S 08-Apr-2025 12:44:45 PM 24 1265.00 AQEU
GENMAB A/S 08-Apr-2025 12:44:45 PM 87 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:45:01 PM 44 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:45:17 PM 15 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:45:17 PM 22 1265.00 XCSE
GENMAB A/S 08-Apr-2025 12:45:17 PM 35 1264.50 TQEX
GENMAB A/S 08-Apr-2025 12:45:29 PM 11 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:45:29 PM 72 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:46:01 PM 34 1264.00 CEUX

80

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 12:46:30 PM 11 1264.00 AQEU
GENMAB A/S 08-Apr-2025 12:48:16 PM 13 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:48:52 PM 15 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:48:52 PM 63 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:48:52 PM 1 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:48:52 PM 15 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:48:52 PM 16 1266.00 XCSE
GENMAB A/S 08-Apr-2025 12:50:01 PM 88 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:50:01 PM 42 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:50:01 PM 15 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:50:01 PM 4 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:50:03 PM 24 1265.00 AQEU
GENMAB A/S 08-Apr-2025 12:50:03 PM 85 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:50:20 PM 83 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:50:26 PM 34 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:50:26 PM 4 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:50:31 PM 11 1264.00 AQEU
GENMAB A/S 08-Apr-2025 12:50:35 PM 2 1264.00 AQEU
GENMAB A/S 08-Apr-2025 12:51:10 PM 37 1263.50 XCSE
GENMAB A/S 08-Apr-2025 12:51:10 PM 37 1263.50 XCSE
GENMAB A/S 08-Apr-2025 12:51:35 PM 11 1263.50 AQEU
GENMAB A/S 08-Apr-2025 12:51:58 PM 14 1263.50 AQEU
GENMAB A/S 08-Apr-2025 12:52:57 PM 84 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:53:02 PM 8 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:53:02 PM 8 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:53:02 PM 74 1264.00 CEUX
GENMAB A/S 08-Apr-2025 12:56:50 PM 27 1266.50 XCSE
GENMAB A/S 08-Apr-2025 12:56:51 PM 42 1266.50 XCSE
GENMAB A/S 08-Apr-2025 12:57:04 PM 42 1266.50 XCSE
GENMAB A/S 08-Apr-2025 12:57:04 PM 30 1266.50 XCSE
GENMAB A/S 08-Apr-2025 12:57:46 PM 10 1266.00 TQEX
GENMAB A/S 08-Apr-2025 12:57:46 PM 14 1266.00 TQEX
GENMAB A/S 08-Apr-2025 12:57:46 PM 43 1266.00 CEUX
GENMAB A/S 08-Apr-2025 12:57:46 PM 46 1266.00 CEUX
GENMAB A/S 08-Apr-2025 12:58:06 PM 9 1266.50 CEUX
GENMAB A/S 08-Apr-2025 12:58:50 PM 85 1266.50 XCSE
GENMAB A/S 08-Apr-2025 12:58:50 PM 24 1266.50 TQEX
GENMAB A/S 08-Apr-2025 12:58:50 PM 74 1266.50 CEUX
GENMAB A/S 08-Apr-2025 12:59:00 PM 30 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:59:00 PM 57 1265.50 XCSE
GENMAB A/S 08-Apr-2025 12:59:16 PM 27 1265.00 AQEU
GENMAB A/S 08-Apr-2025 12:59:16 PM 86 1265.00 CEUX
GENMAB A/S 08-Apr-2025 12:59:43 PM 10 1264.50 XCSE

81

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 12:59:43 PM 1 1264.50 XCSE
GENMAB A/S 08-Apr-2025 12:59:43 PM 77 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:01:20 PM 36 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:02:10 PM 6 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:02:31 PM 42 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:02:31 PM 31 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:03:51 PM 48 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:03:51 PM 23 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:04:28 PM 42 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:04:28 PM 22 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:05:06 PM 34 1264.00 XCSE
GENMAB A/S 08-Apr-2025 13:05:06 PM 49 1264.00 XCSE
GENMAB A/S 08-Apr-2025 13:05:06 PM 3 1264.00 TQEX
GENMAB A/S 08-Apr-2025 13:05:06 PM 21 1264.00 TQEX
GENMAB A/S 08-Apr-2025 13:05:06 PM 89 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:05:18 PM 26 1263.00 CEUX
GENMAB A/S 08-Apr-2025 13:05:24 PM 87 1263.00 XCSE
GENMAB A/S 08-Apr-2025 13:05:25 PM 27 1263.00 TQEX
GENMAB A/S 08-Apr-2025 13:05:25 PM 60 1263.00 CEUX
GENMAB A/S 08-Apr-2025 13:09:43 PM 42 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:09:43 PM 32 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:09:43 PM 39 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:09:58 PM 26 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:09:58 PM 12 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:10:03 PM 24 1265.00 TQEX
GENMAB A/S 08-Apr-2025 13:10:03 PM 24 1265.00 AQEU
GENMAB A/S 08-Apr-2025 13:10:03 PM 83 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:11:22 PM 27 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:11:22 PM 3 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:11:22 PM 39 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:11:22 PM 16 1265.50 XCSE
GENMAB A/S 08-Apr-2025 13:11:25 PM 72 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:11:39 PM 2 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:11:39 PM 1 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:11:39 PM 83 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:11:39 PM 1 1265.00 AQEU
GENMAB A/S 08-Apr-2025 13:11:39 PM 18 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:11:41 PM 24 1265.00 AQEU
GENMAB A/S 08-Apr-2025 13:11:51 PM 89 1264.00 XCSE
GENMAB A/S 08-Apr-2025 13:11:51 PM 36 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:11:51 PM 26 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:12:57 PM 25 1265.00 AQEU
GENMAB A/S 08-Apr-2025 13:12:57 PM 23 1265.00 CEUX

82

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 13:12:57 PM 9 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:13:03 PM 24 1265.00 TQEX
GENMAB A/S 08-Apr-2025 13:13:03 PM 20 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:13:25 PM 85 1264.00 XCSE
GENMAB A/S 08-Apr-2025 13:13:25 PM 10 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:13:25 PM 48 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:14:46 PM 39 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:14:55 PM 29 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:15:08 PM 26 1264.50 AQEU
GENMAB A/S 08-Apr-2025 13:15:11 PM 87 1264.00 XCSE
GENMAB A/S 08-Apr-2025 13:15:11 PM 26 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:17:39 PM 28 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:17:39 PM 5 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:17:39 PM 28 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:17:39 PM 7 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:17:39 PM 8 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:18:21 PM 31 1266.50 CEUX
GENMAB A/S 08-Apr-2025 13:18:49 PM 24 1267.50 TQEX
GENMAB A/S 08-Apr-2025 13:19:52 PM 40 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:19:52 PM 48 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:19:52 PM 24 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:19:52 PM 21 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:20:15 PM 17 1266.50 CEUX
GENMAB A/S 08-Apr-2025 13:20:44 PM 63 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:22:58 PM 16 1266.00 AQEU
GENMAB A/S 08-Apr-2025 13:23:45 PM 65 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:23:45 PM 16 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:23:45 PM 7 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:23:45 PM 25 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:24:00 PM 64 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:24:00 PM 28 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:24:38 PM 57 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:24:57 PM 3 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:24:57 PM 1 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:24:58 PM 10 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:24:58 PM 9 1266.00 AQEU
GENMAB A/S 08-Apr-2025 13:25:14 PM 89 1265.00 XCSE
GENMAB A/S 08-Apr-2025 13:25:14 PM 24 1265.00 TQEX
GENMAB A/S 08-Apr-2025 13:25:14 PM 41 1265.00 CEUX
GENMAB A/S 08-Apr-2025 13:26:41 PM 26 1264.00 CEUX
GENMAB A/S 08-Apr-2025 13:27:08 PM 3 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:27:08 PM 4 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:27:08 PM 42 1264.50 XCSE

83

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 13:27:08 PM 28 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:28:18 PM 10 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:28:39 PM 33 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:28:58 PM 39 1264.50 XCSE
GENMAB A/S 08-Apr-2025 13:30:26 PM 24 1264.00 TQEX
GENMAB A/S 08-Apr-2025 13:30:32 PM 9 1263.50 XCSE
GENMAB A/S 08-Apr-2025 13:30:32 PM 77 1263.50 XCSE
GENMAB A/S 08-Apr-2025 13:32:15 PM 52 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:15 PM 25 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:15 PM 3 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:15 PM 4 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:15 PM 29 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:34 PM 2 1266.00 CEUX
GENMAB A/S 08-Apr-2025 13:32:34 PM 35 1266.00 CEUX
GENMAB A/S 08-Apr-2025 13:32:51 PM 24 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:58 PM 43 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:58 PM 15 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:32:58 PM 23 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:34:08 PM 34 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:34:08 PM 2 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:34:24 PM 1 1266.00 CEUX
GENMAB A/S 08-Apr-2025 13:34:24 PM 32 1266.00 CEUX
GENMAB A/S 08-Apr-2025 13:34:48 PM 1 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:34:48 PM 4 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:34:48 PM 4 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:35:15 PM 8 1266.00 AQEU
GENMAB A/S 08-Apr-2025 13:35:37 PM 1 1266.50 TQEX
GENMAB A/S 08-Apr-2025 13:35:37 PM 6 1266.50 TQEX
GENMAB A/S 08-Apr-2025 13:35:37 PM 22 1266.50 TQEX
GENMAB A/S 08-Apr-2025 13:35:43 PM 10 1266.00 XCSE
GENMAB A/S 08-Apr-2025 13:36:31 PM 36 1266.50 CEUX
GENMAB A/S 08-Apr-2025 13:37:12 PM 6 1267.00 CEUX
GENMAB A/S 08-Apr-2025 13:37:12 PM 31 1267.00 CEUX
GENMAB A/S 08-Apr-2025 13:37:16 PM 8 1267.50 XCSE
GENMAB A/S 08-Apr-2025 13:37:22 PM 24 1267.50 CEUX
GENMAB A/S 08-Apr-2025 13:37:22 PM 20 1267.50 CEUX
GENMAB A/S 08-Apr-2025 13:38:20 PM 37 1267.50 XCSE
GENMAB A/S 08-Apr-2025 13:38:20 PM 7 1267.50 TQEX
GENMAB A/S 08-Apr-2025 13:38:20 PM 25 1267.50 TQEX
GENMAB A/S 08-Apr-2025 13:38:28 PM 32 1267.50 CEUX
GENMAB A/S 08-Apr-2025 13:38:31 PM 1 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:38:31 PM 82 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:38:31 PM 25 1267.00 XCSE

84

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 13:38:31 PM 25 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:38:31 PM 42 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:38:31 PM 16 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:38:31 PM 5 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:38:31 PM 28 1267.00 AQEU
GENMAB A/S 08-Apr-2025 13:38:31 PM 88 1267.00 CEUX
GENMAB A/S 08-Apr-2025 13:38:42 PM 30 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:39:08 PM 29 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:39:28 PM 4 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:39:41 PM 23 1266.00 CEUX
GENMAB A/S 08-Apr-2025 13:40:05 PM 14 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:40:05 PM 25 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:40:05 PM 42 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:40:42 PM 26 1266.50 TQEX
GENMAB A/S 08-Apr-2025 13:41:08 PM 42 1267.00 XCSE
GENMAB A/S 08-Apr-2025 13:41:24 PM 24 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:41:38 PM 45 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:42:18 PM 4 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:42:18 PM 9 1266.50 XCSE
GENMAB A/S 08-Apr-2025 13:43:14 PM 83 1269.00 XCSE
GENMAB A/S 08-Apr-2025 13:43:14 PM 25 1269.00 TQEX
GENMAB A/S 08-Apr-2025 13:43:14 PM 43 1269.00 CEUX
GENMAB A/S 08-Apr-2025 13:43:14 PM 41 1269.00 CEUX
GENMAB A/S 08-Apr-2025 13:43:41 PM 33 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:44:19 PM 40 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:44:19 PM 43 1270.00 AQEU
GENMAB A/S 08-Apr-2025 13:44:38 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:44:38 PM 7 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:45:16 PM 88 1269.50 XCSE
GENMAB A/S 08-Apr-2025 13:45:16 PM 32 1270.00 CEUX
GENMAB A/S 08-Apr-2025 13:45:46 PM 36 1270.00 CEUX
GENMAB A/S 08-Apr-2025 13:45:46 PM 35 1270.00 CEUX
GENMAB A/S 08-Apr-2025 13:45:47 PM 24 1269.50 AQEU
GENMAB A/S 08-Apr-2025 13:45:47 PM 85 1269.50 CEUX
GENMAB A/S 08-Apr-2025 13:47:12 PM 86 1269.00 XCSE
GENMAB A/S 08-Apr-2025 13:47:12 PM 24 1269.00 TQEX
GENMAB A/S 08-Apr-2025 13:47:12 PM 25 1269.00 AQEU
GENMAB A/S 08-Apr-2025 13:47:12 PM 38 1269.00 CEUX
GENMAB A/S 08-Apr-2025 13:47:12 PM 46 1269.00 CEUX
GENMAB A/S 08-Apr-2025 13:47:14 PM 24 1269.00 AQEU
GENMAB A/S 08-Apr-2025 13:48:12 PM 90 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:48:12 PM 30 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:48:12 PM 42 1270.00 XCSE

85

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 13:48:12 PM 29 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:48:12 PM 78 1270.00 AQEU
GENMAB A/S 08-Apr-2025 13:48:12 PM 83 1270.00 CEUX
GENMAB A/S 08-Apr-2025 13:49:52 PM 24 1271.00 TQEX
GENMAB A/S 08-Apr-2025 13:49:53 PM 9 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:49:53 PM 85 1270.50 CEUX
GENMAB A/S 08-Apr-2025 13:49:59 PM 6 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:49:59 PM 6 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:50:02 PM 2 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:50:02 PM 2 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:50:02 PM 1 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:50:08 PM 62 1270.50 XCSE
GENMAB A/S 08-Apr-2025 13:50:08 PM 37 1270.50 AQEU
GENMAB A/S 08-Apr-2025 13:52:30 PM 22 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:52:30 PM 11 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:52:30 PM 9 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:53:47 PM 83 1269.00 XCSE
GENMAB A/S 08-Apr-2025 13:53:47 PM 42 1269.50 XCSE
GENMAB A/S 08-Apr-2025 13:53:47 PM 7 1269.50 XCSE
GENMAB A/S 08-Apr-2025 13:53:47 PM 27 1269.50 XCSE
GENMAB A/S 08-Apr-2025 13:53:47 PM 37 1269.50 XCSE
GENMAB A/S 08-Apr-2025 13:53:47 PM 30 1269.50 TQEX
GENMAB A/S 08-Apr-2025 13:53:47 PM 14 1269.50 TQEX
GENMAB A/S 08-Apr-2025 13:53:47 PM 37 1269.00 CEUX
GENMAB A/S 08-Apr-2025 13:54:40 PM 10 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:54:40 PM 25 1270.00 AQEU
GENMAB A/S 08-Apr-2025 13:54:40 PM 88 1270.00 CEUX
GENMAB A/S 08-Apr-2025 13:56:07 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:56:07 PM 6 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:56:07 PM 30 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:56:07 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 13:59:19 PM 23 1270.00 AQEU
GENMAB A/S 08-Apr-2025 13:59:19 PM 14 1270.00 AQEU
GENMAB A/S 08-Apr-2025 13:59:19 PM 90 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:00:29 PM 3 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:00:29 PM 7 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:00:45 PM 3 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:00:56 PM 2 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:01:23 PM 49 1271.00 AQEU
GENMAB A/S 08-Apr-2025 14:01:23 PM 12 1271.00 AQEU
GENMAB A/S 08-Apr-2025 14:01:23 PM 32 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:01:24 PM 42 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:01:24 PM 39 1271.00 XCSE

86

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:01:24 PM 90 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:24 PM 24 1270.50 TQEX
GENMAB A/S 08-Apr-2025 14:01:24 PM 88 1270.50 CEUX
GENMAB A/S 08-Apr-2025 14:01:25 PM 85 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 28 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 19 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 24 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 42 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 28 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 46 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 14 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 16 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:25 PM 37 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:26 PM 14 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:26 PM 13 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:26 PM 13 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:26 PM 16 1270.50 XCSE
GENMAB A/S 08-Apr-2025 14:01:30 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:01:30 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:01:30 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:01:30 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:01:30 PM 27 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:01:30 PM 10 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:04:15 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:04:18 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:04:19 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:04:20 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:04:21 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:04:25 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:04:26 PM 16 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:05:06 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:05:06 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:05:06 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:05:06 PM 87 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:05:06 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:05:50 PM 13 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:06:10 PM 3 1270.50 CEUX
GENMAB A/S 08-Apr-2025 14:06:41 PM 4 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:09:25 PM 24 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:09:25 PM 33 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:09:29 PM 79 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:09:29 PM 24 1271.00 TQEX
GENMAB A/S 08-Apr-2025 14:09:29 PM 33 1271.00 CEUX

87

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:09:29 PM 41 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:09:29 PM 7 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:09:29 PM 9 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:03 PM 87 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:03 PM 11 1271.00 TQEX
GENMAB A/S 08-Apr-2025 14:12:04 PM 39 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:04 PM 6 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:20 PM 3 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:20 PM 1 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:20 PM 79 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:20 PM 13 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:20 PM 13 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:20 PM 9 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:20 PM 15 1271.00 TQEX
GENMAB A/S 08-Apr-2025 14:12:20 PM 1 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:20 PM 38 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:20 PM 8 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:20 PM 7 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:35 PM 26 1271.00 TQEX
GENMAB A/S 08-Apr-2025 14:12:35 PM 41 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:35 PM 9 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:35 PM 7 1271.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:43 PM 42 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:43 PM 16 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 30 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 42 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 15 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 14 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 13 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 42 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:57 PM 13 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 30 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 42 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 13 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 14 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 14 1271.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 85 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 83 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 4 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:12:58 PM 26 1270.00 TQEX
GENMAB A/S 08-Apr-2025 14:12:58 PM 41 1270.50 CEUX
GENMAB A/S 08-Apr-2025 14:12:58 PM 25 1270.50 CEUX

88

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:12:58 PM 73 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:12:58 PM 4 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:12:58 PM 1 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:12:58 PM 21 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:14:39 PM 14 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:17:11 PM 57 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:17:45 PM 27 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:17:45 PM 1 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:17:45 PM 31 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:17:45 PM 53 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:17:45 PM 40 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:17:45 PM 41 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:17:45 PM 68 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:18:06 PM 19 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:19:33 PM 44 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:20:30 PM 40 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:21:15 PM 60 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:15 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:15 PM 88 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:21:16 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:16 PM 16 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:16 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:16 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:17 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:17 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:17 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:18 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:18 PM 42 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:18 PM 2 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:18 PM 28 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:18 PM 28 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:20 PM 16 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:23 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:23 PM 1 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:34 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 85 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 30 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 16 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 18 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 16 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 33 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:45 PM 85 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:21:45 PM 83 1270.00 CEUX

89

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:21:45 PM 51 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:21:47 PM 3 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:47 PM 5 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:47 PM 1 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:21:47 PM 25 1269.50 TQEX
GENMAB A/S 08-Apr-2025 14:21:48 PM 80 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:23:08 PM 3 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:23:15 PM 82 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:23:15 PM 83 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:23:30 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:23:48 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:23:48 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:23:48 PM 34 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:25:14 PM 60 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:25:14 PM 20 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:25:14 PM 2 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:25:14 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:25:14 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 14:25:14 PM 86 1270.00 CEUX
GENMAB A/S 08-Apr-2025 14:25:14 PM 1 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:25:14 PM 4 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:25:14 PM 1 1270.00 AQEU
GENMAB A/S 08-Apr-2025 14:28:23 PM 100 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:28:23 PM 13 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:29:44 PM 53 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:29:44 PM 19 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:29:44 PM 17 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:29:44 PM 85 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:29:44 PM 20 1274.50 TQEX
GENMAB A/S 08-Apr-2025 14:29:44 PM 21 1274.50 TQEX
GENMAB A/S 08-Apr-2025 14:29:44 PM 41 1273.50 TQEX
GENMAB A/S 08-Apr-2025 14:29:44 PM 85 1275.00 CEUX
GENMAB A/S 08-Apr-2025 14:29:44 PM 70 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:29:44 PM 72 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:29:44 PM 11 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:29:44 PM 51 1274.50 AQEU
GENMAB A/S 08-Apr-2025 14:29:44 PM 53 1273.00 AQEU
GENMAB A/S 08-Apr-2025 14:29:54 PM 3 1273.00 XCSE
GENMAB A/S 08-Apr-2025 14:30:35 PM 2 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:32:57 PM 88 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:32:57 PM 52 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:32:57 PM 53 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:32:57 PM 8 1275.00 XCSE

90

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:32:57 PM 88 1275.00 CEUX
GENMAB A/S 08-Apr-2025 14:34:30 PM 55 1276.00 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 4 1276.00 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 4 1276.00 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 50 1276.00 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 87 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 3 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 24 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 53 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 3 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:30 PM 4 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:34:33 PM 87 1275.00 CEUX
GENMAB A/S 08-Apr-2025 14:34:33 PM 32 1275.00 AQEU
GENMAB A/S 08-Apr-2025 14:34:38 PM 15 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:34:38 PM 53 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:34:38 PM 7 1275.00 XCSE
GENMAB A/S 08-Apr-2025 14:36:29 PM 38 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:29 PM 50 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:29 PM 25 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:29 PM 18 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:29 PM 4 1275.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:29 PM 38 1275.50 TQEX
GENMAB A/S 08-Apr-2025 14:36:29 PM 84 1275.50 CEUX
GENMAB A/S 08-Apr-2025 14:36:29 PM 24 1275.50 AQEU
GENMAB A/S 08-Apr-2025 14:36:38 PM 83 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:38 PM 24 1274.50 TQEX
GENMAB A/S 08-Apr-2025 14:36:42 PM 80 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:36:42 PM 29 1274.00 AQEU
GENMAB A/S 08-Apr-2025 14:36:45 PM 89 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:36:45 PM 10 1273.50 TQEX
GENMAB A/S 08-Apr-2025 14:36:45 PM 15 1273.50 TQEX
GENMAB A/S 08-Apr-2025 14:36:49 PM 36 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:36:49 PM 16 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:36:50 PM 8 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:38:17 PM 87 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:39:58 PM 3 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:39:59 PM 16 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:39:59 PM 8 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:40:19 PM 13 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:40:19 PM 53 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:40:58 PM 2 1274.50 XCSE

91

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:40:58 PM 47 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:40:59 PM 25 1274.00 TQEX
GENMAB A/S 08-Apr-2025 14:40:59 PM 41 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:41:24 PM 85 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:41:24 PM 46 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:42:22 PM 85 1273.00 XCSE
GENMAB A/S 08-Apr-2025 14:42:22 PM 4 1273.00 TQEX
GENMAB A/S 08-Apr-2025 14:42:22 PM 1 1273.00 TQEX
GENMAB A/S 08-Apr-2025 14:42:22 PM 20 1273.00 TQEX
GENMAB A/S 08-Apr-2025 14:42:22 PM 29 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:42:22 PM 34 1273.00 AQEU
GENMAB A/S 08-Apr-2025 14:43:12 PM 90 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:43:12 PM 27 1273.50 AQEU
GENMAB A/S 08-Apr-2025 14:43:15 PM 84 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:43:20 PM 24 1272.50 TQEX
GENMAB A/S 08-Apr-2025 14:43:33 PM 83 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:43:33 PM 28 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:43:33 PM 49 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:45:48 PM 12 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:45:48 PM 2 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:45:55 PM 16 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:46:49 PM 83 1271.50 XCSE
GENMAB A/S 08-Apr-2025 14:46:49 PM 85 1271.50 CEUX
GENMAB A/S 08-Apr-2025 14:47:31 PM 71 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:47:31 PM 10 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:47:32 PM 3 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:48:34 PM 30 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:48:39 PM 16 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:48:39 PM 25 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:48:39 PM 40 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:48:40 PM 11 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:48:40 PM 25 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:48:40 PM 56 1272.50 XCSE
GENMAB A/S 08-Apr-2025 14:48:40 PM 12 1272.50 XCSE
GENMAB A/S 08-Apr-2025 14:48:40 PM 4 1272.50 XCSE
GENMAB A/S 08-Apr-2025 14:48:40 PM 5 1272.50 XCSE
GENMAB A/S 08-Apr-2025 14:49:08 PM 9 1272.00 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 67 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 17 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 30 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 15 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 40 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 28 1274.00 XCSE

92

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:51:56 PM 83 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 30 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:51:56 PM 33 1273.50 TQEX
GENMAB A/S 08-Apr-2025 14:51:56 PM 26 1273.50 AQEU
GENMAB A/S 08-Apr-2025 14:52:38 PM 30 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:52:42 PM 14 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:52:48 PM 14 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:52:58 PM 1 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:52:58 PM 4 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:53:26 PM 18 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:53:43 PM 1 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:53:46 PM 18 1274.50 CEUX
GENMAB A/S 08-Apr-2025 14:54:42 PM 30 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:42 PM 25 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:42 PM 40 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:42 PM 15 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:42 PM 24 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:42 PM 32 1274.50 CEUX
GENMAB A/S 08-Apr-2025 14:54:43 PM 24 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:43 PM 3 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:43 PM 11 1274.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:47 PM 27 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:54:47 PM 88 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:54:49 PM 88 1273.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:49 PM 28 1273.50 TQEX
GENMAB A/S 08-Apr-2025 14:54:49 PM 88 1273.00 CEUX
GENMAB A/S 08-Apr-2025 14:54:49 PM 24 1273.50 AQEU
GENMAB A/S 08-Apr-2025 14:54:50 PM 84 1272.50 XCSE
GENMAB A/S 08-Apr-2025 14:54:50 PM 33 1272.50 TQEX
GENMAB A/S 08-Apr-2025 14:54:50 PM 48 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:54:50 PM 25 1272.50 AQEU
GENMAB A/S 08-Apr-2025 14:54:51 PM 24 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:54:52 PM 11 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:55:25 PM 7 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:56:09 PM 52 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:56:09 PM 11 1272.00 CEUX
GENMAB A/S 08-Apr-2025 14:56:55 PM 3 1272.50 XCSE
GENMAB A/S 08-Apr-2025 14:58:19 PM 85 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:58:19 PM 87 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:59:58 PM 83 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:59:58 PM 50 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:59:58 PM 16 1274.00 XCSE
GENMAB A/S 08-Apr-2025 14:59:58 PM 15 1274.00 XCSE

93

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 14:59:58 PM 20 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:59:58 PM 3 1274.00 CEUX
GENMAB A/S 08-Apr-2025 14:59:58 PM 67 1274.00 CEUX
GENMAB A/S 08-Apr-2025 15:02:10 PM 28 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:02:10 PM 34 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:02:10 PM 30 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:02:10 PM 4 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:04:18 PM 13 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:04:18 PM 40 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:04:18 PM 30 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:04:18 PM 16 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:04:18 PM 14 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:04:18 PM 5 1274.50 TQEX
GENMAB A/S 08-Apr-2025 15:04:18 PM 23 1274.50 TQEX
GENMAB A/S 08-Apr-2025 15:04:20 PM 7 1274.50 TQEX
GENMAB A/S 08-Apr-2025 15:06:09 PM 7 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:06:09 PM 8 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:06:09 PM 5 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:08:14 PM 36 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:08:46 PM 47 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:08:46 PM 16 1275.00 TQEX
GENMAB A/S 08-Apr-2025 15:08:46 PM 88 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:08:47 PM 7 1275.00 TQEX
GENMAB A/S 08-Apr-2025 15:08:47 PM 13 1275.00 TQEX
GENMAB A/S 08-Apr-2025 15:09:00 PM 32 1275.50 AQEU
GENMAB A/S 08-Apr-2025 15:09:00 PM 9 1275.50 AQEU
GENMAB A/S 08-Apr-2025 15:09:05 PM 29 1275.50 TQEX
GENMAB A/S 08-Apr-2025 15:09:05 PM 84 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:09:58 PM 30 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:09:58 PM 22 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:09:58 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:09:58 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:09:58 PM 31 1275.50 TQEX
GENMAB A/S 08-Apr-2025 15:09:58 PM 84 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:09:58 PM 25 1275.50 AQEU
GENMAB A/S 08-Apr-2025 15:09:59 PM 12 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:09:59 PM 17 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 88 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 17 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 26 1275.50 XCSE

94

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:10:03 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 18 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:03 PM 25 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:18 PM 22 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:10:18 PM 78 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:18 PM 3 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:18 PM 3 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:18 PM 7 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:19 PM 40 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:19 PM 15 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:19 PM 15 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:19 PM 16 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:19 PM 19 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:20 PM 40 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:20 PM 13 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:20 PM 47 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:20 PM 1 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:10:20 PM 10 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:02 PM 90 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:11:02 PM 15 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:11:02 PM 15 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:11:02 PM 32 1276.50 CEUX
GENMAB A/S 08-Apr-2025 15:11:04 PM 14 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:11:04 PM 7 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:11:37 PM 32 1277.00 TQEX
GENMAB A/S 08-Apr-2025 15:11:37 PM 88 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:11:38 PM 2 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:38 PM 1 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:41 PM 15 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:44 PM 4 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:44 PM 16 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:44 PM 30 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:45 PM 3 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:46 PM 16 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:47 PM 13 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:11:47 PM 11 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:12:01 PM 16 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:12:10 PM 40 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:12:10 PM 13 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:12:10 PM 10 1277.00 XCSE
GENMAB A/S 08-Apr-2025 15:12:11 PM 1 1276.50 XCSE

95

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:12:56 PM 15 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:12:56 PM 9 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:16 PM 2 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:16 PM 1 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:16 PM 14 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:16 PM 19 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:18 PM 82 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:13:18 PM 24 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:13:18 PM 27 1276.00 TQEX
GENMAB A/S 08-Apr-2025 15:13:18 PM 43 1276.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:18 PM 43 1276.00 CEUX
GENMAB A/S 08-Apr-2025 15:13:18 PM 26 1276.50 AQEU
GENMAB A/S 08-Apr-2025 15:15:08 PM 54 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:08 PM 30 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:10 PM 89 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:10 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:10 PM 11 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:10 PM 11 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:15:10 PM 15 1275.50 AQEU
GENMAB A/S 08-Apr-2025 15:15:10 PM 21 1275.50 AQEU
GENMAB A/S 08-Apr-2025 15:15:18 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:28 PM 4 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:28 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:28 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:28 PM 12 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:15:36 PM 52 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:15:55 PM 25 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:16:08 PM 1 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:08 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:08 PM 4 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:28 PM 2 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:28 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:28 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:28 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:48 PM 1 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:48 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:49 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:49 PM 2 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:16:59 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:10 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:10 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:21 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:21 PM 34 1275.50 XCSE

96

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:17:38 PM 2 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:38 PM 4 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:39 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:54 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:17:55 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:18:02 PM 1 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:18:12 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:18:12 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:18:29 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:18:30 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:18:30 PM 34 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:19:08 PM 19 1275.50 TQEX
GENMAB A/S 08-Apr-2025 15:19:08 PM 16 1275.50 TQEX
GENMAB A/S 08-Apr-2025 15:19:30 PM 13 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:19:31 PM 113 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:19:31 PM 5 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:19:31 PM 12 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:19:31 PM 46 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:19:31 PM 50 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:19:40 PM 40 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:19:40 PM 15 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:19:40 PM 14 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:19:40 PM 90 1275.00 CEUX
GENMAB A/S 08-Apr-2025 15:19:41 PM 11 1275.00 TQEX
GENMAB A/S 08-Apr-2025 15:19:41 PM 11 1274.50 AQEU
GENMAB A/S 08-Apr-2025 15:20:26 PM 38 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:20:26 PM 15 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:22:05 PM 30 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:22:05 PM 9 1276.00 XCSE
GENMAB A/S 08-Apr-2025 15:22:59 PM 89 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:22:59 PM 40 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:22:59 PM 10 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:22:59 PM 31 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:22:59 PM 19 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:22:59 PM 7 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:22:59 PM 78 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:22:59 PM 8 1282.00 AQEU
GENMAB A/S 08-Apr-2025 15:22:59 PM 7 1282.00 AQEU
GENMAB A/S 08-Apr-2025 15:22:59 PM 13 1282.00 AQEU
GENMAB A/S 08-Apr-2025 15:23:05 PM 90 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:23:05 PM 12 1282.00 TQEX
GENMAB A/S 08-Apr-2025 15:23:05 PM 89 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:23:08 PM 30 1282.50 XCSE

97

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:23:08 PM 40 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:23:08 PM 30 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:23:08 PM 14 1282.00 TQEX
GENMAB A/S 08-Apr-2025 15:23:08 PM 2 1282.00 AQEU
GENMAB A/S 08-Apr-2025 15:23:17 PM 40 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:23:17 PM 30 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:23:29 PM 40 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:23:29 PM 6 1282.00 AQEU
GENMAB A/S 08-Apr-2025 15:23:29 PM 4 1282.00 AQEU
GENMAB A/S 08-Apr-2025 15:24:15 PM 27 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:15 PM 4 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:15 PM 40 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:15 PM 14 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:15 PM 40 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:15 PM 16 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:15 PM 30 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:24:21 PM 86 1283.50 XCSE
GENMAB A/S 08-Apr-2025 15:24:21 PM 24 1283.00 TQEX
GENMAB A/S 08-Apr-2025 15:24:21 PM 86 1283.50 CEUX
GENMAB A/S 08-Apr-2025 15:24:21 PM 5 1283.00 AQEU
GENMAB A/S 08-Apr-2025 15:24:21 PM 26 1283.00 AQEU
GENMAB A/S 08-Apr-2025 15:24:48 PM 24 1283.50 XCSE
GENMAB A/S 08-Apr-2025 15:24:48 PM 40 1283.50 XCSE
GENMAB A/S 08-Apr-2025 15:24:48 PM 30 1283.50 XCSE
GENMAB A/S 08-Apr-2025 15:25:00 PM 88 1285.50 XCSE
GENMAB A/S 08-Apr-2025 15:25:00 PM 29 1285.00 TQEX
GENMAB A/S 08-Apr-2025 15:25:00 PM 40 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:25:00 PM 47 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:25:00 PM 24 1285.00 AQEU
GENMAB A/S 08-Apr-2025 15:25:04 PM 90 1285.50 XCSE
GENMAB A/S 08-Apr-2025 15:25:04 PM 52 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:25:04 PM 35 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:25:04 PM 24 1285.00 AQEU
GENMAB A/S 08-Apr-2025 15:25:24 PM 25 1286.00 TQEX
GENMAB A/S 08-Apr-2025 15:25:26 PM 11 1285.50 AQEU
GENMAB A/S 08-Apr-2025 15:25:29 PM 85 1285.50 XCSE
GENMAB A/S 08-Apr-2025 15:25:29 PM 79 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:25:29 PM 6 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:25:29 PM 13 1285.50 AQEU
GENMAB A/S 08-Apr-2025 15:26:37 PM 11 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:26:38 PM 3 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:26:55 PM 3 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:26:55 PM 48 1286.50 XCSE

98

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:27:22 PM 87 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:27:22 PM 31 1286.00 AQEU
GENMAB A/S 08-Apr-2025 15:28:00 PM 49 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:28:00 PM 36 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:28:00 PM 11 1285.50 TQEX
GENMAB A/S 08-Apr-2025 15:28:00 PM 1 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:28:00 PM 13 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:28:42 PM 40 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:28:42 PM 45 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:28:42 PM 50 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:28:42 PM 35 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:28:42 PM 20 1286.50 XCSE
GENMAB A/S 08-Apr-2025 15:28:42 PM 29 1286.50 TQEX
GENMAB A/S 08-Apr-2025 15:28:42 PM 87 1286.50 CEUX
GENMAB A/S 08-Apr-2025 15:28:42 PM 24 1287.00 AQEU
GENMAB A/S 08-Apr-2025 15:28:42 PM 11 1286.00 AQEU
GENMAB A/S 08-Apr-2025 15:29:34 PM 83 1285.50 XCSE
GENMAB A/S 08-Apr-2025 15:29:34 PM 14 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:29:34 PM 13 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:29:34 PM 15 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:29:34 PM 32 1286.00 TQEX
GENMAB A/S 08-Apr-2025 15:29:34 PM 76 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:29:34 PM 36 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:29:35 PM 15 1285.00 CEUX
GENMAB A/S 08-Apr-2025 15:29:35 PM 2 1285.00 AQEU
GENMAB A/S 08-Apr-2025 15:30:01 PM 88 1284.50 XCSE
GENMAB A/S 08-Apr-2025 15:30:01 PM 49 1287.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:01 PM 13 1287.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:01 PM 9 1287.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:01 PM 9 1287.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:01 PM 83 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:01 PM 10 1285.00 CEUX
GENMAB A/S 08-Apr-2025 15:30:01 PM 86 1284.50 CEUX
GENMAB A/S 08-Apr-2025 15:30:01 PM 85 1286.50 CEUX
GENMAB A/S 08-Apr-2025 15:30:01 PM 24 1285.00 AQEU
GENMAB A/S 08-Apr-2025 15:30:02 PM 41 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:30:02 PM 17 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:30:02 PM 31 1285.50 CEUX
GENMAB A/S 08-Apr-2025 15:30:03 PM 13 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:03 PM 55 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:03 PM 20 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:08 PM 87 1284.50 CEUX
GENMAB A/S 08-Apr-2025 15:30:10 PM 84 1284.00 XCSE

99

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:30:10 PM 5 1283.00 CEUX
GENMAB A/S 08-Apr-2025 15:30:10 PM 8 1283.00 CEUX
GENMAB A/S 08-Apr-2025 15:30:11 PM 30 1283.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:21 PM 56 1283.00 XCSE
GENMAB A/S 08-Apr-2025 15:30:21 PM 27 1283.00 TQEX
GENMAB A/S 08-Apr-2025 15:30:21 PM 77 1283.00 CEUX
GENMAB A/S 08-Apr-2025 15:30:38 PM 14 1283.50 XCSE
GENMAB A/S 08-Apr-2025 15:30:38 PM 40 1283.50 XCSE
GENMAB A/S 08-Apr-2025 15:31:09 PM 31 1286.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:11 PM 85 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:11 PM 21 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:11 PM 40 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:11 PM 21 1285.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:11 PM 31 1285.50 XCSE
GENMAB A/S 08-Apr-2025 15:31:11 PM 21 1285.50 TQEX
GENMAB A/S 08-Apr-2025 15:31:11 PM 9 1285.50 TQEX
GENMAB A/S 08-Apr-2025 15:31:11 PM 27 1284.50 TQEX
GENMAB A/S 08-Apr-2025 15:31:11 PM 83 1285.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:11 PM 9 1284.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:11 PM 27 1285.00 AQEU
GENMAB A/S 08-Apr-2025 15:31:11 PM 14 1284.00 AQEU
GENMAB A/S 08-Apr-2025 15:31:12 PM 50 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:13 PM 38 1284.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:13 PM 76 1284.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:13 PM 14 1284.00 AQEU
GENMAB A/S 08-Apr-2025 15:31:16 PM 56 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:31:17 PM 13 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:31:17 PM 77 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:31:26 PM 90 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:31:26 PM 86 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:31:26 PM 77 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:26 PM 88 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 5 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 3 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 8 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 41 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 1 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 6 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:26 PM 17 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:27 PM 30 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:29 PM 72 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:34 PM 32 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:34 PM 10 1280.00 TQEX

100

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:31:37 PM 48 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:37 PM 11 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:31:37 PM 24 1279.00 TQEX
GENMAB A/S 08-Apr-2025 15:31:37 PM 33 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:37 PM 24 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:31:37 PM 30 1280.00 AQEU
GENMAB A/S 08-Apr-2025 15:31:54 PM 29 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:02 PM 40 1283.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:02 PM 21 1283.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:02 PM 30 1283.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:02 PM 16 1283.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:02 PM 30 1282.50 TQEX
GENMAB A/S 08-Apr-2025 15:33:02 PM 20 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:33:02 PM 67 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:33:03 PM 88 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:03 PM 85 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:33:03 PM 33 1281.50 TQEX
GENMAB A/S 08-Apr-2025 15:33:03 PM 50 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:33:03 PM 11 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:33:03 PM 30 1281.50 AQEU
GENMAB A/S 08-Apr-2025 15:33:03 PM 19 1280.50 AQEU
GENMAB A/S 08-Apr-2025 15:33:33 PM 85 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:33 PM 90 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:33 PM 16 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:33 PM 83 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:33 PM 5 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:33:33 PM 20 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:33:33 PM 1 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:33:33 PM 63 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:33:33 PM 30 1281.50 AQEU
GENMAB A/S 08-Apr-2025 15:33:43 PM 10 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:43 PM 73 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:43 PM 87 1281.00 CEUX
GENMAB A/S 08-Apr-2025 15:33:44 PM 28 1280.50 TQEX
GENMAB A/S 08-Apr-2025 15:33:48 PM 10 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:33:48 PM 44 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:33:49 PM 20 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:34:00 PM 10 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:34:00 PM 30 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:34:00 PM 14 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:34:05 PM 40 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:05 PM 43 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:38 PM 15 1281.50 XCSE

101

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:34:38 PM 15 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:34:38 PM 40 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:38 PM 16 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:38 PM 21 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:38 PM 6 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:50 PM 86 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:51 PM 57 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:51 PM 40 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:51 PM 16 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:34:51 PM 39 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:34:51 PM 20 1280.50 AQEU
GENMAB A/S 08-Apr-2025 15:35:00 PM 35 1280.50 TQEX
GENMAB A/S 08-Apr-2025 15:35:00 PM 47 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:00 PM 6 1280.50 AQEU
GENMAB A/S 08-Apr-2025 15:35:27 PM 15 1281.00 CEUX
GENMAB A/S 08-Apr-2025 15:35:36 PM 30 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 1 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 20 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 2 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 63 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 36 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 14 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:36 PM 25 1280.50 TQEX
GENMAB A/S 08-Apr-2025 15:35:36 PM 32 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:36 PM 33 1280.50 AQEU
GENMAB A/S 08-Apr-2025 15:35:42 PM 5 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:51 PM 12 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:51 PM 12 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:55 PM 89 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 30 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 15 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 40 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 16 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 12 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 21 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 14 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 2 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 15 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 40 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 10 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 11 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:55 PM 20 1280.50 CEUX

102

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:35:55 PM 41 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:55 PM 27 1281.00 AQEU
GENMAB A/S 08-Apr-2025 15:35:56 PM 15 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:35:56 PM 18 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:56 PM 5 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:35:57 PM 47 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:35:57 PM 16 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:36:15 PM 19 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:36:25 PM 36 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:36:25 PM 49 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:36:37 PM 43 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:36:37 PM 44 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:36:37 PM 29 1278.50 TQEX
GENMAB A/S 08-Apr-2025 15:36:37 PM 89 1278.50 CEUX
GENMAB A/S 08-Apr-2025 15:36:44 PM 37 1277.50 XCSE
GENMAB A/S 08-Apr-2025 15:36:44 PM 52 1277.50 XCSE
GENMAB A/S 08-Apr-2025 15:36:44 PM 44 1277.50 CEUX
GENMAB A/S 08-Apr-2025 15:36:44 PM 38 1277.50 CEUX
GENMAB A/S 08-Apr-2025 15:36:45 PM 6 1277.50 CEUX
GENMAB A/S 08-Apr-2025 15:36:53 PM 20 1277.00 AQEU
GENMAB A/S 08-Apr-2025 15:37:22 PM 89 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:37:22 PM 25 1279.50 TQEX
GENMAB A/S 08-Apr-2025 15:37:47 PM 86 1278.00 XCSE
GENMAB A/S 08-Apr-2025 15:37:47 PM 30 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:37:47 PM 40 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:37:47 PM 16 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:37:47 PM 21 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:37:47 PM 6 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:37:47 PM 83 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:01 PM 84 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:38:01 PM 15 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:01 PM 13 1279.50 AQEU
GENMAB A/S 08-Apr-2025 15:38:09 PM 73 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:24 PM 24 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:29 PM 89 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:54 PM 87 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:38:54 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:38:54 PM 15 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:38:54 PM 16 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:38:54 PM 15 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:38:54 PM 79 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:55 PM 36 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:38:56 PM 20 1280.00 CEUX

103

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:39:08 PM 27 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:08 PM 13 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:08 PM 16 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:08 PM 2 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:08 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:08 PM 21 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:14 PM 79 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:14 PM 7 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:39:14 PM 28 1279.50 TQEX
GENMAB A/S 08-Apr-2025 15:39:25 PM 45 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:39:25 PM 3 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:39:26 PM 14 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:39:26 PM 4 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:39:53 PM 17 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:39:53 PM 26 1280.00 TQEX
GENMAB A/S 08-Apr-2025 15:40:01 PM 69 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:01 PM 40 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:01 PM 18 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:01 PM 13 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:01 PM 22 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:01 PM 13 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:01 PM 61 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:40:01 PM 24 1279.50 AQEU
GENMAB A/S 08-Apr-2025 15:40:09 PM 34 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:40:09 PM 52 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:40:09 PM 36 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:40:09 PM 24 1278.50 AQEU
GENMAB A/S 08-Apr-2025 15:40:20 PM 28 1278.50 TQEX
GENMAB A/S 08-Apr-2025 15:40:20 PM 10 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:20 PM 12 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:20 PM 23 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:20 PM 45 1278.50 AQEU
GENMAB A/S 08-Apr-2025 15:40:35 PM 89 1277.50 XCSE
GENMAB A/S 08-Apr-2025 15:40:35 PM 42 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:47 PM 14 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:48 PM 28 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:48 PM 21 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:52 PM 86 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:40:52 PM 10 1277.50 XCSE
GENMAB A/S 08-Apr-2025 15:40:57 PM 35 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:40:57 PM 3 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:41:00 PM 2 1278.00 CEUX
GENMAB A/S 08-Apr-2025 15:41:02 PM 76 1277.50 XCSE

104

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:41:27 PM 25 1277.50 TQEX
GENMAB A/S 08-Apr-2025 15:41:42 PM 5 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:41:42 PM 46 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:42:05 PM 16 1277.00 TQEX
GENMAB A/S 08-Apr-2025 15:42:05 PM 20 1277.00 AQEU
GENMAB A/S 08-Apr-2025 15:42:15 PM 90 1278.00 XCSE
GENMAB A/S 08-Apr-2025 15:42:32 PM 13 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:42:32 PM 15 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:42:32 PM 15 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:02 PM 28 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:02 PM 15 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:02 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:02 PM 15 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:03 PM 14 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:03 PM 16 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:03 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:08 PM 16 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:08 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:13 PM 85 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:43:13 PM 10 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:43:13 PM 4 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:43:13 PM 2 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:43:13 PM 3 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:43:13 PM 2 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:43:13 PM 3 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:43:28 PM 16 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:28 PM 16 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:28 PM 16 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:28 PM 14 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:28 PM 14 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:29 PM 14 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:29 PM 13 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:31 PM 55 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:37 PM 14 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:37 PM 40 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:43:48 PM 23 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:04 PM 31 1281.50 TQEX
GENMAB A/S 08-Apr-2025 15:44:04 PM 11 1281.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:04 PM 4 1281.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:04 PM 27 1281.50 AQEU
GENMAB A/S 08-Apr-2025 15:44:12 PM 41 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:44:12 PM 50 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:44:12 PM 3 1282.50 XCSE

105

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:44:17 PM 32 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:44:17 PM 1 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:17 PM 21 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:17 PM 5 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:17 PM 5 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:21 PM 89 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:21 PM 52 1282.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:35 PM 40 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:35 PM 6 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:35 PM 30 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:35 PM 14 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:35 PM 23 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:35 PM 16 1281.50 TQEX
GENMAB A/S 08-Apr-2025 15:44:35 PM 8 1281.50 TQEX
GENMAB A/S 08-Apr-2025 15:44:35 PM 24 1281.50 AQEU
GENMAB A/S 08-Apr-2025 15:44:36 PM 83 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:44:36 PM 13 1280.50 TQEX
GENMAB A/S 08-Apr-2025 15:44:36 PM 45 1281.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:36 PM 29 1281.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:44 PM 83 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:44:44 PM 3 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:44 PM 46 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:44 PM 36 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:44 PM 88 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:50 PM 1 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:44:50 PM 1 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:44:58 PM 12 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:44:58 PM 43 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:45:09 PM 86 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:45:18 PM 63 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:45:47 PM 22 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:45:49 PM 21 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:45:56 PM 8 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:45:56 PM 10 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:46:01 PM 30 1281.00 TQEX
GENMAB A/S 08-Apr-2025 15:46:02 PM 3 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:46:02 PM 45 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:46:27 PM 13 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:46:40 PM 81 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 7 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 70 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 15 1282.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 15 1282.50 XCSE

106

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:47:00 PM 13 1282.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 1 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 1 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 1 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 24 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 20 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 28 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 1 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:00 PM 24 1282.50 TQEX
GENMAB A/S 08-Apr-2025 15:47:00 PM 89 1282.50 CEUX
GENMAB A/S 08-Apr-2025 15:47:00 PM 10 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:47:00 PM 24 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:47:00 PM 32 1281.50 CEUX
GENMAB A/S 08-Apr-2025 15:47:00 PM 25 1282.50 AQEU
GENMAB A/S 08-Apr-2025 15:47:00 PM 24 1281.50 AQEU
GENMAB A/S 08-Apr-2025 15:47:07 PM 82 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:07 PM 48 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:07 PM 40 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:07 PM 19 1280.50 XCSE
GENMAB A/S 08-Apr-2025 15:47:07 PM 12 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:47:07 PM 8 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:47:07 PM 27 1280.50 AQEU
GENMAB A/S 08-Apr-2025 15:47:28 PM 13 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:28 PM 11 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:28 PM 14 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:28 PM 20 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:29 PM 1 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:29 PM 60 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:29 PM 23 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:47:29 PM 44 1280.00 CEUX
GENMAB A/S 08-Apr-2025 15:47:36 PM 30 1279.50 TQEX
GENMAB A/S 08-Apr-2025 15:47:36 PM 83 1279.00 CEUX
GENMAB A/S 08-Apr-2025 15:48:07 PM 1 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 61 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 40 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 15 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 14 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 16 1281.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 24 1281.00 XCSE
GENMAB A/S 08-Apr-2025 15:48:11 PM 12 1281.00 AQEU
GENMAB A/S 08-Apr-2025 15:48:14 PM 4 1280.50 TQEX
GENMAB A/S 08-Apr-2025 15:48:14 PM 12 1280.50 TQEX
GENMAB A/S 08-Apr-2025 15:48:14 PM 20 1280.50 CEUX

107

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:48:14 PM 17 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:14 PM 20 1280.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:27 PM 85 1280.00 XCSE
GENMAB A/S 08-Apr-2025 15:48:28 PM 3 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 33 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:48:33 PM 52 1279.00 XCSE
GENMAB A/S 08-Apr-2025 15:48:33 PM 14 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:33 PM 16 1279.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:33 PM 10 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 9 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 3 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 12 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 30 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 8 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 5 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 1 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:33 PM 6 1279.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:35 PM 23 1278.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:45 PM 15 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:45 PM 12 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:45 PM 15 1279.00 TQEX
GENMAB A/S 08-Apr-2025 15:48:45 PM 6 1279.00 TQEX
GENMAB A/S 08-Apr-2025 15:48:45 PM 3 1279.00 TQEX
GENMAB A/S 08-Apr-2025 15:48:45 PM 7 1278.50 CEUX
GENMAB A/S 08-Apr-2025 15:48:57 PM 60 1278.50 XCSE
GENMAB A/S 08-Apr-2025 15:48:57 PM 14 1278.50 CEUX
GENMAB A/S 08-Apr-2025 15:49:00 PM 88 1277.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:08 PM 48 1277.00 CEUX
GENMAB A/S 08-Apr-2025 15:49:09 PM 83 1276.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 87 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 90 1274.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 40 1274.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 12 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 1 1275.50 XCSE
GENMAB A/S 08-Apr-2025 15:49:09 PM 26 1275.50 CEUX
GENMAB A/S 08-Apr-2025 15:49:09 PM 49 1274.00 CEUX
GENMAB A/S 08-Apr-2025 15:49:09 PM 26 1274.50 CEUX
GENMAB A/S 08-Apr-2025 15:49:09 PM 31 1276.00 AQEU
GENMAB A/S 08-Apr-2025 15:49:09 PM 27 1275.00 AQEU
GENMAB A/S 08-Apr-2025 15:49:18 PM 14 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:49:54 PM 12 1275.00 XCSE
GENMAB A/S 08-Apr-2025 15:49:54 PM 24 1275.50 CEUX

108

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:49:57 PM 15 1274.50 CEUX
GENMAB A/S 08-Apr-2025 15:49:57 PM 11 1274.50 CEUX
GENMAB A/S 08-Apr-2025 15:50:17 PM 33 1274.50 CEUX
GENMAB A/S 08-Apr-2025 15:50:27 PM 25 1274.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:27 PM 5 1273.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:27 PM 33 1273.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:27 PM 30 1274.00 TQEX
GENMAB A/S 08-Apr-2025 15:50:27 PM 16 1273.00 TQEX
GENMAB A/S 08-Apr-2025 15:50:27 PM 15 1273.00 CEUX
GENMAB A/S 08-Apr-2025 15:50:27 PM 10 1273.00 CEUX
GENMAB A/S 08-Apr-2025 15:50:49 PM 7 1273.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:49 PM 59 1273.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:49 PM 21 1273.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:50 PM 89 1272.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:53 PM 10 1272.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:53 PM 40 1272.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:53 PM 38 1272.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:53 PM 7 1271.00 XCSE
GENMAB A/S 08-Apr-2025 15:50:53 PM 15 1271.50 CEUX
GENMAB A/S 08-Apr-2025 15:50:53 PM 5 1271.50 CEUX
GENMAB A/S 08-Apr-2025 15:50:53 PM 11 1271.50 CEUX
GENMAB A/S 08-Apr-2025 15:50:53 PM 4 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:51:01 PM 76 1271.00 XCSE
GENMAB A/S 08-Apr-2025 15:51:01 PM 25 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:51:01 PM 36 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:51:01 PM 24 1270.00 AQEU
GENMAB A/S 08-Apr-2025 15:51:09 PM 36 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:51:09 PM 12 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:51:27 PM 33 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:51:55 PM 86 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:51:56 PM 57 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:51:56 PM 24 1270.00 TQEX
GENMAB A/S 08-Apr-2025 15:51:56 PM 10 1269.50 CEUX
GENMAB A/S 08-Apr-2025 15:51:56 PM 33 1269.50 CEUX
GENMAB A/S 08-Apr-2025 15:52:00 PM 30 1269.00 AQEU
GENMAB A/S 08-Apr-2025 15:52:30 PM 15 1269.50 CEUX
GENMAB A/S 08-Apr-2025 15:52:31 PM 25 1270.00 TQEX
GENMAB A/S 08-Apr-2025 15:52:31 PM 64 1269.50 CEUX
GENMAB A/S 08-Apr-2025 15:52:57 PM 90 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:52:59 PM 29 1270.50 TQEX
GENMAB A/S 08-Apr-2025 15:52:59 PM 24 1270.50 AQEU
GENMAB A/S 08-Apr-2025 15:53:09 PM 5 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:53:09 PM 79 1270.50 XCSE

109

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:53:09 PM 84 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:53:17 PM 11 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:53:17 PM 77 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:53:17 PM 5 1268.50 XCSE
GENMAB A/S 08-Apr-2025 15:53:17 PM 90 1269.50 CEUX
GENMAB A/S 08-Apr-2025 15:53:17 PM 9 1268.50 CEUX
GENMAB A/S 08-Apr-2025 15:53:34 PM 41 1268.50 XCSE
GENMAB A/S 08-Apr-2025 15:53:34 PM 13 1268.50 CEUX
GENMAB A/S 08-Apr-2025 15:53:34 PM 22 1268.50 CEUX
GENMAB A/S 08-Apr-2025 15:53:48 PM 12 1268.00 TQEX
GENMAB A/S 08-Apr-2025 15:54:02 PM 30 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:02 PM 52 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:03 PM 5 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:17 PM 75 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:54:27 PM 90 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:27 PM 64 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:54:38 PM 34 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:38 PM 43 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:38 PM 8 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:54:38 PM 5 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:54:38 PM 22 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:54:57 PM 7 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:54:57 PM 29 1268.50 TQEX
GENMAB A/S 08-Apr-2025 15:54:57 PM 11 1268.50 CEUX
GENMAB A/S 08-Apr-2025 15:54:57 PM 14 1268.50 CEUX
GENMAB A/S 08-Apr-2025 15:54:57 PM 24 1268.50 AQEU
GENMAB A/S 08-Apr-2025 15:55:11 PM 3 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 40 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 22 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 1 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 16 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 13 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 41 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:55:30 PM 25 1268.50 TQEX
GENMAB A/S 08-Apr-2025 15:55:30 PM 24 1268.50 AQEU
GENMAB A/S 08-Apr-2025 15:55:57 PM 48 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:55:57 PM 40 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:55:57 PM 16 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:55:57 PM 43 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:55:57 PM 20 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:56:00 PM 40 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:00 PM 20 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:00 PM 16 1269.50 XCSE

110

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:56:00 PM 14 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:00 PM 23 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:00 PM 22 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:56:41 PM 15 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:41 PM 30 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:41 PM 18 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:56:41 PM 37 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:56:41 PM 48 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:56:41 PM 25 1270.50 AQEU
GENMAB A/S 08-Apr-2025 15:56:45 PM 86 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 3 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 40 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 19 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 30 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 10 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:56:45 PM 24 1270.00 TQEX
GENMAB A/S 08-Apr-2025 15:56:46 PM 83 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:03 PM 28 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:03 PM 22 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:03 PM 40 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:04 PM 21 1268.00 AQEU
GENMAB A/S 08-Apr-2025 15:57:16 PM 49 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:16 PM 40 1268.50 XCSE
GENMAB A/S 08-Apr-2025 15:57:16 PM 20 1268.50 XCSE
GENMAB A/S 08-Apr-2025 15:57:16 PM 16 1268.50 XCSE
GENMAB A/S 08-Apr-2025 15:57:16 PM 8 1268.50 XCSE
GENMAB A/S 08-Apr-2025 15:57:16 PM 5 1268.50 TQEX
GENMAB A/S 08-Apr-2025 15:57:16 PM 16 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:16 PM 18 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:16 PM 41 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:22 PM 86 1269.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:22 PM 29 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:22 PM 40 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:22 PM 11 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:22 PM 45 1269.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:22 PM 50 1268.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:23 PM 10 1268.00 XCSE
GENMAB A/S 08-Apr-2025 15:57:27 PM 74 1267.00 CEUX
GENMAB A/S 08-Apr-2025 15:57:47 PM 84 1267.50 XCSE
GENMAB A/S 08-Apr-2025 15:58:05 PM 11 1268.00 AQEU
GENMAB A/S 08-Apr-2025 15:58:34 PM 68 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:58:35 PM 1 1269.50 XCSE

111

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 15:58:35 PM 5 1270.00 TQEX
GENMAB A/S 08-Apr-2025 15:58:35 PM 25 1270.00 TQEX
GENMAB A/S 08-Apr-2025 15:58:44 PM 61 1271.00 XCSE
GENMAB A/S 08-Apr-2025 15:58:52 PM 11 1271.00 XCSE
GENMAB A/S 08-Apr-2025 15:58:52 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 15:58:52 PM 20 1271.50 XCSE
GENMAB A/S 08-Apr-2025 15:58:52 PM 3 1272.00 XCSE
GENMAB A/S 08-Apr-2025 15:58:52 PM 14 1271.00 XCSE
GENMAB A/S 08-Apr-2025 15:58:52 PM 30 1271.50 TQEX
GENMAB A/S 08-Apr-2025 15:58:52 PM 64 1271.50 CEUX
GENMAB A/S 08-Apr-2025 15:58:52 PM 10 1271.50 CEUX
GENMAB A/S 08-Apr-2025 15:59:05 PM 62 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:59:14 PM 85 1271.00 XCSE
GENMAB A/S 08-Apr-2025 15:59:28 PM 25 1271.00 CEUX
GENMAB A/S 08-Apr-2025 15:59:28 PM 5 1271.00 AQEU
GENMAB A/S 08-Apr-2025 15:59:28 PM 19 1271.00 AQEU
GENMAB A/S 08-Apr-2025 15:59:30 PM 40 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:30 PM 14 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:30 PM 15 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:30 PM 20 1270.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:30 PM 6 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:59:30 PM 31 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:59:30 PM 19 1270.50 CEUX
GENMAB A/S 08-Apr-2025 15:59:58 PM 88 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 14 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 15 1269.50 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 40 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 18 1270.00 XCSE
GENMAB A/S 08-Apr-2025 15:59:58 PM 19 1269.50 CEUX
GENMAB A/S 08-Apr-2025 15:59:58 PM 20 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:00:03 PM 24 1270.50 AQEU
GENMAB A/S 08-Apr-2025 16:00:03 PM 9 1270.50 AQEU
GENMAB A/S 08-Apr-2025 16:00:06 PM 83 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:00:06 PM 9 1270.00 TQEX
GENMAB A/S 08-Apr-2025 16:00:06 PM 37 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:00:06 PM 8 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:00:17 PM 85 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:00:17 PM 32 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:00:17 PM 13 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:00:25 PM 80 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:00:28 PM 7 1270.00 XCSE

112

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:00:28 PM 4 1270.00 TQEX
GENMAB A/S 08-Apr-2025 16:00:28 PM 15 1270.00 TQEX
GENMAB A/S 08-Apr-2025 16:00:28 PM 26 1270.00 TQEX
GENMAB A/S 08-Apr-2025 16:00:28 PM 32 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:00:42 PM 83 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:00:42 PM 33 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:00:59 PM 17 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:00:59 PM 65 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:00:59 PM 28 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:01:05 PM 6 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:01:05 PM 11 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:01:06 PM 10 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:01:15 PM 87 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:01:15 PM 20 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:01:15 PM 11 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:01:37 PM 84 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:01:53 PM 74 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:01:53 PM 4 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:01:53 PM 3 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:01:53 PM 3 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:01:53 PM 24 1268.50 CEUX
GENMAB A/S 08-Apr-2025 16:01:53 PM 35 1269.00 AQEU
GENMAB A/S 08-Apr-2025 16:02:10 PM 73 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:02:11 PM 11 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:02:11 PM 14 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:02:12 PM 84 1267.50 XCSE
GENMAB A/S 08-Apr-2025 16:02:12 PM 11 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:02:12 PM 15 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:02:12 PM 27 1267.50 CEUX
GENMAB A/S 08-Apr-2025 16:02:57 PM 52 1267.50 XCSE
GENMAB A/S 08-Apr-2025 16:03:03 PM 59 1267.50 CEUX
GENMAB A/S 08-Apr-2025 16:03:17 PM 29 1266.50 XCSE
GENMAB A/S 08-Apr-2025 16:03:28 PM 88 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:03:28 PM 26 1267.50 CEUX
GENMAB A/S 08-Apr-2025 16:03:28 PM 12 1267.50 CEUX
GENMAB A/S 08-Apr-2025 16:03:34 PM 83 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:03:34 PM 73 1268.50 CEUX
GENMAB A/S 08-Apr-2025 16:03:47 PM 47 1267.50 CEUX
GENMAB A/S 08-Apr-2025 16:03:47 PM 18 1268.00 AQEU
GENMAB A/S 08-Apr-2025 16:03:47 PM 16 1268.00 AQEU
GENMAB A/S 08-Apr-2025 16:04:00 PM 24 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:04:02 PM 20 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:04:02 PM 34 1268.00 CEUX

113

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:04:13 PM 89 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:04:13 PM 3 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:04:13 PM 12 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:04:35 PM 89 1267.50 XCSE
GENMAB A/S 08-Apr-2025 16:04:35 PM 49 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:04:42 PM 45 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:04:42 PM 40 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:04:42 PM 22 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:04:42 PM 1 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:04:42 PM 24 1267.50 TQEX
GENMAB A/S 08-Apr-2025 16:04:46 PM 63 1267.00 CEUX
GENMAB A/S 08-Apr-2025 16:04:51 PM 21 1267.00 CEUX
GENMAB A/S 08-Apr-2025 16:04:51 PM 10 1267.00 CEUX
GENMAB A/S 08-Apr-2025 16:05:04 PM 28 1266.50 XCSE
GENMAB A/S 08-Apr-2025 16:05:04 PM 18 1266.50 XCSE
GENMAB A/S 08-Apr-2025 16:05:04 PM 18 1266.00 CEUX
GENMAB A/S 08-Apr-2025 16:05:04 PM 11 1266.00 CEUX
GENMAB A/S 08-Apr-2025 16:05:05 PM 69 1265.50 XCSE
GENMAB A/S 08-Apr-2025 16:05:05 PM 20 1265.50 XCSE
GENMAB A/S 08-Apr-2025 16:05:15 PM 38 1265.50 CEUX
GENMAB A/S 08-Apr-2025 16:05:16 PM 24 1266.00 CEUX
GENMAB A/S 08-Apr-2025 16:05:26 PM 36 1267.00 XCSE
GENMAB A/S 08-Apr-2025 16:05:26 PM 10 1266.50 CEUX
GENMAB A/S 08-Apr-2025 16:05:29 PM 10 1266.50 CEUX
GENMAB A/S 08-Apr-2025 16:05:29 PM 4 1266.50 CEUX
GENMAB A/S 08-Apr-2025 16:05:29 PM 31 1266.50 AQEU
GENMAB A/S 08-Apr-2025 16:05:43 PM 46 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:05:43 PM 10 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:05:43 PM 40 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:05:43 PM 6 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:06:07 PM 48 1267.00 XCSE
GENMAB A/S 08-Apr-2025 16:06:11 PM 48 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:06:34 PM 16 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:06:34 PM 40 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:06:35 PM 40 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:06:36 PM 36 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:06:43 PM 89 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:06:43 PM 4 1268.00 TQEX
GENMAB A/S 08-Apr-2025 16:06:43 PM 1 1268.00 TQEX
GENMAB A/S 08-Apr-2025 16:06:44 PM 28 1268.00 TQEX
GENMAB A/S 08-Apr-2025 16:07:06 PM 37 1267.50 CEUX
GENMAB A/S 08-Apr-2025 16:07:17 PM 40 1267.00 XCSE
GENMAB A/S 08-Apr-2025 16:07:37 PM 83 1268.00 XCSE

114

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:07:41 PM 2 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:07:41 PM 62 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:07:41 PM 20 1268.00 AQEU
GENMAB A/S 08-Apr-2025 16:07:42 PM 21 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:07:45 PM 40 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:07:45 PM 5 1268.00 AQEU
GENMAB A/S 08-Apr-2025 16:07:56 PM 5 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:07:57 PM 7 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:07:58 PM 14 1268.50 TQEX
GENMAB A/S 08-Apr-2025 16:08:10 PM 8 1269.00 TQEX
GENMAB A/S 08-Apr-2025 16:08:10 PM 86 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:08:10 PM 10 1269.00 AQEU
GENMAB A/S 08-Apr-2025 16:08:10 PM 7 1269.00 AQEU
GENMAB A/S 08-Apr-2025 16:09:07 PM 50 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 38 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 19 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 33 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 34 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 40 1269.00 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 30 1269.00 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 13 1269.00 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 30 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:07 PM 33 1269.50 TQEX
GENMAB A/S 08-Apr-2025 16:09:07 PM 24 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:09:07 PM 59 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:09:07 PM 21 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:09:07 PM 15 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:09:07 PM 26 1270.00 AQEU
GENMAB A/S 08-Apr-2025 16:09:07 PM 7 1269.00 AQEU
GENMAB A/S 08-Apr-2025 16:09:08 PM 16 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 40 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 15 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 22 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 15 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 5 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 8 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 13 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 40 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:09:08 PM 15 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 84 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 60 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 20 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 9 1271.50 XCSE

115

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:10:15 PM 40 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 29 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 16 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 26 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 2 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:10:15 PM 38 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:10:15 PM 85 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:10:15 PM 6 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:10:15 PM 20 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:10:15 PM 64 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:10:15 PM 39 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:10:21 PM 36 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:10:27 PM 83 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:11:01 PM 85 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:11:01 PM 30 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:11:01 PM 28 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:11:01 PM 20 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:11:01 PM 7 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:11:17 PM 48 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:11:17 PM 40 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:11:19 PM 24 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:11:20 PM 3 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:11:20 PM 12 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:11:31 PM 84 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:11:31 PM 79 1272.00 CEUX
GENMAB A/S 08-Apr-2025 16:11:57 PM 87 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:12:17 PM 2 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:12:17 PM 35 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:12:17 PM 1 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:12:17 PM 13 1271.50 AQEU
GENMAB A/S 08-Apr-2025 16:12:24 PM 11 1271.50 AQEU
GENMAB A/S 08-Apr-2025 16:12:25 PM 3 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:12:25 PM 58 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:13:27 PM 47 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:13:47 PM 13 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:13:59 PM 6 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:13:59 PM 22 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:14:17 PM 81 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:17 PM 20 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:14:18 PM 46 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:18 PM 45 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:18 PM 30 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:18 PM 15 1271.50 XCSE

116

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:14:18 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:18 PM 8 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:18 PM 84 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:14:18 PM 36 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:14:18 PM 8 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:14:18 PM 27 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:14:18 PM 20 1271.00 AQEU
GENMAB A/S 08-Apr-2025 16:14:18 PM 13 1271.00 AQEU
GENMAB A/S 08-Apr-2025 16:14:28 PM 46 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:28 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:28 PM 27 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:28 PM 20 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:28 PM 16 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:28 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:28 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 14 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 16 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 14 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 21 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:14:29 PM 14 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:15:17 PM 32 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:15:17 PM 24 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:15:23 PM 55 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 15 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 14 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 85 1268.50 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 40 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 30 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 21 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:15:23 PM 13 1270.50 TQEX
GENMAB A/S 08-Apr-2025 16:15:23 PM 5 1270.50 TQEX
GENMAB A/S 08-Apr-2025 16:15:23 PM 21 1270.50 TQEX
GENMAB A/S 08-Apr-2025 16:15:23 PM 1 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 20 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 30 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 39 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 85 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 24 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 46 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:15:23 PM 28 1270.50 AQEU
GENMAB A/S 08-Apr-2025 16:15:37 PM 85 1269.50 XCSE

117

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:15:45 PM 71 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:15:46 PM 16 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:16:06 PM 86 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:16:38 PM 30 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:16:38 PM 81 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:16:39 PM 3 1270.00 AQEU
GENMAB A/S 08-Apr-2025 16:16:39 PM 8 1270.00 AQEU
GENMAB A/S 08-Apr-2025 16:17:15 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:17:15 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:17:15 PM 18 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:17:16 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:17:16 PM 23 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:17:52 PM 24 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:17:58 PM 71 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:17:58 PM 15 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:17:58 PM 17 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:17:59 PM 47 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:17:59 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:17:59 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:00 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:00 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:00 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:00 PM 3 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:00 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:01 PM 23 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:01 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:07 PM 25 1271.00 AQEU
GENMAB A/S 08-Apr-2025 16:18:08 PM 14 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:08 PM 23 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:08 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:08 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:08 PM 23 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:22 PM 86 1272.00 CEUX
GENMAB A/S 08-Apr-2025 16:18:22 PM 2 1272.00 CEUX
GENMAB A/S 08-Apr-2025 16:18:22 PM 39 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:18:24 PM 89 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:18:24 PM 26 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:18:30 PM 12 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:18:30 PM 73 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:19:07 PM 90 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:19:27 PM 24 1270.50 TQEX
GENMAB A/S 08-Apr-2025 16:19:42 PM 37 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:19:44 PM 49 1270.50 CEUX

118

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:19:47 PM 14 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:15 PM 40 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:20:15 PM 24 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:20:15 PM 10 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:20:15 PM 4 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:20:15 PM 5 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:20:22 PM 9 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:22 PM 40 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:22 PM 13 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:22 PM 15 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:42 PM 24 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:42 PM 49 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:20:47 PM 24 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:21:25 PM 40 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:21:25 PM 24 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:25 PM 40 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:25 PM 9 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 40 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 16 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 9 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 9 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 22 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 40 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 16 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:26 PM 7 1270.50 TQEX
GENMAB A/S 08-Apr-2025 16:21:26 PM 9 1270.50 TQEX
GENMAB A/S 08-Apr-2025 16:21:27 PM 14 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:21:45 PM 12 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:22:12 PM 31 1272.50 TQEX
GENMAB A/S 08-Apr-2025 16:22:14 PM 36 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:22:37 PM 36 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:22:57 PM 36 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:22:57 PM 38 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:23:02 PM 36 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:23:08 PM 4 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:23:25 PM 18 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:23:29 PM 71 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:23:29 PM 36 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:23:29 PM 25 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:23:29 PM 24 1273.00 AQEU
GENMAB A/S 08-Apr-2025 16:23:47 PM 87 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:23:47 PM 45 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:23:47 PM 16 1272.50 TQEX

119

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:23:47 PM 13 1272.50 TQEX
GENMAB A/S 08-Apr-2025 16:23:47 PM 36 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:23:48 PM 48 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:23:48 PM 10 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:23:48 PM 4 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:23:51 PM 13 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:23:51 PM 16 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:23:51 PM 20 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:23:55 PM 30 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:23:55 PM 14 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:23:55 PM 83 1272.00 CEUX
GENMAB A/S 08-Apr-2025 16:23:55 PM 3 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:23:56 PM 48 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:23:56 PM 30 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:23:56 PM 26 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:24:28 PM 90 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:24:28 PM 48 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:24:28 PM 12 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:24:28 PM 13 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:24:28 PM 21 1271.50 TQEX
GENMAB A/S 08-Apr-2025 16:24:57 PM 50 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:24:57 PM 36 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:24:57 PM 90 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:25:17 PM 1 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 33 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 10 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 45 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 40 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 15 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 13 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:25:17 PM 21 1270.00 TQEX
GENMAB A/S 08-Apr-2025 16:25:17 PM 3 1270.00 TQEX
GENMAB A/S 08-Apr-2025 16:25:17 PM 6 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:25:17 PM 20 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:25:17 PM 10 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:25:17 PM 45 1270.50 AQEU
GENMAB A/S 08-Apr-2025 16:25:24 PM 100 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:26 PM 45 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:26 PM 33 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:26:26 PM 20 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:26:41 PM 20 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:26:41 PM 41 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:26:41 PM 23 1271.00 CEUX

120

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:26:41 PM 16 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:26:41 PM 5 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:26:42 PM 15 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:42 PM 31 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 8 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 14 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 31 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 20 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 47 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 40 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 15 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 11 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:49 PM 89 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:26:50 PM 13 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:50 PM 31 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:50 PM 40 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:50 PM 14 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:50 PM 15 1271.00 XCSE
GENMAB A/S 08-Apr-2025 16:26:56 PM 24 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:26:56 PM 39 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:26:56 PM 7 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:27:00 PM 14 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:01 PM 9 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:01 PM 5 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:17 PM 53 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:17 PM 46 1272.00 CEUX
GENMAB A/S 08-Apr-2025 16:27:28 PM 3 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:28 PM 30 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:28 PM 16 1271.50 AQEU
GENMAB A/S 08-Apr-2025 16:27:28 PM 1 1271.50 AQEU
GENMAB A/S 08-Apr-2025 16:27:30 PM 48 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:30 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:30 PM 23 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:30 PM 10 1271.50 AQEU
GENMAB A/S 08-Apr-2025 16:27:57 PM 87 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:27:57 PM 1 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:06 PM 43 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:17 PM 43 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:17 PM 83 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:17 PM 29 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:28:17 PM 37 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:28:45 PM 40 1271.50 XCSE

121

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:28:45 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:45 PM 48 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:45 PM 21 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:45 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:45 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:28:45 PM 68 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:29:17 PM 24 1271.50 AQEU
GENMAB A/S 08-Apr-2025 16:29:26 PM 45 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 15 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 30 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 15 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 14 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 15 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:26 PM 39 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:27 PM 13 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:27 PM 25 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:27 PM 40 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:27 PM 16 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:27 PM 19 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:29:31 PM 6 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:29:47 PM 24 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:29:48 PM 10 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:29:52 PM 2 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:29:52 PM 24 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:30:03 PM 21 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:03 PM 40 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:03 PM 39 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:03 PM 13 1271.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:03 PM 84 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:03 PM 19 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:30:03 PM 87 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:30:04 PM 6 1270.50 AQEU
GENMAB A/S 08-Apr-2025 16:30:11 PM 22 1270.50 AQEU
GENMAB A/S 08-Apr-2025 16:30:35 PM 2 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:30:35 PM 41 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:30:35 PM 43 1270.50 CEUX
GENMAB A/S 08-Apr-2025 16:30:36 PM 27 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:36 PM 31 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:37 PM 29 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:55 PM 75 1269.50 XCSE
GENMAB A/S 08-Apr-2025 16:30:55 PM 2 1269.50 CEUX
GENMAB A/S 08-Apr-2025 16:30:55 PM 49 1269.50 CEUX

122

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:31:27 PM 27 1268.00 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 90 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 13 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 40 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 21 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 31 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 15 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 40 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:26 PM 14 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:27 PM 13 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:27 PM 40 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:27 PM 16 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:29 PM 36 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:32:29 PM 44 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:32:29 PM 42 1273.00 AQEU
GENMAB A/S 08-Apr-2025 16:32:38 PM 13 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:38 PM 40 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:38 PM 30 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:38 PM 8 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:38 PM 34 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:32:38 PM 49 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:32:45 PM 25 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:32:54 PM 7 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:33:07 PM 23 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:33:07 PM 26 1273.00 TQEX
GENMAB A/S 08-Apr-2025 16:33:27 PM 44 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:33:37 PM 42 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:33:37 PM 2 1273.00 TQEX
GENMAB A/S 08-Apr-2025 16:33:37 PM 85 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:33:37 PM 36 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:33:37 PM 25 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:33:47 PM 45 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:33:47 PM 40 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:33:47 PM 44 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:33:49 PM 16 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:33:50 PM 9 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:33:55 PM 5 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:34:07 PM 14 1273.00 TQEX
GENMAB A/S 08-Apr-2025 16:34:07 PM 9 1273.00 TQEX
GENMAB A/S 08-Apr-2025 16:34:07 PM 24 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:34:15 PM 40 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:34:15 PM 24 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:34:15 PM 66 1272.50 XCSE

123

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:34:15 PM 6 1273.00 TQEX
GENMAB A/S 08-Apr-2025 16:34:56 PM 37 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:34:56 PM 51 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:34:56 PM 30 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:34:56 PM 15 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:34:56 PM 38 1274.00 TQEX
GENMAB A/S 08-Apr-2025 16:34:56 PM 17 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:34:56 PM 72 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:34:56 PM 27 1274.00 AQEU
GENMAB A/S 08-Apr-2025 16:34:57 PM 25 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:07 PM 5 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:35:07 PM 20 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:35:13 PM 84 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 29 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 1 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 10 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 1 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 4 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 40 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 13 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 25 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 16 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 19 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:13 PM 25 1276.00 AQEU
GENMAB A/S 08-Apr-2025 16:35:14 PM 70 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:35:38 PM 47 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:38 PM 17 1276.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:46 PM 10 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:46 PM 51 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:35:46 PM 20 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:35:57 PM 29 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:35:57 PM 45 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:36:19 PM 83 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:36:19 PM 42 1277.00 CEUX
GENMAB A/S 08-Apr-2025 16:36:19 PM 24 1277.00 CEUX
GENMAB A/S 08-Apr-2025 16:36:19 PM 61 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:36:19 PM 36 1277.00 AQEU
GENMAB A/S 08-Apr-2025 16:36:23 PM 15 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:36:30 PM 20 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:36:30 PM 40 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:36:30 PM 25 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:36:30 PM 13 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:36:30 PM 10 1276.50 XCSE

124

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:36:30 PM 55 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:36:30 PM 42 1276.50 TQEX
GENMAB A/S 08-Apr-2025 16:36:30 PM 10 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:36:30 PM 14 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:36:52 PM 35 1277.00 CEUX
GENMAB A/S 08-Apr-2025 16:36:57 PM 3 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:09 PM 40 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:09 PM 24 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:09 PM 38 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:09 PM 11 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:09 PM 33 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:37:17 PM 33 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:37:21 PM 20 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:21 PM 70 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:21 PM 10 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:37:21 PM 19 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:37:31 PM 50 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:31 PM 3 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:48 PM 67 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:50 PM 4 1275.50 AQEU
GENMAB A/S 08-Apr-2025 16:37:50 PM 12 1275.50 AQEU
GENMAB A/S 08-Apr-2025 16:37:50 PM 19 1275.50 AQEU
GENMAB A/S 08-Apr-2025 16:37:56 PM 42 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:37:56 PM 25 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:38:12 PM 67 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:38:24 PM 40 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:38:24 PM 12 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:38:24 PM 17 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:38:24 PM 1 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:38:29 PM 24 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:38:56 PM 26 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:38:56 PM 32 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:38:56 PM 36 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:39:01 PM 5 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:39:03 PM 18 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:39:07 PM 84 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:39:07 PM 11 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:39:12 PM 13 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:39:19 PM 79 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:39:25 PM 8 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:39:25 PM 5 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:39:30 PM 1 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:39:30 PM 5 1275.00 TQEX

125

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:39:47 PM 39 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:39:47 PM 32 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:40:07 PM 50 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:20 PM 40 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:20 PM 28 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:20 PM 15 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:20 PM 16 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:20 PM 14 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:20 PM 7 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 8 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 23 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 13 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 11 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 9 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 7 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:40:20 PM 8 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:40:21 PM 40 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:21 PM 16 1276.50 XCSE
GENMAB A/S 08-Apr-2025 16:40:21 PM 14 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:40:21 PM 40 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:40:21 PM 16 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:40:22 PM 14 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:40:22 PM 40 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:40:22 PM 13 1277.00 XCSE
GENMAB A/S 08-Apr-2025 16:40:26 PM 25 1276.00 AQEU
GENMAB A/S 08-Apr-2025 16:40:28 PM 14 1276.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:02 PM 2 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:41:02 PM 36 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:41:02 PM 36 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:02 PM 10 1276.00 AQEU
GENMAB A/S 08-Apr-2025 16:41:03 PM 27 1276.00 TQEX
GENMAB A/S 08-Apr-2025 16:41:04 PM 19 1276.00 AQEU
GENMAB A/S 08-Apr-2025 16:41:10 PM 88 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:41:10 PM 25 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:10 PM 10 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:10 PM 10 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:10 PM 8 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:26 PM 3 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:41:26 PM 14 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:41:29 PM 16 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:37 PM 15 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:41:37 PM 7 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:41:37 PM 4 1275.00 TQEX

126

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:41:37 PM 21 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:45 PM 35 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:45 PM 13 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:41:48 PM 6 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:41:53 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:41:53 PM 21 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:41:53 PM 6 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:41:53 PM 42 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:42:01 PM 47 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:42:01 PM 66 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:42:01 PM 34 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:42:01 PM 17 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:42:01 PM 1 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:42:01 PM 3 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:42:06 PM 10 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:42:06 PM 15 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:42:17 PM 68 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:42:17 PM 27 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:43:17 PM 33 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:17 PM 14 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:43:17 PM 4 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:43:17 PM 36 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:17 PM 43 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:17 PM 4 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:23 PM 3 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:43:23 PM 3 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:24 PM 45 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:24 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:24 PM 26 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:24 PM 2 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:24 PM 15 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:43:25 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:25 PM 26 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:25 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:25 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:25 PM 20 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:26 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:26 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 46 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 40 1275.50 XCSE

127

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:43:27 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:27 PM 1 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:43:27 PM 9 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:28 PM 37 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 11 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 65 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 35 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 30 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 32 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:28 PM 2 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:29 PM 7 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:34 PM 36 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:34 PM 7 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:34 PM 8 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:34 PM 5 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:34 PM 1 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:36 PM 24 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:43:36 PM 36 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:36 PM 9 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:36 PM 7 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:43:39 PM 1 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:44 PM 1 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:47 PM 4 1275.00 AQEU
GENMAB A/S 08-Apr-2025 16:43:53 PM 1 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:44:03 PM 26 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:03 PM 10 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:08 PM 51 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:44:08 PM 30 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:08 PM 1 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:08 PM 13 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:08 PM 24 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:24 PM 1 1274.00 TQEX
GENMAB A/S 08-Apr-2025 16:44:37 PM 87 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:44:47 PM 38 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:44:47 PM 19 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:44:57 PM 84 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:44:57 PM 2 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:44:57 PM 32 1274.50 AQEU
GENMAB A/S 08-Apr-2025 16:45:10 PM 12 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 38 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 40 1275.50 XCSE

128

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:45:10 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 8 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 6 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 30 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 10 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 30 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 6 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 32 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:10 PM 30 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:26 PM 38 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:26 PM 40 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:26 PM 48 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:26 PM 58 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:27 PM 16 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:45:27 PM 36 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:45:28 PM 36 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:45:28 PM 10 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:28 PM 7 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:33 PM 21 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:35 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:35 PM 8 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:45:35 PM 27 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:35 PM 24 1275.00 TQEX
GENMAB A/S 08-Apr-2025 16:45:36 PM 24 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:45:39 PM 2 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:47 PM 16 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:47 PM 32 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:47 PM 25 1274.50 AQEU
GENMAB A/S 08-Apr-2025 16:45:54 PM 24 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:54 PM 23 1274.00 TQEX
GENMAB A/S 08-Apr-2025 16:45:54 PM 31 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:45:54 PM 26 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:45:55 PM 45 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:45:55 PM 67 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:46:01 PM 12 1273.50 AQEU
GENMAB A/S 08-Apr-2025 16:46:01 PM 15 1273.50 AQEU
GENMAB A/S 08-Apr-2025 16:46:06 PM 1 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:46:06 PM 52 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:46:37 PM 36 1273.50 CEUX

129

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:46:37 PM 8 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:46:37 PM 38 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:46:53 PM 2 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:46:53 PM 8 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:46:53 PM 19 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:46:53 PM 3 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:46:53 PM 57 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:46:57 PM 89 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:47:07 PM 36 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:47:31 PM 44 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:47:31 PM 44 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:47:40 PM 25 1274.00 AQEU
GENMAB A/S 08-Apr-2025 16:48:07 PM 70 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:07 PM 4 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:07 PM 32 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:48:07 PM 48 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:48:07 PM 36 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:48:08 PM 40 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:08 PM 14 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:08 PM 33 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:08 PM 26 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:08 PM 7 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:48:08 PM 9 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:48:08 PM 38 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:48:11 PM 47 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:11 PM 39 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:11 PM 27 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 6 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 38 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 29 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 14 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 14 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 12 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 40 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 15 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 29 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 15 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 14 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 30 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 13 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 29 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 13 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:12 PM 28 1274.00 XCSE

130

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:48:14 PM 1 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:14 PM 36 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:48:18 PM 15 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:18 PM 25 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:48:20 PM 10 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:20 PM 3 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:20 PM 6 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:48:31 PM 11 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:48:31 PM 1 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:49:04 PM 40 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 19 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 40 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 14 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 15 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 14 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 40 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:04 PM 11 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:49:07 PM 77 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:49:27 PM 65 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:36 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:36 PM 3 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:36 PM 15 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:36 PM 32 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:36 PM 23 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:36 PM 21 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:49:44 PM 40 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:44 PM 13 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:44 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:49:45 PM 39 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:49:59 PM 3 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:49:59 PM 13 1276.00 CEUX
GENMAB A/S 08-Apr-2025 16:50:04 PM 36 1275.50 TQEX
GENMAB A/S 08-Apr-2025 16:50:04 PM 68 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:04 PM 10 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:04 PM 6 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:09 PM 28 1275.50 AQEU
GENMAB A/S 08-Apr-2025 16:50:17 PM 67 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:50:19 PM 23 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:22 PM 38 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:22 PM 16 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:22 PM 14 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:22 PM 38 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:22 PM 7 1275.50 XCSE

131

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:50:22 PM 26 1275.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:22 PM 36 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:22 PM 7 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:22 PM 8 1275.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:23 PM 54 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:50:23 PM 25 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:50:23 PM 40 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:50:23 PM 15 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:50:23 PM 8 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:50:23 PM 12 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:50:23 PM 5 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:50:23 PM 11 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:50:23 PM 36 1275.00 CEUX
GENMAB A/S 08-Apr-2025 16:50:23 PM 85 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:23 PM 24 1274.50 AQEU
GENMAB A/S 08-Apr-2025 16:50:27 PM 5 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:27 PM 10 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:27 PM 6 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:31 PM 10 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:31 PM 20 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:32 PM 10 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:32 PM 20 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:50:32 PM 10 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:32 PM 20 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:50:50 PM 49 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:07 PM 9 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:07 PM 12 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:09 PM 40 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 15 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 40 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 18 1275.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 43 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 14 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 14 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 15 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 11 1274.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:09 PM 24 1274.50 TQEX
GENMAB A/S 08-Apr-2025 16:51:09 PM 40 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:09 PM 36 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:09 PM 34 1274.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:09 PM 40 1274.50 AQEU
GENMAB A/S 08-Apr-2025 16:51:27 PM 27 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:27 PM 1 1274.00 XCSE

132

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:51:27 PM 27 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:27 PM 40 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:27 PM 2 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:27 PM 29 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:51:27 PM 87 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:27 PM 36 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:51:27 PM 8 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:51:27 PM 7 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:51:37 PM 57 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:51:47 PM 12 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:47 PM 2 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:51:47 PM 30 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:51:47 PM 2 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:47 PM 44 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:51:57 PM 39 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:51:57 PM 1 1273.00 AQEU
GENMAB A/S 08-Apr-2025 16:52:06 PM 13 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:06 PM 13 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:06 PM 13 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:06 PM 13 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:06 PM 11 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:06 PM 1 1273.00 AQEU
GENMAB A/S 08-Apr-2025 16:52:06 PM 27 1273.00 AQEU
GENMAB A/S 08-Apr-2025 16:52:07 PM 16 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:52:07 PM 22 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:07 PM 19 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:08 PM 13 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:52:10 PM 3 1273.50 XCSE
GENMAB A/S 08-Apr-2025 16:52:14 PM 44 1273.00 AQEU
GENMAB A/S 08-Apr-2025 16:52:15 PM 1 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:15 PM 8 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:15 PM 1 1273.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:20 PM 1 1272.50 TQEX
GENMAB A/S 08-Apr-2025 16:52:20 PM 11 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:20 PM 1 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:21 PM 10 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:21 PM 15 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:23 PM 27 1272.50 CEUX
GENMAB A/S 08-Apr-2025 16:52:26 PM 14 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:52:47 PM 90 1273.00 XCSE
GENMAB A/S 08-Apr-2025 16:53:13 PM 13 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:53:13 PM 16 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:53:13 PM 38 1274.00 XCSE

133

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:53:13 PM 18 1274.00 CEUX
GENMAB A/S 08-Apr-2025 16:53:13 PM 1 1273.50 AQEU
GENMAB A/S 08-Apr-2025 16:53:16 PM 13 1274.00 XCSE
GENMAB A/S 08-Apr-2025 16:53:18 PM 42 1273.00 CEUX
GENMAB A/S 08-Apr-2025 16:53:18 PM 2 1273.50 AQEU
GENMAB A/S 08-Apr-2025 16:53:18 PM 20 1273.50 AQEU
GENMAB A/S 08-Apr-2025 16:53:18 PM 1 1273.50 AQEU
GENMAB A/S 08-Apr-2025 16:53:27 PM 17 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:53:28 PM 15 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:53:28 PM 15 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:53:28 PM 9 1273.50 TQEX
GENMAB A/S 08-Apr-2025 16:53:57 PM 23 1272.50 TQEX
GENMAB A/S 08-Apr-2025 16:53:57 PM 49 1272.00 CEUX
GENMAB A/S 08-Apr-2025 16:54:00 PM 14 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:54:01 PM 32 1272.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:01 PM 53 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:01 PM 89 1269.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:01 PM 90 1269.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:01 PM 90 1267.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:01 PM 90 1266.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:01 PM 30 1271.00 TQEX
GENMAB A/S 08-Apr-2025 16:54:01 PM 36 1271.00 CEUX
GENMAB A/S 08-Apr-2025 16:54:01 PM 86 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:54:01 PM 90 1269.00 CEUX
GENMAB A/S 08-Apr-2025 16:54:01 PM 36 1271.50 CEUX
GENMAB A/S 08-Apr-2025 16:54:01 PM 46 1270.00 CEUX
GENMAB A/S 08-Apr-2025 16:54:01 PM 64 1268.00 CEUX
GENMAB A/S 08-Apr-2025 16:54:01 PM 10 1272.00 AQEU
GENMAB A/S 08-Apr-2025 16:54:03 PM 40 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:03 PM 32 1270.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:03 PM 90 1269.00 XCSE
GENMAB A/S 08-Apr-2025 16:54:26 PM 40 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:26 PM 28 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:45 PM 35 1270.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 23 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 36 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 16 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 16 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 6 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 26 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 13 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:53 PM 13 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:54 PM 30 1272.50 XCSE

134

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 08-Apr-2025 16:54:54 PM 15 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:54 PM 35 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:54 PM 23 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:54 PM 10 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:54 PM 12 1272.50 XCSE
GENMAB A/S 08-Apr-2025 16:54:54 PM 3 1272.50 XCSE
GENMAB A/S 09-Apr-2025 09:30:02 AM 81 1203.00 CEUX
GENMAB A/S 09-Apr-2025 09:30:21 AM 12 1204.00 AQEU
GENMAB A/S 09-Apr-2025 09:30:22 AM 70 1204.00 AQEU
GENMAB A/S 09-Apr-2025 09:30:33 AM 84 1203.50 XCSE
GENMAB A/S 09-Apr-2025 09:30:33 AM 25 1203.50 CEUX
GENMAB A/S 09-Apr-2025 09:30:43 AM 10 1203.00 AQEU
GENMAB A/S 09-Apr-2025 09:30:43 AM 31 1203.00 AQEU
GENMAB A/S 09-Apr-2025 09:30:44 AM 28 1203.00 AQEU
GENMAB A/S 09-Apr-2025 09:30:51 AM 55 1202.50 XCSE
GENMAB A/S 09-Apr-2025 09:30:51 AM 14 1202.50 XCSE
GENMAB A/S 09-Apr-2025 09:30:51 AM 69 1202.50 TQEX
GENMAB A/S 09-Apr-2025 09:30:51 AM 17 1202.50 TQEX
GENMAB A/S 09-Apr-2025 09:30:51 AM 10 1202.50 CEUX
GENMAB A/S 09-Apr-2025 09:30:51 AM 45 1202.50 CEUX
GENMAB A/S 09-Apr-2025 09:30:51 AM 3 1202.50 CEUX
GENMAB A/S 09-Apr-2025 09:30:59 AM 86 1201.50 XCSE
GENMAB A/S 09-Apr-2025 09:30:59 AM 75 1201.50 CEUX
GENMAB A/S 09-Apr-2025 09:30:59 AM 8 1201.50 AQEU
GENMAB A/S 09-Apr-2025 09:30:59 AM 74 1201.50 AQEU
GENMAB A/S 09-Apr-2025 09:31:24 AM 24 1202.00 CEUX
GENMAB A/S 09-Apr-2025 09:31:26 AM 26 1201.50 XCSE
GENMAB A/S 09-Apr-2025 09:31:32 AM 24 1200.00 XCSE
GENMAB A/S 09-Apr-2025 09:31:32 AM 30 1201.00 TQEX
GENMAB A/S 09-Apr-2025 09:31:32 AM 37 1201.00 TQEX
GENMAB A/S 09-Apr-2025 09:31:32 AM 24 1201.00 CEUX
GENMAB A/S 09-Apr-2025 09:31:33 AM 13 1200.00 XCSE
GENMAB A/S 09-Apr-2025 09:31:33 AM 1 1200.00 XCSE
GENMAB A/S 09-Apr-2025 09:31:33 AM 37 1200.00 XCSE
GENMAB A/S 09-Apr-2025 09:31:34 AM 20 1199.50 CEUX
GENMAB A/S 09-Apr-2025 09:31:54 AM 43 1199.50 TQEX
GENMAB A/S 09-Apr-2025 09:31:55 AM 27 1199.00 XCSE
GENMAB A/S 09-Apr-2025 09:32:37 AM 26 1201.00 CEUX
GENMAB A/S 09-Apr-2025 09:33:18 AM 41 1202.50 XCSE
GENMAB A/S 09-Apr-2025 09:33:18 AM 46 1202.50 XCSE
GENMAB A/S 09-Apr-2025 09:35:09 AM 81 1205.50 XCSE
GENMAB A/S 09-Apr-2025 09:35:09 AM 64 1205.50 CEUX
GENMAB A/S 09-Apr-2025 09:35:28 AM 85 1205.50 XCSE

135

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 09:35:28 AM 40 1205.50 CEUX
GENMAB A/S 09-Apr-2025 09:36:49 AM 87 1208.50 XCSE
GENMAB A/S 09-Apr-2025 09:37:50 AM 86 1207.50 XCSE
GENMAB A/S 09-Apr-2025 09:37:50 AM 55 1207.50 CEUX
GENMAB A/S 09-Apr-2025 09:39:35 AM 92 1208.50 XCSE
GENMAB A/S 09-Apr-2025 09:39:55 AM 14 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:39:55 AM 42 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:39:55 AM 5 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:41:07 AM 15 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:41:07 AM 42 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:41:07 AM 14 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:41:07 AM 13 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:41:07 AM 3 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:41:07 AM 43 1209.50 TQEX
GENMAB A/S 09-Apr-2025 09:41:07 AM 88 1209.50 CEUX
GENMAB A/S 09-Apr-2025 09:41:09 AM 85 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:41:09 AM 16 1210.50 XCSE
GENMAB A/S 09-Apr-2025 09:41:09 AM 8 1210.50 XCSE
GENMAB A/S 09-Apr-2025 09:42:02 AM 79 1211.50 CEUX
GENMAB A/S 09-Apr-2025 09:42:02 AM 3 1211.50 CEUX
GENMAB A/S 09-Apr-2025 09:42:14 AM 27 1212.50 XCSE
GENMAB A/S 09-Apr-2025 09:42:42 AM 42 1213.00 XCSE
GENMAB A/S 09-Apr-2025 09:42:42 AM 4 1213.00 XCSE
GENMAB A/S 09-Apr-2025 09:42:44 AM 25 1212.50 TQEX
GENMAB A/S 09-Apr-2025 09:42:53 AM 88 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:42:55 AM 25 1211.50 CEUX
GENMAB A/S 09-Apr-2025 09:42:55 AM 63 1211.50 CEUX
GENMAB A/S 09-Apr-2025 09:43:04 AM 47 1211.00 XCSE
GENMAB A/S 09-Apr-2025 09:43:04 AM 38 1211.00 XCSE
GENMAB A/S 09-Apr-2025 09:43:04 AM 53 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:43:04 AM 31 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:43:04 AM 81 1210.50 CEUX
GENMAB A/S 09-Apr-2025 09:43:11 AM 84 1209.50 CEUX
GENMAB A/S 09-Apr-2025 09:43:18 AM 81 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:44:17 AM 24 1209.50 TQEX
GENMAB A/S 09-Apr-2025 09:45:01 AM 78 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:45:01 AM 22 1209.00 CEUX
GENMAB A/S 09-Apr-2025 09:45:01 AM 2 1209.00 CEUX
GENMAB A/S 09-Apr-2025 09:47:01 AM 82 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:47:01 AM 24 1209.00 TQEX
GENMAB A/S 09-Apr-2025 09:47:01 AM 75 1209.00 CEUX
GENMAB A/S 09-Apr-2025 09:47:34 AM 53 1211.00 CEUX
GENMAB A/S 09-Apr-2025 09:48:05 AM 26 1210.50 TQEX

136

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 09:48:15 AM 85 1210.00 XCSE
GENMAB A/S 09-Apr-2025 09:48:15 AM 5 1210.00 CEUX
GENMAB A/S 09-Apr-2025 09:48:15 AM 39 1210.00 CEUX
GENMAB A/S 09-Apr-2025 09:48:31 AM 24 1209.50 TQEX
GENMAB A/S 09-Apr-2025 09:48:55 AM 12 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:49:15 AM 12 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:49:15 AM 12 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:49:22 AM 12 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:49:22 AM 14 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:49:22 AM 10 1209.50 XCSE
GENMAB A/S 09-Apr-2025 09:49:27 AM 69 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:49:27 AM 56 1209.00 CEUX
GENMAB A/S 09-Apr-2025 09:49:28 AM 12 1208.50 CEUX
GENMAB A/S 09-Apr-2025 09:50:00 AM 81 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:50:08 AM 83 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:50:19 AM 85 1209.00 XCSE
GENMAB A/S 09-Apr-2025 09:50:21 AM 8 1208.50 CEUX
GENMAB A/S 09-Apr-2025 09:50:21 AM 21 1208.50 CEUX
GENMAB A/S 09-Apr-2025 09:50:31 AM 88 1208.00 XCSE
GENMAB A/S 09-Apr-2025 09:52:21 AM 49 1207.50 CEUX
GENMAB A/S 09-Apr-2025 09:53:21 AM 8 1207.50 XCSE
GENMAB A/S 09-Apr-2025 09:53:21 AM 79 1207.50 XCSE
GENMAB A/S 09-Apr-2025 09:53:21 AM 63 1207.50 CEUX
GENMAB A/S 09-Apr-2025 09:53:36 AM 8 1206.50 XCSE
GENMAB A/S 09-Apr-2025 09:53:36 AM 76 1206.50 XCSE
GENMAB A/S 09-Apr-2025 09:54:27 AM 26 1206.00 CEUX
GENMAB A/S 09-Apr-2025 09:54:53 AM 44 1208.50 CEUX
GENMAB A/S 09-Apr-2025 09:56:29 AM 24 1211.00 TQEX
GENMAB A/S 09-Apr-2025 09:56:49 AM 15 1210.50 XCSE
GENMAB A/S 09-Apr-2025 09:56:49 AM 50 1210.50 XCSE
GENMAB A/S 09-Apr-2025 09:56:49 AM 20 1210.50 CEUX
GENMAB A/S 09-Apr-2025 09:57:12 AM 15 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:57:12 AM 42 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:57:12 AM 14 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:57:42 AM 42 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:57:42 AM 36 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:57:42 AM 15 1212.00 XCSE
GENMAB A/S 09-Apr-2025 09:57:43 AM 82 1211.50 CEUX
GENMAB A/S 09-Apr-2025 09:58:57 AM 15 1211.00 TQEX
GENMAB A/S 09-Apr-2025 09:58:57 AM 16 1211.00 TQEX
GENMAB A/S 09-Apr-2025 09:59:00 AM 10 1211.50 XCSE
GENMAB A/S 09-Apr-2025 09:59:00 AM 14 1211.50 XCSE
GENMAB A/S 09-Apr-2025 09:59:00 AM 14 1211.50 XCSE

137

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 09:59:00 AM 12 1211.50 XCSE
GENMAB A/S 09-Apr-2025 09:59:00 AM 42 1211.50 XCSE
GENMAB A/S 09-Apr-2025 09:59:00 AM 13 1211.50 XCSE
GENMAB A/S 09-Apr-2025 09:59:00 AM 5 1211.50 XCSE
GENMAB A/S 09-Apr-2025 09:59:59 AM 3 1211.50 XCSE
GENMAB A/S 09-Apr-2025 10:00:06 AM 15 1212.00 CEUX
GENMAB A/S 09-Apr-2025 10:00:08 AM 25 1212.00 TQEX
GENMAB A/S 09-Apr-2025 10:00:08 AM 68 1212.00 CEUX
GENMAB A/S 09-Apr-2025 10:00:13 AM 83 1211.50 XCSE
GENMAB A/S 09-Apr-2025 10:00:13 AM 45 1212.00 XCSE
GENMAB A/S 09-Apr-2025 10:00:13 AM 19 1212.00 XCSE
GENMAB A/S 09-Apr-2025 10:00:13 AM 28 1212.00 XCSE
GENMAB A/S 09-Apr-2025 10:00:20 AM 29 1211.00 TQEX
GENMAB A/S 09-Apr-2025 10:00:33 AM 16 1210.50 XCSE
GENMAB A/S 09-Apr-2025 10:00:33 AM 5 1210.50 XCSE
GENMAB A/S 09-Apr-2025 10:00:33 AM 54 1210.50 CEUX
GENMAB A/S 09-Apr-2025 10:02:02 AM 12 1210.50 XCSE
GENMAB A/S 09-Apr-2025 10:02:02 AM 12 1210.50 XCSE
GENMAB A/S 09-Apr-2025 10:02:02 AM 13 1210.50 XCSE
GENMAB A/S 09-Apr-2025 10:02:02 AM 42 1210.50 XCSE
GENMAB A/S 09-Apr-2025 10:02:05 AM 83 1209.50 XCSE
GENMAB A/S 09-Apr-2025 10:02:05 AM 14 1209.50 TQEX
GENMAB A/S 09-Apr-2025 10:02:05 AM 29 1209.50 CEUX
GENMAB A/S 09-Apr-2025 10:02:05 AM 23 1209.50 CEUX
GENMAB A/S 09-Apr-2025 10:02:09 AM 12 1209.50 TQEX
GENMAB A/S 09-Apr-2025 10:02:51 AM 24 1210.50 TQEX
GENMAB A/S 09-Apr-2025 10:03:32 AM 11 1211.50 XCSE
GENMAB A/S 09-Apr-2025 10:03:32 AM 19 1211.50 XCSE
GENMAB A/S 09-Apr-2025 10:03:36 AM 88 1211.00 XCSE
GENMAB A/S 09-Apr-2025 10:03:42 AM 54 1210.50 CEUX
GENMAB A/S 09-Apr-2025 10:03:42 AM 26 1210.50 CEUX
GENMAB A/S 09-Apr-2025 10:03:45 AM 84 1210.00 XCSE
GENMAB A/S 09-Apr-2025 10:04:05 AM 24 1209.50 TQEX
GENMAB A/S 09-Apr-2025 10:04:05 AM 3 1209.50 CEUX
GENMAB A/S 09-Apr-2025 10:04:05 AM 83 1209.50 CEUX
GENMAB A/S 09-Apr-2025 10:04:06 AM 84 1209.00 XCSE
GENMAB A/S 09-Apr-2025 10:04:08 AM 62 1208.50 CEUX
GENMAB A/S 09-Apr-2025 10:04:12 AM 5 1207.50 XCSE
GENMAB A/S 09-Apr-2025 10:04:12 AM 79 1207.50 XCSE
GENMAB A/S 09-Apr-2025 10:04:12 AM 62 1207.00 CEUX
GENMAB A/S 09-Apr-2025 10:04:28 AM 82 1206.00 XCSE
GENMAB A/S 09-Apr-2025 10:04:41 AM 25 1207.00 XCSE
GENMAB A/S 09-Apr-2025 10:04:44 AM 35 1206.00 XCSE

138

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 10:04:53 AM 2 1205.50 CEUX
GENMAB A/S 09-Apr-2025 10:05:02 AM 25 1205.50 CEUX
GENMAB A/S 09-Apr-2025 10:05:04 AM 85 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:05:04 AM 7 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:05:04 AM 18 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:05:04 AM 30 1204.50 CEUX
GENMAB A/S 09-Apr-2025 10:06:35 AM 30 1202.50 CEUX
GENMAB A/S 09-Apr-2025 10:06:41 AM 56 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:06:41 AM 26 1202.50 TQEX
GENMAB A/S 09-Apr-2025 10:06:48 AM 24 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:06:50 AM 16 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:06:50 AM 13 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:07:48 AM 51 1202.00 XCSE
GENMAB A/S 09-Apr-2025 10:08:03 AM 24 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:10:41 AM 87 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:10:41 AM 25 1202.50 TQEX
GENMAB A/S 09-Apr-2025 10:10:41 AM 58 1202.50 CEUX
GENMAB A/S 09-Apr-2025 10:11:59 AM 75 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:11:59 AM 35 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:11:59 AM 3 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:12:50 AM 88 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:12:50 AM 62 1202.50 CEUX
GENMAB A/S 09-Apr-2025 10:12:55 AM 24 1202.00 TQEX
GENMAB A/S 09-Apr-2025 10:13:01 AM 82 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:13:01 AM 61 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:14:09 AM 68 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:14:09 AM 13 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:14:09 AM 25 1201.50 TQEX
GENMAB A/S 09-Apr-2025 10:14:09 AM 53 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:15:27 AM 12 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:16:02 AM 34 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:02 AM 19 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:41 AM 19 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:41 AM 42 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:41 AM 36 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:42 AM 17 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:42 AM 64 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:16:42 AM 49 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:17:27 AM 16 1200.50 XCSE
GENMAB A/S 09-Apr-2025 10:17:27 AM 43 1200.50 XCSE
GENMAB A/S 09-Apr-2025 10:17:29 AM 26 1200.50 CEUX
GENMAB A/S 09-Apr-2025 10:18:13 AM 74 1200.50 CEUX
GENMAB A/S 09-Apr-2025 10:18:14 AM 81 1199.50 XCSE

139

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 10:18:14 AM 53 1199.00 CEUX
GENMAB A/S 09-Apr-2025 10:18:34 AM 24 1198.50 CEUX
GENMAB A/S 09-Apr-2025 10:19:40 AM 25 1198.50 CEUX
GENMAB A/S 09-Apr-2025 10:20:04 AM 42 1199.50 XCSE
GENMAB A/S 09-Apr-2025 10:20:04 AM 30 1199.50 XCSE
GENMAB A/S 09-Apr-2025 10:20:07 AM 8 1199.00 XCSE
GENMAB A/S 09-Apr-2025 10:20:09 AM 25 1199.50 TQEX
GENMAB A/S 09-Apr-2025 10:20:37 AM 43 1200.50 XCSE
GENMAB A/S 09-Apr-2025 10:21:03 AM 14 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:21:05 AM 85 1200.50 XCSE
GENMAB A/S 09-Apr-2025 10:21:05 AM 36 1200.50 CEUX
GENMAB A/S 09-Apr-2025 10:22:03 AM 86 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:22:03 AM 52 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:22:03 AM 7 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:22:23 AM 24 1201.50 TQEX
GENMAB A/S 09-Apr-2025 10:23:22 AM 3 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:23:22 AM 6 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:23:22 AM 13 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:23:22 AM 42 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:23:22 AM 46 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:23:56 AM 88 1200.00 XCSE
GENMAB A/S 09-Apr-2025 10:23:56 AM 57 1200.00 CEUX
GENMAB A/S 09-Apr-2025 10:24:16 AM 74 1199.00 XCSE
GENMAB A/S 09-Apr-2025 10:24:16 AM 43 1199.00 CEUX
GENMAB A/S 09-Apr-2025 10:24:23 AM 26 1199.50 AQEU
GENMAB A/S 09-Apr-2025 10:25:32 AM 2 1202.00 TQEX
GENMAB A/S 09-Apr-2025 10:26:51 AM 64 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:26:51 AM 70 1202.50 CEUX
GENMAB A/S 09-Apr-2025 10:27:03 AM 3 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:27:04 AM 12 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:27:27 AM 12 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:27:27 AM 34 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:27:31 AM 82 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:27:38 AM 29 1202.00 AQEU
GENMAB A/S 09-Apr-2025 10:27:38 AM 22 1202.00 TQEX
GENMAB A/S 09-Apr-2025 10:27:42 AM 49 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:27:45 AM 83 1201.00 XCSE
GENMAB A/S 09-Apr-2025 10:27:45 AM 35 1200.50 AQEU
GENMAB A/S 09-Apr-2025 10:27:45 AM 24 1201.00 TQEX
GENMAB A/S 09-Apr-2025 10:27:45 AM 55 1200.50 CEUX
GENMAB A/S 09-Apr-2025 10:30:11 AM 83 1200.00 XCSE
GENMAB A/S 09-Apr-2025 10:30:15 AM 49 1199.00 XCSE
GENMAB A/S 09-Apr-2025 10:30:15 AM 39 1199.00 XCSE

140

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 10:30:15 AM 52 1199.00 CEUX
GENMAB A/S 09-Apr-2025 10:30:20 AM 5 1199.00 CEUX
GENMAB A/S 09-Apr-2025 10:31:01 AM 84 1198.50 XCSE
GENMAB A/S 09-Apr-2025 10:31:38 AM 17 1198.00 CEUX
GENMAB A/S 09-Apr-2025 10:31:38 AM 17 1198.00 CEUX
GENMAB A/S 09-Apr-2025 10:33:09 AM 82 1197.50 XCSE
GENMAB A/S 09-Apr-2025 10:33:09 AM 24 1197.50 TQEX
GENMAB A/S 09-Apr-2025 10:33:13 AM 6 1196.50 CEUX
GENMAB A/S 09-Apr-2025 10:33:20 AM 83 1196.50 XCSE
GENMAB A/S 09-Apr-2025 10:33:20 AM 26 1196.50 CEUX
GENMAB A/S 09-Apr-2025 10:34:11 AM 76 1197.00 XCSE
GENMAB A/S 09-Apr-2025 10:34:11 AM 1 1197.00 XCSE
GENMAB A/S 09-Apr-2025 10:34:11 AM 5 1197.00 XCSE
GENMAB A/S 09-Apr-2025 10:34:11 AM 24 1197.00 AQEU
GENMAB A/S 09-Apr-2025 10:35:07 AM 85 1197.00 XCSE
GENMAB A/S 09-Apr-2025 10:35:07 AM 16 1196.50 CEUX
GENMAB A/S 09-Apr-2025 10:35:07 AM 56 1196.50 CEUX
GENMAB A/S 09-Apr-2025 10:37:22 AM 24 1202.00 XCSE
GENMAB A/S 09-Apr-2025 10:37:47 AM 35 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:38:23 AM 85 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:38:23 AM 28 1204.50 TQEX
GENMAB A/S 09-Apr-2025 10:38:28 AM 86 1204.00 CEUX
GENMAB A/S 09-Apr-2025 10:39:38 AM 12 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:39:38 AM 12 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:39:38 AM 52 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:39:48 AM 30 1204.00 CEUX
GENMAB A/S 09-Apr-2025 10:40:48 AM 16 1204.50 TQEX
GENMAB A/S 09-Apr-2025 10:41:29 AM 81 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:41:29 AM 42 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:41:29 AM 12 1205.00 XCSE
GENMAB A/S 09-Apr-2025 10:41:29 AM 42 1205.50 XCSE
GENMAB A/S 09-Apr-2025 10:41:29 AM 14 1205.50 XCSE
GENMAB A/S 09-Apr-2025 10:41:29 AM 88 1204.00 XCSE
GENMAB A/S 09-Apr-2025 10:41:29 AM 9 1204.50 TQEX
GENMAB A/S 09-Apr-2025 10:41:29 AM 32 1203.50 TQEX
GENMAB A/S 09-Apr-2025 10:41:29 AM 86 1205.00 CEUX
GENMAB A/S 09-Apr-2025 10:41:29 AM 46 1204.00 CEUX
GENMAB A/S 09-Apr-2025 10:41:30 AM 10 1203.00 XCSE
GENMAB A/S 09-Apr-2025 10:42:14 AM 10 1203.00 XCSE
GENMAB A/S 09-Apr-2025 10:42:14 AM 66 1203.00 XCSE
GENMAB A/S 09-Apr-2025 10:42:14 AM 82 1203.00 CEUX
GENMAB A/S 09-Apr-2025 10:42:16 AM 87 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:42:16 AM 26 1202.00 CEUX

141

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 10:42:16 AM 54 1202.00 CEUX
GENMAB A/S 09-Apr-2025 10:42:30 AM 30 1200.50 XCSE
GENMAB A/S 09-Apr-2025 10:42:30 AM 57 1200.50 XCSE
GENMAB A/S 09-Apr-2025 10:42:30 AM 44 1200.50 CEUX
GENMAB A/S 09-Apr-2025 10:43:01 AM 27 1199.50 XCSE
GENMAB A/S 09-Apr-2025 10:43:01 AM 60 1199.50 XCSE
GENMAB A/S 09-Apr-2025 10:43:01 AM 26 1199.50 CEUX
GENMAB A/S 09-Apr-2025 10:45:47 AM 26 1203.50 AQEU
GENMAB A/S 09-Apr-2025 10:45:47 AM 1 1203.50 AQEU
GENMAB A/S 09-Apr-2025 10:45:47 AM 28 1203.50 TQEX
GENMAB A/S 09-Apr-2025 10:46:12 AM 64 1203.00 XCSE
GENMAB A/S 09-Apr-2025 10:46:13 AM 28 1202.50 CEUX
GENMAB A/S 09-Apr-2025 10:47:22 AM 87 1203.00 XCSE
GENMAB A/S 09-Apr-2025 10:47:22 AM 17 1203.50 TQEX
GENMAB A/S 09-Apr-2025 10:47:22 AM 12 1203.50 TQEX
GENMAB A/S 09-Apr-2025 10:47:22 AM 45 1203.00 CEUX
GENMAB A/S 09-Apr-2025 10:49:30 AM 6 1204.00 XCSE
GENMAB A/S 09-Apr-2025 10:49:30 AM 75 1204.00 XCSE
GENMAB A/S 09-Apr-2025 10:49:55 AM 22 1203.00 CEUX
GENMAB A/S 09-Apr-2025 10:50:02 AM 87 1203.00 XCSE
GENMAB A/S 09-Apr-2025 10:50:02 AM 35 1203.00 CEUX
GENMAB A/S 09-Apr-2025 10:51:35 AM 58 1202.00 XCSE
GENMAB A/S 09-Apr-2025 10:52:28 AM 25 1201.50 TQEX
GENMAB A/S 09-Apr-2025 10:52:28 AM 25 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:53:52 AM 2 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:53:52 AM 6 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:53:52 AM 3 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:53:52 AM 3 1201.50 XCSE
GENMAB A/S 09-Apr-2025 10:54:24 AM 84 1201.50 CEUX
GENMAB A/S 09-Apr-2025 10:55:19 AM 17 1202.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 47 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 30 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 21 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 12 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 19 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 42 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:56:12 AM 24 1203.00 TQEX
GENMAB A/S 09-Apr-2025 10:56:12 AM 87 1203.00 CEUX
GENMAB A/S 09-Apr-2025 10:56:52 AM 86 1203.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 13 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 12 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 14 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 42 1204.50 XCSE

142

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 10:59:42 AM 14 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 12 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 14 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:42 AM 42 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:43 AM 13 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:52 AM 13 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:52 AM 13 1204.50 XCSE
GENMAB A/S 09-Apr-2025 10:59:52 AM 8 1204.50 XCSE
GENMAB A/S 09-Apr-2025 11:00:07 AM 24 1204.50 TQEX
GENMAB A/S 09-Apr-2025 11:01:01 AM 86 1204.00 XCSE
GENMAB A/S 09-Apr-2025 11:01:01 AM 25 1203.50 TQEX
GENMAB A/S 09-Apr-2025 11:01:01 AM 85 1204.00 CEUX
GENMAB A/S 09-Apr-2025 11:01:03 AM 87 1203.50 XCSE
GENMAB A/S 09-Apr-2025 11:02:49 AM 14 1204.00 XCSE
GENMAB A/S 09-Apr-2025 11:02:49 AM 10 1204.00 XCSE
GENMAB A/S 09-Apr-2025 11:03:09 AM 85 1203.50 XCSE
GENMAB A/S 09-Apr-2025 11:03:09 AM 27 1204.00 XCSE
GENMAB A/S 09-Apr-2025 11:04:01 AM 25 1203.00 AQEU
GENMAB A/S 09-Apr-2025 11:04:01 AM 75 1203.00 CEUX
GENMAB A/S 09-Apr-2025 11:04:53 AM 13 1203.50 XCSE
GENMAB A/S 09-Apr-2025 11:04:53 AM 42 1203.50 XCSE
GENMAB A/S 09-Apr-2025 11:04:53 AM 8 1203.50 XCSE
GENMAB A/S 09-Apr-2025 11:05:16 AM 58 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:05:16 AM 25 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:05:42 AM 85 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:06:37 AM 86 1203.00 CEUX
GENMAB A/S 09-Apr-2025 11:06:38 AM 88 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:07:42 AM 18 1202.00 CEUX
GENMAB A/S 09-Apr-2025 11:08:30 AM 25 1202.00 TQEX
GENMAB A/S 09-Apr-2025 11:08:30 AM 60 1202.00 CEUX
GENMAB A/S 09-Apr-2025 11:09:02 AM 46 1202.00 XCSE
GENMAB A/S 09-Apr-2025 11:09:02 AM 64 1202.00 XCSE
GENMAB A/S 09-Apr-2025 11:09:18 AM 23 1201.50 XCSE
GENMAB A/S 09-Apr-2025 11:09:18 AM 63 1201.50 XCSE
GENMAB A/S 09-Apr-2025 11:09:57 AM 2 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:09:57 AM 79 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:10:09 AM 19 1203.00 XCSE
GENMAB A/S 09-Apr-2025 11:10:09 AM 68 1203.00 XCSE
GENMAB A/S 09-Apr-2025 11:10:09 AM 78 1203.00 CEUX
GENMAB A/S 09-Apr-2025 11:10:09 AM 10 1203.00 CEUX
GENMAB A/S 09-Apr-2025 11:11:51 AM 81 1203.50 CEUX
GENMAB A/S 09-Apr-2025 11:11:52 AM 76 1203.00 XCSE
GENMAB A/S 09-Apr-2025 11:11:54 AM 24 1203.00 TQEX

143

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 11:12:13 AM 32 1202.00 XCSE
GENMAB A/S 09-Apr-2025 11:12:13 AM 52 1202.00 XCSE
GENMAB A/S 09-Apr-2025 11:12:13 AM 87 1202.00 CEUX
GENMAB A/S 09-Apr-2025 11:12:16 AM 64 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:12:25 AM 36 1202.00 CEUX
GENMAB A/S 09-Apr-2025 11:12:53 AM 42 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:12:53 AM 20 1202.50 AQEU
GENMAB A/S 09-Apr-2025 11:12:53 AM 7 1202.50 AQEU
GENMAB A/S 09-Apr-2025 11:12:53 AM 58 1203.00 CEUX
GENMAB A/S 09-Apr-2025 11:12:58 AM 53 1202.00 CEUX
GENMAB A/S 09-Apr-2025 11:13:04 AM 35 1201.50 XCSE
GENMAB A/S 09-Apr-2025 11:13:06 AM 34 1201.00 CEUX
GENMAB A/S 09-Apr-2025 11:13:07 AM 41 1201.00 CEUX
GENMAB A/S 09-Apr-2025 11:15:05 AM 77 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:15:05 AM 24 1202.50 TQEX
GENMAB A/S 09-Apr-2025 11:15:05 AM 31 1202.50 CEUX
GENMAB A/S 09-Apr-2025 11:15:49 AM 32 1202.50 CEUX
GENMAB A/S 09-Apr-2025 11:15:50 AM 30 1202.50 CEUX
GENMAB A/S 09-Apr-2025 11:16:03 AM 27 1202.00 AQEU
GENMAB A/S 09-Apr-2025 11:17:26 AM 30 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:17:26 AM 51 1202.50 XCSE
GENMAB A/S 09-Apr-2025 11:18:05 AM 24 1202.00 CEUX
GENMAB A/S 09-Apr-2025 11:18:51 AM 74 1201.50 XCSE
GENMAB A/S 09-Apr-2025 11:18:53 AM 24 1201.00 TQEX
GENMAB A/S 09-Apr-2025 11:19:36 AM 44 1201.50 CEUX
GENMAB A/S 09-Apr-2025 11:19:57 AM 24 1200.50 XCSE
GENMAB A/S 09-Apr-2025 11:19:57 AM 60 1200.50 XCSE
GENMAB A/S 09-Apr-2025 11:19:57 AM 28 1200.50 CEUX
GENMAB A/S 09-Apr-2025 11:20:53 AM 24 1201.00 TQEX
GENMAB A/S 09-Apr-2025 11:21:26 AM 84 1201.00 XCSE
GENMAB A/S 09-Apr-2025 11:21:53 AM 88 1200.00 XCSE
GENMAB A/S 09-Apr-2025 11:21:53 AM 30 1200.00 CEUX
GENMAB A/S 09-Apr-2025 11:22:45 AM 45 1201.00 CEUX
GENMAB A/S 09-Apr-2025 11:23:27 AM 81 1200.50 XCSE
GENMAB A/S 09-Apr-2025 11:23:34 AM 39 1200.00 CEUX
GENMAB A/S 09-Apr-2025 11:25:00 AM 75 1199.00 XCSE
GENMAB A/S 09-Apr-2025 11:25:00 AM 29 1199.00 CEUX
GENMAB A/S 09-Apr-2025 11:25:16 AM 24 1198.50 TQEX
GENMAB A/S 09-Apr-2025 11:25:35 AM 6 1198.00 XCSE
GENMAB A/S 09-Apr-2025 11:25:35 AM 76 1198.00 XCSE
GENMAB A/S 09-Apr-2025 11:25:56 AM 28 1197.50 CEUX
GENMAB A/S 09-Apr-2025 11:28:30 AM 53 1198.50 CEUX
GENMAB A/S 09-Apr-2025 11:28:36 AM 81 1198.00 XCSE

144

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 11:28:39 AM 24 1197.50 TQEX
GENMAB A/S 09-Apr-2025 11:28:39 AM 9 1197.50 CEUX
GENMAB A/S 09-Apr-2025 11:28:39 AM 41 1197.50 CEUX
GENMAB A/S 09-Apr-2025 11:29:13 AM 78 1197.00 XCSE
GENMAB A/S 09-Apr-2025 11:29:14 AM 25 1196.50 CEUX
GENMAB A/S 09-Apr-2025 11:29:33 AM 85 1196.50 XCSE
GENMAB A/S 09-Apr-2025 11:29:33 AM 29 1196.50 CEUX
GENMAB A/S 09-Apr-2025 11:33:06 AM 13 1197.50 XCSE
GENMAB A/S 09-Apr-2025 11:33:06 AM 36 1197.50 XCSE
GENMAB A/S 09-Apr-2025 11:33:09 AM 1 1197.50 XCSE
GENMAB A/S 09-Apr-2025 11:33:25 AM 87 1197.50 XCSE
GENMAB A/S 09-Apr-2025 11:33:25 AM 70 1197.50 CEUX
GENMAB A/S 09-Apr-2025 11:33:26 AM 81 1196.50 XCSE
GENMAB A/S 09-Apr-2025 11:33:26 AM 29 1196.50 CEUX
GENMAB A/S 09-Apr-2025 11:33:39 AM 24 1196.00 TQEX
GENMAB A/S 09-Apr-2025 11:33:48 AM 82 1195.50 XCSE
GENMAB A/S 09-Apr-2025 11:35:06 AM 45 1195.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:12 AM 84 1194.50 XCSE
GENMAB A/S 09-Apr-2025 11:35:14 AM 15 1194.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:14 AM 8 1194.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:14 AM 2 1194.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:41 AM 42 1194.00 XCSE
GENMAB A/S 09-Apr-2025 11:35:41 AM 13 1194.00 XCSE
GENMAB A/S 09-Apr-2025 11:35:41 AM 33 1194.00 XCSE
GENMAB A/S 09-Apr-2025 11:35:41 AM 17 1193.00 XCSE
GENMAB A/S 09-Apr-2025 11:35:41 AM 23 1193.00 XCSE
GENMAB A/S 09-Apr-2025 11:35:41 AM 47 1193.00 XCSE
GENMAB A/S 09-Apr-2025 11:35:41 AM 24 1193.50 TQEX
GENMAB A/S 09-Apr-2025 11:35:41 AM 24 1193.50 AQEU
GENMAB A/S 09-Apr-2025 11:35:41 AM 24 1193.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:41 AM 9 1193.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:41 AM 17 1193.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:45 AM 1 1192.00 CEUX
GENMAB A/S 09-Apr-2025 11:35:57 AM 29 1192.00 CEUX
GENMAB A/S 09-Apr-2025 11:37:43 AM 67 1191.50 XCSE
GENMAB A/S 09-Apr-2025 11:38:03 AM 25 1190.50 CEUX
GENMAB A/S 09-Apr-2025 11:38:05 AM 36 1190.00 XCSE
GENMAB A/S 09-Apr-2025 11:38:43 AM 31 1190.50 CEUX
GENMAB A/S 09-Apr-2025 11:39:06 AM 13 1189.50 XCSE
GENMAB A/S 09-Apr-2025 11:39:06 AM 57 1189.50 XCSE
GENMAB A/S 09-Apr-2025 11:39:22 AM 33 1190.50 CEUX
GENMAB A/S 09-Apr-2025 11:39:30 AM 24 1190.00 TQEX
GENMAB A/S 09-Apr-2025 11:42:25 AM 86 1190.50 XCSE

145

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 11:42:25 AM 12 1190.50 CEUX
GENMAB A/S 09-Apr-2025 11:42:25 AM 40 1190.50 CEUX
GENMAB A/S 09-Apr-2025 11:42:59 AM 56 1189.50 XCSE
GENMAB A/S 09-Apr-2025 11:42:59 AM 25 1189.50 CEUX
GENMAB A/S 09-Apr-2025 11:43:45 AM 38 1190.00 CEUX
GENMAB A/S 09-Apr-2025 11:44:48 AM 86 1189.50 XCSE
GENMAB A/S 09-Apr-2025 11:45:41 AM 14 1188.50 CEUX
GENMAB A/S 09-Apr-2025 11:45:43 AM 25 1188.50 XCSE
GENMAB A/S 09-Apr-2025 11:45:43 AM 24 1188.50 TQEX
GENMAB A/S 09-Apr-2025 11:45:43 AM 11 1188.50 CEUX
GENMAB A/S 09-Apr-2025 11:45:51 AM 81 1187.50 XCSE
GENMAB A/S 09-Apr-2025 11:45:51 AM 35 1187.00 CEUX
GENMAB A/S 09-Apr-2025 11:46:56 AM 85 1187.50 XCSE
GENMAB A/S 09-Apr-2025 11:46:56 AM 39 1188.00 CEUX
GENMAB A/S 09-Apr-2025 11:47:05 AM 34 1187.00 CEUX
GENMAB A/S 09-Apr-2025 11:49:45 AM 38 1188.00 AQEU
GENMAB A/S 09-Apr-2025 11:49:45 AM 43 1188.00 CEUX
GENMAB A/S 09-Apr-2025 11:49:53 AM 87 1187.50 XCSE
GENMAB A/S 09-Apr-2025 11:49:53 AM 24 1187.50 TQEX
GENMAB A/S 09-Apr-2025 11:50:35 AM 87 1186.50 XCSE
GENMAB A/S 09-Apr-2025 11:50:35 AM 27 1187.00 CEUX
GENMAB A/S 09-Apr-2025 11:51:48 AM 18 1187.50 TQEX
GENMAB A/S 09-Apr-2025 11:51:48 AM 44 1187.50 CEUX
GENMAB A/S 09-Apr-2025 11:52:59 AM 6 1187.50 TQEX
GENMAB A/S 09-Apr-2025 11:53:01 AM 86 1186.50 XCSE
GENMAB A/S 09-Apr-2025 11:53:01 AM 24 1186.50 AQEU
GENMAB A/S 09-Apr-2025 11:53:01 AM 35 1186.50 CEUX
GENMAB A/S 09-Apr-2025 11:55:56 AM 14 1186.50 XCSE
GENMAB A/S 09-Apr-2025 11:55:56 AM 18 1186.50 XCSE
GENMAB A/S 09-Apr-2025 11:56:10 AM 88 1185.50 XCSE
GENMAB A/S 09-Apr-2025 11:56:10 AM 32 1186.00 XCSE
GENMAB A/S 09-Apr-2025 11:56:10 AM 34 1185.50 CEUX
GENMAB A/S 09-Apr-2025 11:58:33 AM 42 1188.50 XCSE
GENMAB A/S 09-Apr-2025 11:58:33 AM 5 1188.50 XCSE
GENMAB A/S 09-Apr-2025 11:58:33 AM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 11:58:33 AM 20 1188.50 XCSE
GENMAB A/S 09-Apr-2025 11:59:42 AM 43 1189.00 XCSE
GENMAB A/S 09-Apr-2025 11:59:42 AM 42 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:00:19 PM 88 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:00:52 PM 85 1189.50 CEUX
GENMAB A/S 09-Apr-2025 12:00:52 PM 3 1189.50 CEUX
GENMAB A/S 09-Apr-2025 12:02:23 PM 84 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:02:23 PM 27 1189.50 XCSE

146

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 12:02:23 PM 31 1189.00 TQEX
GENMAB A/S 09-Apr-2025 12:02:23 PM 24 1189.00 AQEU
GENMAB A/S 09-Apr-2025 12:03:37 PM 85 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:03:37 PM 31 1189.00 TQEX
GENMAB A/S 09-Apr-2025 12:03:37 PM 40 1189.00 AQEU
GENMAB A/S 09-Apr-2025 12:04:54 PM 85 1188.50 CEUX
GENMAB A/S 09-Apr-2025 12:05:12 PM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 12:05:12 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 12:05:12 PM 2 1188.50 XCSE
GENMAB A/S 09-Apr-2025 12:05:14 PM 84 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:05:14 PM 34 1188.00 TQEX
GENMAB A/S 09-Apr-2025 12:06:04 PM 71 1187.50 CEUX
GENMAB A/S 09-Apr-2025 12:07:32 PM 4 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:07:32 PM 2 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:07:32 PM 47 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:07:32 PM 4 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:08:32 PM 87 1191.00 CEUX
GENMAB A/S 09-Apr-2025 12:09:03 PM 42 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:09:03 PM 13 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:09:03 PM 1 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:09:03 PM 13 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:09:03 PM 36 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:10:25 PM 88 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:10:25 PM 82 1192.00 CEUX
GENMAB A/S 09-Apr-2025 12:11:49 PM 86 1192.50 XCSE
GENMAB A/S 09-Apr-2025 12:13:25 PM 6 1193.50 XCSE
GENMAB A/S 09-Apr-2025 12:13:25 PM 17 1193.50 XCSE
GENMAB A/S 09-Apr-2025 12:13:25 PM 24 1193.50 TQEX
GENMAB A/S 09-Apr-2025 12:13:44 PM 35 1194.00 XCSE
GENMAB A/S 09-Apr-2025 12:14:07 PM 81 1194.00 XCSE
GENMAB A/S 09-Apr-2025 12:14:07 PM 83 1194.00 CEUX
GENMAB A/S 09-Apr-2025 12:15:04 PM 83 1194.50 XCSE
GENMAB A/S 09-Apr-2025 12:15:04 PM 36 1195.00 XCSE
GENMAB A/S 09-Apr-2025 12:15:04 PM 76 1194.50 CEUX
GENMAB A/S 09-Apr-2025 12:15:35 PM 10 1194.00 AQEU
GENMAB A/S 09-Apr-2025 12:15:35 PM 17 1194.00 AQEU
GENMAB A/S 09-Apr-2025 12:19:26 PM 6 1195.50 TQEX
GENMAB A/S 09-Apr-2025 12:19:26 PM 28 1195.50 TQEX
GENMAB A/S 09-Apr-2025 12:19:26 PM 88 1195.50 CEUX
GENMAB A/S 09-Apr-2025 12:19:27 PM 14 1195.50 XCSE
GENMAB A/S 09-Apr-2025 12:19:27 PM 15 1195.50 XCSE
GENMAB A/S 09-Apr-2025 12:19:47 PM 82 1195.00 XCSE
GENMAB A/S 09-Apr-2025 12:19:47 PM 50 1195.00 XCSE

147

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 12:19:47 PM 15 1195.00 XCSE
GENMAB A/S 09-Apr-2025 12:19:47 PM 45 1195.50 XCSE
GENMAB A/S 09-Apr-2025 12:19:51 PM 24 1194.50 TQEX
GENMAB A/S 09-Apr-2025 12:20:03 PM 82 1194.00 XCSE
GENMAB A/S 09-Apr-2025 12:20:03 PM 77 1194.00 CEUX
GENMAB A/S 09-Apr-2025 12:20:15 PM 84 1193.00 XCSE
GENMAB A/S 09-Apr-2025 12:20:15 PM 81 1193.00 CEUX
GENMAB A/S 09-Apr-2025 12:20:36 PM 6 1192.00 CEUX
GENMAB A/S 09-Apr-2025 12:20:36 PM 37 1192.00 CEUX
GENMAB A/S 09-Apr-2025 12:21:49 PM 82 1191.50 XCSE
GENMAB A/S 09-Apr-2025 12:21:49 PM 24 1191.50 AQEU
GENMAB A/S 09-Apr-2025 12:21:50 PM 24 1190.50 CEUX
GENMAB A/S 09-Apr-2025 12:22:43 PM 82 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:23:31 PM 27 1190.50 CEUX
GENMAB A/S 09-Apr-2025 12:25:22 PM 81 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:25:45 PM 85 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:25:45 PM 44 1190.00 CEUX
GENMAB A/S 09-Apr-2025 12:25:48 PM 88 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:25:48 PM 25 1189.00 TQEX
GENMAB A/S 09-Apr-2025 12:25:48 PM 17 1189.00 CEUX
GENMAB A/S 09-Apr-2025 12:25:48 PM 8 1189.00 CEUX
GENMAB A/S 09-Apr-2025 12:27:28 PM 3 1192.00 CEUX
GENMAB A/S 09-Apr-2025 12:27:32 PM 36 1192.00 CEUX
GENMAB A/S 09-Apr-2025 12:28:38 PM 3 1191.00 XCSE
GENMAB A/S 09-Apr-2025 12:29:17 PM 66 1191.00 XCSE
GENMAB A/S 09-Apr-2025 12:29:17 PM 25 1191.00 CEUX
GENMAB A/S 09-Apr-2025 12:30:06 PM 5 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:30:29 PM 20 1191.00 CEUX
GENMAB A/S 09-Apr-2025 12:30:44 PM 60 1191.00 XCSE
GENMAB A/S 09-Apr-2025 12:30:44 PM 26 1191.00 XCSE
GENMAB A/S 09-Apr-2025 12:30:44 PM 25 1191.00 CEUX
GENMAB A/S 09-Apr-2025 12:30:46 PM 32 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:30:46 PM 28 1190.50 TQEX
GENMAB A/S 09-Apr-2025 12:30:46 PM 33 1190.00 CEUX
GENMAB A/S 09-Apr-2025 12:30:48 PM 4 1189.50 AQEU
GENMAB A/S 09-Apr-2025 12:30:48 PM 1 1189.50 AQEU
GENMAB A/S 09-Apr-2025 12:30:48 PM 24 1189.50 AQEU
GENMAB A/S 09-Apr-2025 12:30:50 PM 34 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:30:50 PM 33 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:32:19 PM 26 1188.50 CEUX
GENMAB A/S 09-Apr-2025 12:33:25 PM 37 1188.00 CEUX
GENMAB A/S 09-Apr-2025 12:33:27 PM 84 1187.50 XCSE
GENMAB A/S 09-Apr-2025 12:33:27 PM 24 1187.50 AQEU

148

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 12:33:30 PM 24 1187.00 CEUX
GENMAB A/S 09-Apr-2025 12:33:41 PM 2 1186.50 TQEX
GENMAB A/S 09-Apr-2025 12:33:41 PM 1 1187.00 CEUX
GENMAB A/S 09-Apr-2025 12:33:42 PM 1 1186.50 TQEX
GENMAB A/S 09-Apr-2025 12:33:42 PM 25 1186.50 TQEX
GENMAB A/S 09-Apr-2025 12:33:48 PM 65 1186.00 XCSE
GENMAB A/S 09-Apr-2025 12:33:49 PM 11 1185.50 CEUX
GENMAB A/S 09-Apr-2025 12:33:49 PM 10 1185.50 CEUX
GENMAB A/S 09-Apr-2025 12:35:27 PM 3 1188.50 CEUX
GENMAB A/S 09-Apr-2025 12:35:42 PM 84 1188.50 XCSE
GENMAB A/S 09-Apr-2025 12:35:42 PM 21 1188.50 CEUX
GENMAB A/S 09-Apr-2025 12:35:52 PM 24 1187.50 CEUX
GENMAB A/S 09-Apr-2025 12:35:58 PM 25 1187.00 XCSE
GENMAB A/S 09-Apr-2025 12:35:58 PM 54 1187.00 XCSE
GENMAB A/S 09-Apr-2025 12:36:46 PM 24 1187.00 CEUX
GENMAB A/S 09-Apr-2025 12:37:26 PM 72 1187.00 XCSE
GENMAB A/S 09-Apr-2025 12:38:44 PM 24 1186.50 CEUX
GENMAB A/S 09-Apr-2025 12:38:45 PM 7 1186.00 XCSE
GENMAB A/S 09-Apr-2025 12:38:45 PM 67 1186.00 XCSE
GENMAB A/S 09-Apr-2025 12:39:42 PM 59 1187.00 XCSE
GENMAB A/S 09-Apr-2025 12:40:26 PM 25 1188.50 TQEX
GENMAB A/S 09-Apr-2025 12:40:26 PM 33 1188.50 CEUX
GENMAB A/S 09-Apr-2025 12:41:45 PM 30 1188.50 AQEU
GENMAB A/S 09-Apr-2025 12:42:10 PM 42 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:42:17 PM 36 1187.50 CEUX
GENMAB A/S 09-Apr-2025 12:44:51 PM 24 1189.00 TQEX
GENMAB A/S 09-Apr-2025 12:44:51 PM 47 1189.00 CEUX
GENMAB A/S 09-Apr-2025 12:45:48 PM 82 1189.00 XCSE
GENMAB A/S 09-Apr-2025 12:46:42 PM 40 1188.50 CEUX
GENMAB A/S 09-Apr-2025 12:47:39 PM 87 1188.00 XCSE
GENMAB A/S 09-Apr-2025 12:51:35 PM 26 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:51:52 PM 3 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:51:52 PM 26 1190.00 XCSE
GENMAB A/S 09-Apr-2025 12:52:24 PM 3 1190.50 XCSE
GENMAB A/S 09-Apr-2025 12:52:52 PM 79 1191.00 XCSE
GENMAB A/S 09-Apr-2025 12:54:10 PM 83 1191.50 CEUX
GENMAB A/S 09-Apr-2025 12:54:10 PM 1 1191.50 CEUX
GENMAB A/S 09-Apr-2025 12:55:38 PM 35 1192.50 XCSE
GENMAB A/S 09-Apr-2025 12:55:38 PM 47 1192.50 XCSE
GENMAB A/S 09-Apr-2025 12:55:38 PM 30 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:55:38 PM 26 1192.50 TQEX
GENMAB A/S 09-Apr-2025 12:55:38 PM 88 1192.50 CEUX
GENMAB A/S 09-Apr-2025 12:56:46 PM 83 1194.00 XCSE

149

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 12:57:13 PM 19 1194.00 XCSE
GENMAB A/S 09-Apr-2025 12:57:13 PM 64 1194.00 XCSE
GENMAB A/S 09-Apr-2025 12:57:13 PM 73 1193.50 CEUX
GENMAB A/S 09-Apr-2025 12:57:22 PM 87 1193.00 XCSE
GENMAB A/S 09-Apr-2025 12:57:22 PM 24 1193.50 TQEX
GENMAB A/S 09-Apr-2025 12:57:22 PM 24 1192.50 TQEX
GENMAB A/S 09-Apr-2025 12:57:22 PM 29 1193.50 AQEU
GENMAB A/S 09-Apr-2025 12:57:22 PM 59 1192.50 CEUX
GENMAB A/S 09-Apr-2025 12:58:04 PM 28 1193.00 XCSE
GENMAB A/S 09-Apr-2025 12:58:04 PM 6 1193.00 XCSE
GENMAB A/S 09-Apr-2025 12:58:04 PM 54 1193.00 XCSE
GENMAB A/S 09-Apr-2025 12:58:47 PM 24 1192.50 CEUX
GENMAB A/S 09-Apr-2025 12:58:51 PM 51 1192.00 XCSE
GENMAB A/S 09-Apr-2025 12:59:49 PM 20 1191.50 CEUX
GENMAB A/S 09-Apr-2025 12:59:50 PM 60 1191.50 CEUX
GENMAB A/S 09-Apr-2025 12:59:51 PM 86 1191.00 XCSE
GENMAB A/S 09-Apr-2025 12:59:52 PM 25 1190.50 CEUX
GENMAB A/S 09-Apr-2025 12:59:53 PM 79 1189.50 XCSE
GENMAB A/S 09-Apr-2025 12:59:53 PM 79 1188.50 XCSE
GENMAB A/S 09-Apr-2025 12:59:53 PM 25 1189.50 CEUX
GENMAB A/S 09-Apr-2025 12:59:54 PM 10 1187.00 XCSE
GENMAB A/S 09-Apr-2025 12:59:55 PM 21 1187.00 XCSE
GENMAB A/S 09-Apr-2025 13:00:00 PM 24 1186.00 AQEU
GENMAB A/S 09-Apr-2025 13:00:18 PM 32 1182.00 XCSE
GENMAB A/S 09-Apr-2025 13:00:34 PM 26 1180.00 AQEU
GENMAB A/S 09-Apr-2025 13:00:47 PM 29 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:01:00 PM 27 1178.50 CEUX
GENMAB A/S 09-Apr-2025 13:01:31 PM 3 1180.00 TQEX
GENMAB A/S 09-Apr-2025 13:01:31 PM 23 1180.00 TQEX
GENMAB A/S 09-Apr-2025 13:02:03 PM 33 1181.00 XCSE
GENMAB A/S 09-Apr-2025 13:02:04 PM 26 1180.00 XCSE
GENMAB A/S 09-Apr-2025 13:02:40 PM 29 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:02:40 PM 25 1179.00 CEUX
GENMAB A/S 09-Apr-2025 13:03:32 PM 24 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:03:39 PM 9 1177.50 CEUX
GENMAB A/S 09-Apr-2025 13:03:39 PM 15 1177.50 CEUX
GENMAB A/S 09-Apr-2025 13:04:17 PM 30 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:04:27 PM 24 1177.00 XCSE
GENMAB A/S 09-Apr-2025 13:04:39 PM 14 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:04:39 PM 17 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:05:06 PM 9 1177.50 CEUX
GENMAB A/S 09-Apr-2025 13:05:06 PM 15 1177.50 CEUX
GENMAB A/S 09-Apr-2025 13:05:25 PM 25 1179.00 XCSE

150

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 13:05:48 PM 30 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:06:00 PM 28 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:06:00 PM 24 1178.50 CEUX
GENMAB A/S 09-Apr-2025 13:06:37 PM 7 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:06:38 PM 10 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:06:38 PM 26 1179.00 AQEU
GENMAB A/S 09-Apr-2025 13:06:52 PM 8 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:07:15 PM 27 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:07:27 PM 14 1178.50 CEUX
GENMAB A/S 09-Apr-2025 13:07:27 PM 10 1178.50 CEUX
GENMAB A/S 09-Apr-2025 13:08:03 PM 29 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:08:31 PM 24 1177.50 CEUX
GENMAB A/S 09-Apr-2025 13:08:34 PM 25 1177.00 XCSE
GENMAB A/S 09-Apr-2025 13:08:34 PM 24 1176.50 CEUX
GENMAB A/S 09-Apr-2025 13:08:35 PM 25 1176.00 XCSE
GENMAB A/S 09-Apr-2025 13:08:44 PM 24 1175.50 CEUX
GENMAB A/S 09-Apr-2025 13:08:48 PM 26 1175.00 XCSE
GENMAB A/S 09-Apr-2025 13:09:40 PM 27 1176.00 AQEU
GENMAB A/S 09-Apr-2025 13:09:42 PM 24 1175.50 CEUX
GENMAB A/S 09-Apr-2025 13:11:13 PM 48 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:12:39 PM 61 1180.50 XCSE
GENMAB A/S 09-Apr-2025 13:13:02 PM 25 1180.50 AQEU
GENMAB A/S 09-Apr-2025 13:13:06 PM 24 1180.00 TQEX
GENMAB A/S 09-Apr-2025 13:13:46 PM 65 1179.50 XCSE
GENMAB A/S 09-Apr-2025 13:13:46 PM 36 1179.50 CEUX
GENMAB A/S 09-Apr-2025 13:14:11 PM 59 1178.50 XCSE
GENMAB A/S 09-Apr-2025 13:14:11 PM 42 1178.50 CEUX
GENMAB A/S 09-Apr-2025 13:15:47 PM 20 1181.50 XCSE
GENMAB A/S 09-Apr-2025 13:15:47 PM 49 1181.50 XCSE
GENMAB A/S 09-Apr-2025 13:15:58 PM 24 1181.00 TQEX
GENMAB A/S 09-Apr-2025 13:16:52 PM 59 1180.00 XCSE
GENMAB A/S 09-Apr-2025 13:16:52 PM 46 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:18:17 PM 34 1178.50 XCSE
GENMAB A/S 09-Apr-2025 13:18:17 PM 40 1178.50 CEUX
GENMAB A/S 09-Apr-2025 13:19:44 PM 82 1181.00 XCSE
GENMAB A/S 09-Apr-2025 13:19:46 PM 24 1181.00 TQEX
GENMAB A/S 09-Apr-2025 13:19:51 PM 81 1180.00 XCSE
GENMAB A/S 09-Apr-2025 13:19:51 PM 36 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:19:51 PM 27 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:19:55 PM 24 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:19:55 PM 55 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:21:04 PM 28 1178.50 XCSE
GENMAB A/S 09-Apr-2025 13:21:04 PM 53 1178.50 CEUX

151

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 13:21:17 PM 9 1177.50 XCSE
GENMAB A/S 09-Apr-2025 13:23:41 PM 24 1178.00 TQEX
GENMAB A/S 09-Apr-2025 13:23:43 PM 30 1177.50 XCSE
GENMAB A/S 09-Apr-2025 13:23:43 PM 32 1177.50 CEUX
GENMAB A/S 09-Apr-2025 13:25:04 PM 87 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:26:53 PM 81 1180.00 XCSE
GENMAB A/S 09-Apr-2025 13:26:53 PM 66 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:27:20 PM 54 1179.00 XCSE
GENMAB A/S 09-Apr-2025 13:27:20 PM 75 1179.00 CEUX
GENMAB A/S 09-Apr-2025 13:27:21 PM 7 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:27:21 PM 24 1178.50 TQEX
GENMAB A/S 09-Apr-2025 13:27:37 PM 24 1178.50 AQEU
GENMAB A/S 09-Apr-2025 13:29:55 PM 24 1178.00 CEUX
GENMAB A/S 09-Apr-2025 13:30:29 PM 71 1178.00 XCSE
GENMAB A/S 09-Apr-2025 13:30:29 PM 55 1178.00 CEUX
GENMAB A/S 09-Apr-2025 13:32:42 PM 70 1176.50 XCSE
GENMAB A/S 09-Apr-2025 13:32:42 PM 24 1176.50 TQEX
GENMAB A/S 09-Apr-2025 13:32:42 PM 11 1176.50 CEUX
GENMAB A/S 09-Apr-2025 13:32:42 PM 15 1176.50 CEUX
GENMAB A/S 09-Apr-2025 13:32:44 PM 25 1175.50 CEUX
GENMAB A/S 09-Apr-2025 13:32:55 PM 42 1175.00 XCSE
GENMAB A/S 09-Apr-2025 13:33:04 PM 39 1174.50 CEUX
GENMAB A/S 09-Apr-2025 13:33:53 PM 86 1174.00 XCSE
GENMAB A/S 09-Apr-2025 13:34:49 PM 51 1174.50 CEUX
GENMAB A/S 09-Apr-2025 13:35:10 PM 86 1174.00 XCSE
GENMAB A/S 09-Apr-2025 13:36:01 PM 88 1174.50 XCSE
GENMAB A/S 09-Apr-2025 13:36:01 PM 24 1174.50 TQEX
GENMAB A/S 09-Apr-2025 13:39:40 PM 24 1176.00 TQEX
GENMAB A/S 09-Apr-2025 13:39:55 PM 88 1175.50 XCSE
GENMAB A/S 09-Apr-2025 13:39:55 PM 60 1175.50 CEUX
GENMAB A/S 09-Apr-2025 13:40:06 PM 69 1174.50 XCSE
GENMAB A/S 09-Apr-2025 13:40:06 PM 57 1174.50 CEUX
GENMAB A/S 09-Apr-2025 13:40:33 PM 20 1177.00 XCSE
GENMAB A/S 09-Apr-2025 13:40:33 PM 65 1177.00 XCSE
GENMAB A/S 09-Apr-2025 13:40:33 PM 24 1177.00 AQEU
GENMAB A/S 09-Apr-2025 13:40:33 PM 52 1177.00 CEUX
GENMAB A/S 09-Apr-2025 13:41:39 PM 44 1176.50 CEUX
GENMAB A/S 09-Apr-2025 13:41:39 PM 4 1176.50 CEUX
GENMAB A/S 09-Apr-2025 13:42:41 PM 26 1176.50 CEUX
GENMAB A/S 09-Apr-2025 13:42:43 PM 24 1177.00 CEUX
GENMAB A/S 09-Apr-2025 13:42:43 PM 1 1177.00 CEUX
GENMAB A/S 09-Apr-2025 13:43:26 PM 83 1182.50 XCSE
GENMAB A/S 09-Apr-2025 13:43:44 PM 24 1182.50 TQEX

152

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 13:44:01 PM 85 1182.50 XCSE
GENMAB A/S 09-Apr-2025 13:44:20 PM 85 1181.50 XCSE
GENMAB A/S 09-Apr-2025 13:44:20 PM 39 1182.00 CEUX
GENMAB A/S 09-Apr-2025 13:44:23 PM 26 1181.00 CEUX
GENMAB A/S 09-Apr-2025 13:44:30 PM 40 1180.50 XCSE
GENMAB A/S 09-Apr-2025 13:44:30 PM 26 1181.00 CEUX
GENMAB A/S 09-Apr-2025 13:44:40 PM 5 1180.50 XCSE
GENMAB A/S 09-Apr-2025 13:44:40 PM 40 1180.50 XCSE
GENMAB A/S 09-Apr-2025 13:45:01 PM 32 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:45:41 PM 30 1181.00 AQEU
GENMAB A/S 09-Apr-2025 13:45:41 PM 24 1181.00 CEUX
GENMAB A/S 09-Apr-2025 13:46:02 PM 52 1180.00 XCSE
GENMAB A/S 09-Apr-2025 13:46:02 PM 22 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:46:02 PM 3 1180.00 CEUX
GENMAB A/S 09-Apr-2025 13:47:17 PM 82 1182.50 XCSE
GENMAB A/S 09-Apr-2025 13:47:17 PM 18 1182.00 CEUX
GENMAB A/S 09-Apr-2025 13:47:18 PM 28 1182.00 AQEU
GENMAB A/S 09-Apr-2025 13:47:18 PM 6 1182.00 CEUX
GENMAB A/S 09-Apr-2025 13:47:35 PM 25 1182.00 AQEU
GENMAB A/S 09-Apr-2025 13:47:35 PM 15 1182.00 CEUX
GENMAB A/S 09-Apr-2025 13:47:35 PM 12 1182.00 CEUX
GENMAB A/S 09-Apr-2025 13:48:22 PM 24 1185.50 TQEX
GENMAB A/S 09-Apr-2025 13:48:22 PM 17 1185.50 CEUX
GENMAB A/S 09-Apr-2025 13:48:22 PM 16 1185.50 CEUX
GENMAB A/S 09-Apr-2025 13:48:23 PM 14 1185.50 XCSE
GENMAB A/S 09-Apr-2025 13:48:23 PM 69 1185.50 XCSE
GENMAB A/S 09-Apr-2025 13:49:17 PM 25 1187.00 CEUX
GENMAB A/S 09-Apr-2025 13:49:40 PM 67 1186.50 XCSE
GENMAB A/S 09-Apr-2025 13:49:56 PM 72 1185.50 XCSE
GENMAB A/S 09-Apr-2025 13:49:56 PM 24 1185.50 CEUX
GENMAB A/S 09-Apr-2025 13:50:19 PM 9 1185.50 XCSE
GENMAB A/S 09-Apr-2025 13:50:19 PM 31 1185.50 XCSE
GENMAB A/S 09-Apr-2025 13:50:43 PM 24 1187.50 TQEX
GENMAB A/S 09-Apr-2025 13:50:43 PM 29 1187.50 CEUX
GENMAB A/S 09-Apr-2025 13:50:44 PM 10 1187.00 XCSE
GENMAB A/S 09-Apr-2025 13:51:01 PM 55 1187.00 XCSE
GENMAB A/S 09-Apr-2025 13:51:31 PM 26 1187.00 CEUX
GENMAB A/S 09-Apr-2025 13:51:52 PM 25 1186.00 XCSE
GENMAB A/S 09-Apr-2025 13:51:52 PM 71 1185.50 XCSE
GENMAB A/S 09-Apr-2025 13:51:53 PM 26 1185.00 CEUX
GENMAB A/S 09-Apr-2025 13:52:40 PM 25 1185.00 CEUX
GENMAB A/S 09-Apr-2025 13:53:04 PM 82 1184.50 XCSE
GENMAB A/S 09-Apr-2025 13:54:02 PM 27 1184.50 CEUX

153

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 13:55:28 PM 20 1185.00 CEUX
GENMAB A/S 09-Apr-2025 13:55:28 PM 12 1185.00 CEUX
GENMAB A/S 09-Apr-2025 13:55:51 PM 74 1184.50 XCSE
GENMAB A/S 09-Apr-2025 13:55:51 PM 41 1183.50 XCSE
GENMAB A/S 09-Apr-2025 13:55:51 PM 24 1184.50 TQEX
GENMAB A/S 09-Apr-2025 13:55:51 PM 31 1184.50 AQEU
GENMAB A/S 09-Apr-2025 13:55:51 PM 24 1183.50 CEUX
GENMAB A/S 09-Apr-2025 13:55:52 PM 29 1182.50 XCSE
GENMAB A/S 09-Apr-2025 13:55:52 PM 25 1182.50 CEUX
GENMAB A/S 09-Apr-2025 13:56:16 PM 24 1182.50 CEUX
GENMAB A/S 09-Apr-2025 13:57:55 PM 37 1182.50 CEUX
GENMAB A/S 09-Apr-2025 13:58:32 PM 60 1182.50 XCSE
GENMAB A/S 09-Apr-2025 13:58:32 PM 22 1182.50 XCSE
GENMAB A/S 09-Apr-2025 13:58:32 PM 25 1182.50 AQEU
GENMAB A/S 09-Apr-2025 13:58:32 PM 29 1182.50 CEUX
GENMAB A/S 09-Apr-2025 13:59:42 PM 4 1182.00 TQEX
GENMAB A/S 09-Apr-2025 13:59:49 PM 38 1182.50 CEUX
GENMAB A/S 09-Apr-2025 13:59:55 PM 7 1182.00 TQEX
GENMAB A/S 09-Apr-2025 14:00:08 PM 7 1182.00 TQEX
GENMAB A/S 09-Apr-2025 14:00:08 PM 6 1182.00 TQEX
GENMAB A/S 09-Apr-2025 14:00:29 PM 10 1181.50 XCSE
GENMAB A/S 09-Apr-2025 14:00:29 PM 3 1181.50 XCSE
GENMAB A/S 09-Apr-2025 14:00:29 PM 68 1181.50 XCSE
GENMAB A/S 09-Apr-2025 14:00:29 PM 1 1181.50 CEUX
GENMAB A/S 09-Apr-2025 14:00:29 PM 23 1181.50 CEUX
GENMAB A/S 09-Apr-2025 14:00:35 PM 71 1180.50 XCSE
GENMAB A/S 09-Apr-2025 14:00:35 PM 24 1180.50 TQEX
GENMAB A/S 09-Apr-2025 14:00:35 PM 25 1180.50 CEUX
GENMAB A/S 09-Apr-2025 14:01:18 PM 83 1183.50 XCSE
GENMAB A/S 09-Apr-2025 14:01:18 PM 25 1184.00 AQEU
GENMAB A/S 09-Apr-2025 14:01:18 PM 25 1184.50 AQEU
GENMAB A/S 09-Apr-2025 14:01:18 PM 24 1183.50 CEUX
GENMAB A/S 09-Apr-2025 14:01:18 PM 30 1183.50 CEUX
GENMAB A/S 09-Apr-2025 14:01:44 PM 87 1182.50 XCSE
GENMAB A/S 09-Apr-2025 14:01:44 PM 36 1182.50 AQEU
GENMAB A/S 09-Apr-2025 14:01:44 PM 30 1182.00 CEUX
GENMAB A/S 09-Apr-2025 14:02:54 PM 83 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:02:54 PM 31 1183.00 CEUX
GENMAB A/S 09-Apr-2025 14:04:03 PM 85 1184.50 XCSE
GENMAB A/S 09-Apr-2025 14:04:03 PM 6 1185.00 TQEX
GENMAB A/S 09-Apr-2025 14:04:03 PM 18 1185.00 TQEX
GENMAB A/S 09-Apr-2025 14:04:03 PM 44 1184.50 AQEU
GENMAB A/S 09-Apr-2025 14:04:18 PM 25 1186.00 AQEU

154

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 14:04:18 PM 34 1186.00 CEUX
GENMAB A/S 09-Apr-2025 14:04:54 PM 16 1186.00 CEUX
GENMAB A/S 09-Apr-2025 14:05:09 PM 26 1187.00 AQEU
GENMAB A/S 09-Apr-2025 14:05:09 PM 20 1187.00 CEUX
GENMAB A/S 09-Apr-2025 14:05:09 PM 6 1187.00 CEUX
GENMAB A/S 09-Apr-2025 14:05:09 PM 2 1187.00 CEUX
GENMAB A/S 09-Apr-2025 14:05:10 PM 81 1186.50 XCSE
GENMAB A/S 09-Apr-2025 14:05:39 PM 8 1187.00 AQEU
GENMAB A/S 09-Apr-2025 14:05:39 PM 19 1187.00 AQEU
GENMAB A/S 09-Apr-2025 14:05:39 PM 27 1187.00 CEUX
GENMAB A/S 09-Apr-2025 14:05:51 PM 1 1186.50 XCSE
GENMAB A/S 09-Apr-2025 14:05:51 PM 82 1186.50 XCSE
GENMAB A/S 09-Apr-2025 14:06:00 PM 26 1186.00 AQEU
GENMAB A/S 09-Apr-2025 14:06:00 PM 9 1186.00 CEUX
GENMAB A/S 09-Apr-2025 14:06:27 PM 11 1186.00 TQEX
GENMAB A/S 09-Apr-2025 14:06:27 PM 13 1186.00 TQEX
GENMAB A/S 09-Apr-2025 14:07:51 PM 82 1185.50 XCSE
GENMAB A/S 09-Apr-2025 14:08:02 PM 26 1185.00 AQEU
GENMAB A/S 09-Apr-2025 14:09:28 PM 6 1186.50 XCSE
GENMAB A/S 09-Apr-2025 14:09:28 PM 78 1186.50 XCSE
GENMAB A/S 09-Apr-2025 14:09:28 PM 7 1186.50 AQEU
GENMAB A/S 09-Apr-2025 14:09:28 PM 7 1186.50 AQEU
GENMAB A/S 09-Apr-2025 14:09:28 PM 13 1186.50 AQEU
GENMAB A/S 09-Apr-2025 14:09:28 PM 71 1186.50 CEUX
GENMAB A/S 09-Apr-2025 14:09:29 PM 24 1186.00 TQEX
GENMAB A/S 09-Apr-2025 14:09:29 PM 6 1185.50 CEUX
GENMAB A/S 09-Apr-2025 14:09:29 PM 7 1185.50 CEUX
GENMAB A/S 09-Apr-2025 14:09:29 PM 1 1185.50 CEUX
GENMAB A/S 09-Apr-2025 14:10:10 PM 88 1185.50 XCSE
GENMAB A/S 09-Apr-2025 14:10:10 PM 33 1185.50 CEUX
GENMAB A/S 09-Apr-2025 14:10:28 PM 83 1184.50 XCSE
GENMAB A/S 09-Apr-2025 14:10:28 PM 36 1184.50 CEUX
GENMAB A/S 09-Apr-2025 14:12:25 PM 22 1185.00 TQEX
GENMAB A/S 09-Apr-2025 14:12:25 PM 2 1185.00 TQEX
GENMAB A/S 09-Apr-2025 14:13:50 PM 87 1184.50 XCSE
GENMAB A/S 09-Apr-2025 14:13:52 PM 24 1184.00 XCSE
GENMAB A/S 09-Apr-2025 14:13:52 PM 58 1184.00 CEUX
GENMAB A/S 09-Apr-2025 14:14:36 PM 4 1184.50 XCSE
GENMAB A/S 09-Apr-2025 14:14:36 PM 43 1184.50 XCSE
GENMAB A/S 09-Apr-2025 14:14:36 PM 40 1184.50 XCSE
GENMAB A/S 09-Apr-2025 14:16:23 PM 81 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:16:23 PM 43 1183.50 XCSE
GENMAB A/S 09-Apr-2025 14:16:23 PM 4 1183.50 XCSE

155

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 14:16:23 PM 14 1183.50 XCSE
GENMAB A/S 09-Apr-2025 14:16:23 PM 15 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:16:23 PM 42 1183.00 AQEU
GENMAB A/S 09-Apr-2025 14:16:23 PM 27 1183.00 CEUX
GENMAB A/S 09-Apr-2025 14:16:23 PM 20 1183.00 CEUX
GENMAB A/S 09-Apr-2025 14:16:30 PM 5 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:16:52 PM 65 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:16:55 PM 24 1182.50 TQEX
GENMAB A/S 09-Apr-2025 14:17:25 PM 84 1182.00 XCSE
GENMAB A/S 09-Apr-2025 14:17:25 PM 34 1182.00 CEUX
GENMAB A/S 09-Apr-2025 14:17:52 PM 81 1181.00 XCSE
GENMAB A/S 09-Apr-2025 14:18:26 PM 85 1181.50 CEUX
GENMAB A/S 09-Apr-2025 14:18:27 PM 86 1181.00 XCSE
GENMAB A/S 09-Apr-2025 14:18:27 PM 24 1181.00 TQEX
GENMAB A/S 09-Apr-2025 14:18:27 PM 58 1180.50 CEUX
GENMAB A/S 09-Apr-2025 14:18:41 PM 24 1180.50 AQEU
GENMAB A/S 09-Apr-2025 14:18:41 PM 42 1180.50 CEUX
GENMAB A/S 09-Apr-2025 14:18:58 PM 81 1180.00 XCSE
GENMAB A/S 09-Apr-2025 14:19:25 PM 79 1179.50 XCSE
GENMAB A/S 09-Apr-2025 14:20:04 PM 55 1179.00 CEUX
GENMAB A/S 09-Apr-2025 14:20:04 PM 29 1179.00 CEUX
GENMAB A/S 09-Apr-2025 14:20:31 PM 25 1179.00 CEUX
GENMAB A/S 09-Apr-2025 14:20:34 PM 82 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:20:42 PM 4 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:20:42 PM 25 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:21:23 PM 6 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:21:42 PM 84 1177.00 XCSE
GENMAB A/S 09-Apr-2025 14:21:42 PM 20 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:21:42 PM 4 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:22:03 PM 55 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:22:03 PM 24 1176.00 TQEX
GENMAB A/S 09-Apr-2025 14:22:03 PM 25 1175.50 CEUX
GENMAB A/S 09-Apr-2025 14:23:24 PM 39 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:24:07 PM 45 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:24:07 PM 1 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:24:44 PM 6 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:24:44 PM 51 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:25:13 PM 28 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:25:28 PM 24 1175.50 AQEU
GENMAB A/S 09-Apr-2025 14:25:28 PM 27 1175.50 CEUX
GENMAB A/S 09-Apr-2025 14:26:32 PM 36 1175.00 XCSE
GENMAB A/S 09-Apr-2025 14:26:32 PM 36 1175.00 XCSE
GENMAB A/S 09-Apr-2025 14:26:32 PM 24 1175.00 TQEX

156

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 14:26:47 PM 85 1174.00 XCSE
GENMAB A/S 09-Apr-2025 14:26:47 PM 25 1174.00 CEUX
GENMAB A/S 09-Apr-2025 14:27:38 PM 6 1175.00 TQEX
GENMAB A/S 09-Apr-2025 14:27:38 PM 18 1175.00 TQEX
GENMAB A/S 09-Apr-2025 14:27:39 PM 9 1174.50 CEUX
GENMAB A/S 09-Apr-2025 14:28:28 PM 87 1174.50 XCSE
GENMAB A/S 09-Apr-2025 14:28:28 PM 59 1174.50 CEUX
GENMAB A/S 09-Apr-2025 14:28:28 PM 2 1174.50 CEUX
GENMAB A/S 09-Apr-2025 14:28:30 PM 84 1173.50 XCSE
GENMAB A/S 09-Apr-2025 14:28:30 PM 65 1173.50 CEUX
GENMAB A/S 09-Apr-2025 14:28:32 PM 15 1173.50 CEUX
GENMAB A/S 09-Apr-2025 14:30:00 PM 87 1173.50 XCSE
GENMAB A/S 09-Apr-2025 14:30:00 PM 20 1173.50 CEUX
GENMAB A/S 09-Apr-2025 14:30:00 PM 19 1173.50 CEUX
GENMAB A/S 09-Apr-2025 14:30:38 PM 8 1176.00 AQEU
GENMAB A/S 09-Apr-2025 14:30:38 PM 2 1176.00 AQEU
GENMAB A/S 09-Apr-2025 14:30:38 PM 15 1176.00 AQEU
GENMAB A/S 09-Apr-2025 14:30:38 PM 49 1176.00 CEUX
GENMAB A/S 09-Apr-2025 14:31:05 PM 20 1175.50 XCSE
GENMAB A/S 09-Apr-2025 14:31:05 PM 65 1175.50 XCSE
GENMAB A/S 09-Apr-2025 14:31:05 PM 10 1175.50 TQEX
GENMAB A/S 09-Apr-2025 14:31:05 PM 14 1175.50 TQEX
GENMAB A/S 09-Apr-2025 14:31:09 PM 23 1175.00 CEUX
GENMAB A/S 09-Apr-2025 14:31:09 PM 11 1175.00 CEUX
GENMAB A/S 09-Apr-2025 14:31:09 PM 11 1175.00 CEUX
GENMAB A/S 09-Apr-2025 14:31:11 PM 8 1175.00 CEUX
GENMAB A/S 09-Apr-2025 14:31:25 PM 85 1174.50 XCSE
GENMAB A/S 09-Apr-2025 14:31:25 PM 1 1174.50 XCSE
GENMAB A/S 09-Apr-2025 14:31:54 PM 25 1175.00 CEUX
GENMAB A/S 09-Apr-2025 14:32:31 PM 24 1174.50 XCSE
GENMAB A/S 09-Apr-2025 14:32:59 PM 87 1175.00 XCSE
GENMAB A/S 09-Apr-2025 14:33:54 PM 54 1175.00 CEUX
GENMAB A/S 09-Apr-2025 14:34:19 PM 36 1176.00 CEUX
GENMAB A/S 09-Apr-2025 14:35:12 PM 8 1176.50 TQEX
GENMAB A/S 09-Apr-2025 14:35:12 PM 16 1176.50 TQEX
GENMAB A/S 09-Apr-2025 14:35:15 PM 26 1176.00 CEUX
GENMAB A/S 09-Apr-2025 14:35:17 PM 13 1176.00 CEUX
GENMAB A/S 09-Apr-2025 14:36:12 PM 42 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:36:12 PM 1 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:37:09 PM 5 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:37:09 PM 49 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:37:09 PM 30 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:37:09 PM 17 1176.50 CEUX

157

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 14:37:16 PM 20 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:37:24 PM 15 1176.00 TQEX
GENMAB A/S 09-Apr-2025 14:37:24 PM 2 1176.00 TQEX
GENMAB A/S 09-Apr-2025 14:38:23 PM 12 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:38:23 PM 43 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:38:23 PM 18 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:38:23 PM 13 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:38:23 PM 12 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:38:23 PM 15 1177.00 TQEX
GENMAB A/S 09-Apr-2025 14:38:23 PM 37 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:38:23 PM 6 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:38:27 PM 86 1177.00 XCSE
GENMAB A/S 09-Apr-2025 14:38:27 PM 25 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:39:46 PM 26 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:39:46 PM 1 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:39:46 PM 12 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:40:08 PM 30 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:40:29 PM 32 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:40:52 PM 12 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:40:52 PM 43 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:40:52 PM 12 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:42:03 PM 84 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:42:03 PM 88 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:42:03 PM 29 1178.50 TQEX
GENMAB A/S 09-Apr-2025 14:42:03 PM 4 1178.50 TQEX
GENMAB A/S 09-Apr-2025 14:42:03 PM 24 1178.50 AQEU
GENMAB A/S 09-Apr-2025 14:42:03 PM 49 1179.00 CEUX
GENMAB A/S 09-Apr-2025 14:42:03 PM 38 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:42:03 PM 25 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:43:00 PM 83 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:43:00 PM 2 1178.50 CEUX
GENMAB A/S 09-Apr-2025 14:43:00 PM 22 1178.50 CEUX
GENMAB A/S 09-Apr-2025 14:43:01 PM 25 1178.50 AQEU
GENMAB A/S 09-Apr-2025 14:43:05 PM 15 1178.00 TQEX
GENMAB A/S 09-Apr-2025 14:43:05 PM 11 1178.00 TQEX
GENMAB A/S 09-Apr-2025 14:43:05 PM 3 1178.00 TQEX
GENMAB A/S 09-Apr-2025 14:43:06 PM 84 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:43:34 PM 28 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:44:23 PM 88 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:44:40 PM 24 1176.00 CEUX
GENMAB A/S 09-Apr-2025 14:45:02 PM 74 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:45:02 PM 12 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:45:02 PM 24 1178.50 AQEU

158

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 14:45:30 PM 34 1179.00 CEUX
GENMAB A/S 09-Apr-2025 14:45:30 PM 2 1179.00 CEUX
GENMAB A/S 09-Apr-2025 14:45:33 PM 25 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:45:33 PM 62 1178.50 XCSE
GENMAB A/S 09-Apr-2025 14:45:33 PM 24 1178.50 AQEU
GENMAB A/S 09-Apr-2025 14:46:34 PM 20 1178.50 TQEX
GENMAB A/S 09-Apr-2025 14:47:04 PM 24 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:47:10 PM 67 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:47:10 PM 14 1177.50 XCSE
GENMAB A/S 09-Apr-2025 14:47:11 PM 20 1177.00 AQEU
GENMAB A/S 09-Apr-2025 14:47:11 PM 20 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:47:14 PM 6 1177.00 AQEU
GENMAB A/S 09-Apr-2025 14:47:14 PM 11 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:47:42 PM 26 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:47:42 PM 15 1177.00 CEUX
GENMAB A/S 09-Apr-2025 14:48:25 PM 82 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:49:49 PM 24 1177.50 TQEX
GENMAB A/S 09-Apr-2025 14:49:49 PM 2 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:49:49 PM 50 1177.50 CEUX
GENMAB A/S 09-Apr-2025 14:49:53 PM 82 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:49:53 PM 34 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:50:54 PM 24 1175.50 CEUX
GENMAB A/S 09-Apr-2025 14:51:09 PM 40 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:51:09 PM 42 1176.00 XCSE
GENMAB A/S 09-Apr-2025 14:51:33 PM 85 1176.50 XCSE
GENMAB A/S 09-Apr-2025 14:51:33 PM 43 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:51:33 PM 24 1177.00 AQEU
GENMAB A/S 09-Apr-2025 14:51:38 PM 27 1176.50 TQEX
GENMAB A/S 09-Apr-2025 14:51:39 PM 30 1176.50 AQEU
GENMAB A/S 09-Apr-2025 14:52:49 PM 81 1177.00 XCSE
GENMAB A/S 09-Apr-2025 14:52:49 PM 33 1177.00 AQEU
GENMAB A/S 09-Apr-2025 14:52:50 PM 7 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:52:50 PM 34 1176.50 CEUX
GENMAB A/S 09-Apr-2025 14:53:48 PM 28 1177.50 AQEU
GENMAB A/S 09-Apr-2025 14:54:22 PM 43 1178.00 XCSE
GENMAB A/S 09-Apr-2025 14:54:36 PM 84 1178.00 XCSE
GENMAB A/S 09-Apr-2025 14:54:36 PM 52 1178.00 CEUX
GENMAB A/S 09-Apr-2025 14:55:28 PM 29 1181.00 CEUX
GENMAB A/S 09-Apr-2025 14:55:28 PM 22 1181.00 CEUX
GENMAB A/S 09-Apr-2025 14:55:53 PM 83 1181.00 XCSE
GENMAB A/S 09-Apr-2025 14:55:53 PM 24 1181.00 AQEU
GENMAB A/S 09-Apr-2025 14:55:55 PM 25 1180.50 TQEX
GENMAB A/S 09-Apr-2025 14:56:35 PM 4 1181.00 XCSE

159

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 14:57:31 PM 34 1182.50 XCSE
GENMAB A/S 09-Apr-2025 14:57:31 PM 15 1182.50 XCSE
GENMAB A/S 09-Apr-2025 14:57:31 PM 37 1182.50 XCSE
GENMAB A/S 09-Apr-2025 14:57:31 PM 14 1182.50 XCSE
GENMAB A/S 09-Apr-2025 14:57:31 PM 10 1182.50 XCSE
GENMAB A/S 09-Apr-2025 14:57:39 PM 25 1181.50 TQEX
GENMAB A/S 09-Apr-2025 14:58:25 PM 59 1182.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:03 PM 86 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:23 PM 55 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:23 PM 26 1183.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:34 PM 49 1182.50 CEUX
GENMAB A/S 09-Apr-2025 14:59:34 PM 33 1182.50 CEUX
GENMAB A/S 09-Apr-2025 14:59:38 PM 18 1182.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:38 PM 10 1182.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:55 PM 83 1181.00 XCSE
GENMAB A/S 09-Apr-2025 14:59:55 PM 54 1181.00 CEUX
GENMAB A/S 09-Apr-2025 15:00:08 PM 26 1183.00 TQEX
GENMAB A/S 09-Apr-2025 15:00:15 PM 18 1183.50 XCSE
GENMAB A/S 09-Apr-2025 15:00:15 PM 63 1183.50 XCSE
GENMAB A/S 09-Apr-2025 15:01:27 PM 81 1182.50 XCSE
GENMAB A/S 09-Apr-2025 15:01:27 PM 59 1182.50 CEUX
GENMAB A/S 09-Apr-2025 15:01:27 PM 25 1182.50 AQEU
GENMAB A/S 09-Apr-2025 15:01:28 PM 85 1181.50 XCSE
GENMAB A/S 09-Apr-2025 15:01:28 PM 68 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:01:30 PM 65 1181.50 XCSE
GENMAB A/S 09-Apr-2025 15:01:30 PM 17 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:01:30 PM 26 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:01:34 PM 12 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:01:34 PM 19 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:02:30 PM 57 1182.00 XCSE
GENMAB A/S 09-Apr-2025 15:02:30 PM 26 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:02:30 PM 10 1182.00 AQEU
GENMAB A/S 09-Apr-2025 15:02:30 PM 16 1182.00 AQEU
GENMAB A/S 09-Apr-2025 15:03:20 PM 80 1182.50 XCSE
GENMAB A/S 09-Apr-2025 15:03:20 PM 35 1182.50 CEUX
GENMAB A/S 09-Apr-2025 15:03:21 PM 26 1182.00 TQEX
GENMAB A/S 09-Apr-2025 15:03:52 PM 71 1182.00 XCSE
GENMAB A/S 09-Apr-2025 15:03:52 PM 3 1182.00 XCSE
GENMAB A/S 09-Apr-2025 15:04:03 PM 27 1181.50 CEUX
GENMAB A/S 09-Apr-2025 15:04:45 PM 74 1183.00 XCSE
GENMAB A/S 09-Apr-2025 15:04:52 PM 20 1182.50 CEUX
GENMAB A/S 09-Apr-2025 15:04:52 PM 14 1182.50 CEUX
GENMAB A/S 09-Apr-2025 15:04:52 PM 29 1183.00 AQEU

160

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:05:00 PM 61 1182.00 XCSE
GENMAB A/S 09-Apr-2025 15:06:00 PM 13 1183.00 TQEX
GENMAB A/S 09-Apr-2025 15:06:24 PM 61 1182.50 XCSE
GENMAB A/S 09-Apr-2025 15:06:24 PM 30 1182.50 CEUX
GENMAB A/S 09-Apr-2025 15:06:26 PM 8 1182.50 CEUX
GENMAB A/S 09-Apr-2025 15:07:05 PM 30 1184.00 CEUX
GENMAB A/S 09-Apr-2025 15:07:05 PM 14 1184.00 CEUX
GENMAB A/S 09-Apr-2025 15:07:49 PM 84 1184.50 XCSE
GENMAB A/S 09-Apr-2025 15:08:13 PM 83 1183.50 XCSE
GENMAB A/S 09-Apr-2025 15:08:13 PM 38 1184.00 CEUX
GENMAB A/S 09-Apr-2025 15:08:23 PM 30 1184.00 CEUX
GENMAB A/S 09-Apr-2025 15:09:10 PM 25 1185.00 AQEU
GENMAB A/S 09-Apr-2025 15:09:38 PM 86 1184.50 XCSE
GENMAB A/S 09-Apr-2025 15:09:38 PM 29 1184.50 TQEX
GENMAB A/S 09-Apr-2025 15:09:38 PM 25 1184.50 CEUX
GENMAB A/S 09-Apr-2025 15:10:10 PM 31 1184.00 CEUX
GENMAB A/S 09-Apr-2025 15:10:10 PM 17 1184.00 CEUX
GENMAB A/S 09-Apr-2025 15:10:26 PM 62 1183.50 XCSE
GENMAB A/S 09-Apr-2025 15:11:25 PM 84 1185.00 XCSE
GENMAB A/S 09-Apr-2025 15:11:25 PM 55 1185.00 CEUX
GENMAB A/S 09-Apr-2025 15:13:06 PM 82 1186.50 XCSE
GENMAB A/S 09-Apr-2025 15:13:06 PM 46 1186.50 CEUX
GENMAB A/S 09-Apr-2025 15:13:30 PM 14 1186.00 TQEX
GENMAB A/S 09-Apr-2025 15:13:43 PM 68 1185.50 XCSE
GENMAB A/S 09-Apr-2025 15:13:43 PM 19 1185.50 XCSE
GENMAB A/S 09-Apr-2025 15:13:43 PM 43 1185.50 CEUX
GENMAB A/S 09-Apr-2025 15:13:54 PM 12 1185.00 TQEX
GENMAB A/S 09-Apr-2025 15:13:55 PM 11 1185.00 TQEX
GENMAB A/S 09-Apr-2025 15:15:26 PM 14 1186.00 XCSE
GENMAB A/S 09-Apr-2025 15:16:26 PM 82 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:16:34 PM 3 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:17:33 PM 81 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:17:33 PM 35 1188.00 TQEX
GENMAB A/S 09-Apr-2025 15:17:33 PM 41 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:17:33 PM 46 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:18:21 PM 44 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:18:21 PM 37 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:18:50 PM 48 1186.50 CEUX
GENMAB A/S 09-Apr-2025 15:19:33 PM 83 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:19:33 PM 6 1188.00 TQEX
GENMAB A/S 09-Apr-2025 15:19:33 PM 7 1188.00 TQEX
GENMAB A/S 09-Apr-2025 15:19:37 PM 37 1187.50 AQEU
GENMAB A/S 09-Apr-2025 15:20:02 PM 13 1188.00 XCSE

161

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:20:02 PM 12 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:02 PM 43 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:02 PM 12 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:02 PM 14 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:02 PM 46 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:20:03 PM 3 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:03 PM 12 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:03 PM 12 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:03 PM 14 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:03 PM 17 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:03 PM 31 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:20:03 PM 6 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:20:03 PM 4 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:20:13 PM 43 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:13 PM 12 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:13 PM 14 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:13 PM 12 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:19 PM 16 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:20:19 PM 83 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:20:19 PM 26 1187.50 AQEU
GENMAB A/S 09-Apr-2025 15:20:30 PM 28 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:30 PM 16 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:30 PM 30 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:30 PM 7 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:45 PM 17 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:45 PM 71 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:20:45 PM 29 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:21:42 PM 59 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:21:42 PM 22 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:21:53 PM 84 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:21:53 PM 32 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:21:53 PM 55 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:22:19 PM 88 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:22:19 PM 44 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:23:06 PM 27 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:23:06 PM 32 1187.50 TQEX
GENMAB A/S 09-Apr-2025 15:23:06 PM 40 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:23:20 PM 27 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:23:24 PM 27 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:23:52 PM 4 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:23:52 PM 43 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:23:52 PM 36 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:24:15 PM 32 1188.00 XCSE

162

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:24:32 PM 3 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:25:08 PM 43 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:08 PM 19 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:08 PM 13 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:08 PM 12 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:08 PM 14 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 83 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 30 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 17 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 17 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 43 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 3 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:25:29 PM 28 1188.50 TQEX
GENMAB A/S 09-Apr-2025 15:25:29 PM 34 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:25:29 PM 50 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:25:53 PM 15 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:25:56 PM 2 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:25:56 PM 1 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:26:05 PM 6 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:26:09 PM 31 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:26:34 PM 27 1191.00 TQEX
GENMAB A/S 09-Apr-2025 15:26:42 PM 86 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:26:42 PM 62 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:26:43 PM 20 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:26:58 PM 24 1191.00 AQEU
GENMAB A/S 09-Apr-2025 15:27:54 PM 9 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:27:54 PM 14 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:27:54 PM 16 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:27:55 PM 9 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:27:56 PM 5 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:27:56 PM 3 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:28:15 PM 85 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:28:15 PM 15 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:28:16 PM 64 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:28:16 PM 3 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:28:16 PM 29 1191.50 AQEU
GENMAB A/S 09-Apr-2025 15:29:01 PM 20 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:29:01 PM 43 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:29:01 PM 1 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:29:12 PM 54 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:29:12 PM 33 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:29:39 PM 1 1193.00 TQEX
GENMAB A/S 09-Apr-2025 15:29:39 PM 23 1193.00 TQEX

163

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:29:39 PM 8 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:29:39 PM 57 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:29:39 PM 16 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:29:44 PM 85 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:29:44 PM 3 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:29:44 PM 19 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:29:44 PM 43 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:30:00 PM 43 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:30:00 PM 30 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:30:00 PM 16 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:30:00 PM 25 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:30:00 PM 24 1192.00 AQEU
GENMAB A/S 09-Apr-2025 15:30:01 PM 83 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:01 PM 68 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:30:01 PM 5 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:30:01 PM 6 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:30:05 PM 9 1193.00 CEUX
GENMAB A/S 09-Apr-2025 15:30:11 PM 75 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:22 PM 7 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:22 PM 3 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:22 PM 83 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:22 PM 83 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:30 PM 24 1191.00 TQEX
GENMAB A/S 09-Apr-2025 15:30:31 PM 6 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:31 PM 6 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:31 PM 74 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:31 PM 5 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:31 PM 16 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:31 PM 25 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:30:31 PM 32 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:31 PM 3 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:31 PM 32 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:31 PM 20 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:31 PM 64 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:31 PM 23 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:31 PM 5 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:30:34 PM 84 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:30:34 PM 8 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:34 PM 1 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:34 PM 1 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:34 PM 1 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:34 PM 1 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:34 PM 34 1189.50 CEUX

164

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:30:43 PM 88 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:30:43 PM 2 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:30:43 PM 20 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:30:50 PM 39 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:31:03 PM 7 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:03 PM 75 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:03 PM 5 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:03 PM 25 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:03 PM 15 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:03 PM 7 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:03 PM 10 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:04 PM 43 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:04 PM 19 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:04 PM 12 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:04 PM 13 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:04 PM 12 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:04 PM 25 1190.00 TQEX
GENMAB A/S 09-Apr-2025 15:31:04 PM 19 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:05 PM 38 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:36 PM 19 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:36 PM 30 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:36 PM 45 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:36 PM 28 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:55 PM 28 1191.00 TQEX
GENMAB A/S 09-Apr-2025 15:31:55 PM 63 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:58 PM 84 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:58 PM 42 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:31:58 PM 5 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:58 PM 15 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:58 PM 1 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:58 PM 2 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:31:58 PM 1 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:32:31 PM 56 1194.50 XCSE
GENMAB A/S 09-Apr-2025 15:32:31 PM 28 1194.50 XCSE
GENMAB A/S 09-Apr-2025 15:32:34 PM 33 1194.00 TQEX
GENMAB A/S 09-Apr-2025 15:32:34 PM 85 1194.00 CEUX
GENMAB A/S 09-Apr-2025 15:32:35 PM 20 1194.50 XCSE
GENMAB A/S 09-Apr-2025 15:32:54 PM 39 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:02 PM 86 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:33:02 PM 34 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:02 PM 20 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:02 PM 43 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:02 PM 13 1196.50 XCSE

165

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:33:02 PM 3 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:33:02 PM 27 1196.00 AQEU
GENMAB A/S 09-Apr-2025 15:33:06 PM 24 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:33:07 PM 4 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 16 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 43 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 19 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 12 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 43 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 13 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:07 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 12 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 16 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 12 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 43 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 13 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 5 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:08 PM 26 1197.00 TQEX
GENMAB A/S 09-Apr-2025 15:33:08 PM 86 1197.00 CEUX
GENMAB A/S 09-Apr-2025 15:33:11 PM 81 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:11 PM 88 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:33:12 PM 13 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:12 PM 20 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:12 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:12 PM 36 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:12 PM 21 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:33:12 PM 6 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:02 PM 43 1197.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:02 PM 16 1197.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:02 PM 51 1197.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:02 PM 43 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:02 PM 45 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:02 PM 26 1197.00 TQEX
GENMAB A/S 09-Apr-2025 15:34:02 PM 5 1197.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:02 PM 78 1197.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:02 PM 10 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:02 PM 5 1196.00 CEUX

166

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:34:02 PM 40 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:02 PM 7 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:02 PM 8 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:18 PM 11 1196.00 AQEU
GENMAB A/S 09-Apr-2025 15:34:33 PM 2 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:33 PM 80 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:33 PM 1 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:33 PM 21 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:33 PM 34 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:33 PM 15 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:33 PM 26 1196.00 TQEX
GENMAB A/S 09-Apr-2025 15:34:33 PM 1 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:33 PM 2 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:33 PM 84 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:33 PM 10 1196.00 AQEU
GENMAB A/S 09-Apr-2025 15:34:33 PM 3 1196.00 AQEU
GENMAB A/S 09-Apr-2025 15:34:48 PM 82 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:48 PM 34 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:34:48 PM 43 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:48 PM 22 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:48 PM 11 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:48 PM 20 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:48 PM 10 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:48 PM 11 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:48 PM 8 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:48 PM 33 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:34:49 PM 79 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:49 PM 16 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:52 PM 34 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:52 PM 16 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:34:57 PM 26 1195.50 TQEX
GENMAB A/S 09-Apr-2025 15:34:57 PM 24 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:35:00 PM 13 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:00 PM 12 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:00 PM 13 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:00 PM 7 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:00 PM 12 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:01 PM 8 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:01 PM 7 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:10 PM 88 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:10 PM 43 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:10 PM 39 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:12 PM 43 1196.00 XCSE

167

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:35:12 PM 4 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:12 PM 30 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:12 PM 27 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:24 PM 66 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:24 PM 20 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:25 PM 2 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:25 PM 12 1195.50 TQEX
GENMAB A/S 09-Apr-2025 15:35:25 PM 12 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:35:26 PM 63 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:35:35 PM 6 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:35:45 PM 7 1193.50 XCSE
GENMAB A/S 09-Apr-2025 15:35:45 PM 10 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:35:46 PM 78 1193.50 XCSE
GENMAB A/S 09-Apr-2025 15:35:46 PM 72 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:35:46 PM 24 1193.50 AQEU
GENMAB A/S 09-Apr-2025 15:36:00 PM 10 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:36:00 PM 72 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:36:00 PM 65 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:12 PM 70 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:36:12 PM 11 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:36:12 PM 10 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:12 PM 10 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:12 PM 32 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:12 PM 3 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:12 PM 10 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:12 PM 10 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:16 PM 33 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:18 PM 13 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:18 PM 6 1191.50 CEUX
GENMAB A/S 09-Apr-2025 15:36:29 PM 84 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:36:32 PM 82 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:36:32 PM 12 1190.00 TQEX
GENMAB A/S 09-Apr-2025 15:36:32 PM 18 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:32 PM 1 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:32 PM 1 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:32 PM 1 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:32 PM 2 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:32 PM 1 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:33 PM 9 1190.00 TQEX
GENMAB A/S 09-Apr-2025 15:36:34 PM 4 1190.00 TQEX
GENMAB A/S 09-Apr-2025 15:36:37 PM 83 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:36:37 PM 4 1189.00 TQEX
GENMAB A/S 09-Apr-2025 15:36:37 PM 20 1189.00 CEUX

168

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:36:57 PM 1 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:36:57 PM 49 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:36:57 PM 10 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:57 PM 17 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:36:59 PM 37 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:37:00 PM 21 1188.00 AQEU
GENMAB A/S 09-Apr-2025 15:37:49 PM 4 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 7 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:37:56 PM 1 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:37:56 PM 80 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:37:56 PM 12 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:37:56 PM 10 1190.50 TQEX
GENMAB A/S 09-Apr-2025 15:37:56 PM 26 1190.50 TQEX
GENMAB A/S 09-Apr-2025 15:37:56 PM 8 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 21 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 25 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 5 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 11 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 23 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:56 PM 1 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:37:57 PM 10 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:37:57 PM 27 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:38:34 PM 81 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:38:34 PM 13 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:02 PM 63 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:02 PM 26 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:39:05 PM 62 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:39:05 PM 1 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:39:05 PM 18 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:39:05 PM 30 1195.00 TQEX
GENMAB A/S 09-Apr-2025 15:39:06 PM 13 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:06 PM 8 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:06 PM 2 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:06 PM 4 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:06 PM 5 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:06 PM 2 1194.00 AQEU
GENMAB A/S 09-Apr-2025 15:39:43 PM 14 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:39:43 PM 18 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:39:43 PM 6 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:39:43 PM 86 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:39:43 PM 28 1196.00 TQEX
GENMAB A/S 09-Apr-2025 15:39:43 PM 10 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:43 PM 20 1195.50 CEUX

169

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:39:44 PM 24 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:45 PM 15 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:39:53 PM 27 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:39:53 PM 56 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:40:13 PM 34 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:13 PM 16 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:14 PM 1 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:40:14 PM 30 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:40:14 PM 57 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:40:14 PM 5 1195.00 AQEU
GENMAB A/S 09-Apr-2025 15:40:14 PM 8 1195.00 AQEU
GENMAB A/S 09-Apr-2025 15:40:14 PM 16 1195.00 AQEU
GENMAB A/S 09-Apr-2025 15:40:15 PM 1 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:15 PM 7 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:15 PM 17 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:15 PM 1 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:16 PM 4 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:40:25 PM 86 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:40:25 PM 25 1195.00 TQEX
GENMAB A/S 09-Apr-2025 15:40:25 PM 28 1195.00 CEUX
GENMAB A/S 09-Apr-2025 15:40:27 PM 24 1194.50 AQEU
GENMAB A/S 09-Apr-2025 15:41:02 PM 8 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:41:02 PM 15 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:41:02 PM 7 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:41:02 PM 9 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:41:02 PM 10 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:41:02 PM 7 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:41:02 PM 2 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:41:02 PM 8 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:41:02 PM 5 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:41:02 PM 1 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:41:02 PM 11 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:41:17 PM 5 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:41:17 PM 2 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:41:20 PM 19 1197.00 CEUX
GENMAB A/S 09-Apr-2025 15:41:20 PM 50 1197.00 CEUX
GENMAB A/S 09-Apr-2025 15:41:49 PM 25 1197.00 TQEX
GENMAB A/S 09-Apr-2025 15:41:49 PM 47 1197.00 CEUX
GENMAB A/S 09-Apr-2025 15:41:51 PM 65 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:41:51 PM 9 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:41:51 PM 77 1196.50 XCSE
GENMAB A/S 09-Apr-2025 15:42:07 PM 12 1196.00 CEUX
GENMAB A/S 09-Apr-2025 15:42:07 PM 44 1196.00 CEUX

170

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:42:09 PM 39 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:09 PM 3 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:09 PM 25 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:11 PM 39 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:11 PM 24 1196.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:16 PM 57 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:16 PM 24 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:24 PM 53 1195.50 CEUX
GENMAB A/S 09-Apr-2025 15:42:36 PM 2 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:42:45 PM 23 1195.50 AQEU
GENMAB A/S 09-Apr-2025 15:42:50 PM 83 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:42:50 PM 24 1195.00 TQEX
GENMAB A/S 09-Apr-2025 15:43:00 PM 1 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:43:00 PM 39 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:43:10 PM 14 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:43:10 PM 7 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:43:29 PM 33 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:43:29 PM 43 1195.00 XCSE
GENMAB A/S 09-Apr-2025 15:43:29 PM 17 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:43:29 PM 38 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:43:48 PM 16 1194.50 TQEX
GENMAB A/S 09-Apr-2025 15:43:48 PM 1 1194.50 TQEX
GENMAB A/S 09-Apr-2025 15:43:48 PM 1 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:43:48 PM 38 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:43:48 PM 15 1194.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:00 PM 86 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 16 1194.50 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 13 1194.50 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 81 1194.50 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 30 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 8 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 3 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:00 PM 41 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:22 PM 5 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:22 PM 36 1194.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:28 PM 10 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:28 PM 10 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:28 PM 10 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:28 PM 10 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:28 PM 5 1193.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:38 PM 6 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:38 PM 78 1193.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:41 PM 1 1192.50 TQEX

171

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:44:41 PM 40 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:41 PM 1 1192.50 CEUX
GENMAB A/S 09-Apr-2025 15:44:46 PM 29 1192.50 TQEX
GENMAB A/S 09-Apr-2025 15:44:49 PM 63 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:49 PM 25 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:44:52 PM 18 1191.50 AQEU
GENMAB A/S 09-Apr-2025 15:44:52 PM 2 1191.50 AQEU
GENMAB A/S 09-Apr-2025 15:44:52 PM 4 1191.50 AQEU
GENMAB A/S 09-Apr-2025 15:45:25 PM 19 1192.50 AQEU
GENMAB A/S 09-Apr-2025 15:45:25 PM 8 1192.50 AQEU
GENMAB A/S 09-Apr-2025 15:45:26 PM 16 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:45:26 PM 12 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:45:27 PM 33 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:45:46 PM 1 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 8 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 15 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 2 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 2 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 3 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 2 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 3 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 2 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 1 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 2 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:46 PM 1 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:47 PM 60 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:45:47 PM 14 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:45:47 PM 3 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:45:47 PM 32 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:47 PM 8 1192.00 CEUX
GENMAB A/S 09-Apr-2025 15:45:48 PM 43 1192.50 XCSE
GENMAB A/S 09-Apr-2025 15:45:48 PM 82 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:45:48 PM 49 1192.00 XCSE
GENMAB A/S 09-Apr-2025 15:45:48 PM 4 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:45:48 PM 23 1192.00 TQEX
GENMAB A/S 09-Apr-2025 15:46:00 PM 83 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:46:00 PM 35 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:46:00 PM 11 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:46:40 PM 10 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:46:40 PM 51 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:46:40 PM 25 1190.00 AQEU
GENMAB A/S 09-Apr-2025 15:46:42 PM 7 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:46:42 PM 43 1190.50 XCSE

172

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:46:42 PM 21 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:46:42 PM 13 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:46:42 PM 7 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:46:42 PM 14 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:46:42 PM 5 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:46:44 PM 70 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:46:44 PM 16 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:46:44 PM 4 1189.50 TQEX
GENMAB A/S 09-Apr-2025 15:46:54 PM 14 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:46:54 PM 36 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:46:54 PM 35 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:47:22 PM 1 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 5 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 12 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 30 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 43 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 9 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 85 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 10 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 10 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 66 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:47:22 PM 10 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:47:22 PM 10 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:47:22 PM 57 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:47:28 PM 9 1186.50 XCSE
GENMAB A/S 09-Apr-2025 15:47:28 PM 5 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:47:28 PM 11 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:47:28 PM 5 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:47:28 PM 3 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:47:50 PM 43 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:47:50 PM 40 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:47:50 PM 62 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:47:51 PM 24 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:48:11 PM 15 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:48:11 PM 1 1187.00 AQEU
GENMAB A/S 09-Apr-2025 15:48:11 PM 3 1187.00 AQEU
GENMAB A/S 09-Apr-2025 15:48:11 PM 2 1187.00 AQEU
GENMAB A/S 09-Apr-2025 15:48:11 PM 10 1187.00 AQEU
GENMAB A/S 09-Apr-2025 15:48:11 PM 10 1187.00 AQEU
GENMAB A/S 09-Apr-2025 15:48:12 PM 11 1186.50 XCSE
GENMAB A/S 09-Apr-2025 15:48:12 PM 2 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:48:12 PM 7 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:48:12 PM 1 1187.00 AQEU

173

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:48:52 PM 1 1188.00 TQEX
GENMAB A/S 09-Apr-2025 15:48:52 PM 24 1188.00 TQEX
GENMAB A/S 09-Apr-2025 15:49:19 PM 48 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:19 PM 40 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:19 PM 85 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:49:21 PM 79 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:21 PM 6 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:25 PM 7 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:25 PM 9 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:25 PM 43 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:49:25 PM 51 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:50:16 PM 82 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:16 PM 26 1188.50 TQEX
GENMAB A/S 09-Apr-2025 15:50:16 PM 8 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:50:16 PM 15 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:50:16 PM 64 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:50:16 PM 25 1189.00 AQEU
GENMAB A/S 09-Apr-2025 15:50:38 PM 68 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:38 PM 17 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:38 PM 33 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:38 PM 28 1189.00 TQEX
GENMAB A/S 09-Apr-2025 15:50:38 PM 81 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:50:44 PM 35 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:44 PM 22 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:57 PM 43 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:57 PM 16 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:57 PM 13 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:57 PM 14 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:50:57 PM 14 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:51:02 PM 24 1188.50 AQEU
GENMAB A/S 09-Apr-2025 15:51:30 PM 86 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:51:30 PM 43 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:51:30 PM 15 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:51:30 PM 8 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:51:30 PM 35 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:51:30 PM 39 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:51:32 PM 48 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:51:32 PM 34 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 5 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 13 1188.50 XCSE

174

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:52:02 PM 24 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 82 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:02 PM 26 1187.00 TQEX
GENMAB A/S 09-Apr-2025 15:52:02 PM 88 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:52:03 PM 15 1188.00 TQEX
GENMAB A/S 09-Apr-2025 15:52:04 PM 85 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:52:04 PM 84 1187.50 CEUX
GENMAB A/S 09-Apr-2025 15:52:25 PM 86 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:52:42 PM 44 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:52:43 PM 30 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:52:46 PM 8 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:53:02 PM 61 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:53:02 PM 24 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:53:20 PM 58 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:53:20 PM 29 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:53:29 PM 47 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:53:29 PM 37 1191.50 XCSE
GENMAB A/S 09-Apr-2025 15:53:32 PM 27 1191.00 TQEX
GENMAB A/S 09-Apr-2025 15:53:32 PM 10 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:53:32 PM 76 1191.00 CEUX
GENMAB A/S 09-Apr-2025 15:53:49 PM 47 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:53:49 PM 38 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:53:49 PM 20 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:53:50 PM 35 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:54:07 PM 67 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:54:07 PM 17 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:54:14 PM 84 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:54:14 PM 30 1189.50 TQEX
GENMAB A/S 09-Apr-2025 15:54:14 PM 86 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:04 PM 81 1190.50 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 3 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 14 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 30 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 13 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 20 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 30 1191.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:04 PM 76 1190.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:04 PM 29 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:04 PM 27 1190.50 AQEU
GENMAB A/S 09-Apr-2025 15:55:05 PM 48 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:55:05 PM 35 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:55:05 PM 19 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:07 PM 17 1189.50 TQEX

175

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:55:31 PM 5 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:34 PM 76 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:55:34 PM 12 1189.50 XCSE
GENMAB A/S 09-Apr-2025 15:55:34 PM 10 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:34 PM 10 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:35 PM 13 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:45 PM 85 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:55:45 PM 9 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:45 PM 73 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:55:46 PM 10 1188.50 AQEU
GENMAB A/S 09-Apr-2025 15:55:46 PM 10 1188.50 AQEU
GENMAB A/S 09-Apr-2025 15:55:46 PM 4 1188.50 AQEU
GENMAB A/S 09-Apr-2025 15:55:48 PM 45 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:56:09 PM 29 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:56:09 PM 19 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:56:09 PM 24 1189.50 AQEU
GENMAB A/S 09-Apr-2025 15:56:19 PM 45 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:56:20 PM 6 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:56:28 PM 88 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:56:28 PM 21 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:56:28 PM 19 1190.00 CEUX
GENMAB A/S 09-Apr-2025 15:56:28 PM 39 1190.00 AQEU
GENMAB A/S 09-Apr-2025 15:56:44 PM 8 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:56:44 PM 76 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:56:53 PM 25 1189.50 TQEX
GENMAB A/S 09-Apr-2025 15:57:05 PM 18 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:57:05 PM 16 1189.50 CEUX
GENMAB A/S 09-Apr-2025 15:57:05 PM 24 1189.50 AQEU
GENMAB A/S 09-Apr-2025 15:57:13 PM 40 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:13 PM 29 1189.00 TQEX
GENMAB A/S 09-Apr-2025 15:57:32 PM 47 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:32 PM 21 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:38 PM 28 1188.50 CEUX
GENMAB A/S 09-Apr-2025 15:57:48 PM 39 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:48 PM 22 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:48 PM 3 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:48 PM 14 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:48 PM 12 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:48 PM 13 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:57:48 PM 7 1190.00 XCSE
GENMAB A/S 09-Apr-2025 15:58:06 PM 2 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:58:06 PM 1 1189.00 XCSE
GENMAB A/S 09-Apr-2025 15:58:06 PM 83 1189.00 XCSE

176

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 15:58:06 PM 58 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:58:20 PM 88 1188.00 XCSE
GENMAB A/S 09-Apr-2025 15:58:50 PM 36 1189.00 TQEX
GENMAB A/S 09-Apr-2025 15:58:50 PM 10 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:58:50 PM 71 1189.00 CEUX
GENMAB A/S 09-Apr-2025 15:59:03 PM 82 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:03 PM 5 1188.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:03 PM 53 1188.00 CEUX
GENMAB A/S 09-Apr-2025 15:59:19 PM 82 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:51 PM 8 1187.00 CEUX
GENMAB A/S 09-Apr-2025 15:59:51 PM 27 1187.00 CEUX
GENMAB A/S 09-Apr-2025 15:59:53 PM 56 1186.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 26 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 3 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 13 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 12 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 14 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 13 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 12 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 13 1187.00 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 4 1187.50 XCSE
GENMAB A/S 09-Apr-2025 15:59:59 PM 26 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:01 PM 51 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:01 PM 25 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:01 PM 3 1189.00 CEUX
GENMAB A/S 09-Apr-2025 16:00:01 PM 78 1189.00 CEUX
GENMAB A/S 09-Apr-2025 16:00:04 PM 11 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:04 PM 5 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:04 PM 67 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:04 PM 46 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:00:04 PM 39 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:00:05 PM 10 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:05 PM 4 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:00:35 PM 24 1189.50 TQEX
GENMAB A/S 09-Apr-2025 16:00:55 PM 85 1191.00 XCSE
GENMAB A/S 09-Apr-2025 16:00:55 PM 24 1191.00 TQEX
GENMAB A/S 09-Apr-2025 16:00:55 PM 63 1190.50 CEUX
GENMAB A/S 09-Apr-2025 16:01:06 PM 73 1190.00 XCSE
GENMAB A/S 09-Apr-2025 16:01:06 PM 8 1190.00 XCSE
GENMAB A/S 09-Apr-2025 16:01:11 PM 17 1189.50 CEUX
GENMAB A/S 09-Apr-2025 16:01:11 PM 42 1189.50 CEUX
GENMAB A/S 09-Apr-2025 16:01:13 PM 62 1189.00 XCSE
GENMAB A/S 09-Apr-2025 16:01:13 PM 26 1189.00 XCSE

177

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:01:31 PM 53 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:01:33 PM 31 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:02:02 PM 40 1190.00 XCSE
GENMAB A/S 09-Apr-2025 16:02:02 PM 43 1190.00 XCSE
GENMAB A/S 09-Apr-2025 16:02:02 PM 3 1190.00 XCSE
GENMAB A/S 09-Apr-2025 16:02:06 PM 80 1189.50 CEUX
GENMAB A/S 09-Apr-2025 16:02:12 PM 14 1189.00 XCSE
GENMAB A/S 09-Apr-2025 16:02:12 PM 7 1189.50 TQEX
GENMAB A/S 09-Apr-2025 16:02:12 PM 11 1189.50 TQEX
GENMAB A/S 09-Apr-2025 16:02:12 PM 1 1188.50 TQEX
GENMAB A/S 09-Apr-2025 16:02:12 PM 46 1190.50 CEUX
GENMAB A/S 09-Apr-2025 16:02:15 PM 81 1191.50 XCSE
GENMAB A/S 09-Apr-2025 16:02:15 PM 42 1191.50 CEUX
GENMAB A/S 09-Apr-2025 16:02:51 PM 88 1190.50 XCSE
GENMAB A/S 09-Apr-2025 16:02:51 PM 13 1190.50 CEUX
GENMAB A/S 09-Apr-2025 16:02:51 PM 2 1190.50 CEUX
GENMAB A/S 09-Apr-2025 16:02:51 PM 10 1190.50 AQEU
GENMAB A/S 09-Apr-2025 16:02:51 PM 20 1190.50 AQEU
GENMAB A/S 09-Apr-2025 16:02:56 PM 88 1192.50 XCSE
GENMAB A/S 09-Apr-2025 16:02:56 PM 52 1192.50 CEUX
GENMAB A/S 09-Apr-2025 16:02:57 PM 12 1192.00 AQEU
GENMAB A/S 09-Apr-2025 16:03:00 PM 12 1192.00 AQEU
GENMAB A/S 09-Apr-2025 16:03:17 PM 48 1192.00 XCSE
GENMAB A/S 09-Apr-2025 16:03:17 PM 35 1192.00 XCSE
GENMAB A/S 09-Apr-2025 16:03:25 PM 33 1191.50 CEUX
GENMAB A/S 09-Apr-2025 16:03:26 PM 1 1191.50 TQEX
GENMAB A/S 09-Apr-2025 16:03:26 PM 11 1191.50 CEUX
GENMAB A/S 09-Apr-2025 16:03:27 PM 23 1191.50 TQEX
GENMAB A/S 09-Apr-2025 16:03:43 PM 83 1191.00 XCSE
GENMAB A/S 09-Apr-2025 16:03:43 PM 38 1191.50 XCSE
GENMAB A/S 09-Apr-2025 16:03:44 PM 67 1191.00 XCSE
GENMAB A/S 09-Apr-2025 16:03:44 PM 14 1191.00 XCSE
GENMAB A/S 09-Apr-2025 16:03:53 PM 88 1190.00 XCSE
GENMAB A/S 09-Apr-2025 16:03:53 PM 28 1190.00 TQEX
GENMAB A/S 09-Apr-2025 16:03:53 PM 10 1190.50 CEUX
GENMAB A/S 09-Apr-2025 16:03:53 PM 43 1190.50 CEUX
GENMAB A/S 09-Apr-2025 16:03:53 PM 25 1190.50 AQEU
GENMAB A/S 09-Apr-2025 16:03:58 PM 20 1190.00 AQEU
GENMAB A/S 09-Apr-2025 16:03:58 PM 4 1190.00 AQEU
GENMAB A/S 09-Apr-2025 16:04:22 PM 36 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:04:22 PM 51 1189.50 CEUX
GENMAB A/S 09-Apr-2025 16:05:11 PM 82 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:05:11 PM 1 1189.50 XCSE

178

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:05:41 PM 81 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:05:41 PM 28 1189.50 TQEX
GENMAB A/S 09-Apr-2025 16:05:42 PM 9 1189.00 CEUX
GENMAB A/S 09-Apr-2025 16:05:43 PM 14 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:05:43 PM 12 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:05:43 PM 14 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:06:03 PM 43 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:06:03 PM 40 1189.50 XCSE
GENMAB A/S 09-Apr-2025 16:06:12 PM 4 1189.00 CEUX
GENMAB A/S 09-Apr-2025 16:06:12 PM 72 1189.00 CEUX
GENMAB A/S 09-Apr-2025 16:06:13 PM 14 1189.00 XCSE
GENMAB A/S 09-Apr-2025 16:06:15 PM 81 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:06:15 PM 5 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:06:15 PM 7 1188.50 AQEU
GENMAB A/S 09-Apr-2025 16:06:16 PM 20 1188.50 AQEU
GENMAB A/S 09-Apr-2025 16:06:16 PM 12 1188.50 AQEU
GENMAB A/S 09-Apr-2025 16:06:24 PM 78 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:06:24 PM 49 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:06:27 PM 9 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:06:27 PM 10 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:06:27 PM 18 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:07:00 PM 40 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:07:00 PM 43 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:07:00 PM 13 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:07:00 PM 12 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:07:00 PM 2 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:07:00 PM 42 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:07:00 PM 40 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:07:02 PM 48 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:07:02 PM 40 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:07:22 PM 84 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:07:22 PM 79 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:07:22 PM 6 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:08:01 PM 86 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:08:01 PM 1 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:08:01 PM 44 1185.00 CEUX
GENMAB A/S 09-Apr-2025 16:08:13 PM 88 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:08:13 PM 14 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:08:13 PM 3 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:08:13 PM 7 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:08:13 PM 47 1185.00 CEUX
GENMAB A/S 09-Apr-2025 16:08:13 PM 26 1185.00 CEUX
GENMAB A/S 09-Apr-2025 16:08:52 PM 18 1186.50 XCSE

179

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:08:52 PM 68 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:08:53 PM 13 1186.50 TQEX
GENMAB A/S 09-Apr-2025 16:09:08 PM 7 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:09:08 PM 43 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:09:08 PM 24 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:09:08 PM 23 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:09:08 PM 1 1187.50 TQEX
GENMAB A/S 09-Apr-2025 16:09:26 PM 81 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:09:26 PM 38 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:09:26 PM 31 1187.50 TQEX
GENMAB A/S 09-Apr-2025 16:10:02 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:10:02 PM 37 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:10:08 PM 83 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:10:08 PM 30 1187.50 TQEX
GENMAB A/S 09-Apr-2025 16:10:08 PM 59 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:10:08 PM 24 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:10:08 PM 37 1188.00 AQEU
GENMAB A/S 09-Apr-2025 16:10:55 PM 83 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:10:55 PM 24 1187.50 TQEX
GENMAB A/S 09-Apr-2025 16:10:56 PM 26 1187.50 AQEU
GENMAB A/S 09-Apr-2025 16:11:01 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:11:01 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:11:01 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:11:01 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:11:01 PM 16 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:11:01 PM 85 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:11:08 PM 15 1187.50 TQEX
GENMAB A/S 09-Apr-2025 16:11:19 PM 84 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:11:22 PM 83 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:11:22 PM 32 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:04 PM 43 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:04 PM 10 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:04 PM 14 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:19 PM 67 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:12:19 PM 17 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:12:23 PM 24 1188.00 TQEX
GENMAB A/S 09-Apr-2025 16:12:47 PM 83 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:12:47 PM 85 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:12:47 PM 37 1187.50 AQEU
GENMAB A/S 09-Apr-2025 16:12:52 PM 4 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:52 PM 30 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:52 PM 24 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:12:58 PM 83 1186.50 XCSE

180

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:12:59 PM 84 1186.00 CEUX
GENMAB A/S 09-Apr-2025 16:13:02 PM 84 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:02 PM 27 1186.00 TQEX
GENMAB A/S 09-Apr-2025 16:13:19 PM 11 1185.50 AQEU
GENMAB A/S 09-Apr-2025 16:13:19 PM 1 1185.50 AQEU
GENMAB A/S 09-Apr-2025 16:13:37 PM 17 1185.50 AQEU
GENMAB A/S 09-Apr-2025 16:13:38 PM 2 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:13:44 PM 12 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:46 PM 13 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:46 PM 13 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:46 PM 16 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:46 PM 12 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:46 PM 37 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:13:46 PM 64 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:14:01 PM 5 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:07 PM 4 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:11 PM 19 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:14:11 PM 5 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:14:25 PM 24 1185.50 AQEU
GENMAB A/S 09-Apr-2025 16:14:26 PM 82 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 17 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 16 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 9 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 25 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 12 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 4 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 27 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:14:26 PM 2 1184.50 TQEX
GENMAB A/S 09-Apr-2025 16:14:26 PM 6 1184.50 TQEX
GENMAB A/S 09-Apr-2025 16:15:00 PM 10 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:15:11 PM 87 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:15:11 PM 37 1186.50 TQEX
GENMAB A/S 09-Apr-2025 16:15:11 PM 54 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:15:11 PM 30 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:15:33 PM 56 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:15:38 PM 23 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:15:45 PM 8 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:15:48 PM 81 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:15:48 PM 43 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:15:48 PM 13 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:15:48 PM 10 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:15:48 PM 42 1187.00 XCSE
GENMAB A/S 09-Apr-2025 16:15:48 PM 87 1186.50 CEUX

181

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:15:48 PM 26 1187.00 AQEU
GENMAB A/S 09-Apr-2025 16:16:06 PM 10 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:16:06 PM 43 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:16:06 PM 57 1188.00 XCSE
GENMAB A/S 09-Apr-2025 16:16:06 PM 44 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:06 PM 38 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:16:06 PM 35 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:16:13 PM 10 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:13 PM 34 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:19 PM 13 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:16:19 PM 44 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:16:57 PM 7 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:57 PM 1 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:57 PM 44 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:57 PM 10 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:16:57 PM 20 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:17:00 PM 16 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:17:00 PM 13 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:17:00 PM 2 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:17:00 PM 5 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:17:00 PM 49 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:17:00 PM 34 1188.00 TQEX
GENMAB A/S 09-Apr-2025 16:17:00 PM 3 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:17:00 PM 18 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:17:00 PM 48 1188.00 CEUX
GENMAB A/S 09-Apr-2025 16:17:00 PM 2 1187.50 AQEU
GENMAB A/S 09-Apr-2025 16:17:00 PM 31 1187.50 AQEU
GENMAB A/S 09-Apr-2025 16:18:22 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:22 PM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:22 PM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:22 PM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:22 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:26 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:26 PM 23 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:26 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:26 PM 14 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:26 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:29 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:29 PM 16 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:29 PM 12 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:29 PM 13 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:18:42 PM 1 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:19:26 PM 80 1187.50 XCSE

182

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:19:26 PM 21 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:19:26 PM 18 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:19:26 PM 25 1187.50 AQEU
GENMAB A/S 09-Apr-2025 16:20:04 PM 7 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:04 PM 7 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:04 PM 7 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:08 PM 84 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:08 PM 13 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:08 PM 16 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:08 PM 14 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:08 PM 13 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:08 PM 24 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:09 PM 12 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:16 PM 38 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:33 PM 55 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:33 PM 29 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:36 PM 1 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:43 PM 21 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:43 PM 30 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:43 PM 43 1188.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:48 PM 82 1187.50 XCSE
GENMAB A/S 09-Apr-2025 16:20:48 PM 29 1187.50 TQEX
GENMAB A/S 09-Apr-2025 16:20:48 PM 50 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:20:48 PM 26 1187.50 AQEU
GENMAB A/S 09-Apr-2025 16:20:55 PM 36 1187.50 CEUX
GENMAB A/S 09-Apr-2025 16:21:24 PM 82 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:21:24 PM 14 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:21:24 PM 13 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:21:24 PM 32 1186.50 TQEX
GENMAB A/S 09-Apr-2025 16:21:24 PM 51 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:21:33 PM 12 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:21:33 PM 52 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:21:34 PM 36 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:21:36 PM 67 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:21:38 PM 14 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:21:54 PM 10 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:21:54 PM 14 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:21:54 PM 12 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:21:54 PM 14 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:21:54 PM 20 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:02 PM 80 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:02 PM 3 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:02 PM 33 1185.00 TQEX

183

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:22:02 PM 36 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:22:02 PM 8 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:22:02 PM 6 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:22:02 PM 7 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:22:32 PM 12 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:32 PM 13 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:32 PM 12 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:32 PM 43 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:32 PM 2 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:35 PM 87 1184.00 XCSE
GENMAB A/S 09-Apr-2025 16:22:35 PM 23 1184.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 58 1184.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 6 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 5 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 15 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 10 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 26 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 24 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:22:35 PM 2 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:23:11 PM 12 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:23:11 PM 13 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:23:11 PM 14 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:23:11 PM 49 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:23:11 PM 41 1184.50 TQEX
GENMAB A/S 09-Apr-2025 16:23:45 PM 85 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:23:45 PM 30 1186.00 AQEU
GENMAB A/S 09-Apr-2025 16:23:51 PM 65 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:23:51 PM 20 1186.00 XCSE
GENMAB A/S 09-Apr-2025 16:23:51 PM 26 1186.00 AQEU
GENMAB A/S 09-Apr-2025 16:24:20 PM 86 1186.50 XCSE
GENMAB A/S 09-Apr-2025 16:24:20 PM 85 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:24:20 PM 36 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:24:20 PM 36 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:24:20 PM 8 1187.00 CEUX
GENMAB A/S 09-Apr-2025 16:24:20 PM 28 1186.50 AQEU
GENMAB A/S 09-Apr-2025 16:24:27 PM 32 1186.50 CEUX
GENMAB A/S 09-Apr-2025 16:24:31 PM 31 1186.50 AQEU
GENMAB A/S 09-Apr-2025 16:24:44 PM 39 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:24:44 PM 47 1185.50 CEUX
GENMAB A/S 09-Apr-2025 16:24:46 PM 66 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:24:46 PM 16 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:24:46 PM 47 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:25:33 PM 38 1185.50 CEUX

184

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:25:43 PM 82 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:25:50 PM 21 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:25:50 PM 14 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:25:50 PM 14 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:25:50 PM 12 1185.50 XCSE
GENMAB A/S 09-Apr-2025 16:25:50 PM 38 1185.00 TQEX
GENMAB A/S 09-Apr-2025 16:25:50 PM 26 1185.00 AQEU
GENMAB A/S 09-Apr-2025 16:26:00 PM 52 1184.50 CEUX
GENMAB A/S 09-Apr-2025 16:26:00 PM 36 1184.50 CEUX
GENMAB A/S 09-Apr-2025 16:26:02 PM 13 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:26:02 PM 13 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:26:02 PM 43 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:26:02 PM 14 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:26:02 PM 12 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:26:02 PM 13 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:26:02 PM 2 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:26:16 PM 76 1184.00 XCSE
GENMAB A/S 09-Apr-2025 16:26:30 PM 50 1183.50 CEUX
GENMAB A/S 09-Apr-2025 16:26:30 PM 22 1183.50 AQEU
GENMAB A/S 09-Apr-2025 16:26:30 PM 9 1183.50 AQEU
GENMAB A/S 09-Apr-2025 16:26:44 PM 70 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:27:12 PM 30 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:27:12 PM 43 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:27:12 PM 3 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:27:12 PM 64 1182.00 XCSE
GENMAB A/S 09-Apr-2025 16:27:12 PM 9 1182.00 XCSE
GENMAB A/S 09-Apr-2025 16:27:12 PM 35 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:27:47 PM 57 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:28:07 PM 70 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:28:07 PM 8 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:28:10 PM 39 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:28:10 PM 32 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:10 PM 22 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:10 PM 14 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:10 PM 13 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:10 PM 29 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:10 PM 25 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:28:46 PM 43 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:46 PM 30 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:46 PM 23 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:46 PM 14 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:28:46 PM 26 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:29:02 PM 12 1181.00 XCSE

185

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:29:02 PM 4 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:29:02 PM 14 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:29:02 PM 14 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:29:07 PM 86 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:29:19 PM 36 1181.50 CEUX
GENMAB A/S 09-Apr-2025 16:30:18 PM 40 1182.50 TQEX
GENMAB A/S 09-Apr-2025 16:30:24 PM 55 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:30:24 PM 31 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:30:24 PM 15 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:30:24 PM 10 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:30:24 PM 43 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:30:53 PM 27 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:30:53 PM 19 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:30:53 PM 37 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:30:54 PM 8 1183.50 CEUX
GENMAB A/S 09-Apr-2025 16:30:54 PM 7 1183.50 CEUX
GENMAB A/S 09-Apr-2025 16:30:54 PM 20 1183.50 CEUX
GENMAB A/S 09-Apr-2025 16:30:55 PM 36 1183.50 CEUX
GENMAB A/S 09-Apr-2025 16:31:01 PM 84 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:31:03 PM 17 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:31:03 PM 36 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:31:11 PM 87 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:11 PM 36 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:11 PM 23 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 43 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 36 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 13 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 14 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 4 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 84 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:31:14 PM 84 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:31:14 PM 81 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:31:36 PM 33 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:31:36 PM 3 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:32:05 PM 47 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 43 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 16 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 12 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 14 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 13 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 12 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:32:05 PM 4 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:32:05 PM 33 1181.00 CEUX

186

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:32:58 PM 15 1183.00 TQEX
GENMAB A/S 09-Apr-2025 16:32:58 PM 23 1183.00 TQEX
GENMAB A/S 09-Apr-2025 16:32:58 PM 61 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:32:58 PM 40 1183.00 AQEU
GENMAB A/S 09-Apr-2025 16:33:06 PM 13 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:33:06 PM 12 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:33:06 PM 12 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:33:06 PM 28 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:33:06 PM 59 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:33:06 PM 11 1184.00 XCSE
GENMAB A/S 09-Apr-2025 16:33:06 PM 50 1184.00 XCSE
GENMAB A/S 09-Apr-2025 16:33:18 PM 26 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:33:18 PM 46 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:33:19 PM 85 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:33:19 PM 3 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:33:19 PM 41 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:33:48 PM 50 1182.00 XCSE
GENMAB A/S 09-Apr-2025 16:33:48 PM 20 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:33:48 PM 32 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:34:16 PM 2 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:16 PM 4 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:16 PM 43 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:16 PM 43 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:16 PM 12 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:16 PM 13 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:16 PM 5 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:57 PM 78 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:34:57 PM 35 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:34:57 PM 1 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:34:57 PM 43 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:34:57 PM 40 1183.00 TQEX
GENMAB A/S 09-Apr-2025 16:34:57 PM 59 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:35:12 PM 3 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:35:12 PM 4 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:35:12 PM 43 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:35:12 PM 36 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:35:18 PM 84 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:35:18 PM 5 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:35:18 PM 70 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:35:43 PM 56 1183.00 XCSE
GENMAB A/S 09-Apr-2025 16:35:48 PM 40 1184.00 CEUX
GENMAB A/S 09-Apr-2025 16:35:48 PM 24 1184.00 CEUX
GENMAB A/S 09-Apr-2025 16:36:03 PM 43 1184.50 XCSE

187

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:36:03 PM 25 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:36:03 PM 25 1184.50 CEUX
GENMAB A/S 09-Apr-2025 16:36:03 PM 24 1184.50 AQEU
GENMAB A/S 09-Apr-2025 16:36:21 PM 23 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:36:21 PM 25 1185.00 XCSE
GENMAB A/S 09-Apr-2025 16:36:21 PM 87 1184.50 XCSE
GENMAB A/S 09-Apr-2025 16:36:23 PM 59 1184.00 CEUX
GENMAB A/S 09-Apr-2025 16:36:27 PM 26 1184.00 AQEU
GENMAB A/S 09-Apr-2025 16:36:31 PM 68 1183.50 XCSE
GENMAB A/S 09-Apr-2025 16:36:32 PM 20 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:36:32 PM 33 1183.00 CEUX
GENMAB A/S 09-Apr-2025 16:36:46 PM 30 1183.00 TQEX
GENMAB A/S 09-Apr-2025 16:37:09 PM 4 1182.50 AQEU
GENMAB A/S 09-Apr-2025 16:37:11 PM 85 1182.00 XCSE
GENMAB A/S 09-Apr-2025 16:37:11 PM 43 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:37:11 PM 21 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:37:11 PM 1 1182.50 XCSE
GENMAB A/S 09-Apr-2025 16:37:11 PM 27 1181.50 TQEX
GENMAB A/S 09-Apr-2025 16:37:11 PM 38 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:37:11 PM 11 1182.00 CEUX
GENMAB A/S 09-Apr-2025 16:37:11 PM 23 1182.50 AQEU
GENMAB A/S 09-Apr-2025 16:37:15 PM 45 1181.50 CEUX
GENMAB A/S 09-Apr-2025 16:37:25 PM 44 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:37:26 PM 26 1181.00 AQEU
GENMAB A/S 09-Apr-2025 16:37:43 PM 67 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:37:44 PM 24 1180.50 CEUX
GENMAB A/S 09-Apr-2025 16:38:02 PM 6 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:38:02 PM 21 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:38:02 PM 43 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:38:02 PM 3 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:38:02 PM 54 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:38:02 PM 27 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:38:02 PM 48 1180.50 CEUX
GENMAB A/S 09-Apr-2025 16:38:03 PM 24 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:38:10 PM 2 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:38:10 PM 29 1180.00 AQEU
GENMAB A/S 09-Apr-2025 16:38:11 PM 16 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:38:16 PM 44 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:38:16 PM 15 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:38:17 PM 5 1179.00 AQEU
GENMAB A/S 09-Apr-2025 16:38:21 PM 19 1179.00 AQEU
GENMAB A/S 09-Apr-2025 16:38:24 PM 29 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:38:24 PM 5 1178.50 XCSE

188

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:39:03 PM 26 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:39:03 PM 38 1177.50 TQEX
GENMAB A/S 09-Apr-2025 16:39:03 PM 39 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:39:03 PM 24 1177.50 AQEU
GENMAB A/S 09-Apr-2025 16:39:05 PM 19 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:39:05 PM 15 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:39:39 PM 20 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:39:39 PM 6 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:39:39 PM 36 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:39:39 PM 64 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:39:40 PM 43 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:39:40 PM 14 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:39:44 PM 110 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:39:45 PM 5 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 43 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 25 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 2 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 3 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 3 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 3 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 2 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 2 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:15 PM 16 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:40:23 PM 43 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:23 PM 12 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:23 PM 13 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:23 PM 37 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:23 PM 5 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:24 PM 28 1176.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:24 PM 29 1176.00 CEUX
GENMAB A/S 09-Apr-2025 16:40:37 PM 38 1176.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:37 PM 16 1176.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:37 PM 42 1176.00 XCSE
GENMAB A/S 09-Apr-2025 16:40:37 PM 5 1175.00 CEUX
GENMAB A/S 09-Apr-2025 16:40:47 PM 29 1175.50 TQEX
GENMAB A/S 09-Apr-2025 16:40:47 PM 1 1176.00 CEUX
GENMAB A/S 09-Apr-2025 16:40:55 PM 1 1176.50 CEUX
GENMAB A/S 09-Apr-2025 16:41:06 PM 14 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:41:06 PM 14 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:41:06 PM 13 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:41:06 PM 36 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:41:06 PM 7 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:41:17 PM 86 1177.00 XCSE

189

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:41:17 PM 7 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:41:17 PM 14 1177.00 XCSE
GENMAB A/S 09-Apr-2025 16:41:17 PM 11 1177.00 TQEX
GENMAB A/S 09-Apr-2025 16:41:17 PM 14 1177.00 TQEX
GENMAB A/S 09-Apr-2025 16:41:17 PM 15 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:41:17 PM 2 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:41:17 PM 4 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:41:24 PM 36 1176.50 CEUX
GENMAB A/S 09-Apr-2025 16:41:43 PM 78 1176.00 XCSE
GENMAB A/S 09-Apr-2025 16:41:43 PM 12 1176.50 XCSE
GENMAB A/S 09-Apr-2025 16:41:43 PM 16 1176.50 XCSE
GENMAB A/S 09-Apr-2025 16:41:43 PM 43 1176.50 XCSE
GENMAB A/S 09-Apr-2025 16:41:43 PM 14 1176.50 XCSE
GENMAB A/S 09-Apr-2025 16:41:43 PM 25 1176.50 XCSE
GENMAB A/S 09-Apr-2025 16:41:43 PM 64 1176.00 CEUX
GENMAB A/S 09-Apr-2025 16:43:04 PM 48 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:43:45 PM 88 1178.50 CEUX
GENMAB A/S 09-Apr-2025 16:44:05 PM 74 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:44:08 PM 6 1178.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:08 PM 7 1178.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:08 PM 23 1178.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:08 PM 3 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:16 PM 30 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 43 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 14 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 10 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 110 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 9 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 50 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 50 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:16 PM 1 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 12 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 43 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 29 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 28 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 12 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 43 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:17 PM 14 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:22 PM 14 1178.50 XCSE

190

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:44:22 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:44:22 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:44:22 PM 12 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:22 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:33 PM 30 1178.00 TQEX
GENMAB A/S 09-Apr-2025 16:44:33 PM 63 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:33 PM 23 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:34 PM 15 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:34 PM 2 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:34 PM 36 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:34 PM 2 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:54 PM 28 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:54 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:54 PM 1 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:54 PM 47 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:54 PM 14 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:54 PM 7 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:44:57 PM 83 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:44:57 PM 15 1177.00 TQEX
GENMAB A/S 09-Apr-2025 16:44:57 PM 23 1177.00 TQEX
GENMAB A/S 09-Apr-2025 16:44:57 PM 5 1177.00 TQEX
GENMAB A/S 09-Apr-2025 16:44:57 PM 38 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:44:57 PM 38 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:44:57 PM 34 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:44:57 PM 20 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:57 PM 2 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:57 PM 14 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:44:57 PM 47 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:45:04 PM 32 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:45:27 PM 41 1177.00 CEUX
GENMAB A/S 09-Apr-2025 16:46:07 PM 33 1179.00 TQEX
GENMAB A/S 09-Apr-2025 16:46:07 PM 86 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:46:09 PM 82 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:46:09 PM 43 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:46:09 PM 14 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:46:09 PM 37 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:46:09 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:46:09 PM 3 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:46:13 PM 78 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:46:13 PM 9 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:46:24 PM 12 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:46:24 PM 14 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:46:24 PM 14 1178.50 XCSE

191

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:46:24 PM 46 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:46:49 PM 26 1179.00 TQEX
GENMAB A/S 09-Apr-2025 16:46:49 PM 36 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:46:49 PM 6 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:47:55 PM 87 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:47:55 PM 43 1179.50 TQEX
GENMAB A/S 09-Apr-2025 16:47:55 PM 44 1179.50 AQEU
GENMAB A/S 09-Apr-2025 16:47:56 PM 4 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 61 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 42 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 7 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 43 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 14 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 42 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 11 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:02 PM 20 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:02 PM 64 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:03 PM 9 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:03 PM 5 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:03 PM 4 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:03 PM 6 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:03 PM 3 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:03 PM 5 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:03 PM 31 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:03 PM 40 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:04 PM 43 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:04 PM 13 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:04 PM 12 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:04 PM 37 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:04 PM 5 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:04 PM 36 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:48:04 PM 6 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:48:04 PM 6 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:48:04 PM 7 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:48:04 PM 12 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:05 PM 9 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:05 PM 42 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:05 PM 72 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:05 PM 15 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:12 PM 65 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:13 PM 22 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:16 PM 80 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:16 PM 8 1178.50 XCSE

192

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:48:16 PM 36 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:16 PM 57 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:48:47 PM 52 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:48:47 PM 31 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:49:10 PM 81 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:49:10 PM 3 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:49:10 PM 14 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:49:10 PM 43 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:49:10 PM 40 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:49:10 PM 44 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:49:10 PM 8 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:49:10 PM 36 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:49:10 PM 6 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:49:10 PM 8 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:49:10 PM 13 1179.50 AQEU
GENMAB A/S 09-Apr-2025 16:49:10 PM 15 1179.50 AQEU
GENMAB A/S 09-Apr-2025 16:49:10 PM 5 1179.50 AQEU
GENMAB A/S 09-Apr-2025 16:49:39 PM 23 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:49:39 PM 43 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:49:39 PM 7 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:49:39 PM 37 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:49:39 PM 5 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:49:40 PM 36 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:15 PM 86 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:50:15 PM 37 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:50:15 PM 47 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:50:15 PM 25 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:50:15 PM 25 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:50:15 PM 46 1180.50 CEUX
GENMAB A/S 09-Apr-2025 16:50:15 PM 32 1180.50 CEUX
GENMAB A/S 09-Apr-2025 16:50:15 PM 33 1180.50 AQEU
GENMAB A/S 09-Apr-2025 16:50:16 PM 38 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 16 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 21 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 35 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 18 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 18 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 58 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 12 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 4 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 9 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 32 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 16 1181.00 XCSE

193

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:50:16 PM 43 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:16 PM 10 1181.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:17 PM 6 1180.00 AQEU
GENMAB A/S 09-Apr-2025 16:50:17 PM 31 1180.00 AQEU
GENMAB A/S 09-Apr-2025 16:50:19 PM 28 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 6 1180.00 TQEX
GENMAB A/S 09-Apr-2025 16:50:40 PM 21 1180.00 TQEX
GENMAB A/S 09-Apr-2025 16:50:40 PM 6 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 4 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 3 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 2 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 4 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 1 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:50:40 PM 24 1180.00 AQEU
GENMAB A/S 09-Apr-2025 16:50:46 PM 45 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:46 PM 9 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:46 PM 43 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:46 PM 12 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:46 PM 1 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:46 PM 35 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:50:46 PM 40 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:50:47 PM 12 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:47 PM 43 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:47 PM 14 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:47 PM 12 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:47 PM 29 1180.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:48 PM 25 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:54 PM 2 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:50:54 PM 72 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:54 PM 2 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:50:55 PM 11 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:51:12 PM 28 1178.50 AQEU
GENMAB A/S 09-Apr-2025 16:51:13 PM 38 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:13 PM 86 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:17 PM 2 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:17 PM 12 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:17 PM 12 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:17 PM 13 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:18 PM 10 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:51:18 PM 27 1179.50 AQEU
GENMAB A/S 09-Apr-2025 16:51:47 PM 47 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:51:47 PM 77 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:51:48 PM 3 1178.50 TQEX

194

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:51:48 PM 3 1178.50 TQEX
GENMAB A/S 09-Apr-2025 16:51:48 PM 2 1178.50 TQEX
GENMAB A/S 09-Apr-2025 16:51:48 PM 3 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 79 1181.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:55 PM 30 1182.00 TQEX
GENMAB A/S 09-Apr-2025 16:51:55 PM 36 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 51 1182.50 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 24 1182.50 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 70 1181.50 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 8 1181.50 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 20 1181.50 CEUX
GENMAB A/S 09-Apr-2025 16:51:55 PM 1 1181.00 AQEU
GENMAB A/S 09-Apr-2025 16:51:55 PM 23 1181.00 AQEU
GENMAB A/S 09-Apr-2025 16:51:56 PM 77 1180.50 XCSE
GENMAB A/S 09-Apr-2025 16:51:56 PM 8 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:51:56 PM 8 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:51:56 PM 3 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:51:56 PM 5 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:51:56 PM 5 1181.00 CEUX
GENMAB A/S 09-Apr-2025 16:52:01 PM 9 1180.50 TQEX
GENMAB A/S 09-Apr-2025 16:52:07 PM 72 1180.00 CEUX
GENMAB A/S 09-Apr-2025 16:52:08 PM 72 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:08 PM 10 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:11 PM 15 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:11 PM 26 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:11 PM 30 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:12 PM 27 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:52:35 PM 76 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 43 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 22 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 24 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 12 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 9 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 4 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 14 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 16 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 43 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 20 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:57 PM 28 1178.50 TQEX
GENMAB A/S 09-Apr-2025 16:52:57 PM 24 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:52:57 PM 24 1178.50 AQEU
GENMAB A/S 09-Apr-2025 16:52:58 PM 15 1178.50 XCSE

195

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:52:58 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:58 PM 12 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:58 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:58 PM 14 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:52:58 PM 9 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:02 PM 1 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:05 PM 14 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:05 PM 9 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:05 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:05 PM 13 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:12 PM 12 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:12 PM 43 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:12 PM 5 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:12 PM 30 1178.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:12 PM 36 1178.50 CEUX
GENMAB A/S 09-Apr-2025 16:53:12 PM 8 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:53:12 PM 47 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:53:16 PM 10 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:53:23 PM 36 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:53:24 PM 36 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:53:25 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:25 PM 14 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:25 PM 31 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:27 PM 10 1178.00 CEUX
GENMAB A/S 09-Apr-2025 16:53:32 PM 34 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:32 PM 13 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:32 PM 1 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:32 PM 2 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:41 PM 25 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:53:41 PM 25 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:41 PM 27 1178.50 TQEX
GENMAB A/S 09-Apr-2025 16:53:41 PM 43 1178.50 CEUX
GENMAB A/S 09-Apr-2025 16:53:49 PM 28 1178.50 XCSE
GENMAB A/S 09-Apr-2025 16:53:49 PM 5 1178.50 CEUX
GENMAB A/S 09-Apr-2025 16:53:49 PM 1 1178.50 CEUX
GENMAB A/S 09-Apr-2025 16:53:49 PM 24 1178.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:16 PM 43 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:54:16 PM 12 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:54:16 PM 12 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:54:16 PM 14 1179.50 XCSE
GENMAB A/S 09-Apr-2025 16:54:16 PM 2 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:54:16 PM 37 1179.00 XCSE
GENMAB A/S 09-Apr-2025 16:54:16 PM 8 1179.00 XCSE

196

Exhibit 99.1(a)

APPENDIX Share buy-back programme - Specification for April 7 – April 9, 2025

Graphic

GENMAB A/S 09-Apr-2025 16:54:16 PM 36 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:54:16 PM 7 1179.00 CEUX
GENMAB A/S 09-Apr-2025 16:54:16 PM 23 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:16 PM 8 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:16 PM 8 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:16 PM 1 1179.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:18 PM 24 1178.00 AQEU
GENMAB A/S 09-Apr-2025 16:54:25 PM 13 1177.50 XCSE
GENMAB A/S 09-Apr-2025 16:54:25 PM 28 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:34 PM 3 1177.00 AQEU
GENMAB A/S 09-Apr-2025 16:54:45 PM 22 1177.00 AQEU
GENMAB A/S 09-Apr-2025 16:54:49 PM 2 1177.50 CEUX
GENMAB A/S 09-Apr-2025 16:54:49 PM 26 1177.50 AQEU

197

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 09:37:32 AM 1 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:37:32 AM 87 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:37:32 AM 78 1259.50 XCSE
GENMAB A/S 10-Apr-2025 09:37:32 AM 86 1260.50 CEUX
GENMAB A/S 10-Apr-2025 09:37:32 AM 74 1259.50 CEUX
GENMAB A/S 10-Apr-2025 09:37:32 AM 76 1260.00 AQEU
GENMAB A/S 10-Apr-2025 09:38:01 AM 3 1258.50 XCSE
GENMAB A/S 10-Apr-2025 09:38:01 AM 77 1258.50 XCSE
GENMAB A/S 10-Apr-2025 09:38:01 AM 83 1259.00 TQEX
GENMAB A/S 10-Apr-2025 09:38:01 AM 81 1259.00 AQEU
GENMAB A/S 10-Apr-2025 09:38:12 AM 53 1259.00 TQEX
GENMAB A/S 10-Apr-2025 09:38:54 AM 55 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:38:54 AM 26 1260.50 TQEX
GENMAB A/S 10-Apr-2025 09:38:54 AM 27 1260.50 CEUX
GENMAB A/S 10-Apr-2025 09:39:12 AM 30 1259.50 XCSE
GENMAB A/S 10-Apr-2025 09:39:12 AM 26 1260.00 AQEU
GENMAB A/S 10-Apr-2025 09:39:13 AM 11 1259.50 CEUX
GENMAB A/S 10-Apr-2025 09:39:29 AM 3 1260.00 AQEU
GENMAB A/S 10-Apr-2025 09:39:39 AM 47 1259.50 XCSE
GENMAB A/S 10-Apr-2025 09:39:39 AM 38 1258.50 XCSE
GENMAB A/S 10-Apr-2025 09:39:39 AM 37 1259.00 TQEX
GENMAB A/S 10-Apr-2025 09:39:39 AM 15 1259.50 CEUX
GENMAB A/S 10-Apr-2025 09:39:39 AM 26 1258.50 CEUX
GENMAB A/S 10-Apr-2025 09:39:39 AM 23 1260.00 AQEU
GENMAB A/S 10-Apr-2025 09:40:09 AM 32 1261.00 XCSE
GENMAB A/S 10-Apr-2025 09:40:09 AM 19 1261.00 XCSE
GENMAB A/S 10-Apr-2025 09:40:24 AM 36 1261.00 XCSE
GENMAB A/S 10-Apr-2025 09:40:24 AM 36 1260.50 CEUX
GENMAB A/S 10-Apr-2025 09:40:59 AM 26 1261.00 XCSE
GENMAB A/S 10-Apr-2025 09:40:59 AM 37 1261.00 CEUX
GENMAB A/S 10-Apr-2025 09:42:03 AM 23 1263.00 XCSE
GENMAB A/S 10-Apr-2025 09:42:05 AM 55 1263.00 XCSE
GENMAB A/S 10-Apr-2025 09:43:05 AM 6 1262.00 XCSE
GENMAB A/S 10-Apr-2025 09:43:05 AM 74 1262.00 XCSE
GENMAB A/S 10-Apr-2025 09:43:05 AM 23 1262.00 CEUX
GENMAB A/S 10-Apr-2025 09:43:05 AM 22 1262.00 CEUX
GENMAB A/S 10-Apr-2025 09:43:06 AM 27 1261.00 CEUX
GENMAB A/S 10-Apr-2025 09:43:29 AM 61 1262.00 XCSE
GENMAB A/S 10-Apr-2025 09:43:29 AM 58 1262.00 CEUX
GENMAB A/S 10-Apr-2025 09:44:26 AM 68 1261.00 XCSE
GENMAB A/S 10-Apr-2025 09:44:26 AM 14 1261.00 CEUX
GENMAB A/S 10-Apr-2025 09:44:29 AM 32 1260.00 XCSE
GENMAB A/S 10-Apr-2025 09:44:29 AM 20 1260.00 XCSE

1

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 09:44:31 AM 37 1259.00 XCSE
GENMAB A/S 10-Apr-2025 09:44:31 AM 34 1259.50 CEUX
GENMAB A/S 10-Apr-2025 09:44:39 AM 26 1259.00 XCSE
GENMAB A/S 10-Apr-2025 09:45:02 AM 35 1258.00 CEUX
GENMAB A/S 10-Apr-2025 09:45:05 AM 9 1257.50 XCSE
GENMAB A/S 10-Apr-2025 09:45:05 AM 1 1257.50 XCSE
GENMAB A/S 10-Apr-2025 09:45:05 AM 29 1257.50 XCSE
GENMAB A/S 10-Apr-2025 09:45:06 AM 45 1257.50 CEUX
GENMAB A/S 10-Apr-2025 09:45:29 AM 1 1257.50 CEUX
GENMAB A/S 10-Apr-2025 09:45:43 AM 29 1257.50 CEUX
GENMAB A/S 10-Apr-2025 09:45:48 AM 33 1257.00 XCSE
GENMAB A/S 10-Apr-2025 09:45:48 AM 50 1256.50 CEUX
GENMAB A/S 10-Apr-2025 09:45:59 AM 11 1256.00 XCSE
GENMAB A/S 10-Apr-2025 09:46:03 AM 21 1256.00 XCSE
GENMAB A/S 10-Apr-2025 09:46:17 AM 13 1255.00 XCSE
GENMAB A/S 10-Apr-2025 09:46:17 AM 13 1255.00 XCSE
GENMAB A/S 10-Apr-2025 09:46:36 AM 35 1254.00 XCSE
GENMAB A/S 10-Apr-2025 09:46:49 AM 29 1253.50 CEUX
GENMAB A/S 10-Apr-2025 09:47:38 AM 40 1253.00 XCSE
GENMAB A/S 10-Apr-2025 09:48:01 AM 27 1252.50 CEUX
GENMAB A/S 10-Apr-2025 09:48:02 AM 31 1252.00 XCSE
GENMAB A/S 10-Apr-2025 09:48:02 AM 18 1251.50 CEUX
GENMAB A/S 10-Apr-2025 09:48:02 AM 19 1251.50 CEUX
GENMAB A/S 10-Apr-2025 09:48:19 AM 63 1251.50 XCSE
GENMAB A/S 10-Apr-2025 09:48:19 AM 40 1251.00 TQEX
GENMAB A/S 10-Apr-2025 09:48:19 AM 30 1251.50 CEUX
GENMAB A/S 10-Apr-2025 09:48:20 AM 38 1250.50 XCSE
GENMAB A/S 10-Apr-2025 09:48:24 AM 31 1251.00 XCSE
GENMAB A/S 10-Apr-2025 09:48:41 AM 27 1250.00 XCSE
GENMAB A/S 10-Apr-2025 09:48:41 AM 27 1249.50 CEUX
GENMAB A/S 10-Apr-2025 09:48:44 AM 31 1248.50 XCSE
GENMAB A/S 10-Apr-2025 09:49:41 AM 2 1253.50 TQEX
GENMAB A/S 10-Apr-2025 09:49:41 AM 40 1253.50 TQEX
GENMAB A/S 10-Apr-2025 09:50:56 AM 70 1256.00 XCSE
GENMAB A/S 10-Apr-2025 09:51:36 AM 26 1255.50 TQEX
GENMAB A/S 10-Apr-2025 09:51:50 AM 75 1255.00 XCSE
GENMAB A/S 10-Apr-2025 09:51:50 AM 32 1255.00 CEUX
GENMAB A/S 10-Apr-2025 09:53:53 AM 65 1259.00 CEUX
GENMAB A/S 10-Apr-2025 09:54:13 AM 28 1258.50 AQEU
GENMAB A/S 10-Apr-2025 09:55:16 AM 78 1261.00 CEUX
GENMAB A/S 10-Apr-2025 09:55:19 AM 25 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:55:19 AM 57 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:55:19 AM 43 1260.50 TQEX

2

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 09:55:23 AM 75 1260.00 CEUX
GENMAB A/S 10-Apr-2025 09:55:37 AM 82 1260.00 XCSE
GENMAB A/S 10-Apr-2025 09:55:37 AM 9 1260.00 TQEX
GENMAB A/S 10-Apr-2025 09:55:37 AM 35 1260.00 TQEX
GENMAB A/S 10-Apr-2025 09:55:37 AM 27 1260.00 CEUX
GENMAB A/S 10-Apr-2025 09:57:00 AM 3 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:57:00 AM 57 1260.50 XCSE
GENMAB A/S 10-Apr-2025 09:57:53 AM 79 1259.50 XCSE
GENMAB A/S 10-Apr-2025 09:59:02 AM 72 1261.50 CEUX
GENMAB A/S 10-Apr-2025 09:59:16 AM 87 1261.00 XCSE
GENMAB A/S 10-Apr-2025 09:59:35 AM 75 1260.00 XCSE
GENMAB A/S 10-Apr-2025 09:59:35 AM 9 1260.00 XCSE
GENMAB A/S 10-Apr-2025 09:59:35 AM 72 1260.00 CEUX
GENMAB A/S 10-Apr-2025 09:59:55 AM 37 1260.00 XCSE
GENMAB A/S 10-Apr-2025 09:59:55 AM 47 1260.00 XCSE
GENMAB A/S 10-Apr-2025 09:59:55 AM 7 1260.00 CEUX
GENMAB A/S 10-Apr-2025 09:59:55 AM 35 1260.00 CEUX
GENMAB A/S 10-Apr-2025 10:00:07 AM 84 1261.00 XCSE
GENMAB A/S 10-Apr-2025 10:00:15 AM 87 1261.00 XCSE
GENMAB A/S 10-Apr-2025 10:00:43 AM 37 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:00:47 AM 25 1260.00 XCSE
GENMAB A/S 10-Apr-2025 10:00:55 AM 57 1260.00 XCSE
GENMAB A/S 10-Apr-2025 10:00:55 AM 29 1260.00 CEUX
GENMAB A/S 10-Apr-2025 10:02:45 AM 40 1259.00 XCSE
GENMAB A/S 10-Apr-2025 10:02:45 AM 49 1259.00 XCSE
GENMAB A/S 10-Apr-2025 10:02:45 AM 26 1259.00 CEUX
GENMAB A/S 10-Apr-2025 10:02:52 AM 54 1259.50 CEUX
GENMAB A/S 10-Apr-2025 10:04:51 AM 79 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:05:31 AM 20 1262.00 XCSE
GENMAB A/S 10-Apr-2025 10:05:31 AM 1 1262.00 XCSE
GENMAB A/S 10-Apr-2025 10:05:31 AM 63 1262.00 XCSE
GENMAB A/S 10-Apr-2025 10:05:31 AM 1 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:05:31 AM 62 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:05:40 AM 86 1261.00 XCSE
GENMAB A/S 10-Apr-2025 10:05:40 AM 83 1260.00 XCSE
GENMAB A/S 10-Apr-2025 10:05:40 AM 51 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:05:40 AM 43 1260.00 CEUX
GENMAB A/S 10-Apr-2025 10:07:13 AM 34 1263.00 CEUX
GENMAB A/S 10-Apr-2025 10:07:13 AM 16 1263.00 CEUX
GENMAB A/S 10-Apr-2025 10:07:30 AM 29 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:07:37 AM 60 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:07:56 AM 35 1262.00 TQEX
GENMAB A/S 10-Apr-2025 10:08:01 AM 1 1261.50 CEUX

3

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 10:09:38 AM 1 1263.00 CEUX
GENMAB A/S 10-Apr-2025 10:10:12 AM 1 1263.50 TQEX
GENMAB A/S 10-Apr-2025 10:10:27 AM 29 1263.50 TQEX
GENMAB A/S 10-Apr-2025 10:10:29 AM 84 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:10:29 AM 68 1263.00 CEUX
GENMAB A/S 10-Apr-2025 10:10:40 AM 43 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:10:40 AM 15 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:10:40 AM 24 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:11:23 AM 29 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:11:23 AM 59 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:11:25 AM 17 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:11:59 AM 10 1263.50 TQEX
GENMAB A/S 10-Apr-2025 10:11:59 AM 13 1263.50 CEUX
GENMAB A/S 10-Apr-2025 10:11:59 AM 69 1263.50 CEUX
GENMAB A/S 10-Apr-2025 10:12:01 AM 19 1263.50 TQEX
GENMAB A/S 10-Apr-2025 10:12:13 AM 20 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:12:15 AM 12 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:12:15 AM 3 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:12:15 AM 30 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:12:59 AM 43 1266.00 XCSE
GENMAB A/S 10-Apr-2025 10:12:59 AM 32 1266.00 XCSE
GENMAB A/S 10-Apr-2025 10:12:59 AM 51 1265.50 TQEX
GENMAB A/S 10-Apr-2025 10:13:00 AM 82 1265.00 XCSE
GENMAB A/S 10-Apr-2025 10:13:00 AM 43 1265.00 XCSE
GENMAB A/S 10-Apr-2025 10:13:00 AM 11 1265.00 XCSE
GENMAB A/S 10-Apr-2025 10:13:00 AM 84 1265.00 CEUX
GENMAB A/S 10-Apr-2025 10:13:05 AM 82 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:13:05 AM 69 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:13:05 AM 81 1264.00 CEUX
GENMAB A/S 10-Apr-2025 10:13:28 AM 65 1262.50 CEUX
GENMAB A/S 10-Apr-2025 10:13:28 AM 13 1262.50 CEUX
GENMAB A/S 10-Apr-2025 10:14:53 AM 83 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:15:45 AM 31 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:16:10 AM 53 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:16:14 AM 4 1262.00 TQEX
GENMAB A/S 10-Apr-2025 10:16:14 AM 41 1262.00 TQEX
GENMAB A/S 10-Apr-2025 10:16:14 AM 43 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:16:14 AM 5 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:16:14 AM 7 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:18:02 AM 16 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:18:02 AM 1 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:18:02 AM 69 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:18:06 AM 29 1261.00 CEUX

4

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 10:19:42 AM 43 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:19:42 AM 30 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:19:42 AM 14 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:19:42 AM 46 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:19:42 AM 20 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:11 AM 18 1263.50 XCSE
GENMAB A/S 10-Apr-2025 10:20:11 AM 15 1263.50 XCSE
GENMAB A/S 10-Apr-2025 10:20:11 AM 45 1263.50 XCSE
GENMAB A/S 10-Apr-2025 10:20:11 AM 15 1263.50 XCSE
GENMAB A/S 10-Apr-2025 10:20:29 AM 47 1263.00 XCSE
GENMAB A/S 10-Apr-2025 10:20:29 AM 77 1263.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:30 AM 82 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:20:30 AM 6 1262.50 TQEX
GENMAB A/S 10-Apr-2025 10:20:30 AM 16 1262.50 TQEX
GENMAB A/S 10-Apr-2025 10:20:33 AM 11 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:37 AM 82 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:20:37 AM 49 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:37 AM 17 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:37 AM 4 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:37 AM 4 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:20:37 AM 24 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:21:22 AM 16 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:22:57 AM 1 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:22:57 AM 88 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:22:57 AM 27 1262.50 TQEX
GENMAB A/S 10-Apr-2025 10:23:19 AM 56 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:23:19 AM 30 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:23:19 AM 45 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:23:20 AM 10 1260.50 XCSE
GENMAB A/S 10-Apr-2025 10:23:48 AM 88 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:23:48 AM 40 1262.50 CEUX
GENMAB A/S 10-Apr-2025 10:24:30 AM 50 1262.50 TQEX
GENMAB A/S 10-Apr-2025 10:24:57 AM 39 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:24:57 AM 47 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:25:06 AM 50 1261.00 CEUX
GENMAB A/S 10-Apr-2025 10:28:46 AM 10 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:29:04 AM 25 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:29:05 AM 88 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:30:42 AM 88 1266.50 XCSE
GENMAB A/S 10-Apr-2025 10:30:42 AM 50 1266.00 XCSE
GENMAB A/S 10-Apr-2025 10:30:42 AM 30 1266.00 XCSE
GENMAB A/S 10-Apr-2025 10:30:42 AM 3 1266.00 XCSE
GENMAB A/S 10-Apr-2025 10:30:42 AM 29 1266.00 XCSE

5

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 10:30:42 AM 48 1266.00 TQEX
GENMAB A/S 10-Apr-2025 10:30:42 AM 88 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:30:42 AM 65 1265.50 CEUX
GENMAB A/S 10-Apr-2025 10:30:43 AM 4 1265.00 XCSE
GENMAB A/S 10-Apr-2025 10:31:55 AM 87 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:31:55 AM 10 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:32:04 AM 45 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:32:13 AM 26 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:32:17 AM 43 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:32:17 AM 36 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:32:17 AM 3 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:32:21 AM 4 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:32:29 AM 87 1266.00 XCSE
GENMAB A/S 10-Apr-2025 10:32:29 AM 73 1265.50 CEUX
GENMAB A/S 10-Apr-2025 10:32:55 AM 84 1265.00 XCSE
GENMAB A/S 10-Apr-2025 10:33:00 AM 50 1264.50 CEUX
GENMAB A/S 10-Apr-2025 10:33:28 AM 84 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:36:02 AM 64 1264.50 CEUX
GENMAB A/S 10-Apr-2025 10:36:37 AM 86 1263.50 XCSE
GENMAB A/S 10-Apr-2025 10:36:54 AM 26 1263.00 TQEX
GENMAB A/S 10-Apr-2025 10:36:54 AM 61 1263.00 CEUX
GENMAB A/S 10-Apr-2025 10:37:16 AM 89 1262.50 XCSE
GENMAB A/S 10-Apr-2025 10:37:17 AM 36 1262.00 CEUX
GENMAB A/S 10-Apr-2025 10:37:23 AM 86 1261.50 XCSE
GENMAB A/S 10-Apr-2025 10:39:52 AM 10 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:39:52 AM 36 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:39:52 AM 43 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:39:52 AM 17 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:39:52 AM 6 1264.00 XCSE
GENMAB A/S 10-Apr-2025 10:41:21 AM 8 1268.00 XCSE
GENMAB A/S 10-Apr-2025 10:41:21 AM 8 1268.00 XCSE
GENMAB A/S 10-Apr-2025 10:41:21 AM 14 1268.00 XCSE
GENMAB A/S 10-Apr-2025 10:41:21 AM 26 1268.00 XCSE
GENMAB A/S 10-Apr-2025 10:41:25 AM 83 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:41:42 AM 3 1267.00 TQEX
GENMAB A/S 10-Apr-2025 10:42:40 AM 2 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:44:32 AM 8 1266.50 XCSE
GENMAB A/S 10-Apr-2025 10:44:33 AM 36 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:44:33 AM 21 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:44:34 AM 21 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:44:50 AM 43 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:44:50 AM 30 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:44:50 AM 36 1267.50 XCSE

6

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 10:46:06 AM 86 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:46:06 AM 30 1267.50 TQEX
GENMAB A/S 10-Apr-2025 10:46:06 AM 88 1267.50 CEUX
GENMAB A/S 10-Apr-2025 10:46:07 AM 10 1266.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:25 AM 10 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:25 AM 29 1267.50 TQEX
GENMAB A/S 10-Apr-2025 10:48:25 AM 3 1267.50 TQEX
GENMAB A/S 10-Apr-2025 10:48:25 AM 89 1267.50 CEUX
GENMAB A/S 10-Apr-2025 10:48:28 AM 36 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:28 AM 43 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:28 AM 30 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:32 AM 13 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:32 AM 36 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:36 AM 71 1266.50 XCSE
GENMAB A/S 10-Apr-2025 10:48:36 AM 28 1266.50 TQEX
GENMAB A/S 10-Apr-2025 10:48:36 AM 1 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:48:36 AM 87 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:49:04 AM 85 1266.50 XCSE
GENMAB A/S 10-Apr-2025 10:49:04 AM 88 1266.50 CEUX
GENMAB A/S 10-Apr-2025 10:49:12 AM 3 1265.50 CEUX
GENMAB A/S 10-Apr-2025 10:49:59 AM 1 1265.50 XCSE
GENMAB A/S 10-Apr-2025 10:49:59 AM 1 1265.50 XCSE
GENMAB A/S 10-Apr-2025 10:49:59 AM 1 1265.50 XCSE
GENMAB A/S 10-Apr-2025 10:49:59 AM 85 1265.50 XCSE
GENMAB A/S 10-Apr-2025 10:49:59 AM 1 1265.50 CEUX
GENMAB A/S 10-Apr-2025 10:49:59 AM 60 1265.50 CEUX
GENMAB A/S 10-Apr-2025 10:49:59 AM 24 1265.50 CEUX
GENMAB A/S 10-Apr-2025 10:50:00 AM 10 1265.00 XCSE
GENMAB A/S 10-Apr-2025 10:51:34 AM 8 1267.50 CEUX
GENMAB A/S 10-Apr-2025 10:51:34 AM 63 1267.50 CEUX
GENMAB A/S 10-Apr-2025 10:51:35 AM 10 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:51:35 AM 79 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:52:57 AM 30 1267.50 CEUX
GENMAB A/S 10-Apr-2025 10:52:57 AM 46 1267.50 CEUX
GENMAB A/S 10-Apr-2025 10:54:38 AM 81 1268.00 XCSE
GENMAB A/S 10-Apr-2025 10:54:38 AM 6 1268.00 XCSE
GENMAB A/S 10-Apr-2025 10:54:38 AM 18 1268.00 CEUX
GENMAB A/S 10-Apr-2025 10:54:38 AM 37 1268.00 CEUX
GENMAB A/S 10-Apr-2025 10:54:38 AM 8 1268.00 CEUX
GENMAB A/S 10-Apr-2025 10:54:57 AM 16 1267.50 TQEX
GENMAB A/S 10-Apr-2025 10:56:46 AM 10 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:56:46 AM 20 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:56:46 AM 13 1267.50 XCSE

7

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 10:56:46 AM 2 1267.50 TQEX
GENMAB A/S 10-Apr-2025 10:56:46 AM 9 1267.50 TQEX
GENMAB A/S 10-Apr-2025 10:56:58 AM 4 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:56:58 AM 82 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:56:58 AM 10 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:56:58 AM 20 1267.00 XCSE
GENMAB A/S 10-Apr-2025 10:57:41 AM 36 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:57:47 AM 36 1267.50 XCSE
GENMAB A/S 10-Apr-2025 10:58:57 AM 43 1268.50 XCSE
GENMAB A/S 10-Apr-2025 10:58:57 AM 36 1268.50 XCSE
GENMAB A/S 10-Apr-2025 10:58:57 AM 14 1268.50 XCSE
GENMAB A/S 10-Apr-2025 10:58:57 AM 19 1268.50 XCSE
GENMAB A/S 10-Apr-2025 10:58:57 AM 86 1268.00 CEUX
GENMAB A/S 10-Apr-2025 10:59:25 AM 18 1269.50 XCSE
GENMAB A/S 10-Apr-2025 10:59:25 AM 28 1269.50 XCSE
GENMAB A/S 10-Apr-2025 10:59:47 AM 14 1269.50 XCSE
GENMAB A/S 10-Apr-2025 10:59:55 AM 4 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:00:04 AM 1 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:01:33 AM 83 1270.50 XCSE
GENMAB A/S 10-Apr-2025 11:01:33 AM 35 1271.00 XCSE
GENMAB A/S 10-Apr-2025 11:01:33 AM 43 1271.00 XCSE
GENMAB A/S 10-Apr-2025 11:01:33 AM 34 1271.00 XCSE
GENMAB A/S 10-Apr-2025 11:01:33 AM 26 1270.50 TQEX
GENMAB A/S 10-Apr-2025 11:01:33 AM 34 1271.00 CEUX
GENMAB A/S 10-Apr-2025 11:01:33 AM 51 1271.00 CEUX
GENMAB A/S 10-Apr-2025 11:01:49 AM 27 1270.00 CEUX
GENMAB A/S 10-Apr-2025 11:01:49 AM 61 1270.00 CEUX
GENMAB A/S 10-Apr-2025 11:02:02 AM 83 1269.50 XCSE
GENMAB A/S 10-Apr-2025 11:02:02 AM 35 1269.50 TQEX
GENMAB A/S 10-Apr-2025 11:04:07 AM 83 1270.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:07 AM 89 1269.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:07 AM 50 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:04:07 AM 23 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:04:07 AM 1 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:07 AM 50 1269.50 AQEU
GENMAB A/S 10-Apr-2025 11:04:07 AM 76 1270.00 CEUX
GENMAB A/S 10-Apr-2025 11:04:07 AM 51 1269.00 CEUX
GENMAB A/S 10-Apr-2025 11:04:07 AM 34 1269.00 CEUX
GENMAB A/S 10-Apr-2025 11:04:08 AM 10 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:08 AM 70 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:53 AM 25 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:53 AM 57 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:04:53 AM 81 1267.50 CEUX

8

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 11:04:53 AM 1 1267.50 CEUX
GENMAB A/S 10-Apr-2025 11:05:13 AM 45 1268.00 XCSE
GENMAB A/S 10-Apr-2025 11:05:41 AM 57 1267.00 XCSE
GENMAB A/S 10-Apr-2025 11:05:41 AM 26 1267.00 TQEX
GENMAB A/S 10-Apr-2025 11:05:41 AM 26 1267.50 CEUX
GENMAB A/S 10-Apr-2025 11:05:42 AM 10 1267.00 XCSE
GENMAB A/S 10-Apr-2025 11:05:50 AM 13 1267.00 XCSE
GENMAB A/S 10-Apr-2025 11:05:50 AM 3 1267.00 XCSE
GENMAB A/S 10-Apr-2025 11:06:03 AM 26 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:06:07 AM 6 1266.00 XCSE
GENMAB A/S 10-Apr-2025 11:06:07 AM 31 1266.00 XCSE
GENMAB A/S 10-Apr-2025 11:06:07 AM 50 1266.00 XCSE
GENMAB A/S 10-Apr-2025 11:06:07 AM 31 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:06:07 AM 16 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:08:07 AM 28 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:08:57 AM 59 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:08:57 AM 8 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:10:22 AM 10 1267.00 TQEX
GENMAB A/S 10-Apr-2025 11:10:31 AM 16 1267.00 TQEX
GENMAB A/S 10-Apr-2025 11:10:43 AM 1 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:10:43 AM 9 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:10:43 AM 72 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:10:43 AM 5 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:10:43 AM 9 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:10:43 AM 28 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:10:47 AM 54 1265.50 XCSE
GENMAB A/S 10-Apr-2025 11:10:47 AM 26 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:13:40 AM 30 1268.00 TQEX
GENMAB A/S 10-Apr-2025 11:14:12 AM 89 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:14:12 AM 24 1267.50 CEUX
GENMAB A/S 10-Apr-2025 11:14:12 AM 16 1267.50 CEUX
GENMAB A/S 10-Apr-2025 11:15:28 AM 89 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:15:28 AM 26 1267.00 TQEX
GENMAB A/S 10-Apr-2025 11:15:28 AM 57 1267.50 CEUX
GENMAB A/S 10-Apr-2025 11:15:34 AM 8 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:16:29 AM 77 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:16:29 AM 14 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:16:29 AM 25 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:18:21 AM 18 1265.50 XCSE
GENMAB A/S 10-Apr-2025 11:18:21 AM 44 1265.50 XCSE
GENMAB A/S 10-Apr-2025 11:18:21 AM 18 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:18:21 AM 9 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:18:29 AM 21 1265.50 AQEU

9

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 11:18:35 AM 28 1265.50 AQEU
GENMAB A/S 10-Apr-2025 11:21:17 AM 25 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:21:42 AM 62 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:21:42 AM 20 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:21:42 AM 66 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:22:01 AM 21 1266.00 CEUX
GENMAB A/S 10-Apr-2025 11:23:14 AM 82 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:23:14 AM 10 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:23:14 AM 16 1268.50 XCSE
GENMAB A/S 10-Apr-2025 11:25:19 AM 16 1268.00 XCSE
GENMAB A/S 10-Apr-2025 11:25:19 AM 53 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:25:19 AM 16 1268.00 TQEX
GENMAB A/S 10-Apr-2025 11:25:19 AM 21 1268.00 TQEX
GENMAB A/S 10-Apr-2025 11:25:19 AM 87 1268.00 CEUX
GENMAB A/S 10-Apr-2025 11:25:38 AM 16 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:25:38 AM 19 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:25:38 AM 41 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:25:59 AM 36 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:25:59 AM 1 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:26:05 AM 10 1267.00 XCSE
GENMAB A/S 10-Apr-2025 11:26:05 AM 26 1267.00 TQEX
GENMAB A/S 10-Apr-2025 11:26:05 AM 23 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:26:05 AM 60 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:26:50 AM 88 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:26:57 AM 62 1266.00 CEUX
GENMAB A/S 10-Apr-2025 11:27:52 AM 36 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:27:52 AM 36 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:27:52 AM 40 1266.50 XCSE
GENMAB A/S 10-Apr-2025 11:28:11 AM 86 1266.00 XCSE
GENMAB A/S 10-Apr-2025 11:28:11 AM 61 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:28:11 AM 10 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:29:54 AM 83 1266.00 XCSE
GENMAB A/S 10-Apr-2025 11:29:54 AM 32 1266.00 TQEX
GENMAB A/S 10-Apr-2025 11:29:54 AM 13 1265.50 CEUX
GENMAB A/S 10-Apr-2025 11:32:35 AM 55 1272.00 XCSE
GENMAB A/S 10-Apr-2025 11:32:35 AM 57 1272.00 XCSE
GENMAB A/S 10-Apr-2025 11:32:40 AM 85 1271.50 XCSE
GENMAB A/S 10-Apr-2025 11:32:40 AM 86 1272.00 CEUX
GENMAB A/S 10-Apr-2025 11:32:41 AM 26 1271.50 TQEX
GENMAB A/S 10-Apr-2025 11:32:41 AM 29 1271.50 AQEU
GENMAB A/S 10-Apr-2025 11:37:34 AM 11 1273.50 XCSE
GENMAB A/S 10-Apr-2025 11:37:34 AM 97 1273.50 XCSE
GENMAB A/S 10-Apr-2025 11:37:34 AM 11 1273.50 TQEX

10

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 11:37:34 AM 11 1273.50 CEUX
GENMAB A/S 10-Apr-2025 11:37:34 AM 74 1273.50 CEUX
GENMAB A/S 10-Apr-2025 11:37:35 AM 43 1273.50 XCSE
GENMAB A/S 10-Apr-2025 11:37:35 AM 60 1273.50 XCSE
GENMAB A/S 10-Apr-2025 11:37:35 AM 9 1273.50 XCSE
GENMAB A/S 10-Apr-2025 11:37:35 AM 26 1273.50 AQEU
GENMAB A/S 10-Apr-2025 11:38:50 AM 83 1272.50 XCSE
GENMAB A/S 10-Apr-2025 11:38:50 AM 28 1272.50 AQEU
GENMAB A/S 10-Apr-2025 11:38:50 AM 86 1272.50 CEUX
GENMAB A/S 10-Apr-2025 11:39:32 AM 82 1271.50 XCSE
GENMAB A/S 10-Apr-2025 11:39:32 AM 43 1272.00 XCSE
GENMAB A/S 10-Apr-2025 11:39:32 AM 28 1272.00 XCSE
GENMAB A/S 10-Apr-2025 11:39:32 AM 30 1272.00 XCSE
GENMAB A/S 10-Apr-2025 11:39:32 AM 11 1272.00 XCSE
GENMAB A/S 10-Apr-2025 11:39:36 AM 17 1271.50 XCSE
GENMAB A/S 10-Apr-2025 11:40:05 AM 72 1271.50 XCSE
GENMAB A/S 10-Apr-2025 11:40:41 AM 85 1271.50 XCSE
GENMAB A/S 10-Apr-2025 11:40:41 AM 4 1271.50 AQEU
GENMAB A/S 10-Apr-2025 11:40:41 AM 4 1271.50 AQEU
GENMAB A/S 10-Apr-2025 11:40:41 AM 30 1271.50 AQEU
GENMAB A/S 10-Apr-2025 11:40:42 AM 82 1271.00 CEUX
GENMAB A/S 10-Apr-2025 11:40:44 AM 31 1271.00 TQEX
GENMAB A/S 10-Apr-2025 11:40:51 AM 87 1270.50 XCSE
GENMAB A/S 10-Apr-2025 11:42:48 AM 73 1270.00 CEUX
GENMAB A/S 10-Apr-2025 11:42:48 AM 16 1270.00 CEUX
GENMAB A/S 10-Apr-2025 11:43:43 AM 69 1269.00 XCSE
GENMAB A/S 10-Apr-2025 11:43:43 AM 17 1269.00 XCSE
GENMAB A/S 10-Apr-2025 11:43:43 AM 28 1269.00 TQEX
GENMAB A/S 10-Apr-2025 11:43:43 AM 83 1269.00 CEUX
GENMAB A/S 10-Apr-2025 11:44:04 AM 77 1268.50 CEUX
GENMAB A/S 10-Apr-2025 11:45:09 AM 88 1269.00 XCSE
GENMAB A/S 10-Apr-2025 11:46:03 AM 81 1268.00 XCSE
GENMAB A/S 10-Apr-2025 11:47:21 AM 86 1267.50 CEUX
GENMAB A/S 10-Apr-2025 11:47:27 AM 28 1267.00 XCSE
GENMAB A/S 10-Apr-2025 11:47:40 AM 4 1266.50 TQEX
GENMAB A/S 10-Apr-2025 11:47:40 AM 1 1266.50 TQEX
GENMAB A/S 10-Apr-2025 11:47:40 AM 1 1266.50 TQEX
GENMAB A/S 10-Apr-2025 11:47:40 AM 74 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:47:40 AM 12 1266.50 CEUX
GENMAB A/S 10-Apr-2025 11:50:42 AM 41 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:50:42 AM 28 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:50:42 AM 16 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:50:42 AM 27 1267.50 XCSE

11

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 11:52:38 AM 86 1267.50 XCSE
GENMAB A/S 10-Apr-2025 11:52:38 AM 37 1267.50 TQEX
GENMAB A/S 10-Apr-2025 11:52:39 AM 10 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:52:46 AM 39 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:52:46 AM 36 1267.00 CEUX
GENMAB A/S 10-Apr-2025 11:52:47 AM 10 1266.00 XCSE
GENMAB A/S 10-Apr-2025 11:55:16 AM 76 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:55:16 AM 13 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:55:16 AM 16 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:55:17 AM 15 1269.50 CEUX
GENMAB A/S 10-Apr-2025 11:55:19 AM 11 1269.50 CEUX
GENMAB A/S 10-Apr-2025 11:55:21 AM 1 1269.50 TQEX
GENMAB A/S 10-Apr-2025 11:56:48 AM 88 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:57:15 AM 85 1270.50 XCSE
GENMAB A/S 10-Apr-2025 11:57:15 AM 87 1270.50 CEUX
GENMAB A/S 10-Apr-2025 11:58:48 AM 82 1270.00 XCSE
GENMAB A/S 10-Apr-2025 11:58:59 AM 9 1269.50 TQEX
GENMAB A/S 10-Apr-2025 11:58:59 AM 20 1269.50 CEUX
GENMAB A/S 10-Apr-2025 11:59:21 AM 39 1269.50 CEUX
GENMAB A/S 10-Apr-2025 11:59:22 AM 87 1269.00 XCSE
GENMAB A/S 10-Apr-2025 11:59:22 AM 19 1269.50 TQEX
GENMAB A/S 10-Apr-2025 12:00:58 PM 84 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:00:58 PM 13 1268.50 TQEX
GENMAB A/S 10-Apr-2025 12:00:58 PM 1 1268.50 TQEX
GENMAB A/S 10-Apr-2025 12:02:02 PM 23 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:02:02 PM 10 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:02:32 PM 43 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:02:32 PM 23 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:02:32 PM 19 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:03:41 PM 84 1268.00 XCSE
GENMAB A/S 10-Apr-2025 12:03:41 PM 38 1268.50 XCSE
GENMAB A/S 10-Apr-2025 12:03:41 PM 31 1268.00 TQEX
GENMAB A/S 10-Apr-2025 12:03:41 PM 21 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:03:41 PM 23 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:03:41 PM 41 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:04:46 PM 4 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:04:46 PM 83 1269.00 XCSE
GENMAB A/S 10-Apr-2025 12:04:46 PM 86 1269.00 CEUX
GENMAB A/S 10-Apr-2025 12:04:56 PM 88 1268.00 XCSE
GENMAB A/S 10-Apr-2025 12:04:56 PM 48 1268.50 AQEU
GENMAB A/S 10-Apr-2025 12:04:56 PM 8 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:04:56 PM 14 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:04:56 PM 13 1268.00 CEUX

12

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 12:04:56 PM 9 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:05:59 PM 25 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:05:59 PM 4 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:06:08 PM 14 1268.00 CEUX
GENMAB A/S 10-Apr-2025 12:08:30 PM 34 1271.00 XCSE
GENMAB A/S 10-Apr-2025 12:08:30 PM 13 1271.00 XCSE
GENMAB A/S 10-Apr-2025 12:08:36 PM 79 1272.00 XCSE
GENMAB A/S 10-Apr-2025 12:08:36 PM 9 1272.00 XCSE
GENMAB A/S 10-Apr-2025 12:08:58 PM 28 1272.00 TQEX
GENMAB A/S 10-Apr-2025 12:09:25 PM 21 1273.50 XCSE
GENMAB A/S 10-Apr-2025 12:09:25 PM 10 1273.50 CEUX
GENMAB A/S 10-Apr-2025 12:09:28 PM 10 1273.50 XCSE
GENMAB A/S 10-Apr-2025 12:09:28 PM 19 1273.50 CEUX
GENMAB A/S 10-Apr-2025 12:09:28 PM 57 1273.50 CEUX
GENMAB A/S 10-Apr-2025 12:09:29 PM 56 1273.50 XCSE
GENMAB A/S 10-Apr-2025 12:09:29 PM 26 1273.00 TQEX
GENMAB A/S 10-Apr-2025 12:09:50 PM 23 1273.00 XCSE
GENMAB A/S 10-Apr-2025 12:09:50 PM 63 1273.00 XCSE
GENMAB A/S 10-Apr-2025 12:11:26 PM 86 1274.00 XCSE
GENMAB A/S 10-Apr-2025 12:12:01 PM 6 1273.00 XCSE
GENMAB A/S 10-Apr-2025 12:12:01 PM 85 1273.50 CEUX
GENMAB A/S 10-Apr-2025 12:12:02 PM 78 1273.00 XCSE
GENMAB A/S 10-Apr-2025 12:13:31 PM 82 1276.00 XCSE
GENMAB A/S 10-Apr-2025 12:13:31 PM 48 1275.50 TQEX
GENMAB A/S 10-Apr-2025 12:16:07 PM 88 1276.00 XCSE
GENMAB A/S 10-Apr-2025 12:16:44 PM 71 1275.00 XCSE
GENMAB A/S 10-Apr-2025 12:16:57 PM 13 1275.00 XCSE
GENMAB A/S 10-Apr-2025 12:16:57 PM 89 1275.00 CEUX
GENMAB A/S 10-Apr-2025 12:17:23 PM 86 1275.00 XCSE
GENMAB A/S 10-Apr-2025 12:20:07 PM 7 1276.50 CEUX
GENMAB A/S 10-Apr-2025 12:21:40 PM 89 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:21:40 PM 32 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:21:47 PM 15 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:22:17 PM 73 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:23:01 PM 49 1278.00 TQEX
GENMAB A/S 10-Apr-2025 12:23:02 PM 15 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:23:34 PM 10 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:23:34 PM 30 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:24:17 PM 68 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:24:17 PM 10 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:24:17 PM 34 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:24:17 PM 34 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:24:17 PM 48 1277.50 CEUX

13

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 12:25:05 PM 62 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:25:05 PM 17 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:25:05 PM 10 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:25:52 PM 45 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:26:28 PM 18 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:26:28 PM 71 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:27:21 PM 40 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:27:52 PM 15 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:27:55 PM 74 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:28:02 PM 41 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:29:59 PM 89 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:29:59 PM 47 1279.00 TQEX
GENMAB A/S 10-Apr-2025 12:29:59 PM 26 1279.00 AQEU
GENMAB A/S 10-Apr-2025 12:29:59 PM 84 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:31:32 PM 27 1280.00 AQEU
GENMAB A/S 10-Apr-2025 12:31:57 PM 46 1280.00 XCSE
GENMAB A/S 10-Apr-2025 12:31:57 PM 11 1280.00 XCSE
GENMAB A/S 10-Apr-2025 12:31:57 PM 55 1280.00 XCSE
GENMAB A/S 10-Apr-2025 12:32:04 PM 84 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:32:04 PM 82 1279.50 CEUX
GENMAB A/S 10-Apr-2025 12:32:05 PM 40 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:33:00 PM 20 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:33:00 PM 12 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:33:07 PM 2 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:33:40 PM 4 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:34:00 PM 4 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:34:00 PM 9 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:35:00 PM 3 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:35:04 PM 4 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:35:04 PM 1 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:35:04 PM 22 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:35:06 PM 107 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:35:06 PM 5 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:35:09 PM 19 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:35:09 PM 25 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:36:33 PM 10 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:36:33 PM 74 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:37:44 PM 26 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:38:11 PM 13 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:38:12 PM 87 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:40:20 PM 99 1280.00 XCSE
GENMAB A/S 10-Apr-2025 12:40:50 PM 35 1279.50 CEUX
GENMAB A/S 10-Apr-2025 12:40:50 PM 49 1279.50 CEUX

14

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 12:41:38 PM 82 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:41:38 PM 60 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:41:38 PM 30 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:41:38 PM 22 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:41:49 PM 50 1278.50 TQEX
GENMAB A/S 10-Apr-2025 12:41:49 PM 42 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:41:49 PM 40 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:41:58 PM 40 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:41:58 PM 9 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:43:38 PM 15 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:43:50 PM 24 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:45:14 PM 53 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:46:26 PM 16 1277.50 XCSE
GENMAB A/S 10-Apr-2025 12:46:52 PM 15 1277.50 XCSE
GENMAB A/S 10-Apr-2025 12:48:28 PM 60 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:48:28 PM 2 1278.50 TQEX
GENMAB A/S 10-Apr-2025 12:48:28 PM 84 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:50:00 PM 26 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:50:00 PM 60 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:50:00 PM 26 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:50:00 PM 26 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:51:48 PM 83 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:52:20 PM 26 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:52:32 PM 32 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:53:10 PM 13 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:53:10 PM 13 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:53:10 PM 59 1278.50 CEUX
GENMAB A/S 10-Apr-2025 12:53:11 PM 25 1278.50 TQEX
GENMAB A/S 10-Apr-2025 12:53:11 PM 1 1278.50 TQEX
GENMAB A/S 10-Apr-2025 12:53:11 PM 18 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:53:11 PM 31 1278.50 AQEU
GENMAB A/S 10-Apr-2025 12:53:17 PM 83 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:53:17 PM 48 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:53:17 PM 7 1278.50 XCSE
GENMAB A/S 10-Apr-2025 12:53:17 PM 9 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:53:17 PM 2 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:53:17 PM 74 1277.50 CEUX
GENMAB A/S 10-Apr-2025 12:54:10 PM 88 1277.00 XCSE
GENMAB A/S 10-Apr-2025 12:54:15 PM 13 1276.50 AQEU
GENMAB A/S 10-Apr-2025 12:57:02 PM 14 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:57:22 PM 27 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:58:04 PM 16 1278.00 CEUX
GENMAB A/S 10-Apr-2025 12:58:19 PM 28 1278.50 XCSE

15

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 12:58:19 PM 58 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:58:19 PM 16 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:58:19 PM 10 1279.00 XCSE
GENMAB A/S 10-Apr-2025 12:58:20 PM 89 1278.00 XCSE
GENMAB A/S 10-Apr-2025 12:58:20 PM 26 1278.00 TQEX
GENMAB A/S 10-Apr-2025 12:58:20 PM 8 1278.00 TQEX
GENMAB A/S 10-Apr-2025 12:58:20 PM 68 1278.00 CEUX
GENMAB A/S 10-Apr-2025 13:01:35 PM 85 1278.00 CEUX
GENMAB A/S 10-Apr-2025 13:01:36 PM 15 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:02:05 PM 35 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:02:05 PM 16 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:02:14 PM 28 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:02:42 PM 35 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:02:42 PM 10 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:02:42 PM 60 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:02:42 PM 7 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:04:15 PM 28 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:04:41 PM 89 1277.00 XCSE
GENMAB A/S 10-Apr-2025 13:04:41 PM 14 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:04:41 PM 14 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:04:41 PM 35 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:04:41 PM 42 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:04:41 PM 82 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:05:00 PM 21 1276.50 AQEU
GENMAB A/S 10-Apr-2025 13:06:28 PM 87 1276.00 CEUX
GENMAB A/S 10-Apr-2025 13:06:44 PM 89 1275.50 XCSE
GENMAB A/S 10-Apr-2025 13:09:12 PM 13 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:09:12 PM 36 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:09:12 PM 10 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:09:12 PM 12 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:10:02 PM 1 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:10:02 PM 30 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:10:02 PM 4 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:10:40 PM 11 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:11:01 PM 10 1275.50 AQEU
GENMAB A/S 10-Apr-2025 13:11:01 PM 16 1275.50 AQEU
GENMAB A/S 10-Apr-2025 13:11:28 PM 40 1275.50 XCSE
GENMAB A/S 10-Apr-2025 13:11:28 PM 45 1275.50 XCSE
GENMAB A/S 10-Apr-2025 13:14:06 PM 19 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:14:19 PM 32 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:14:36 PM 26 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:14:37 PM 18 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:15:49 PM 32 1277.00 TQEX

16

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 13:15:49 PM 32 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:16:22 PM 44 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:16:22 PM 46 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:16:22 PM 22 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:16:22 PM 17 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:16:22 PM 70 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:16:22 PM 26 1276.50 AQEU
GENMAB A/S 10-Apr-2025 13:16:22 PM 32 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:16:22 PM 85 1276.00 CEUX
GENMAB A/S 10-Apr-2025 13:16:48 PM 15 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:16:54 PM 13 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:16:55 PM 12 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:17:05 PM 14 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:17:05 PM 39 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:17:23 PM 4 1276.00 CEUX
GENMAB A/S 10-Apr-2025 13:20:41 PM 29 1280.00 TQEX
GENMAB A/S 10-Apr-2025 13:20:41 PM 36 1280.00 CEUX
GENMAB A/S 10-Apr-2025 13:21:03 PM 15 1280.00 XCSE
GENMAB A/S 10-Apr-2025 13:21:03 PM 13 1280.00 XCSE
GENMAB A/S 10-Apr-2025 13:24:13 PM 89 1281.50 XCSE
GENMAB A/S 10-Apr-2025 13:24:13 PM 33 1281.50 XCSE
GENMAB A/S 10-Apr-2025 13:24:13 PM 40 1281.50 CEUX
GENMAB A/S 10-Apr-2025 13:25:19 PM 12 1281.00 TQEX
GENMAB A/S 10-Apr-2025 13:25:19 PM 14 1281.00 TQEX
GENMAB A/S 10-Apr-2025 13:25:19 PM 46 1281.00 CEUX
GENMAB A/S 10-Apr-2025 13:25:19 PM 42 1281.00 CEUX
GENMAB A/S 10-Apr-2025 13:25:31 PM 36 1281.50 CEUX
GENMAB A/S 10-Apr-2025 13:26:08 PM 32 1281.00 XCSE
GENMAB A/S 10-Apr-2025 13:26:08 PM 26 1281.00 AQEU
GENMAB A/S 10-Apr-2025 13:26:28 PM 83 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:30 PM 13 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:30 PM 30 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:30 PM 45 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:30 PM 24 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:30 PM 28 1280.00 TQEX
GENMAB A/S 10-Apr-2025 13:26:30 PM 1 1280.00 CEUX
GENMAB A/S 10-Apr-2025 13:26:30 PM 85 1280.00 CEUX
GENMAB A/S 10-Apr-2025 13:26:31 PM 14 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:31 PM 14 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:31 PM 30 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:31 PM 35 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:31 PM 30 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:26:31 PM 13 1280.50 XCSE

17

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 13:26:32 PM 46 1280.50 XCSE
GENMAB A/S 10-Apr-2025 13:27:00 PM 83 1279.50 XCSE
GENMAB A/S 10-Apr-2025 13:27:14 PM 86 1279.00 CEUX
GENMAB A/S 10-Apr-2025 13:28:03 PM 87 1278.00 XCSE
GENMAB A/S 10-Apr-2025 13:28:04 PM 3 1277.50 CEUX
GENMAB A/S 10-Apr-2025 13:28:09 PM 26 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:28:09 PM 1 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:28:09 PM 2 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:28:09 PM 80 1277.50 CEUX
GENMAB A/S 10-Apr-2025 13:30:07 PM 5 1276.50 CEUX
GENMAB A/S 10-Apr-2025 13:30:19 PM 84 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:30:19 PM 5 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:30:19 PM 21 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:30:19 PM 79 1276.50 CEUX
GENMAB A/S 10-Apr-2025 13:31:11 PM 86 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:31:11 PM 27 1277.50 CEUX
GENMAB A/S 10-Apr-2025 13:31:11 PM 55 1277.50 CEUX
GENMAB A/S 10-Apr-2025 13:31:19 PM 26 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:31:19 PM 56 1276.50 XCSE
GENMAB A/S 10-Apr-2025 13:31:19 PM 80 1276.50 CEUX
GENMAB A/S 10-Apr-2025 13:35:00 PM 36 1278.50 XCSE
GENMAB A/S 10-Apr-2025 13:35:00 PM 63 1278.00 CEUX
GENMAB A/S 10-Apr-2025 13:35:32 PM 75 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:36:12 PM 2 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:36:12 PM 3 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:36:12 PM 5 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:36:36 PM 11 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:36:36 PM 38 1277.50 TQEX
GENMAB A/S 10-Apr-2025 13:36:52 PM 5 1277.50 XCSE
GENMAB A/S 10-Apr-2025 13:36:53 PM 3 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:36:53 PM 2 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:36:59 PM 22 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:36:59 PM 9 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:37:00 PM 42 1277.00 XCSE
GENMAB A/S 10-Apr-2025 13:37:00 PM 4 1277.00 CEUX
GENMAB A/S 10-Apr-2025 13:41:26 PM 85 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:41:26 PM 63 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:41:26 PM 13 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:41:26 PM 40 1276.00 CEUX
GENMAB A/S 10-Apr-2025 13:41:26 PM 12 1276.00 CEUX
GENMAB A/S 10-Apr-2025 13:41:42 PM 30 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:42:10 PM 35 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:42:11 PM 35 1276.00 XCSE

18

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 13:42:11 PM 31 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:42:52 PM 35 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:42:52 PM 10 1276.00 XCSE
GENMAB A/S 10-Apr-2025 13:42:59 PM 32 1275.00 AQEU
GENMAB A/S 10-Apr-2025 13:43:04 PM 63 1275.00 CEUX
GENMAB A/S 10-Apr-2025 13:44:59 PM 83 1275.00 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 89 1274.00 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 88 1272.50 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 45 1271.00 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 30 1271.00 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 10 1271.50 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 41 1270.00 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 41 1270.00 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 87 1268.50 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 9 1267.50 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 76 1267.50 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 30 1266.50 XCSE
GENMAB A/S 10-Apr-2025 13:44:59 PM 50 1275.00 TQEX
GENMAB A/S 10-Apr-2025 13:44:59 PM 7 1275.00 AQEU
GENMAB A/S 10-Apr-2025 13:44:59 PM 27 1270.00 AQEU
GENMAB A/S 10-Apr-2025 13:44:59 PM 76 1269.00 AQEU
GENMAB A/S 10-Apr-2025 13:44:59 PM 9 1267.50 AQEU
GENMAB A/S 10-Apr-2025 13:44:59 PM 2 1267.50 AQEU
GENMAB A/S 10-Apr-2025 13:44:59 PM 54 1267.50 AQEU
GENMAB A/S 10-Apr-2025 13:44:59 PM 63 1274.00 CEUX
GENMAB A/S 10-Apr-2025 13:44:59 PM 84 1272.50 CEUX
GENMAB A/S 10-Apr-2025 13:44:59 PM 87 1271.00 CEUX
GENMAB A/S 10-Apr-2025 13:44:59 PM 87 1270.00 CEUX
GENMAB A/S 10-Apr-2025 13:45:00 PM 72 1261.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:00 PM 79 1260.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:00 PM 71 1259.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:00 PM 49 1257.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:02 PM 43 1263.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:03 PM 28 1265.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:04 PM 30 1265.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 30 1264.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 28 1263.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 28 1262.50 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 26 1263.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 26 1262.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 20 1261.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 14 1261.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:08 PM 32 1260.00 AQEU

19

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 13:45:10 PM 45 1264.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:10 PM 41 1263.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:10 PM 37 1262.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:29 PM 27 1267.00 AQEU
GENMAB A/S 10-Apr-2025 13:45:41 PM 27 1266.50 CEUX
GENMAB A/S 10-Apr-2025 13:45:48 PM 29 1267.50 XCSE
GENMAB A/S 10-Apr-2025 13:45:48 PM 27 1267.00 AQEU
GENMAB A/S 10-Apr-2025 13:47:15 PM 34 1267.00 XCSE
GENMAB A/S 10-Apr-2025 13:47:49 PM 26 1268.00 AQEU
GENMAB A/S 10-Apr-2025 13:47:50 PM 38 1268.00 XCSE
GENMAB A/S 10-Apr-2025 13:47:50 PM 31 1267.50 CEUX
GENMAB A/S 10-Apr-2025 13:47:51 PM 25 1267.00 XCSE
GENMAB A/S 10-Apr-2025 13:47:51 PM 13 1267.00 XCSE
GENMAB A/S 10-Apr-2025 13:47:51 PM 31 1267.00 AQEU
GENMAB A/S 10-Apr-2025 13:49:40 PM 37 1267.50 CEUX
GENMAB A/S 10-Apr-2025 13:50:21 PM 5 1269.00 AQEU
GENMAB A/S 10-Apr-2025 13:51:43 PM 35 1268.50 XCSE
GENMAB A/S 10-Apr-2025 13:51:43 PM 26 1268.50 XCSE
GENMAB A/S 10-Apr-2025 13:51:43 PM 49 1268.50 TQEX
GENMAB A/S 10-Apr-2025 13:51:43 PM 26 1269.00 AQEU
GENMAB A/S 10-Apr-2025 13:51:43 PM 3 1269.00 AQEU
GENMAB A/S 10-Apr-2025 13:51:43 PM 32 1268.50 CEUX
GENMAB A/S 10-Apr-2025 13:51:43 PM 2 1268.50 CEUX
GENMAB A/S 10-Apr-2025 13:53:22 PM 31 1269.00 CEUX
GENMAB A/S 10-Apr-2025 13:53:25 PM 33 1269.00 AQEU
GENMAB A/S 10-Apr-2025 13:53:25 PM 43 1269.00 CEUX
GENMAB A/S 10-Apr-2025 13:53:36 PM 86 1268.50 XCSE
GENMAB A/S 10-Apr-2025 13:53:58 PM 27 1268.00 AQEU
GENMAB A/S 10-Apr-2025 13:53:59 PM 34 1267.50 CEUX
GENMAB A/S 10-Apr-2025 13:54:02 PM 65 1267.00 XCSE
GENMAB A/S 10-Apr-2025 13:54:08 PM 20 1266.50 CEUX
GENMAB A/S 10-Apr-2025 13:54:08 PM 20 1266.50 CEUX
GENMAB A/S 10-Apr-2025 13:54:44 PM 35 1266.00 XCSE
GENMAB A/S 10-Apr-2025 13:56:30 PM 6 1266.50 AQEU
GENMAB A/S 10-Apr-2025 13:57:10 PM 50 1270.50 XCSE
GENMAB A/S 10-Apr-2025 13:57:10 PM 7 1270.50 XCSE
GENMAB A/S 10-Apr-2025 13:57:10 PM 27 1270.50 XCSE
GENMAB A/S 10-Apr-2025 13:57:10 PM 85 1269.50 XCSE
GENMAB A/S 10-Apr-2025 13:57:10 PM 33 1270.00 TQEX
GENMAB A/S 10-Apr-2025 13:57:10 PM 26 1270.00 AQEU
GENMAB A/S 10-Apr-2025 13:57:10 PM 36 1270.00 CEUX
GENMAB A/S 10-Apr-2025 13:57:10 PM 32 1270.00 CEUX
GENMAB A/S 10-Apr-2025 13:57:10 PM 72 1269.00 CEUX

20

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 13:57:11 PM 10 1268.50 XCSE
GENMAB A/S 10-Apr-2025 13:57:14 PM 78 1268.50 XCSE
GENMAB A/S 10-Apr-2025 13:57:14 PM 26 1268.50 AQEU
GENMAB A/S 10-Apr-2025 13:57:55 PM 10 1268.00 CEUX
GENMAB A/S 10-Apr-2025 13:57:55 PM 63 1268.00 CEUX
GENMAB A/S 10-Apr-2025 13:58:59 PM 9 1267.00 XCSE
GENMAB A/S 10-Apr-2025 13:58:59 PM 77 1267.00 XCSE
GENMAB A/S 10-Apr-2025 13:58:59 PM 27 1267.00 AQEU
GENMAB A/S 10-Apr-2025 13:59:09 PM 16 1266.00 CEUX
GENMAB A/S 10-Apr-2025 13:59:09 PM 17 1266.00 CEUX
GENMAB A/S 10-Apr-2025 13:59:34 PM 5 1265.50 XCSE
GENMAB A/S 10-Apr-2025 13:59:34 PM 23 1265.50 XCSE
GENMAB A/S 10-Apr-2025 13:59:47 PM 12 1266.00 CEUX
GENMAB A/S 10-Apr-2025 13:59:48 PM 15 1266.00 CEUX
GENMAB A/S 10-Apr-2025 14:00:19 PM 30 1267.00 TQEX
GENMAB A/S 10-Apr-2025 14:00:39 PM 83 1266.50 XCSE
GENMAB A/S 10-Apr-2025 14:00:39 PM 27 1266.50 CEUX
GENMAB A/S 10-Apr-2025 14:03:46 PM 11 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:03:54 PM 10 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:01 PM 2 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:10 PM 10 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:10 PM 2 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:10 PM 54 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:10 PM 40 1267.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:10 PM 27 1267.50 TQEX
GENMAB A/S 10-Apr-2025 14:04:10 PM 53 1267.00 CEUX
GENMAB A/S 10-Apr-2025 14:04:14 PM 44 1266.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:14 PM 2 1266.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:14 PM 37 1266.50 XCSE
GENMAB A/S 10-Apr-2025 14:04:15 PM 21 1266.00 CEUX
GENMAB A/S 10-Apr-2025 14:04:15 PM 8 1266.00 CEUX
GENMAB A/S 10-Apr-2025 14:04:15 PM 1 1266.00 CEUX
GENMAB A/S 10-Apr-2025 14:05:21 PM 2 1266.00 CEUX
GENMAB A/S 10-Apr-2025 14:05:21 PM 47 1266.00 AQEU
GENMAB A/S 10-Apr-2025 14:05:27 PM 10 1266.00 XCSE
GENMAB A/S 10-Apr-2025 14:05:27 PM 10 1266.00 XCSE
GENMAB A/S 10-Apr-2025 14:05:27 PM 22 1266.00 XCSE
GENMAB A/S 10-Apr-2025 14:05:27 PM 22 1265.50 XCSE
GENMAB A/S 10-Apr-2025 14:05:27 PM 34 1265.50 XCSE
GENMAB A/S 10-Apr-2025 14:07:10 PM 50 1265.00 XCSE
GENMAB A/S 10-Apr-2025 14:07:10 PM 34 1265.00 XCSE
GENMAB A/S 10-Apr-2025 14:07:10 PM 5 1265.50 XCSE
GENMAB A/S 10-Apr-2025 14:07:10 PM 28 1265.00 CEUX

21

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 14:07:48 PM 83 1264.00 XCSE
GENMAB A/S 10-Apr-2025 14:07:48 PM 29 1264.00 TQEX
GENMAB A/S 10-Apr-2025 14:07:48 PM 39 1264.00 CEUX
GENMAB A/S 10-Apr-2025 14:07:49 PM 25 1264.00 AQEU
GENMAB A/S 10-Apr-2025 14:09:25 PM 85 1264.00 CEUX
GENMAB A/S 10-Apr-2025 14:09:26 PM 32 1264.50 XCSE
GENMAB A/S 10-Apr-2025 14:09:26 PM 51 1264.50 XCSE
GENMAB A/S 10-Apr-2025 14:09:28 PM 84 1263.50 XCSE
GENMAB A/S 10-Apr-2025 14:09:28 PM 37 1262.50 XCSE
GENMAB A/S 10-Apr-2025 14:09:28 PM 50 1263.50 TQEX
GENMAB A/S 10-Apr-2025 14:09:28 PM 1 1263.00 CEUX
GENMAB A/S 10-Apr-2025 14:09:28 PM 34 1263.00 CEUX
GENMAB A/S 10-Apr-2025 14:09:28 PM 40 1263.00 CEUX
GENMAB A/S 10-Apr-2025 14:09:30 PM 39 1262.50 XCSE
GENMAB A/S 10-Apr-2025 14:10:03 PM 10 1262.50 XCSE
GENMAB A/S 10-Apr-2025 14:10:04 PM 76 1261.50 CEUX
GENMAB A/S 10-Apr-2025 14:10:05 PM 20 1261.00 XCSE
GENMAB A/S 10-Apr-2025 14:10:05 PM 64 1261.00 XCSE
GENMAB A/S 10-Apr-2025 14:10:15 PM 80 1260.00 XCSE
GENMAB A/S 10-Apr-2025 14:10:15 PM 20 1260.50 CEUX
GENMAB A/S 10-Apr-2025 14:10:15 PM 19 1260.50 CEUX
GENMAB A/S 10-Apr-2025 14:10:18 PM 7 1260.00 XCSE
GENMAB A/S 10-Apr-2025 14:10:18 PM 1 1259.50 AQEU
GENMAB A/S 10-Apr-2025 14:10:19 PM 4 1260.00 XCSE
GENMAB A/S 10-Apr-2025 14:10:19 PM 6 1259.50 AQEU
GENMAB A/S 10-Apr-2025 14:10:21 PM 33 1260.00 XCSE
GENMAB A/S 10-Apr-2025 14:11:51 PM 24 1259.00 XCSE
GENMAB A/S 10-Apr-2025 14:11:52 PM 22 1259.00 XCSE
GENMAB A/S 10-Apr-2025 14:11:52 PM 43 1259.00 XCSE
GENMAB A/S 10-Apr-2025 14:12:01 PM 69 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:12:01 PM 18 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:12:01 PM 5 1258.00 CEUX
GENMAB A/S 10-Apr-2025 14:12:01 PM 20 1258.00 CEUX
GENMAB A/S 10-Apr-2025 14:12:01 PM 1 1258.00 CEUX
GENMAB A/S 10-Apr-2025 14:12:04 PM 5 1258.00 CEUX
GENMAB A/S 10-Apr-2025 14:12:12 PM 22 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:12:12 PM 6 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:12:12 PM 20 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:12:12 PM 1 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:12:13 PM 5 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:13:11 PM 7 1256.50 AQEU
GENMAB A/S 10-Apr-2025 14:15:01 PM 24 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:15:01 PM 52 1257.00 XCSE

22

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 14:15:01 PM 52 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:15:01 PM 23 1256.50 AQEU
GENMAB A/S 10-Apr-2025 14:16:52 PM 12 1260.00 TQEX
GENMAB A/S 10-Apr-2025 14:16:52 PM 18 1260.00 AQEU
GENMAB A/S 10-Apr-2025 14:17:59 PM 19 1260.50 XCSE
GENMAB A/S 10-Apr-2025 14:17:59 PM 16 1260.50 XCSE
GENMAB A/S 10-Apr-2025 14:17:59 PM 10 1260.50 XCSE
GENMAB A/S 10-Apr-2025 14:18:54 PM 22 1260.00 XCSE
GENMAB A/S 10-Apr-2025 14:18:58 PM 61 1260.00 XCSE
GENMAB A/S 10-Apr-2025 14:18:58 PM 26 1260.00 TQEX
GENMAB A/S 10-Apr-2025 14:18:58 PM 58 1260.00 CEUX
GENMAB A/S 10-Apr-2025 14:18:58 PM 10 1260.00 CEUX
GENMAB A/S 10-Apr-2025 14:18:58 PM 10 1260.00 CEUX
GENMAB A/S 10-Apr-2025 14:20:27 PM 86 1259.00 XCSE
GENMAB A/S 10-Apr-2025 14:20:27 PM 55 1259.00 CEUX
GENMAB A/S 10-Apr-2025 14:20:30 PM 8 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:20:30 PM 2 1258.00 CEUX
GENMAB A/S 10-Apr-2025 14:21:21 PM 15 1259.00 CEUX
GENMAB A/S 10-Apr-2025 14:21:24 PM 46 1259.00 XCSE
GENMAB A/S 10-Apr-2025 14:21:24 PM 13 1259.00 XCSE
GENMAB A/S 10-Apr-2025 14:21:24 PM 28 1258.50 TQEX
GENMAB A/S 10-Apr-2025 14:21:24 PM 74 1259.00 CEUX
GENMAB A/S 10-Apr-2025 14:21:24 PM 29 1258.50 AQEU
GENMAB A/S 10-Apr-2025 14:22:52 PM 78 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:22:52 PM 28 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:22:52 PM 14 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:22:52 PM 38 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:22:52 PM 19 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:22:52 PM 13 1258.00 XCSE
GENMAB A/S 10-Apr-2025 14:22:52 PM 48 1258.00 CEUX
GENMAB A/S 10-Apr-2025 14:23:08 PM 58 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:23:30 PM 15 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:23:30 PM 11 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:23:30 PM 9 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:23:30 PM 32 1257.00 AQEU
GENMAB A/S 10-Apr-2025 14:23:42 PM 5 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:23:42 PM 11 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:23:42 PM 25 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:23:42 PM 9 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:23:54 PM 23 1256.50 XCSE
GENMAB A/S 10-Apr-2025 14:24:32 PM 11 1257.00 XCSE
GENMAB A/S 10-Apr-2025 14:24:33 PM 64 1256.50 XCSE
GENMAB A/S 10-Apr-2025 14:25:43 PM 82 1257.00 XCSE

23

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 14:25:43 PM 23 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:25:43 PM 58 1257.00 CEUX
GENMAB A/S 10-Apr-2025 14:25:47 PM 26 1256.50 TQEX
GENMAB A/S 10-Apr-2025 14:25:50 PM 64 1256.00 XCSE
GENMAB A/S 10-Apr-2025 14:25:50 PM 22 1256.00 XCSE
GENMAB A/S 10-Apr-2025 14:25:50 PM 29 1256.00 CEUX
GENMAB A/S 10-Apr-2025 14:25:50 PM 50 1256.00 CEUX
GENMAB A/S 10-Apr-2025 14:25:52 PM 24 1255.50 AQEU
GENMAB A/S 10-Apr-2025 14:26:26 PM 23 1255.00 CEUX
GENMAB A/S 10-Apr-2025 14:26:53 PM 22 1255.50 TQEX
GENMAB A/S 10-Apr-2025 14:26:53 PM 5 1255.50 TQEX
GENMAB A/S 10-Apr-2025 14:27:36 PM 4 1255.00 XCSE
GENMAB A/S 10-Apr-2025 14:27:36 PM 83 1255.00 XCSE
GENMAB A/S 10-Apr-2025 14:27:36 PM 21 1255.00 CEUX
GENMAB A/S 10-Apr-2025 14:28:00 PM 20 1253.50 XCSE
GENMAB A/S 10-Apr-2025 14:28:00 PM 1 1253.50 XCSE
GENMAB A/S 10-Apr-2025 14:28:05 PM 21 1253.50 CEUX
GENMAB A/S 10-Apr-2025 14:28:21 PM 39 1253.50 XCSE
GENMAB A/S 10-Apr-2025 14:28:21 PM 27 1253.50 XCSE
GENMAB A/S 10-Apr-2025 14:28:21 PM 38 1253.50 CEUX
GENMAB A/S 10-Apr-2025 14:29:07 PM 20 1253.00 AQEU
GENMAB A/S 10-Apr-2025 14:30:03 PM 20 1254.00 TQEX
GENMAB A/S 10-Apr-2025 14:30:17 PM 89 1254.50 XCSE
GENMAB A/S 10-Apr-2025 14:30:17 PM 2 1254.00 CEUX
GENMAB A/S 10-Apr-2025 14:30:17 PM 47 1254.00 CEUX
GENMAB A/S 10-Apr-2025 14:30:18 PM 82 1253.50 XCSE
GENMAB A/S 10-Apr-2025 14:30:18 PM 59 1253.00 CEUX
GENMAB A/S 10-Apr-2025 14:30:20 PM 85 1252.50 XCSE
GENMAB A/S 10-Apr-2025 14:30:20 PM 12 1252.00 CEUX
GENMAB A/S 10-Apr-2025 14:32:08 PM 41 1253.00 CEUX
GENMAB A/S 10-Apr-2025 14:32:32 PM 86 1252.50 XCSE
GENMAB A/S 10-Apr-2025 14:32:32 PM 18 1252.00 CEUX
GENMAB A/S 10-Apr-2025 14:32:32 PM 32 1252.00 AQEU
GENMAB A/S 10-Apr-2025 14:32:43 PM 25 1251.50 XCSE
GENMAB A/S 10-Apr-2025 14:32:43 PM 62 1251.50 XCSE
GENMAB A/S 10-Apr-2025 14:32:48 PM 26 1251.00 CEUX
GENMAB A/S 10-Apr-2025 14:32:50 PM 84 1250.50 XCSE
GENMAB A/S 10-Apr-2025 14:32:50 PM 2 1250.50 TQEX
GENMAB A/S 10-Apr-2025 14:32:50 PM 26 1250.50 TQEX
GENMAB A/S 10-Apr-2025 14:32:53 PM 29 1249.50 CEUX
GENMAB A/S 10-Apr-2025 14:33:25 PM 32 1250.50 CEUX
GENMAB A/S 10-Apr-2025 14:34:52 PM 6 1250.00 XCSE
GENMAB A/S 10-Apr-2025 14:34:52 PM 12 1250.00 XCSE

24

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 14:34:52 PM 68 1250.00 XCSE
GENMAB A/S 10-Apr-2025 14:34:52 PM 30 1250.50 CEUX
GENMAB A/S 10-Apr-2025 14:34:53 PM 10 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:34:53 PM 79 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:34:53 PM 27 1249.00 CEUX
GENMAB A/S 10-Apr-2025 14:35:12 PM 71 1250.50 XCSE
GENMAB A/S 10-Apr-2025 14:35:12 PM 24 1250.50 CEUX
GENMAB A/S 10-Apr-2025 14:35:12 PM 11 1251.00 AQEU
GENMAB A/S 10-Apr-2025 14:35:30 PM 18 1250.50 XCSE
GENMAB A/S 10-Apr-2025 14:35:30 PM 51 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:35:30 PM 20 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:35:30 PM 28 1249.50 CEUX
GENMAB A/S 10-Apr-2025 14:36:00 PM 51 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:36:00 PM 49 1248.50 TQEX
GENMAB A/S 10-Apr-2025 14:36:18 PM 47 1247.00 XCSE
GENMAB A/S 10-Apr-2025 14:36:58 PM 43 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:37:49 PM 44 1247.50 XCSE
GENMAB A/S 10-Apr-2025 14:39:03 PM 1 1248.00 AQEU
GENMAB A/S 10-Apr-2025 14:39:25 PM 82 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:39:29 PM 26 1248.50 CEUX
GENMAB A/S 10-Apr-2025 14:39:29 PM 34 1248.50 CEUX
GENMAB A/S 10-Apr-2025 14:40:47 PM 66 1247.50 XCSE
GENMAB A/S 10-Apr-2025 14:40:47 PM 64 1247.50 CEUX
GENMAB A/S 10-Apr-2025 14:40:47 PM 30 1248.00 AQEU
GENMAB A/S 10-Apr-2025 14:40:55 PM 46 1246.50 XCSE
GENMAB A/S 10-Apr-2025 14:40:55 PM 31 1246.50 CEUX
GENMAB A/S 10-Apr-2025 14:43:04 PM 84 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:43:08 PM 48 1248.50 TQEX
GENMAB A/S 10-Apr-2025 14:43:08 PM 61 1248.50 CEUX
GENMAB A/S 10-Apr-2025 14:43:08 PM 29 1248.50 AQEU
GENMAB A/S 10-Apr-2025 14:43:31 PM 86 1248.00 XCSE
GENMAB A/S 10-Apr-2025 14:43:55 PM 25 1247.50 CEUX
GENMAB A/S 10-Apr-2025 14:43:55 PM 40 1247.50 CEUX
GENMAB A/S 10-Apr-2025 14:45:31 PM 13 1247.00 CEUX
GENMAB A/S 10-Apr-2025 14:45:31 PM 26 1247.50 AQEU
GENMAB A/S 10-Apr-2025 14:45:32 PM 24 1247.00 CEUX
GENMAB A/S 10-Apr-2025 14:45:32 PM 27 1247.00 CEUX
GENMAB A/S 10-Apr-2025 14:46:08 PM 21 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:46:12 PM 66 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:48:33 PM 24 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:48:33 PM 29 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:48:33 PM 34 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:49:36 PM 38 1249.00 XCSE

25

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 14:49:36 PM 29 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:49:36 PM 36 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:49:36 PM 50 1248.50 TQEX
GENMAB A/S 10-Apr-2025 14:49:36 PM 20 1248.50 AQEU
GENMAB A/S 10-Apr-2025 14:49:42 PM 12 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:49:42 PM 29 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:49:42 PM 36 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:49:48 PM 14 1249.00 CEUX
GENMAB A/S 10-Apr-2025 14:49:48 PM 68 1249.00 CEUX
GENMAB A/S 10-Apr-2025 14:50:07 PM 3 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:50:07 PM 47 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:50:07 PM 33 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:50:51 PM 5 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:51:16 PM 20 1248.00 CEUX
GENMAB A/S 10-Apr-2025 14:51:16 PM 9 1248.00 CEUX
GENMAB A/S 10-Apr-2025 14:51:16 PM 44 1248.00 CEUX
GENMAB A/S 10-Apr-2025 14:51:29 PM 2 1248.00 XCSE
GENMAB A/S 10-Apr-2025 14:52:42 PM 100 1248.00 XCSE
GENMAB A/S 10-Apr-2025 14:52:59 PM 84 1247.50 XCSE
GENMAB A/S 10-Apr-2025 14:52:59 PM 6 1247.00 AQEU
GENMAB A/S 10-Apr-2025 14:53:32 PM 1 1247.50 XCSE
GENMAB A/S 10-Apr-2025 14:53:32 PM 12 1247.50 XCSE
GENMAB A/S 10-Apr-2025 14:53:45 PM 46 1248.00 TQEX
GENMAB A/S 10-Apr-2025 14:54:44 PM 23 1249.00 AQEU
GENMAB A/S 10-Apr-2025 14:55:29 PM 1 1249.00 AQEU
GENMAB A/S 10-Apr-2025 14:55:29 PM 1 1249.00 AQEU
GENMAB A/S 10-Apr-2025 14:55:34 PM 2 1248.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:16 PM 42 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:16 PM 15 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:16 PM 82 1249.00 CEUX
GENMAB A/S 10-Apr-2025 14:56:26 PM 86 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:26 PM 20 1250.00 XCSE
GENMAB A/S 10-Apr-2025 14:56:26 PM 42 1250.00 XCSE
GENMAB A/S 10-Apr-2025 14:56:26 PM 14 1250.00 XCSE
GENMAB A/S 10-Apr-2025 14:56:26 PM 30 1250.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:26 PM 6 1250.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:26 PM 88 1249.50 CEUX
GENMAB A/S 10-Apr-2025 14:56:26 PM 35 1249.50 AQEU
GENMAB A/S 10-Apr-2025 14:56:27 PM 12 1249.50 CEUX
GENMAB A/S 10-Apr-2025 14:56:27 PM 77 1249.50 CEUX
GENMAB A/S 10-Apr-2025 14:56:28 PM 50 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:56:33 PM 32 1249.50 XCSE
GENMAB A/S 10-Apr-2025 14:57:28 PM 75 1248.50 XCSE

26

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 14:57:28 PM 66 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:57:28 PM 42 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:57:28 PM 4 1249.00 XCSE
GENMAB A/S 10-Apr-2025 14:57:28 PM 9 1248.50 XCSE
GENMAB A/S 10-Apr-2025 15:01:18 PM 33 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:01:18 PM 52 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:02:41 PM 84 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 90 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 22 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 10 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 18 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 13 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 43 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 16 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 12 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:02:41 PM 11 1251.50 TQEX
GENMAB A/S 10-Apr-2025 15:02:41 PM 25 1251.50 TQEX
GENMAB A/S 10-Apr-2025 15:02:41 PM 85 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:02:41 PM 31 1251.50 AQEU
GENMAB A/S 10-Apr-2025 15:02:41 PM 28 1250.50 AQEU
GENMAB A/S 10-Apr-2025 15:02:47 PM 9 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:03:00 PM 12 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:03:00 PM 18 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:04:32 PM 34 1251.50 TQEX
GENMAB A/S 10-Apr-2025 15:04:32 PM 89 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:04:50 PM 16 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:04:53 PM 75 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:04:53 PM 12 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:04:53 PM 7 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:04:53 PM 12 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:04:53 PM 15 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:04:53 PM 41 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:05:07 PM 16 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:05:13 PM 15 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:05:30 PM 11 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:05:33 PM 50 1252.00 AQEU
GENMAB A/S 10-Apr-2025 15:06:27 PM 12 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:06:27 PM 8 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:06:27 PM 52 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:06:27 PM 22 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:06:28 PM 11 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:06:41 PM 14 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:06:42 PM 14 1253.00 XCSE

27

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:06:42 PM 11 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:06:42 PM 13 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:06:43 PM 16 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:07:26 PM 42 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:07:26 PM 13 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:07:31 PM 22 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:07:39 PM 15 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:07:40 PM 15 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:08:23 PM 26 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:09:02 PM 86 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:09:02 PM 15 1251.50 TQEX
GENMAB A/S 10-Apr-2025 15:09:02 PM 44 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:09:02 PM 38 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:09:13 PM 87 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:09:13 PM 60 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:09:13 PM 30 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:09:13 PM 1 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:10:15 PM 17 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:10:15 PM 15 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:10:15 PM 14 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:11:16 PM 21 1251.50 TQEX
GENMAB A/S 10-Apr-2025 15:11:31 PM 17 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:11:31 PM 1 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:12:27 PM 11 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:12:30 PM 14 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:12:30 PM 24 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:12:30 PM 27 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:12:30 PM 3 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:12:52 PM 8 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 36 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 14 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 30 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 15 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 9 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 41 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:12:52 PM 20 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:12:52 PM 21 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:12:52 PM 48 1251.00 AQEU
GENMAB A/S 10-Apr-2025 15:13:27 PM 36 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:13:27 PM 2 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:13:28 PM 57 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:13:28 PM 3 1250.50 CEUX
GENMAB A/S 10-Apr-2025 15:13:29 PM 6 1250.50 CEUX

28

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:13:29 PM 3 1250.50 CEUX
GENMAB A/S 10-Apr-2025 15:13:29 PM 2 1250.50 CEUX
GENMAB A/S 10-Apr-2025 15:13:31 PM 72 1250.50 CEUX
GENMAB A/S 10-Apr-2025 15:15:11 PM 84 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:15:11 PM 16 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:15:20 PM 87 1251.00 XCSE
GENMAB A/S 10-Apr-2025 15:15:20 PM 5 1250.50 TQEX
GENMAB A/S 10-Apr-2025 15:15:20 PM 22 1250.50 TQEX
GENMAB A/S 10-Apr-2025 15:15:20 PM 36 1251.00 CEUX
GENMAB A/S 10-Apr-2025 15:15:20 PM 48 1250.50 AQEU
GENMAB A/S 10-Apr-2025 15:16:14 PM 29 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:16:14 PM 68 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:16:25 PM 20 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:16:34 PM 85 1253.00 CEUX
GENMAB A/S 10-Apr-2025 15:17:20 PM 89 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:17:20 PM 30 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:17:20 PM 12 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:17:20 PM 27 1253.00 CEUX
GENMAB A/S 10-Apr-2025 15:17:21 PM 23 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:17:28 PM 13 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:17:28 PM 16 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:17:31 PM 13 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:17:41 PM 6 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:17:41 PM 2 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:18:27 PM 18 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:18:42 PM 29 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:18:42 PM 7 1252.00 CEUX
GENMAB A/S 10-Apr-2025 15:19:27 PM 14 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:14 PM 14 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:14 PM 20 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:14 PM 27 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:14 PM 49 1252.00 CEUX
GENMAB A/S 10-Apr-2025 15:20:14 PM 29 1252.00 CEUX
GENMAB A/S 10-Apr-2025 15:20:14 PM 43 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:20:14 PM 2 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:20:28 PM 84 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:20:28 PM 15 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:28 PM 7 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:28 PM 30 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:28 PM 42 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:28 PM 18 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:28 PM 26 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:20:28 PM 84 1252.50 CEUX

29

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:20:29 PM 22 1252.00 AQEU
GENMAB A/S 10-Apr-2025 15:20:33 PM 87 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:20:33 PM 36 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:20:33 PM 86 1252.00 CEUX
GENMAB A/S 10-Apr-2025 15:20:33 PM 1 1252.00 CEUX
GENMAB A/S 10-Apr-2025 15:21:21 PM 11 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:21 PM 10 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:21 PM 13 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:21 PM 86 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:21:21 PM 3 1253.00 AQEU
GENMAB A/S 10-Apr-2025 15:21:21 PM 23 1253.00 AQEU
GENMAB A/S 10-Apr-2025 15:21:22 PM 26 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:22 PM 25 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:22 PM 51 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:32 PM 23 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:32 PM 36 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:21:32 PM 24 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:22:17 PM 83 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:22:17 PM 47 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:22:17 PM 2 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:22:22 PM 87 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:23:17 PM 2 1253.50 CEUX
GENMAB A/S 10-Apr-2025 15:23:31 PM 86 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:23:31 PM 32 1253.00 CEUX
GENMAB A/S 10-Apr-2025 15:23:31 PM 79 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:23:31 PM 8 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:23:56 PM 88 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:23:58 PM 83 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:23:58 PM 27 1252.00 AQEU
GENMAB A/S 10-Apr-2025 15:24:32 PM 22 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:24:46 PM 28 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:24:46 PM 7 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:24:46 PM 8 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:24:55 PM 44 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 86 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 80 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 32 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 4 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 60 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 36 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:26:23 PM 26 1254.00 TQEX
GENMAB A/S 10-Apr-2025 15:26:23 PM 85 1254.50 CEUX
GENMAB A/S 10-Apr-2025 15:26:23 PM 49 1254.50 AQEU

30

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:26:28 PM 82 1254.00 XCSE
GENMAB A/S 10-Apr-2025 15:26:28 PM 26 1254.00 TQEX
GENMAB A/S 10-Apr-2025 15:26:28 PM 5 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:26:28 PM 81 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:27:27 PM 89 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:27:27 PM 45 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:27:27 PM 27 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:27:27 PM 40 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:27:27 PM 89 1253.00 CEUX
GENMAB A/S 10-Apr-2025 15:27:30 PM 34 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:27:30 PM 52 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:27:30 PM 89 1252.00 CEUX
GENMAB A/S 10-Apr-2025 15:28:04 PM 87 1253.50 XCSE
GENMAB A/S 10-Apr-2025 15:28:04 PM 26 1253.50 TQEX
GENMAB A/S 10-Apr-2025 15:28:04 PM 26 1253.50 AQEU
GENMAB A/S 10-Apr-2025 15:28:28 PM 83 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:28:28 PM 11 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:28:28 PM 74 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:30:00 PM 82 1253.00 XCSE
GENMAB A/S 10-Apr-2025 15:30:01 PM 40 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:30:02 PM 45 1255.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:04 PM 84 1255.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:04 PM 16 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:04 PM 11 1255.00 TQEX
GENMAB A/S 10-Apr-2025 15:30:04 PM 15 1255.00 TQEX
GENMAB A/S 10-Apr-2025 15:30:04 PM 88 1255.00 CEUX
GENMAB A/S 10-Apr-2025 15:30:05 PM 72 1254.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:05 PM 49 1254.50 AQEU
GENMAB A/S 10-Apr-2025 15:30:06 PM 14 1253.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:06 PM 30 1253.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:06 PM 18 1253.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:06 PM 19 1253.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:06 PM 6 1253.50 XCSE
GENMAB A/S 10-Apr-2025 15:30:06 PM 20 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:30:06 PM 17 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:30:06 PM 7 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:30:06 PM 4 1254.00 CEUX
GENMAB A/S 10-Apr-2025 15:30:21 PM 87 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:30:36 PM 25 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:30:36 PM 57 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:30:41 PM 3 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:30:41 PM 84 1252.00 XCSE
GENMAB A/S 10-Apr-2025 15:30:41 PM 84 1251.50 CEUX

31

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:31:02 PM 11 1253.00 TQEX
GENMAB A/S 10-Apr-2025 15:31:02 PM 27 1253.00 TQEX
GENMAB A/S 10-Apr-2025 15:31:07 PM 84 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:07 PM 42 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:07 PM 28 1252.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:07 PM 59 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:31:07 PM 26 1252.50 CEUX
GENMAB A/S 10-Apr-2025 15:31:11 PM 26 1252.50 TQEX
GENMAB A/S 10-Apr-2025 15:31:17 PM 83 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:17 PM 6 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:17 PM 27 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:17 PM 3 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:17 PM 1 1251.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:17 PM 31 1251.50 CEUX
GENMAB A/S 10-Apr-2025 15:31:17 PM 26 1252.00 AQEU
GENMAB A/S 10-Apr-2025 15:31:30 PM 79 1250.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:30 PM 4 1250.50 XCSE
GENMAB A/S 10-Apr-2025 15:31:31 PM 83 1250.00 CEUX
GENMAB A/S 10-Apr-2025 15:31:38 PM 45 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:31:38 PM 39 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:31:38 PM 82 1250.00 CEUX
GENMAB A/S 10-Apr-2025 15:32:11 PM 42 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:11 PM 17 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:11 PM 24 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:11 PM 29 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:11 PM 20 1249.50 AQEU
GENMAB A/S 10-Apr-2025 15:32:11 PM 8 1249.50 AQEU
GENMAB A/S 10-Apr-2025 15:32:12 PM 12 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:12 PM 42 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:12 PM 16 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:12 PM 14 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 42 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 4 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 1 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 85 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 26 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 26 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 3 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 28 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:22 PM 2 1248.50 TQEX
GENMAB A/S 10-Apr-2025 15:32:22 PM 5 1248.50 TQEX
GENMAB A/S 10-Apr-2025 15:32:22 PM 83 1250.00 CEUX
GENMAB A/S 10-Apr-2025 15:32:22 PM 34 1249.00 CEUX

32

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:32:22 PM 7 1249.00 CEUX
GENMAB A/S 10-Apr-2025 15:32:22 PM 7 1249.00 CEUX
GENMAB A/S 10-Apr-2025 15:32:22 PM 12 1249.00 CEUX
GENMAB A/S 10-Apr-2025 15:32:22 PM 28 1249.50 AQEU
GENMAB A/S 10-Apr-2025 15:32:23 PM 25 1248.50 TQEX
GENMAB A/S 10-Apr-2025 15:32:26 PM 84 1248.00 XCSE
GENMAB A/S 10-Apr-2025 15:32:42 PM 16 1247.50 TQEX
GENMAB A/S 10-Apr-2025 15:32:42 PM 16 1247.50 TQEX
GENMAB A/S 10-Apr-2025 15:32:42 PM 86 1247.50 CEUX
GENMAB A/S 10-Apr-2025 15:33:02 PM 31 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:02 PM 51 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:02 PM 10 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:02 PM 28 1249.50 TQEX
GENMAB A/S 10-Apr-2025 15:33:06 PM 23 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:33:41 PM 7 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:41 PM 42 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:41 PM 16 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:42 PM 16 1249.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:42 PM 1 1248.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:42 PM 81 1248.50 XCSE
GENMAB A/S 10-Apr-2025 15:33:42 PM 30 1249.00 TQEX
GENMAB A/S 10-Apr-2025 15:33:42 PM 7 1248.50 CEUX
GENMAB A/S 10-Apr-2025 15:33:42 PM 5 1248.50 CEUX
GENMAB A/S 10-Apr-2025 15:33:42 PM 66 1248.50 CEUX
GENMAB A/S 10-Apr-2025 15:34:15 PM 87 1248.50 XCSE
GENMAB A/S 10-Apr-2025 15:34:15 PM 27 1248.50 AQEU
GENMAB A/S 10-Apr-2025 15:34:23 PM 28 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:23 PM 59 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:23 PM 32 1250.00 CEUX
GENMAB A/S 10-Apr-2025 15:34:27 PM 30 1250.00 CEUX
GENMAB A/S 10-Apr-2025 15:34:28 PM 85 1250.00 CEUX
GENMAB A/S 10-Apr-2025 15:34:29 PM 42 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:29 PM 31 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:29 PM 23 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 7 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 31 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 13 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 16 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 15 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 11 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 14 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 13 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 16 1250.00 XCSE

33

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:34:30 PM 42 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:30 PM 16 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:31 PM 3 1250.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:39 PM 3 1249.50 TQEX
GENMAB A/S 10-Apr-2025 15:34:39 PM 4 1249.50 TQEX
GENMAB A/S 10-Apr-2025 15:34:39 PM 22 1249.50 TQEX
GENMAB A/S 10-Apr-2025 15:34:40 PM 81 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:40 PM 6 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:46 PM 45 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:46 PM 42 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:46 PM 16 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:46 PM 9 1249.00 XCSE
GENMAB A/S 10-Apr-2025 15:34:46 PM 89 1248.50 CEUX
GENMAB A/S 10-Apr-2025 15:34:54 PM 26 1248.00 TQEX
GENMAB A/S 10-Apr-2025 15:35:11 PM 88 1247.50 XCSE
GENMAB A/S 10-Apr-2025 15:35:11 PM 27 1247.50 XCSE
GENMAB A/S 10-Apr-2025 15:35:11 PM 42 1247.50 XCSE
GENMAB A/S 10-Apr-2025 15:35:11 PM 29 1248.00 XCSE
GENMAB A/S 10-Apr-2025 15:35:11 PM 30 1247.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:11 PM 40 1247.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:11 PM 26 1247.50 AQEU
GENMAB A/S 10-Apr-2025 15:35:14 PM 83 1246.50 XCSE
GENMAB A/S 10-Apr-2025 15:35:14 PM 6 1246.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:14 PM 27 1246.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:14 PM 6 1246.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:14 PM 10 1246.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:14 PM 3 1246.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:14 PM 35 1246.50 CEUX
GENMAB A/S 10-Apr-2025 15:35:20 PM 82 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:01 PM 30 1247.00 AQEU
GENMAB A/S 10-Apr-2025 15:36:04 PM 84 1246.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:04 PM 26 1246.50 TQEX
GENMAB A/S 10-Apr-2025 15:36:19 PM 84 1247.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:19 PM 8 1247.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:19 PM 2 1247.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:19 PM 79 1247.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:19 PM 25 1247.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:19 PM 25 1247.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:19 PM 33 1247.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 86 1246.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 5 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX

34

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:36:26 PM 5 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 13 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 12 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 3 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 3 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 7 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 4 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 3 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 4 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 5 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 3 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 2 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:26 PM 3 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:29 PM 1 1246.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:37 PM 10 1245.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:39 PM 10 1245.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:39 PM 9 1245.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:41 PM 10 1245.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:41 PM 50 1245.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:45 PM 86 1244.50 XCSE
GENMAB A/S 10-Apr-2025 15:36:45 PM 32 1244.00 TQEX
GENMAB A/S 10-Apr-2025 15:36:45 PM 8 1244.00 TQEX
GENMAB A/S 10-Apr-2025 15:36:45 PM 3 1244.00 TQEX
GENMAB A/S 10-Apr-2025 15:36:45 PM 8 1244.00 TQEX
GENMAB A/S 10-Apr-2025 15:36:45 PM 85 1245.00 CEUX
GENMAB A/S 10-Apr-2025 15:36:46 PM 3 1243.50 CEUX
GENMAB A/S 10-Apr-2025 15:36:46 PM 2 1243.50 CEUX
GENMAB A/S 10-Apr-2025 15:36:46 PM 2 1243.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:04 PM 86 1245.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:04 PM 17 1244.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:04 PM 10 1244.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:04 PM 2 1244.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:05 PM 52 1244.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:05 PM 37 1244.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:06 PM 10 1243.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:06 PM 15 1243.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:06 PM 9 1243.50 CEUX
GENMAB A/S 10-Apr-2025 15:37:11 PM 83 1243.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:11 PM 3 1242.00 CEUX

35

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:37:11 PM 3 1242.00 CEUX
GENMAB A/S 10-Apr-2025 15:37:11 PM 8 1242.00 CEUX
GENMAB A/S 10-Apr-2025 15:37:12 PM 6 1242.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:12 PM 2 1242.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:12 PM 48 1242.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:12 PM 2 1242.00 CEUX
GENMAB A/S 10-Apr-2025 15:37:12 PM 10 1242.00 CEUX
GENMAB A/S 10-Apr-2025 15:37:29 PM 33 1242.00 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 10 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 3 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 4 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 5 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 4 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 2 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 5 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 3 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:37:53 PM 31 1241.00 CEUX
GENMAB A/S 10-Apr-2025 15:37:54 PM 9 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:38:06 PM 3 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:38:06 PM 16 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:38:06 PM 61 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:38:06 PM 6 1241.00 CEUX
GENMAB A/S 10-Apr-2025 15:38:06 PM 37 1241.00 CEUX
GENMAB A/S 10-Apr-2025 15:38:06 PM 32 1241.00 AQEU
GENMAB A/S 10-Apr-2025 15:38:07 PM 43 1240.00 XCSE
GENMAB A/S 10-Apr-2025 15:38:07 PM 42 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:38:07 PM 10 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:38:07 PM 40 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:04 PM 1 1240.00 XCSE
GENMAB A/S 10-Apr-2025 15:39:04 PM 37 1240.00 XCSE
GENMAB A/S 10-Apr-2025 15:39:04 PM 47 1240.00 TQEX
GENMAB A/S 10-Apr-2025 15:39:15 PM 36 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:22 PM 87 1240.00 XCSE
GENMAB A/S 10-Apr-2025 15:39:40 PM 85 1241.50 XCSE
GENMAB A/S 10-Apr-2025 15:39:40 PM 36 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:39:40 PM 51 1240.50 XCSE
GENMAB A/S 10-Apr-2025 15:39:40 PM 54 1240.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:40 PM 4 1240.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:40 PM 5 1240.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:40 PM 26 1241.50 AQEU
GENMAB A/S 10-Apr-2025 15:39:57 PM 2 1240.00 XCSE
GENMAB A/S 10-Apr-2025 15:39:57 PM 52 1240.00 XCSE
GENMAB A/S 10-Apr-2025 15:39:57 PM 46 1240.50 CEUX

36

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:39:57 PM 6 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 7 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 6 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 13 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 2 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 4 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 7 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:39:57 PM 5 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:40:02 PM 9 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:40:02 PM 10 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:40:02 PM 8 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:40:15 PM 26 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:40:15 PM 4 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:40:15 PM 13 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:40:15 PM 56 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:40:15 PM 6 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:40:15 PM 20 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:40:15 PM 40 1239.50 AQEU
GENMAB A/S 10-Apr-2025 15:40:38 PM 2 1238.00 TQEX
GENMAB A/S 10-Apr-2025 15:40:38 PM 2 1238.00 TQEX
GENMAB A/S 10-Apr-2025 15:40:38 PM 2 1238.00 TQEX
GENMAB A/S 10-Apr-2025 15:40:38 PM 2 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:40:38 PM 3 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:40:38 PM 3 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:40:38 PM 8 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:15 PM 16 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:26 PM 55 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:41:26 PM 2 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:26 PM 15 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:26 PM 2 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:26 PM 3 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:26 PM 2 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:26 PM 6 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:41:30 PM 2 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:41:30 PM 49 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:05 PM 60 1239.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 25 1239.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 28 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 5 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 15 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 5 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 10 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 8 1238.50 XCSE

37

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:42:05 PM 14 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:05 PM 36 1239.00 TQEX
GENMAB A/S 10-Apr-2025 15:42:05 PM 59 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:05 PM 6 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:05 PM 7 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:05 PM 35 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:05 PM 22 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:07 PM 24 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:07 PM 5 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:42:07 PM 21 1238.50 AQEU
GENMAB A/S 10-Apr-2025 15:42:07 PM 10 1238.50 AQEU
GENMAB A/S 10-Apr-2025 15:42:45 PM 89 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:45 PM 3 1237.50 TQEX
GENMAB A/S 10-Apr-2025 15:42:45 PM 2 1237.50 AQEU
GENMAB A/S 10-Apr-2025 15:42:45 PM 32 1237.50 AQEU
GENMAB A/S 10-Apr-2025 15:42:59 PM 46 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:42:59 PM 42 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:59 PM 23 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:42:59 PM 33 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:42:59 PM 5 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:42:59 PM 27 1237.50 TQEX
GENMAB A/S 10-Apr-2025 15:42:59 PM 1 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:42:59 PM 22 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:42:59 PM 9 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:43:02 PM 83 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:03 PM 4 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:03 PM 9 1238.00 TQEX
GENMAB A/S 10-Apr-2025 15:44:03 PM 43 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:03 PM 15 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:09 PM 42 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:44:09 PM 26 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:44:09 PM 4 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:09 PM 3 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:10 PM 87 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:10 PM 15 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:10 PM 1 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:10 PM 50 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:10 PM 19 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:10 PM 70 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:10 PM 1 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:10 PM 14 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:10 PM 3 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:10 PM 42 1237.00 CEUX

38

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:44:11 PM 27 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:44:23 PM 82 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:23 PM 30 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:35 PM 88 1239.50 XCSE
GENMAB A/S 10-Apr-2025 15:44:35 PM 5 1239.00 TQEX
GENMAB A/S 10-Apr-2025 15:44:35 PM 8 1239.00 TQEX
GENMAB A/S 10-Apr-2025 15:44:35 PM 10 1239.00 TQEX
GENMAB A/S 10-Apr-2025 15:44:35 PM 3 1239.00 TQEX
GENMAB A/S 10-Apr-2025 15:44:35 PM 40 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:44:36 PM 10 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:36 PM 2 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:36 PM 7 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:36 PM 2 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:36 PM 7 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:36 PM 27 1239.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:40 PM 60 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:42 PM 1 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:42 PM 10 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:44:42 PM 10 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:42 PM 15 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:42 PM 10 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:42 PM 1 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:44:59 PM 7 1239.00 AQEU
GENMAB A/S 10-Apr-2025 15:45:09 PM 63 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 23 1239.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 14 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 14 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 11 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 30 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 3 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:09 PM 28 1239.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 3 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 7 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 6 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 2 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 5 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 5 1238.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 2 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 3 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 5 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 11 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:45:09 PM 3 1237.50 CEUX

39

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:45:09 PM 40 1239.00 AQEU
GENMAB A/S 10-Apr-2025 15:45:31 PM 3 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:31 PM 12 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:31 PM 13 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:31 PM 61 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:31 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:31 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:32 PM 3 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:32 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:39 PM 4 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:39 PM 3 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:39 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:39 PM 4 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:40 PM 62 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:40 PM 20 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:40 PM 12 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:45:40 PM 26 1236.00 CEUX
GENMAB A/S 10-Apr-2025 15:45:42 PM 5 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:45:42 PM 5 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:45:44 PM 5 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:45:44 PM 8 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:45:44 PM 6 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:45:44 PM 6 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:45:45 PM 50 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:45 PM 13 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:52 PM 50 1238.50 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 3 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 4 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 6 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 6 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:45:53 PM 2 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:04 PM 8 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:04 PM 2 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:04 PM 2 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:07 PM 3 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:07 PM 3 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:07 PM 13 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:07 PM 12 1238.00 XCSE

40

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:46:07 PM 3 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:07 PM 3 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:07 PM 8 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:07 PM 2 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:07 PM 2 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:10 PM 2 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:10 PM 6 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:10 PM 2 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:10 PM 7 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:10 PM 3 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:10 PM 10 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:10 PM 17 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:27 PM 2 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:46:34 PM 5 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:46:34 PM 7 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:46:34 PM 9 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:46:34 PM 2 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:46:34 PM 9 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:46:34 PM 40 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:34 PM 5 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:57 PM 7 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:57 PM 25 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:46:57 PM 33 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:47:10 PM 5 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:47:10 PM 10 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:47:10 PM 7 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:47:10 PM 2 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:47:10 PM 8 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:47:10 PM 10 1238.00 CEUX
GENMAB A/S 10-Apr-2025 15:47:10 PM 2 1237.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:12 PM 89 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:12 PM 26 1237.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:27 PM 84 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 9 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 4 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 4 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 5 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 7 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 5 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:27 PM 1 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:47:27 PM 3 1236.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:27 PM 11 1236.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:27 PM 2 1236.50 AQEU

41

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:47:27 PM 7 1236.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:27 PM 3 1236.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:27 PM 2 1236.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:27 PM 2 1236.50 AQEU
GENMAB A/S 10-Apr-2025 15:47:28 PM 10 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:35 PM 30 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:47:36 PM 14 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:37 PM 8 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:47:47 PM 12 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:47:47 PM 12 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:47:48 PM 4 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:47:48 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:47:50 PM 20 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 17 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:02 PM 9 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:02 PM 50 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:02 PM 7 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:02 PM 6 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:02 PM 4 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 5 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 4 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 7 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 18 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:02 PM 1 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:06 PM 84 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:06 PM 5 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:06 PM 37 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:19 PM 4 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:32 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:48:32 PM 3 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:48:32 PM 3 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:48:32 PM 3 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:48:32 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:48:32 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:48:32 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:32 PM 3 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:48:32 PM 20 1237.00 AQEU

42

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:48:32 PM 5 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:48:32 PM 7 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:48:32 PM 2 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:48:32 PM 7 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:48:32 PM 3 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:48:37 PM 13 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:37 PM 8 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:37 PM 9 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:37 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:37 PM 2 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:37 PM 10 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:48 PM 62 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:48 PM 46 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:48:59 PM 84 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:48:59 PM 7 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:59 PM 5 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:59 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:48:59 PM 21 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:00 PM 10 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:49:27 PM 75 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:49:27 PM 30 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 7 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 2 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 3 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 12 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 4 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 7 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:27 PM 2 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:41 PM 87 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:49:41 PM 3 1236.00 TQEX
GENMAB A/S 10-Apr-2025 15:49:41 PM 2 1236.00 TQEX
GENMAB A/S 10-Apr-2025 15:49:41 PM 4 1236.00 TQEX
GENMAB A/S 10-Apr-2025 15:49:41 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:41 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:41 PM 35 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:43 PM 12 1236.00 TQEX
GENMAB A/S 10-Apr-2025 15:49:52 PM 2 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:49:52 PM 3 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:52 PM 25 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:49:53 PM 7 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:49:59 PM 76 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:00 PM 10 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:00 PM 2 1235.50 CEUX

43

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:50:00 PM 28 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 79 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:04 PM 4 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 2 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 3 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 10 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 3 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 3 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:04 PM 3 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:14 PM 3 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:14 PM 2 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:50:15 PM 26 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:25 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:50:25 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:50:36 PM 2 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:50:36 PM 3 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:50:36 PM 4 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:50:36 PM 15 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:50:59 PM 7 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:59 PM 10 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:59 PM 7 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:50:59 PM 2 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:51:14 PM 56 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:51:14 PM 2 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:51:14 PM 2 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:51:14 PM 2 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:51:15 PM 88 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:51:15 PM 22 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:51:15 PM 9 1235.50 TQEX
GENMAB A/S 10-Apr-2025 15:51:15 PM 23 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:51:15 PM 10 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:51:15 PM 9 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:51:15 PM 3 1235.50 AQEU
GENMAB A/S 10-Apr-2025 15:51:15 PM 10 1235.50 AQEU
GENMAB A/S 10-Apr-2025 15:51:15 PM 5 1235.50 AQEU
GENMAB A/S 10-Apr-2025 15:51:18 PM 8 1235.50 AQEU
GENMAB A/S 10-Apr-2025 15:51:30 PM 5 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:51:30 PM 2 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:51:30 PM 30 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:51:30 PM 11 1234.50 AQEU
GENMAB A/S 10-Apr-2025 15:51:34 PM 3 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 2 1234.00 XCSE

44

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:51:37 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 5 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 5 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 4 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 3 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:37 PM 11 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:51:53 PM 9 1235.00 CEUX
GENMAB A/S 10-Apr-2025 15:51:53 PM 2 1235.00 CEUX
GENMAB A/S 10-Apr-2025 15:51:53 PM 2 1235.00 CEUX
GENMAB A/S 10-Apr-2025 15:52:25 PM 32 1237.50 TQEX
GENMAB A/S 10-Apr-2025 15:52:26 PM 1 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 6 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 81 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 16 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 42 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 30 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 13 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 11 1238.00 XCSE
GENMAB A/S 10-Apr-2025 15:52:26 PM 25 1237.50 AQEU
GENMAB A/S 10-Apr-2025 15:52:35 PM 88 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 37 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 5 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 3 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 4 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 4 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 4 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 3 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 3 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:04 PM 88 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:53:18 PM 82 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:18 PM 10 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:53:18 PM 5 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:53:31 PM 82 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:53:31 PM 38 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:53:33 PM 15 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:33 PM 12 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:34 PM 72 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:53:34 PM 12 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:53:35 PM 24 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:35 PM 36 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:53:35 PM 8 1236.00 CEUX
GENMAB A/S 10-Apr-2025 15:53:53 PM 86 1237.50 XCSE

45

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:53:53 PM 2 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:54:07 PM 85 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:54:14 PM 17 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:54:14 PM 59 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:54:25 PM 5 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:54:25 PM 15 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:54:27 PM 83 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:54:27 PM 2 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:54:27 PM 6 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:54:27 PM 2 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:54:27 PM 10 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:54:27 PM 66 1237.50 CEUX
GENMAB A/S 10-Apr-2025 15:54:33 PM 56 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:54:47 PM 4 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:54:47 PM 16 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:54:47 PM 6 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:54:48 PM 85 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:55:14 PM 42 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:55:14 PM 14 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:55:14 PM 25 1236.50 XCSE
GENMAB A/S 10-Apr-2025 15:55:36 PM 5 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:55:37 PM 42 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:55:37 PM 16 1237.50 XCSE
GENMAB A/S 10-Apr-2025 15:55:37 PM 5 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 18 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 3 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 7 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 4 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 2 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 5 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 3 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 4 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:37 PM 28 1237.00 CEUX
GENMAB A/S 10-Apr-2025 15:55:41 PM 23 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:55:41 PM 62 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:55:41 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:41 PM 6 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:41 PM 6 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:41 PM 6 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:41 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:41 PM 2 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:41 PM 5 1236.50 TQEX
GENMAB A/S 10-Apr-2025 15:55:42 PM 10 1236.00 XCSE

46

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:55:42 PM 76 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:55:42 PM 81 1236.00 CEUX
GENMAB A/S 10-Apr-2025 15:56:30 PM 87 1237.00 XCSE
GENMAB A/S 10-Apr-2025 15:56:30 PM 25 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:56:30 PM 9 1237.00 TQEX
GENMAB A/S 10-Apr-2025 15:56:30 PM 12 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:56:30 PM 53 1236.50 CEUX
GENMAB A/S 10-Apr-2025 15:56:30 PM 16 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:56:30 PM 22 1237.00 AQEU
GENMAB A/S 10-Apr-2025 15:56:35 PM 2 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:56:35 PM 72 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:56:35 PM 4 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:56:35 PM 4 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:56:35 PM 9 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:57:01 PM 16 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:01 PM 10 1236.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 4 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 14 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 13 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 4 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 8 1235.50 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 82 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:07 PM 10 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:57:07 PM 32 1235.50 CEUX
GENMAB A/S 10-Apr-2025 15:57:27 PM 84 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 7 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 46 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 12 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:57:40 PM 13 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:58:10 PM 28 1234.50 TQEX
GENMAB A/S 10-Apr-2025 15:58:10 PM 5 1234.50 TQEX
GENMAB A/S 10-Apr-2025 15:58:10 PM 26 1234.50 CEUX
GENMAB A/S 10-Apr-2025 15:58:10 PM 28 1234.50 AQEU
GENMAB A/S 10-Apr-2025 15:58:20 PM 10 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:58:20 PM 79 1234.00 XCSE
GENMAB A/S 10-Apr-2025 15:58:20 PM 31 1233.50 TQEX
GENMAB A/S 10-Apr-2025 15:58:20 PM 54 1233.50 CEUX
GENMAB A/S 10-Apr-2025 15:58:33 PM 10 1233.50 XCSE
GENMAB A/S 10-Apr-2025 15:58:40 PM 79 1233.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:00 PM 11 1234.00 XCSE

47

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:59:01 PM 1 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 42 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 30 1235.00 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 16 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 5 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 8 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 7 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 8 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 7 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 8 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 25 1234.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:01 PM 2 1234.00 AQEU
GENMAB A/S 10-Apr-2025 15:59:01 PM 5 1234.00 AQEU
GENMAB A/S 10-Apr-2025 15:59:01 PM 30 1234.00 AQEU
GENMAB A/S 10-Apr-2025 15:59:22 PM 88 1233.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:22 PM 2 1233.50 CEUX
GENMAB A/S 10-Apr-2025 15:59:22 PM 86 1233.50 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 17 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 4 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 4 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 3 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 4 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 8 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 42 1232.50 XCSE
GENMAB A/S 10-Apr-2025 15:59:47 PM 2 1233.00 TQEX
GENMAB A/S 10-Apr-2025 15:59:47 PM 3 1233.00 TQEX
GENMAB A/S 10-Apr-2025 15:59:47 PM 7 1233.00 TQEX
GENMAB A/S 10-Apr-2025 15:59:47 PM 9 1233.00 TQEX
GENMAB A/S 10-Apr-2025 15:59:47 PM 5 1233.00 TQEX
GENMAB A/S 10-Apr-2025 15:59:47 PM 4 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 20 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 5 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 3 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 14 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 6 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 19 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 7 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 5 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 15:59:47 PM 2 1233.00 AQEU
GENMAB A/S 10-Apr-2025 15:59:47 PM 10 1233.00 AQEU
GENMAB A/S 10-Apr-2025 15:59:47 PM 3 1233.00 AQEU

48

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 15:59:47 PM 18 1233.00 AQEU
GENMAB A/S 10-Apr-2025 16:00:04 PM 84 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:00:09 PM 89 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:14 PM 82 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:14 PM 9 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:14 PM 7 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:14 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 89 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:23 PM 10 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 4 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 7 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 2 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:23 PM 36 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 10 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 2 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 10 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 2 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 2 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:28 PM 2 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 86 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:40 PM 6 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 5 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 10 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 10 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 5 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 3 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 4 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 2 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 4 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 3 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 3 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:00:40 PM 2 1232.50 AQEU
GENMAB A/S 10-Apr-2025 16:00:40 PM 19 1232.50 AQEU
GENMAB A/S 10-Apr-2025 16:00:40 PM 3 1232.50 AQEU

49

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:00:40 PM 2 1232.50 AQEU
GENMAB A/S 10-Apr-2025 16:00:45 PM 26 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:00:47 PM 6 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:47 PM 2 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:47 PM 4 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:47 PM 6 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:47 PM 4 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:47 PM 2 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:00:47 PM 61 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:01:17 PM 16 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:17 PM 42 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:18 PM 57 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:18 PM 15 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:18 PM 14 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:18 PM 26 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:22 PM 17 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:22 PM 2 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:22 PM 25 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:22 PM 7 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:22 PM 38 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:22 PM 5 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:22 PM 3 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:22 PM 22 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 2 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:29 PM 7 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:29 PM 3 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:29 PM 5 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:29 PM 3 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:01:29 PM 11 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:01:29 PM 5 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:01:29 PM 8 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:01:29 PM 5 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:01:29 PM 7 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:01:29 PM 2 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 2 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 3 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 2 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 2 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 9 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:29 PM 10 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:01:45 PM 64 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:02:01 PM 46 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:02:04 PM 15 1229.50 XCSE

50

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:02:04 PM 15 1229.50 AQEU
GENMAB A/S 10-Apr-2025 16:02:04 PM 15 1229.50 AQEU
GENMAB A/S 10-Apr-2025 16:02:07 PM 72 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:02:30 PM 7 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:02:30 PM 4 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:02:30 PM 2 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:02:30 PM 12 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:02:30 PM 1 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:02:31 PM 83 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:02:52 PM 27 1229.50 TQEX
GENMAB A/S 10-Apr-2025 16:03:01 PM 10 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:02 PM 73 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:02 PM 25 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:03:02 PM 7 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:03:02 PM 8 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:03:02 PM 6 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:03:02 PM 10 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:03:02 PM 43 1230.00 AQEU
GENMAB A/S 10-Apr-2025 16:03:08 PM 5 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:08 PM 5 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:08 PM 25 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:40 PM 50 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:40 PM 20 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:40 PM 6 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:03:40 PM 21 1229.00 TQEX
GENMAB A/S 10-Apr-2025 16:03:40 PM 4 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:03:51 PM 72 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:05 PM 2 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 10 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 10 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 3 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 5 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 37 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 4 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 2 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 7 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 36 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 5 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:05 PM 2 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:04:09 PM 30 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:09 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:09 PM 16 1231.00 XCSE

51

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:04:09 PM 30 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:04:22 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:32 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:32 PM 30 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:32 PM 29 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:39 PM 89 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:39 PM 88 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:04:39 PM 27 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:04:41 PM 49 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:04:41 PM 20 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:04:41 PM 15 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:04:41 PM 26 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:04:53 PM 10 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:04:53 PM 10 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:04:53 PM 9 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:05:21 PM 20 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:05:39 PM 16 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:05:39 PM 41 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:05:39 PM 25 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:04 PM 50 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:04 PM 35 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:23 PM 86 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:23 PM 24 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:06:23 PM 15 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:06:23 PM 29 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:06:23 PM 17 1234.50 AQEU
GENMAB A/S 10-Apr-2025 16:06:34 PM 3 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:06:34 PM 3 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:06:38 PM 1 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:38 PM 85 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:38 PM 14 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:38 PM 15 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:38 PM 8 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:06:38 PM 25 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:06:38 PM 2 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:06:38 PM 5 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:06:53 PM 51 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:06:55 PM 4 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:06:55 PM 8 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:06:55 PM 73 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:08 PM 42 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:14 PM 83 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:07:14 PM 3 1231.00 CEUX

52

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:07:14 PM 62 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:14 PM 2 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:07:14 PM 4 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:07:14 PM 27 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:07:14 PM 7 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:07:14 PM 3 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:07:15 PM 84 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:31 PM 83 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:31 PM 5 1229.00 TQEX
GENMAB A/S 10-Apr-2025 16:07:31 PM 3 1229.00 TQEX
GENMAB A/S 10-Apr-2025 16:07:31 PM 7 1229.00 TQEX
GENMAB A/S 10-Apr-2025 16:07:31 PM 6 1229.00 TQEX
GENMAB A/S 10-Apr-2025 16:07:31 PM 2 1229.00 TQEX
GENMAB A/S 10-Apr-2025 16:07:31 PM 85 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 5 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 15 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 6 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 2 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 2 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 3 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 2 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 3 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 2 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 5 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 6 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 8 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:31 PM 3 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:44 PM 5 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:44 PM 2 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:44 PM 16 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:44 PM 4 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:45 PM 10 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:49 PM 2 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:07:52 PM 7 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:52 PM 10 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:52 PM 5 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:07:52 PM 8 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:08:10 PM 2 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:08:10 PM 4 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:08:10 PM 11 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:08:10 PM 13 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:08:23 PM 86 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:23 PM 26 1230.50 TQEX

53

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:08:28 PM 4 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 5 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 3 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 7 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 3 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 3 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 15 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 3 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 2 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 2 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:08:28 PM 15 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:08:28 PM 15 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:16 PM 88 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:09:16 PM 11 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:16 PM 15 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:16 PM 2 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:16 PM 20 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:35 PM 52 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:09:35 PM 14 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:09:35 PM 5 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:09:36 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:09:36 PM 42 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:09:36 PM 3 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:36 PM 22 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:36 PM 21 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:09:37 PM 5 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:09:37 PM 5 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:09:37 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 82 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 5 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 13 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 13 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 16 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 16 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:06 PM 7 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:10:25 PM 87 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:10:25 PM 3 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:10:25 PM 2 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:10:25 PM 13 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:10:25 PM 5 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:10:25 PM 4 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:10:25 PM 27 1230.50 AQEU

54

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:10:49 PM 24 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:10:49 PM 15 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:10:49 PM 47 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:10:49 PM 25 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:10:52 PM 43 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:11:32 PM 86 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 17 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 70 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 5 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 20 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 9 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 15 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 16 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 5 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:11:34 PM 1 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:11:34 PM 3 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:11:34 PM 7 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:11:34 PM 4 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:11:34 PM 5 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:11:34 PM 83 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:11:34 PM 35 1231.50 AQEU
GENMAB A/S 10-Apr-2025 16:11:38 PM 86 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:11:38 PM 2 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:11:38 PM 70 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:12:11 PM 88 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:12:11 PM 16 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:12:11 PM 20 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:12:11 PM 32 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:14 PM 80 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:27 PM 2 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:27 PM 1 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:52 PM 6 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:52 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:52 PM 6 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:52 PM 19 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:52 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:13:52 PM 5 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:02 PM 43 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:57 PM 30 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:14:57 PM 1 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:14:57 PM 42 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:14:57 PM 16 1232.50 XCSE

55

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:14:57 PM 16 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:14:57 PM 7 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:14:57 PM 84 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:14:57 PM 86 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:57 PM 5 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:57 PM 8 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:57 PM 4 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:57 PM 8 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:14:57 PM 18 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:15:06 PM 42 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:06 PM 15 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:06 PM 13 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:06 PM 15 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:08 PM 13 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:08 PM 13 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:08 PM 42 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:08 PM 16 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:13 PM 14 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:13 PM 42 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:14 PM 15 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:14 PM 42 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:15:33 PM 76 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:15:35 PM 30 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:35 PM 25 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:37 PM 30 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:37 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:37 PM 42 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:37 PM 13 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:38 PM 15 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:38 PM 15 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:38 PM 42 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:15:40 PM 89 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:16:10 PM 10 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:16:12 PM 24 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:16:12 PM 27 1233.50 AQEU
GENMAB A/S 10-Apr-2025 16:16:32 PM 3 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:16:32 PM 11 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:16:41 PM 87 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:16:41 PM 35 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:16:41 PM 84 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:16:41 PM 26 1233.50 AQEU
GENMAB A/S 10-Apr-2025 16:16:48 PM 33 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:16:48 PM 24 1234.00 XCSE

56

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:16:48 PM 83 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:16:48 PM 1 1233.50 AQEU
GENMAB A/S 10-Apr-2025 16:16:48 PM 16 1233.50 AQEU
GENMAB A/S 10-Apr-2025 16:16:52 PM 38 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:17:06 PM 87 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:16 PM 89 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:27 PM 67 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:33 PM 25 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:33 PM 29 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:33 PM 32 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:17:41 PM 18 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:41 PM 21 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:17:47 PM 32 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:18:01 PM 70 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:18:14 PM 82 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:18:14 PM 83 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:18:21 PM 13 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:18:21 PM 75 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:19:00 PM 84 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:19:27 PM 14 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:19:27 PM 8 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:19:37 PM 18 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:19:37 PM 1 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:19:37 PM 2 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:19:44 PM 1 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:19:44 PM 88 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:19:45 PM 1 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:19:49 PM 71 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:19:49 PM 44 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:20:00 PM 25 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:20:00 PM 4 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:20:00 PM 25 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:20:00 PM 25 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:20:00 PM 13 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:20:00 PM 74 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:20:06 PM 6 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:06 PM 80 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:26 PM 3 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:20:26 PM 50 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:20:32 PM 39 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:39 PM 15 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:20:39 PM 25 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:20:45 PM 5 1231.50 XCSE

57

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:20:45 PM 5 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:52 PM 2 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:52 PM 10 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:52 PM 15 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:20:52 PM 8 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:20:52 PM 29 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:21:13 PM 58 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:13 PM 16 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:13 PM 10 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:16 PM 13 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:21:16 PM 13 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:21:18 PM 1 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:18 PM 12 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:18 PM 49 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:37 PM 40 1230.00 TQEX
GENMAB A/S 10-Apr-2025 16:21:44 PM 5 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:44 PM 32 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:21:44 PM 57 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:21:46 PM 25 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 5 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 2 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 8 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 23 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 42 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 9 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:21:46 PM 2 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:21:46 PM 31 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:21:46 PM 7 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:21:46 PM 3 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:21:49 PM 25 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:21:50 PM 4 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:21:55 PM 2 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:10 PM 5 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:22:19 PM 31 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 58 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 3 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 5 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 3 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 23 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 13 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:22:29 PM 22 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:22:29 PM 2 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:22:33 PM 5 1230.50 CEUX

58

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:22:33 PM 2 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:22:33 PM 2 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:22:33 PM 2 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:22:33 PM 2 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:22:33 PM 2 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:14 PM 35 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:24 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 4 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 13 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 11 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 14 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:23:24 PM 3 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:24 PM 8 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:24 PM 8 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:24 PM 28 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:24 PM 22 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:23:24 PM 16 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:23:25 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:24:12 PM 42 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:24:12 PM 13 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:24:12 PM 15 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:24:12 PM 14 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:24:12 PM 32 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:24:18 PM 60 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:24:26 PM 4 1231.00 TQEX
GENMAB A/S 10-Apr-2025 16:24:27 PM 24 1231.00 TQEX
GENMAB A/S 10-Apr-2025 16:24:27 PM 32 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:24:28 PM 14 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:24:37 PM 33 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:25:10 PM 36 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:25:10 PM 8 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:25:20 PM 1 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:25:20 PM 32 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:25:27 PM 10 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:25:34 PM 85 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 15 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 13 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 22 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 42 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 42 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 14 1231.50 XCSE

59

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:25:34 PM 13 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 14 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 2 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 27 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 35 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 14 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 42 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 14 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 7 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:34 PM 78 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:25:42 PM 9 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:42 PM 2 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:42 PM 15 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:42 PM 16 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:42 PM 36 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:52 PM 82 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:25:52 PM 2 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:25:52 PM 3 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:25:52 PM 7 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:25:52 PM 8 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:25:52 PM 2 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:25:52 PM 3 1230.50 TQEX
GENMAB A/S 10-Apr-2025 16:25:52 PM 82 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:25:52 PM 18 1230.50 AQEU
GENMAB A/S 10-Apr-2025 16:26:27 PM 16 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:27 PM 42 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:27 PM 15 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:27 PM 13 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:58 PM 87 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:58 PM 7 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:58 PM 5 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:58 PM 69 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:26:58 PM 38 1233.00 TQEX
GENMAB A/S 10-Apr-2025 16:26:58 PM 84 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:26:58 PM 15 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:26:58 PM 15 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:26:58 PM 15 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:26:58 PM 30 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:26:58 PM 20 1232.00 AQEU
GENMAB A/S 10-Apr-2025 16:26:58 PM 5 1232.00 AQEU
GENMAB A/S 10-Apr-2025 16:26:58 PM 3 1232.00 AQEU
GENMAB A/S 10-Apr-2025 16:27:25 PM 86 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:27:25 PM 1 1232.00 AQEU

60

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:27:26 PM 15 1232.00 AQEU
GENMAB A/S 10-Apr-2025 16:27:43 PM 14 1232.00 AQEU
GENMAB A/S 10-Apr-2025 16:27:50 PM 16 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:27:50 PM 5 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:27:50 PM 5 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:27:59 PM 3 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:28:16 PM 12 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:28:16 PM 21 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:28:16 PM 19 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:28:16 PM 79 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:28:16 PM 4 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:28:16 PM 8 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:28:16 PM 3 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:28:16 PM 8 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:28:16 PM 8 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:28:16 PM 5 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:28:16 PM 4 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:28:24 PM 8 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:28:28 PM 2 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:28:55 PM 33 1231.00 TQEX
GENMAB A/S 10-Apr-2025 16:28:55 PM 3 1231.00 TQEX
GENMAB A/S 10-Apr-2025 16:28:55 PM 9 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:28:55 PM 11 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:28:55 PM 51 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:28:58 PM 9 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:28:58 PM 17 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:29:04 PM 80 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:20 PM 32 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:29:28 PM 32 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:29:29 PM 7 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:29:41 PM 24 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 60 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 40 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 13 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 37 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 22 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 23 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 60 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:29:41 PM 85 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:29:41 PM 19 1231.00 AQEU
GENMAB A/S 10-Apr-2025 16:29:41 PM 6 1230.00 AQEU
GENMAB A/S 10-Apr-2025 16:29:41 PM 2 1230.00 AQEU
GENMAB A/S 10-Apr-2025 16:29:41 PM 3 1230.00 AQEU

61

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:29:41 PM 15 1230.00 AQEU
GENMAB A/S 10-Apr-2025 16:29:59 PM 56 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:29:59 PM 15 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:29:59 PM 72 1230.50 CEUX
GENMAB A/S 10-Apr-2025 16:30:23 PM 2 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:30:23 PM 24 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:30:25 PM 8 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:30:25 PM 6 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:30:25 PM 11 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:30:25 PM 3 1231.50 CEUX
GENMAB A/S 10-Apr-2025 16:31:16 PM 7 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:31:16 PM 4 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 4 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 3 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 2 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 4 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 8 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 4 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 4 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:16 PM 10 1232.00 TQEX
GENMAB A/S 10-Apr-2025 16:31:17 PM 40 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:31:17 PM 10 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:31:17 PM 31 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:31:17 PM 32 1232.00 CEUX
GENMAB A/S 10-Apr-2025 16:31:27 PM 19 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:31:27 PM 59 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:07 PM 4 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:07 PM 3 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:40 PM 88 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 100 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 12 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 100 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 12 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 63 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 21 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:32:41 PM 8 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:41 PM 9 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:41 PM 18 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:41 PM 87 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:52 PM 15 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:32:52 PM 42 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:32:52 PM 29 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:32:52 PM 22 1234.00 XCSE

62

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:32:52 PM 67 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:52 PM 33 1234.00 AQEU
GENMAB A/S 10-Apr-2025 16:32:53 PM 43 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:32:54 PM 83 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:32:58 PM 27 1233.00 AQEU
GENMAB A/S 10-Apr-2025 16:33:17 PM 9 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:33:17 PM 7 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:33:17 PM 13 1233.50 TQEX
GENMAB A/S 10-Apr-2025 16:33:17 PM 27 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:33:18 PM 3 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 3 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 5 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 4 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 3 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 3 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 43 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:18 PM 37 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:33:42 PM 25 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:42 PM 39 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:33:42 PM 24 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:33:42 PM 19 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:33:42 PM 68 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:34:06 PM 52 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:34:06 PM 26 1234.50 AQEU
GENMAB A/S 10-Apr-2025 16:34:07 PM 100 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:12 PM 28 1234.50 AQEU
GENMAB A/S 10-Apr-2025 16:34:17 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:18 PM 10 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:34:18 PM 5 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:34:32 PM 2 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:32 PM 3 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:32 PM 11 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:32 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:37 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:37 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:39 PM 37 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:56 PM 63 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:34:56 PM 12 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:56 PM 30 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:56 PM 24 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:34:56 PM 3 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:35:00 PM 16 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:35:01 PM 87 1234.00 XCSE

63

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:35:15 PM 39 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:35:52 PM 18 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:35:52 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:35:52 PM 15 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:36:08 PM 36 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:36:17 PM 6 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:36:17 PM 82 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:36:21 PM 85 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:36:21 PM 5 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:36:21 PM 17 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:36:21 PM 30 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:36:21 PM 42 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:36:21 PM 18 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:36:21 PM 47 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:36:21 PM 10 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:36:21 PM 5 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:36:21 PM 42 1234.00 AQEU
GENMAB A/S 10-Apr-2025 16:36:35 PM 62 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:37:16 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:18 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:30 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:33 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:33 PM 36 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:37:35 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:37 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:40 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:41 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:37:46 PM 36 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:37:47 PM 6 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:47 PM 4 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:37:47 PM 2 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:37:47 PM 4 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:37:57 PM 40 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:37:57 PM 15 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:37:57 PM 3 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:37:57 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:37:57 PM 24 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:37:57 PM 30 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:37:57 PM 2 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:37:57 PM 87 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:37:57 PM 32 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:37:58 PM 13 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 13 1235.50 XCSE

64

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:37:58 PM 42 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 14 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 14 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 14 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 24 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 42 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:58 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:59 PM 24 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:59 PM 14 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:59 PM 42 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:37:59 PM 11 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:08 PM 1 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:08 PM 70 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:19 PM 68 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:20 PM 62 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:38:35 PM 62 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:35 PM 17 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:35 PM 24 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:38:37 PM 34 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:06 PM 2 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:08 PM 2 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:10 PM 2 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:12 PM 2 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:14 PM 2 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:17 PM 61 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:17 PM 18 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:39:21 PM 64 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:21 PM 32 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:39:21 PM 28 1235.50 AQEU
GENMAB A/S 10-Apr-2025 16:39:24 PM 58 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:39:24 PM 39 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:39:24 PM 52 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:39:24 PM 2 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:39:24 PM 50 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:39:24 PM 5 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:39:24 PM 11 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:39:24 PM 10 1234.00 AQEU
GENMAB A/S 10-Apr-2025 16:39:28 PM 25 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:39:28 PM 14 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:39:46 PM 30 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:40:14 PM 44 1234.50 XCSE

65

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:40:14 PM 22 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:40:14 PM 42 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:40:14 PM 16 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:40:14 PM 23 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:40:14 PM 5 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:40:14 PM 10 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:40:34 PM 63 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:40:40 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:40:40 PM 25 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:40:40 PM 42 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:40:40 PM 15 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:40:40 PM 15 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:40:58 PM 1 1234.50 AQEU
GENMAB A/S 10-Apr-2025 16:41:15 PM 7 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:41:15 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:41:21 PM 21 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:21 PM 42 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:21 PM 16 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:21 PM 36 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:41:22 PM 42 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:22 PM 30 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:22 PM 42 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:22 PM 15 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:22 PM 11 1235.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:22 PM 32 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:41:22 PM 32 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:41:26 PM 86 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:41:26 PM 4 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:26 PM 36 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:26 PM 33 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:31 PM 28 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:41:31 PM 3 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:41:31 PM 17 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:41:31 PM 6 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:41:31 PM 17 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:31 PM 11 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:36 PM 25 1234.50 AQEU
GENMAB A/S 10-Apr-2025 16:41:40 PM 26 1234.50 AQEU
GENMAB A/S 10-Apr-2025 16:41:52 PM 14 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:52 PM 30 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:41:54 PM 18 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:41:54 PM 15 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:41:54 PM 10 1234.00 TQEX

66

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:41:54 PM 5 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:41:54 PM 12 1234.00 TQEX
GENMAB A/S 10-Apr-2025 16:41:54 PM 63 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:54 PM 3 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:41:54 PM 5 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:42:08 PM 2 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:42:32 PM 43 1237.00 XCSE
GENMAB A/S 10-Apr-2025 16:42:32 PM 10 1237.00 XCSE
GENMAB A/S 10-Apr-2025 16:42:32 PM 15 1237.00 XCSE
GENMAB A/S 10-Apr-2025 16:42:32 PM 15 1237.00 XCSE
GENMAB A/S 10-Apr-2025 16:42:32 PM 5 1237.00 XCSE
GENMAB A/S 10-Apr-2025 16:42:32 PM 38 1237.00 TQEX
GENMAB A/S 10-Apr-2025 16:42:32 PM 56 1236.50 CEUX
GENMAB A/S 10-Apr-2025 16:42:32 PM 39 1237.00 AQEU
GENMAB A/S 10-Apr-2025 16:43:04 PM 42 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 16 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 36 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 14 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 4 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 11 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 14 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 42 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 14 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:04 PM 31 1238.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:08 PM 32 1237.50 CEUX
GENMAB A/S 10-Apr-2025 16:43:11 PM 83 1237.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:11 PM 39 1237.00 CEUX
GENMAB A/S 10-Apr-2025 16:43:18 PM 67 1236.00 XCSE
GENMAB A/S 10-Apr-2025 16:43:18 PM 40 1236.00 CEUX
GENMAB A/S 10-Apr-2025 16:44:02 PM 36 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:44:10 PM 20 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:10 PM 8 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:10 PM 20 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:10 PM 27 1235.00 CEUX
GENMAB A/S 10-Apr-2025 16:44:10 PM 64 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:44:12 PM 3 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:44:15 PM 36 1235.00 TQEX
GENMAB A/S 10-Apr-2025 16:44:26 PM 3 1235.00 AQEU
GENMAB A/S 10-Apr-2025 16:44:42 PM 30 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 2 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 7 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 22 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 2 1235.00 XCSE

67

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:44:42 PM 45 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 42 1235.00 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 27 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:44:42 PM 36 1235.50 CEUX
GENMAB A/S 10-Apr-2025 16:44:42 PM 2 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:44:42 PM 34 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:44:42 PM 38 1235.00 AQEU
GENMAB A/S 10-Apr-2025 16:45:04 PM 52 1234.50 CEUX
GENMAB A/S 10-Apr-2025 16:45:06 PM 42 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:45:06 PM 1 1234.50 XCSE
GENMAB A/S 10-Apr-2025 16:45:15 PM 3 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:45:15 PM 18 1234.00 CEUX
GENMAB A/S 10-Apr-2025 16:45:15 PM 13 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:45:16 PM 2 1234.00 XCSE
GENMAB A/S 10-Apr-2025 16:45:38 PM 26 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:45:38 PM 18 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:45:42 PM 67 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:45:42 PM 42 1233.50 AQEU
GENMAB A/S 10-Apr-2025 16:46:26 PM 28 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:27 PM 14 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:28 PM 30 1233.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:28 PM 30 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:28 PM 42 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:28 PM 10 1233.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:28 PM 36 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:28 PM 3 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:28 PM 7 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:28 PM 9 1233.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:29 PM 30 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:29 PM 40 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:46:29 PM 32 1233.00 CEUX
GENMAB A/S 10-Apr-2025 16:46:29 PM 1 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:29 PM 37 1232.50 CEUX
GENMAB A/S 10-Apr-2025 16:46:36 PM 16 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:36 PM 23 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:36 PM 25 1232.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:36 PM 42 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:36 PM 30 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:36 PM 15 1232.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:36 PM 26 1232.50 TQEX
GENMAB A/S 10-Apr-2025 16:46:49 PM 30 1231.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:49 PM 10 1231.00 CEUX
GENMAB A/S 10-Apr-2025 16:46:49 PM 32 1231.00 CEUX

68

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:46:56 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 4 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 4 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 7 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 8 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 7 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 4 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 13 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 2 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 42 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:56 PM 15 1231.00 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 10 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 75 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 30 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 11 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 4 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 5 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 15 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 25 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 22 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:46:59 PM 8 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:46:59 PM 31 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:47:02 PM 30 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:47:02 PM 42 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:47:02 PM 26 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:47:03 PM 10 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:47:03 PM 42 1230.50 XCSE
GENMAB A/S 10-Apr-2025 16:47:08 PM 30 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:47:08 PM 42 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:47:12 PM 87 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:47:14 PM 26 1230.00 XCSE
GENMAB A/S 10-Apr-2025 16:47:14 PM 39 1230.00 CEUX
GENMAB A/S 10-Apr-2025 16:47:22 PM 7 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:47:22 PM 19 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 15 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 50 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 3 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 12 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 5 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 3 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 2 1229.00 XCSE

69

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:48:10 PM 7 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 9 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 4 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 36 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 52 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:10 PM 36 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:48:10 PM 8 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:10 PM 2 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:10 PM 3 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:10 PM 30 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:12 PM 52 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:12 PM 5 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:12 PM 30 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:48:12 PM 51 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:12 PM 3 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:12 PM 5 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:12 PM 3 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:12 PM 2 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:12 PM 4 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:27 PM 73 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:27 PM 32 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:48:33 PM 2 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:33 PM 2 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:33 PM 3 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:33 PM 2 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:33 PM 2 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:33 PM 47 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:48:40 PM 6 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:48:41 PM 15 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:41 PM 52 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:50 PM 2 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:48:56 PM 5 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:48:56 PM 5 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:48:56 PM 16 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:48:56 PM 45 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:49:09 PM 32 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:49:24 PM 74 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:26 PM 2 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:26 PM 36 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:49:26 PM 7 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:49:26 PM 23 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:49:28 PM 14 1228.00 XCSE

70

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:49:28 PM 52 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:28 PM 32 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:49:28 PM 37 1227.50 CEUX
GENMAB A/S 10-Apr-2025 16:49:53 PM 82 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:53 PM 2 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:53 PM 52 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:53 PM 2 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:53 PM 46 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:49:53 PM 32 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:49:53 PM 34 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:49:55 PM 52 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:55 PM 15 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:55 PM 13 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:55 PM 16 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:49:55 PM 16 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:50:01 PM 52 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:50:07 PM 52 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:50:07 PM 10 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:50:17 PM 26 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:50:17 PM 18 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:50:17 PM 9 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:50:26 PM 35 1227.50 CEUX
GENMAB A/S 10-Apr-2025 16:50:49 PM 29 1227.50 TQEX
GENMAB A/S 10-Apr-2025 16:50:49 PM 27 1227.50 CEUX
GENMAB A/S 10-Apr-2025 16:51:04 PM 36 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:51:09 PM 33 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:51:19 PM 4 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:19 PM 12 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:23 PM 23 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:51:49 PM 52 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:49 PM 37 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:49 PM 14 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:49 PM 13 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:49 PM 52 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:49 PM 17 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:51:49 PM 36 1229.50 CEUX
GENMAB A/S 10-Apr-2025 16:51:50 PM 16 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:50 PM 52 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:50 PM 37 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:51 PM 15 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:51 PM 52 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:51 PM 30 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:51 PM 15 1229.50 XCSE

71

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:51:51 PM 14 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:51 PM 52 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:51 PM 30 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 14 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 52 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 30 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 16 1229.50 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 89 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 13 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 15 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 15 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 37 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:51:52 PM 1 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:51:52 PM 40 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:51:52 PM 25 1229.00 AQEU
GENMAB A/S 10-Apr-2025 16:51:52 PM 8 1229.00 AQEU
GENMAB A/S 10-Apr-2025 16:51:52 PM 2 1229.00 AQEU
GENMAB A/S 10-Apr-2025 16:52:05 PM 15 1229.00 AQEU
GENMAB A/S 10-Apr-2025 16:52:09 PM 14 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:09 PM 52 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:09 PM 37 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:09 PM 2 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:52:09 PM 8 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:09 PM 7 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:09 PM 36 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:52:10 PM 16 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:52:30 PM 2 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:30 PM 4 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:30 PM 4 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:30 PM 2 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:30 PM 8 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:30 PM 9 1228.00 TQEX
GENMAB A/S 10-Apr-2025 16:52:30 PM 7 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:30 PM 27 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:30 PM 4 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:30 PM 2 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:30 PM 11 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:30 PM 4 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:52:30 PM 8 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:52:32 PM 2 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:34 PM 2 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:35 PM 79 1228.00 XCSE

72

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:52:35 PM 36 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:36 PM 36 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:36 PM 10 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:52:37 PM 12 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:52:37 PM 7 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:52:37 PM 3 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:52:38 PM 16 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:52:40 PM 36 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:52:49 PM 36 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:52:51 PM 31 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:52 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:52 PM 3 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:55 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:57 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:52:59 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:01 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:03 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:05 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:07 PM 5 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:07 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:09 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:11 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:12 PM 5 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:13 PM 2 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:14 PM 3 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:15 PM 15 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:15 PM 36 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:53:15 PM 5 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:53:15 PM 25 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:53:15 PM 9 1228.00 CEUX
GENMAB A/S 10-Apr-2025 16:53:15 PM 16 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:53:15 PM 12 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:53:16 PM 13 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:17 PM 19 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:17 PM 10 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:17 PM 5 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:17 PM 10 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:17 PM 4 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:19 PM 36 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:19 PM 35 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:53:19 PM 6 1228.00 AQEU
GENMAB A/S 10-Apr-2025 16:53:22 PM 12 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:24 PM 30 1229.00 XCSE

73

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 10-Apr-2025 16:53:24 PM 26 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:24 PM 37 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:24 PM 13 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:24 PM 6 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:24 PM 4 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:53:24 PM 4 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:53:24 PM 3 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:53:24 PM 2 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:53:24 PM 3 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:53:25 PM 30 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:25 PM 26 1229.00 XCSE
GENMAB A/S 10-Apr-2025 16:53:32 PM 16 1228.50 TQEX
GENMAB A/S 10-Apr-2025 16:54:05 PM 6 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:54:05 PM 34 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:54:05 PM 36 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:54:05 PM 7 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:54:05 PM 9 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:54:05 PM 9 1229.00 CEUX
GENMAB A/S 10-Apr-2025 16:54:13 PM 52 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:54:13 PM 32 1228.50 CEUX
GENMAB A/S 10-Apr-2025 16:54:13 PM 15 1228.50 AQEU
GENMAB A/S 10-Apr-2025 16:54:13 PM 25 1228.50 AQEU
GENMAB A/S 10-Apr-2025 16:54:13 PM 10 1228.50 AQEU
GENMAB A/S 10-Apr-2025 16:54:22 PM 2 1228.50 XCSE
GENMAB A/S 10-Apr-2025 16:54:22 PM 9 1228.50 AQEU
GENMAB A/S 10-Apr-2025 16:54:26 PM 86 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 24 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 10 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 5 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 73 1228.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 16 1227.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 2 1227.00 XCSE
GENMAB A/S 10-Apr-2025 16:54:26 PM 8 1227.50 CEUX
GENMAB A/S 10-Apr-2025 16:54:26 PM 30 1227.50 CEUX
GENMAB A/S 10-Apr-2025 16:54:27 PM 11 1227.00 XCSE
GENMAB A/S 11-Apr-2025 10:23:39 AM 19 1211.00 XCSE
GENMAB A/S 11-Apr-2025 10:23:39 AM 15 1211.00 XCSE
GENMAB A/S 11-Apr-2025 10:23:39 AM 10 1211.00 XCSE
GENMAB A/S 11-Apr-2025 10:23:39 AM 80 1211.00 CEUX
GENMAB A/S 11-Apr-2025 10:23:40 AM 38 1211.00 XCSE
GENMAB A/S 11-Apr-2025 10:26:11 AM 82 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:26:11 AM 86 1213.50 TQEX
GENMAB A/S 11-Apr-2025 10:26:11 AM 52 1213.50 CEUX

74

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 10:26:14 AM 88 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:26:19 AM 22 1213.50 XCSE
GENMAB A/S 11-Apr-2025 10:26:19 AM 65 1213.50 XCSE
GENMAB A/S 11-Apr-2025 10:26:19 AM 63 1213.50 CEUX
GENMAB A/S 11-Apr-2025 10:26:27 AM 41 1213.00 AQEU
GENMAB A/S 11-Apr-2025 10:26:36 AM 30 1213.00 AQEU
GENMAB A/S 11-Apr-2025 10:26:45 AM 9 1213.00 AQEU
GENMAB A/S 11-Apr-2025 10:27:09 AM 79 1212.50 TQEX
GENMAB A/S 11-Apr-2025 10:27:09 AM 49 1212.50 CEUX
GENMAB A/S 11-Apr-2025 10:27:54 AM 88 1212.00 XCSE
GENMAB A/S 11-Apr-2025 10:27:54 AM 46 1212.00 AQEU
GENMAB A/S 11-Apr-2025 10:27:54 AM 26 1212.00 AQEU
GENMAB A/S 11-Apr-2025 10:27:55 AM 3 1212.00 AQEU
GENMAB A/S 11-Apr-2025 10:28:06 AM 28 1211.50 TQEX
GENMAB A/S 11-Apr-2025 10:28:06 AM 47 1211.50 TQEX
GENMAB A/S 11-Apr-2025 10:28:06 AM 39 1211.50 CEUX
GENMAB A/S 11-Apr-2025 10:28:06 AM 19 1211.50 CEUX
GENMAB A/S 11-Apr-2025 10:28:25 AM 21 1211.50 CEUX
GENMAB A/S 11-Apr-2025 10:28:25 AM 23 1211.50 CEUX
GENMAB A/S 11-Apr-2025 10:28:35 AM 10 1211.50 CEUX
GENMAB A/S 11-Apr-2025 10:28:35 AM 16 1211.50 CEUX
GENMAB A/S 11-Apr-2025 10:29:09 AM 65 1211.00 XCSE
GENMAB A/S 11-Apr-2025 10:29:09 AM 77 1211.00 AQEU
GENMAB A/S 11-Apr-2025 10:30:38 AM 17 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:30:38 AM 66 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:30:47 AM 81 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:30:48 AM 88 1212.00 CEUX
GENMAB A/S 11-Apr-2025 10:32:28 AM 3 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:32:28 AM 10 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:34:35 AM 14 1213.50 XCSE
GENMAB A/S 11-Apr-2025 10:34:35 AM 14 1213.50 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 41 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 14 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 14 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 14 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 20 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 61 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:34:59 AM 16 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:35:08 AM 2 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:35:08 AM 80 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:35:25 AM 4 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:35:25 AM 61 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:35:25 AM 34 1214.00 XCSE

75

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 10:37:05 AM 81 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:38:47 AM 31 1214.50 TQEX
GENMAB A/S 11-Apr-2025 10:38:52 AM 82 1214.00 CEUX
GENMAB A/S 11-Apr-2025 10:38:53 AM 11 1215.50 CEUX
GENMAB A/S 11-Apr-2025 10:38:53 AM 17 1215.50 CEUX
GENMAB A/S 11-Apr-2025 10:38:53 AM 11 1215.50 CEUX
GENMAB A/S 11-Apr-2025 10:39:10 AM 30 1215.00 TQEX
GENMAB A/S 11-Apr-2025 10:39:10 AM 83 1215.00 CEUX
GENMAB A/S 11-Apr-2025 10:39:27 AM 100 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:27 AM 11 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:27 AM 16 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:27 AM 12 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:27 AM 32 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:27 AM 51 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:27 AM 84 1214.00 CEUX
GENMAB A/S 11-Apr-2025 10:39:28 AM 13 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:28 AM 14 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:32 AM 100 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:32 AM 11 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:39:33 AM 100 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 72 1216.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 14 1216.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 30 1216.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 12 1216.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 13 1216.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 85 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 40 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 41 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:40:39 AM 13 1216.50 TQEX
GENMAB A/S 11-Apr-2025 10:40:39 AM 15 1216.50 TQEX
GENMAB A/S 11-Apr-2025 10:40:39 AM 30 1214.50 TQEX
GENMAB A/S 11-Apr-2025 10:40:39 AM 86 1216.50 CEUX
GENMAB A/S 11-Apr-2025 10:40:39 AM 84 1215.50 CEUX
GENMAB A/S 11-Apr-2025 10:40:39 AM 88 1214.00 CEUX
GENMAB A/S 11-Apr-2025 10:41:01 AM 12 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:41:01 AM 2 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:41:08 AM 79 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:41:08 AM 41 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:41:08 AM 12 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:41:08 AM 23 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:44:16 AM 5 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:44:19 AM 13 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:44:19 AM 41 1215.50 XCSE

76

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 10:44:19 AM 11 1215.00 CEUX
GENMAB A/S 11-Apr-2025 10:44:19 AM 32 1215.00 CEUX
GENMAB A/S 11-Apr-2025 10:45:03 AM 41 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 30 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 12 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 12 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 13 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 3 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 12 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 35 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 61 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 3 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 28 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 11 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 13 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 13 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 4 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 41 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 1 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:03 AM 87 1215.00 CEUX
GENMAB A/S 11-Apr-2025 10:45:04 AM 26 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:04 AM 2 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:04 AM 24 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:04 AM 36 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:45:04 AM 26 1214.50 TQEX
GENMAB A/S 11-Apr-2025 10:46:43 AM 37 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:46:43 AM 14 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:46:43 AM 10 1214.50 XCSE
GENMAB A/S 11-Apr-2025 10:47:17 AM 40 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:47:17 AM 15 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:47:17 AM 17 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:47:17 AM 12 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:47:43 AM 9 1215.50 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 1 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 11 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 13 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 2 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 4 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 12 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:12 AM 61 1216.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:33 AM 82 1215.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:33 AM 42 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:48:33 AM 20 1214.00 TQEX

77

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 10:48:33 AM 56 1215.00 CEUX
GENMAB A/S 11-Apr-2025 10:48:33 AM 27 1215.00 CEUX
GENMAB A/S 11-Apr-2025 10:48:33 AM 40 1214.00 CEUX
GENMAB A/S 11-Apr-2025 10:49:09 AM 43 1214.00 XCSE
GENMAB A/S 11-Apr-2025 10:49:09 AM 15 1214.00 TQEX
GENMAB A/S 11-Apr-2025 10:51:06 AM 6 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:51:06 AM 2 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:51:48 AM 82 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:51:48 AM 25 1213.00 TQEX
GENMAB A/S 11-Apr-2025 10:51:48 AM 58 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:53:16 AM 83 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:54:23 AM 82 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:23 AM 50 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:23 AM 61 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:23 AM 10 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:23 AM 61 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:23 AM 15 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:23 AM 24 1212.00 TQEX
GENMAB A/S 11-Apr-2025 10:54:23 AM 82 1212.00 CEUX
GENMAB A/S 11-Apr-2025 10:54:48 AM 20 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:54:49 AM 20 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:54:56 AM 17 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:54:56 AM 26 1213.00 XCSE
GENMAB A/S 11-Apr-2025 10:54:57 AM 66 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:54:57 AM 1 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:55:02 AM 16 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:55:45 AM 86 1212.00 CEUX
GENMAB A/S 11-Apr-2025 10:55:52 AM 29 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:56:25 AM 85 1213.00 CEUX
GENMAB A/S 11-Apr-2025 10:56:26 AM 15 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:56:53 AM 69 1212.50 XCSE
GENMAB A/S 11-Apr-2025 10:56:53 AM 24 1212.50 TQEX
GENMAB A/S 11-Apr-2025 10:56:54 AM 81 1212.00 CEUX
GENMAB A/S 11-Apr-2025 10:57:14 AM 58 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:57:28 AM 14 1211.00 TQEX
GENMAB A/S 11-Apr-2025 10:57:34 AM 12 1211.00 TQEX
GENMAB A/S 11-Apr-2025 10:57:48 AM 10 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:58:01 AM 46 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:58:01 AM 29 1211.50 XCSE
GENMAB A/S 11-Apr-2025 10:58:20 AM 22 1211.00 TQEX
GENMAB A/S 11-Apr-2025 10:58:38 AM 83 1210.50 XCSE
GENMAB A/S 11-Apr-2025 10:58:38 AM 5 1211.00 TQEX
GENMAB A/S 11-Apr-2025 10:58:38 AM 24 1210.00 TQEX

78

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 10:58:38 AM 19 1210.50 CEUX
GENMAB A/S 11-Apr-2025 10:58:38 AM 69 1210.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:00 AM 17 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:00:00 AM 36 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:00 AM 18 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:00 AM 18 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:00 AM 1 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:03 AM 14 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:04 AM 66 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:00:04 AM 13 1208.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:04 AM 2 1208.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:04 AM 3 1208.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:04 AM 4 1208.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:04 AM 10 1208.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:04 AM 1 1208.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:10 AM 8 1208.00 XCSE
GENMAB A/S 11-Apr-2025 11:00:11 AM 76 1208.00 XCSE
GENMAB A/S 11-Apr-2025 11:00:20 AM 78 1207.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:38 AM 23 1207.00 XCSE
GENMAB A/S 11-Apr-2025 11:00:38 AM 61 1207.00 XCSE
GENMAB A/S 11-Apr-2025 11:00:38 AM 13 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:38 AM 43 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:00:59 AM 87 1206.00 XCSE
GENMAB A/S 11-Apr-2025 11:01:03 AM 27 1205.50 TQEX
GENMAB A/S 11-Apr-2025 11:01:14 AM 86 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:01:43 AM 22 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:01:43 AM 7 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:01:45 AM 81 1206.50 XCSE
GENMAB A/S 11-Apr-2025 11:02:05 AM 22 1206.00 CEUX
GENMAB A/S 11-Apr-2025 11:02:41 AM 86 1205.50 XCSE
GENMAB A/S 11-Apr-2025 11:02:41 AM 2 1206.00 CEUX
GENMAB A/S 11-Apr-2025 11:02:41 AM 27 1205.00 CEUX
GENMAB A/S 11-Apr-2025 11:03:35 AM 58 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:03:35 AM 24 1205.00 CEUX
GENMAB A/S 11-Apr-2025 11:05:26 AM 82 1207.00 XCSE
GENMAB A/S 11-Apr-2025 11:07:26 AM 47 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:07:26 AM 6 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:07:52 AM 2 1210.50 CEUX
GENMAB A/S 11-Apr-2025 11:07:53 AM 14 1210.50 XCSE
GENMAB A/S 11-Apr-2025 11:07:53 AM 22 1210.50 XCSE
GENMAB A/S 11-Apr-2025 11:07:53 AM 8 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:07:53 AM 17 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:07:53 AM 24 1210.00 TQEX

79

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 11:07:53 AM 25 1210.50 CEUX
GENMAB A/S 11-Apr-2025 11:07:53 AM 61 1210.50 CEUX
GENMAB A/S 11-Apr-2025 11:08:06 AM 2 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:08:06 AM 57 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:08:10 AM 3 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:08:10 AM 2 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:08:10 AM 10 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:08:10 AM 10 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:09:26 AM 12 1211.00 XCSE
GENMAB A/S 11-Apr-2025 11:09:49 AM 37 1211.00 XCSE
GENMAB A/S 11-Apr-2025 11:09:49 AM 48 1211.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 30 1210.50 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 12 1210.50 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 13 1211.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 41 1211.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 15 1211.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 7 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 78 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:26 AM 2 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:26 AM 13 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:26 AM 5 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:26 AM 88 1210.50 CEUX
GENMAB A/S 11-Apr-2025 11:10:29 AM 4 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:29 AM 3 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:29 AM 2 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:29 AM 4 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:29 AM 15 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:10:29 AM 47 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:10:55 AM 25 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:55 AM 56 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:10:55 AM 5 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:55 AM 15 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:10:55 AM 4 1210.00 TQEX
GENMAB A/S 11-Apr-2025 11:11:50 AM 11 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:11:50 AM 15 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:11:50 AM 60 1210.00 XCSE
GENMAB A/S 11-Apr-2025 11:11:51 AM 12 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:11:51 AM 15 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:11:51 AM 17 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:11:59 AM 8 1209.50 CEUX
GENMAB A/S 11-Apr-2025 11:12:00 AM 14 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:12:04 AM 72 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:12:35 AM 88 1208.00 XCSE

80

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 11:12:35 AM 21 1208.00 CEUX
GENMAB A/S 11-Apr-2025 11:12:35 AM 15 1208.00 CEUX
GENMAB A/S 11-Apr-2025 11:12:35 AM 43 1208.00 CEUX
GENMAB A/S 11-Apr-2025 11:14:59 AM 21 1207.00 TQEX
GENMAB A/S 11-Apr-2025 11:14:59 AM 1 1207.00 TQEX
GENMAB A/S 11-Apr-2025 11:15:36 AM 14 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:15:36 AM 13 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:15:36 AM 12 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:15:36 AM 27 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:15:36 AM 38 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:15:58 AM 82 1206.50 XCSE
GENMAB A/S 11-Apr-2025 11:15:58 AM 6 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:15:58 AM 37 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:18:03 AM 21 1207.00 XCSE
GENMAB A/S 11-Apr-2025 11:18:03 AM 3 1207.00 TQEX
GENMAB A/S 11-Apr-2025 11:18:03 AM 31 1207.00 TQEX
GENMAB A/S 11-Apr-2025 11:18:03 AM 83 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:18:49 AM 5 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:18:49 AM 11 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:18:50 AM 13 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:19:54 AM 1 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:19:54 AM 41 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:19:54 AM 38 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:19:59 AM 34 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:20:10 AM 86 1206.50 XCSE
GENMAB A/S 11-Apr-2025 11:20:10 AM 41 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:20:10 AM 38 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:20:10 AM 16 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:20:10 AM 16 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:20:10 AM 24 1207.00 TQEX
GENMAB A/S 11-Apr-2025 11:20:10 AM 51 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:20:21 AM 82 1206.00 CEUX
GENMAB A/S 11-Apr-2025 11:20:56 AM 37 1206.00 XCSE
GENMAB A/S 11-Apr-2025 11:20:56 AM 65 1206.00 XCSE
GENMAB A/S 11-Apr-2025 11:20:56 AM 6 1206.00 XCSE
GENMAB A/S 11-Apr-2025 11:20:56 AM 3 1206.00 XCSE
GENMAB A/S 11-Apr-2025 11:21:12 AM 54 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:21:12 AM 4 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:21:12 AM 27 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:21:12 AM 3 1205.00 CEUX
GENMAB A/S 11-Apr-2025 11:21:12 AM 69 1205.00 CEUX
GENMAB A/S 11-Apr-2025 11:22:57 AM 29 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:23:00 AM 49 1207.00 CEUX

81

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 11:23:00 AM 8 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:24:09 AM 73 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:24:12 AM 9 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:24:35 AM 58 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:24:57 AM 54 1208.00 XCSE
GENMAB A/S 11-Apr-2025 11:24:57 AM 38 1208.00 XCSE
GENMAB A/S 11-Apr-2025 11:26:26 AM 18 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:26:26 AM 2 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:26:26 AM 2 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:26:34 AM 70 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:26:58 AM 5 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:26:58 AM 3 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:26:58 AM 17 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:26:58 AM 10 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:26:59 AM 4 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:27:00 AM 4 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:27:11 AM 3 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:27:11 AM 6 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:27:11 AM 2 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:27:11 AM 3 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:27:11 AM 17 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:27:11 AM 16 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:27:11 AM 10 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:28:38 AM 56 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:29:35 AM 16 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:29:35 AM 59 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:29:56 AM 44 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:29:56 AM 9 1209.50 XCSE
GENMAB A/S 11-Apr-2025 11:30:03 AM 82 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:30:03 AM 15 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:30:03 AM 3 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:30:03 AM 7 1209.00 TQEX
GENMAB A/S 11-Apr-2025 11:30:03 AM 87 1209.00 CEUX
GENMAB A/S 11-Apr-2025 11:30:36 AM 39 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:30:36 AM 12 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:30:36 AM 14 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:30:58 AM 14 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:30:58 AM 13 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:30:58 AM 14 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:30:58 AM 16 1209.00 XCSE
GENMAB A/S 11-Apr-2025 11:31:00 AM 21 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:00 AM 66 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:00 AM 2 1208.50 XCSE

82

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 11:31:00 AM 14 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:00 AM 41 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:00 AM 41 1208.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:08 AM 6 1208.00 TQEX
GENMAB A/S 11-Apr-2025 11:31:08 AM 19 1208.00 TQEX
GENMAB A/S 11-Apr-2025 11:31:08 AM 83 1208.00 CEUX
GENMAB A/S 11-Apr-2025 11:31:16 AM 30 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:16 AM 26 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:16 AM 25 1207.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:22 AM 5 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:31:40 AM 87 1206.50 XCSE
GENMAB A/S 11-Apr-2025 11:31:40 AM 76 1207.00 CEUX
GENMAB A/S 11-Apr-2025 11:31:40 AM 6 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:31:40 AM 14 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:31:40 AM 2 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:31:40 AM 3 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:31:40 AM 1 1206.50 CEUX
GENMAB A/S 11-Apr-2025 11:33:06 AM 88 1206.00 XCSE
GENMAB A/S 11-Apr-2025 11:33:13 AM 23 1205.50 CEUX
GENMAB A/S 11-Apr-2025 11:33:21 AM 65 1205.50 CEUX
GENMAB A/S 11-Apr-2025 11:33:41 AM 84 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:33:41 AM 28 1205.00 TQEX
GENMAB A/S 11-Apr-2025 11:34:11 AM 35 1204.50 CEUX
GENMAB A/S 11-Apr-2025 11:34:11 AM 17 1204.50 CEUX
GENMAB A/S 11-Apr-2025 11:34:11 AM 21 1204.50 CEUX
GENMAB A/S 11-Apr-2025 11:34:52 AM 34 1204.50 CEUX
GENMAB A/S 11-Apr-2025 11:36:18 AM 38 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:36:18 AM 5 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:36:18 AM 41 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:36:18 AM 13 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:36:22 AM 86 1204.00 XCSE
GENMAB A/S 11-Apr-2025 11:37:46 AM 85 1203.50 XCSE
GENMAB A/S 11-Apr-2025 11:40:08 AM 36 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:40:08 AM 16 1205.00 XCSE
GENMAB A/S 11-Apr-2025 11:40:13 AM 19 1204.50 XCSE
GENMAB A/S 11-Apr-2025 11:40:13 AM 62 1204.50 XCSE
GENMAB A/S 11-Apr-2025 11:40:32 AM 24 1204.00 TQEX
GENMAB A/S 11-Apr-2025 11:40:32 AM 22 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:40:32 AM 52 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:41:18 AM 39 1204.00 XCSE
GENMAB A/S 11-Apr-2025 11:41:18 AM 10 1204.00 XCSE
GENMAB A/S 11-Apr-2025 11:41:36 AM 53 1204.00 XCSE
GENMAB A/S 11-Apr-2025 11:41:37 AM 87 1203.50 XCSE

83

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 11:41:38 AM 9 1203.00 CEUX
GENMAB A/S 11-Apr-2025 11:42:02 AM 16 1203.00 CEUX
GENMAB A/S 11-Apr-2025 11:42:12 AM 83 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:42:28 AM 19 1202.00 CEUX
GENMAB A/S 11-Apr-2025 11:43:05 AM 24 1202.50 TQEX
GENMAB A/S 11-Apr-2025 11:43:19 AM 6 1202.00 CEUX
GENMAB A/S 11-Apr-2025 11:44:44 AM 4 1203.50 XCSE
GENMAB A/S 11-Apr-2025 11:44:44 AM 15 1203.50 XCSE
GENMAB A/S 11-Apr-2025 11:44:50 AM 83 1204.50 XCSE
GENMAB A/S 11-Apr-2025 11:44:50 AM 27 1204.50 AQEU
GENMAB A/S 11-Apr-2025 11:45:16 AM 87 1204.50 XCSE
GENMAB A/S 11-Apr-2025 11:45:16 AM 9 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:45:16 AM 7 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:45:16 AM 2 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:45:16 AM 15 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:45:16 AM 12 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:45:16 AM 12 1204.50 AQEU
GENMAB A/S 11-Apr-2025 11:45:16 AM 19 1204.50 AQEU
GENMAB A/S 11-Apr-2025 11:45:22 AM 31 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:45:22 AM 6 1204.00 CEUX
GENMAB A/S 11-Apr-2025 11:47:14 AM 63 1203.50 XCSE
GENMAB A/S 11-Apr-2025 11:47:14 AM 81 1203.00 CEUX
GENMAB A/S 11-Apr-2025 11:47:14 AM 25 1203.50 AQEU
GENMAB A/S 11-Apr-2025 11:47:28 AM 19 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:47:28 AM 62 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:47:33 AM 7 1202.00 TQEX
GENMAB A/S 11-Apr-2025 11:47:33 AM 17 1202.00 TQEX
GENMAB A/S 11-Apr-2025 11:47:33 AM 86 1202.00 CEUX
GENMAB A/S 11-Apr-2025 11:47:34 AM 1 1201.50 AQEU
GENMAB A/S 11-Apr-2025 11:48:53 AM 10 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:49:31 AM 50 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:49:31 AM 24 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:49:56 AM 13 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:49:56 AM 14 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:49:56 AM 32 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:49:56 AM 16 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:50:38 AM 84 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:50:38 AM 22 1202.00 CEUX
GENMAB A/S 11-Apr-2025 11:50:38 AM 53 1202.00 CEUX
GENMAB A/S 11-Apr-2025 11:51:03 AM 84 1201.00 XCSE
GENMAB A/S 11-Apr-2025 11:51:03 AM 25 1201.50 AQEU
GENMAB A/S 11-Apr-2025 11:54:18 AM 65 1201.50 XCSE
GENMAB A/S 11-Apr-2025 11:54:18 AM 19 1201.50 XCSE

84

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 11:54:18 AM 16 1201.50 TQEX
GENMAB A/S 11-Apr-2025 11:54:18 AM 17 1201.50 TQEX
GENMAB A/S 11-Apr-2025 11:54:18 AM 43 1201.50 CEUX
GENMAB A/S 11-Apr-2025 11:54:18 AM 40 1201.50 CEUX
GENMAB A/S 11-Apr-2025 11:55:15 AM 14 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:55:27 AM 33 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:55:27 AM 30 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:55:39 AM 38 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:55:39 AM 4 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:55:39 AM 69 1202.00 XCSE
GENMAB A/S 11-Apr-2025 11:56:03 AM 36 1201.50 AQEU
GENMAB A/S 11-Apr-2025 11:57:02 AM 82 1202.50 XCSE
GENMAB A/S 11-Apr-2025 11:57:02 AM 28 1202.50 TQEX
GENMAB A/S 11-Apr-2025 11:57:02 AM 81 1202.50 CEUX
GENMAB A/S 11-Apr-2025 11:57:33 AM 12 1203.00 XCSE
GENMAB A/S 11-Apr-2025 11:58:17 AM 88 1204.00 XCSE
GENMAB A/S 11-Apr-2025 11:58:17 AM 17 1204.00 TQEX
GENMAB A/S 11-Apr-2025 11:58:17 AM 8 1203.50 CEUX
GENMAB A/S 11-Apr-2025 11:58:17 AM 13 1203.50 CEUX
GENMAB A/S 11-Apr-2025 11:58:30 AM 63 1203.50 CEUX
GENMAB A/S 11-Apr-2025 11:59:25 AM 13 1203.50 XCSE
GENMAB A/S 11-Apr-2025 11:59:25 AM 11 1203.50 XCSE
GENMAB A/S 11-Apr-2025 11:59:25 AM 63 1203.00 XCSE
GENMAB A/S 11-Apr-2025 11:59:25 AM 3 1203.00 XCSE
GENMAB A/S 11-Apr-2025 11:59:25 AM 5 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:00:23 PM 31 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:00:23 PM 22 1202.50 CEUX
GENMAB A/S 11-Apr-2025 12:00:23 PM 61 1202.50 CEUX
GENMAB A/S 11-Apr-2025 12:00:42 PM 35 1203.50 AQEU
GENMAB A/S 11-Apr-2025 12:00:55 PM 19 1204.00 XCSE
GENMAB A/S 11-Apr-2025 12:00:55 PM 23 1204.00 XCSE
GENMAB A/S 11-Apr-2025 12:01:25 PM 83 1204.00 XCSE
GENMAB A/S 11-Apr-2025 12:01:25 PM 32 1204.00 TQEX
GENMAB A/S 11-Apr-2025 12:01:25 PM 84 1204.00 CEUX
GENMAB A/S 11-Apr-2025 12:01:49 PM 1 1203.50 AQEU
GENMAB A/S 11-Apr-2025 12:02:33 PM 51 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:02:39 PM 81 1203.00 CEUX
GENMAB A/S 11-Apr-2025 12:03:03 PM 25 1203.00 TQEX
GENMAB A/S 11-Apr-2025 12:03:13 PM 24 1203.00 AQEU
GENMAB A/S 11-Apr-2025 12:03:14 PM 25 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:03:26 PM 12 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:03:26 PM 13 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:03:26 PM 41 1203.00 XCSE

85

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 12:03:26 PM 48 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:03:30 PM 86 1202.50 XCSE
GENMAB A/S 11-Apr-2025 12:05:39 PM 81 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:05:39 PM 67 1203.50 CEUX
GENMAB A/S 11-Apr-2025 12:05:42 PM 15 1203.50 CEUX
GENMAB A/S 11-Apr-2025 12:08:13 PM 26 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:14 PM 12 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:17 PM 14 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:19 PM 13 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:26 PM 43 1203.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:31 PM 13 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:08:31 PM 11 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:08:31 PM 69 1202.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:31 PM 1 1202.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:31 PM 15 1202.50 XCSE
GENMAB A/S 11-Apr-2025 12:08:31 PM 24 1202.50 TQEX
GENMAB A/S 11-Apr-2025 12:08:31 PM 81 1202.50 CEUX
GENMAB A/S 11-Apr-2025 12:09:29 PM 86 1202.50 XCSE
GENMAB A/S 11-Apr-2025 12:09:29 PM 84 1202.50 CEUX
GENMAB A/S 11-Apr-2025 12:09:34 PM 25 1202.00 AQEU
GENMAB A/S 11-Apr-2025 12:10:08 PM 81 1201.50 XCSE
GENMAB A/S 11-Apr-2025 12:10:08 PM 31 1201.50 TQEX
GENMAB A/S 11-Apr-2025 12:10:08 PM 88 1201.50 CEUX
GENMAB A/S 11-Apr-2025 12:11:18 PM 24 1200.00 CEUX
GENMAB A/S 11-Apr-2025 12:11:23 PM 28 1200.00 CEUX
GENMAB A/S 11-Apr-2025 12:11:27 PM 84 1200.00 XCSE
GENMAB A/S 11-Apr-2025 12:11:27 PM 23 1200.00 CEUX
GENMAB A/S 11-Apr-2025 12:11:27 PM 9 1200.00 CEUX
GENMAB A/S 11-Apr-2025 12:12:56 PM 87 1200.00 XCSE
GENMAB A/S 11-Apr-2025 12:12:56 PM 24 1200.00 TQEX
GENMAB A/S 11-Apr-2025 12:12:56 PM 47 1200.00 CEUX
GENMAB A/S 11-Apr-2025 12:12:56 PM 16 1200.00 CEUX
GENMAB A/S 11-Apr-2025 12:13:57 PM 10 1200.00 XCSE
GENMAB A/S 11-Apr-2025 12:13:57 PM 16 1200.00 XCSE
GENMAB A/S 11-Apr-2025 12:13:57 PM 56 1200.00 XCSE
GENMAB A/S 11-Apr-2025 12:13:57 PM 2 1200.00 XCSE
GENMAB A/S 11-Apr-2025 12:16:04 PM 21 1199.00 XCSE
GENMAB A/S 11-Apr-2025 12:16:04 PM 60 1199.00 XCSE
GENMAB A/S 11-Apr-2025 12:16:04 PM 28 1199.50 XCSE
GENMAB A/S 11-Apr-2025 12:16:42 PM 6 1199.00 XCSE
GENMAB A/S 11-Apr-2025 12:16:42 PM 77 1199.00 XCSE
GENMAB A/S 11-Apr-2025 12:16:42 PM 2 1199.00 TQEX
GENMAB A/S 11-Apr-2025 12:16:42 PM 25 1199.00 TQEX

86

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 12:17:08 PM 27 1203.00 CEUX
GENMAB A/S 11-Apr-2025 12:18:51 PM 88 1203.00 XCSE
GENMAB A/S 11-Apr-2025 12:18:51 PM 44 1202.50 AQEU
GENMAB A/S 11-Apr-2025 12:18:51 PM 55 1203.00 CEUX
GENMAB A/S 11-Apr-2025 12:20:04 PM 16 1204.00 XCSE
GENMAB A/S 11-Apr-2025 12:20:04 PM 30 1203.50 AQEU
GENMAB A/S 11-Apr-2025 12:20:04 PM 87 1203.50 CEUX
GENMAB A/S 11-Apr-2025 12:21:44 PM 16 1207.50 XCSE
GENMAB A/S 11-Apr-2025 12:21:44 PM 25 1207.50 XCSE
GENMAB A/S 11-Apr-2025 12:21:44 PM 18 1207.50 XCSE
GENMAB A/S 11-Apr-2025 12:29:44 PM 12 1209.50 CEUX
GENMAB A/S 11-Apr-2025 12:30:24 PM 60 1209.00 XCSE
GENMAB A/S 11-Apr-2025 12:30:24 PM 25 1209.00 XCSE
GENMAB A/S 11-Apr-2025 12:30:24 PM 26 1209.00 TQEX
GENMAB A/S 11-Apr-2025 12:30:24 PM 10 1209.00 TQEX
GENMAB A/S 11-Apr-2025 12:30:24 PM 86 1209.00 CEUX
GENMAB A/S 11-Apr-2025 12:30:24 PM 36 1209.00 CEUX
GENMAB A/S 11-Apr-2025 12:30:25 PM 25 1209.00 AQEU
GENMAB A/S 11-Apr-2025 12:30:25 PM 2 1209.00 AQEU
GENMAB A/S 11-Apr-2025 12:31:20 PM 16 1211.00 CEUX
GENMAB A/S 11-Apr-2025 12:35:30 PM 65 1213.00 XCSE
GENMAB A/S 11-Apr-2025 12:35:30 PM 41 1213.00 XCSE
GENMAB A/S 11-Apr-2025 12:35:30 PM 2 1213.00 XCSE
GENMAB A/S 11-Apr-2025 12:35:30 PM 3 1213.00 CEUX
GENMAB A/S 11-Apr-2025 12:35:30 PM 4 1213.00 CEUX
GENMAB A/S 11-Apr-2025 12:35:30 PM 9 1213.00 CEUX
GENMAB A/S 11-Apr-2025 12:35:31 PM 11 1213.00 CEUX
GENMAB A/S 11-Apr-2025 12:35:31 PM 11 1213.00 CEUX
GENMAB A/S 11-Apr-2025 12:35:32 PM 17 1213.00 CEUX
GENMAB A/S 11-Apr-2025 12:37:17 PM 35 1215.00 XCSE
GENMAB A/S 11-Apr-2025 12:37:17 PM 46 1215.00 XCSE
GENMAB A/S 11-Apr-2025 12:37:17 PM 85 1215.00 CEUX
GENMAB A/S 11-Apr-2025 12:37:23 PM 88 1215.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:23 PM 44 1215.50 TQEX
GENMAB A/S 11-Apr-2025 12:37:23 PM 83 1215.50 CEUX
GENMAB A/S 11-Apr-2025 12:37:24 PM 32 1215.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:34 PM 14 1217.00 XCSE
GENMAB A/S 11-Apr-2025 12:37:34 PM 13 1217.00 XCSE
GENMAB A/S 11-Apr-2025 12:37:34 PM 26 1217.00 XCSE
GENMAB A/S 11-Apr-2025 12:37:34 PM 13 1217.00 XCSE
GENMAB A/S 11-Apr-2025 12:37:34 PM 39 1216.50 AQEU
GENMAB A/S 11-Apr-2025 12:37:34 PM 25 1216.50 TQEX
GENMAB A/S 11-Apr-2025 12:37:34 PM 6 1217.00 CEUX

87

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 12:37:34 PM 7 1217.00 CEUX
GENMAB A/S 11-Apr-2025 12:37:34 PM 6 1217.00 CEUX
GENMAB A/S 11-Apr-2025 12:37:34 PM 5 1217.00 CEUX
GENMAB A/S 11-Apr-2025 12:37:34 PM 15 1217.00 CEUX
GENMAB A/S 11-Apr-2025 12:37:37 PM 26 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:37 PM 13 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:37 PM 12 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:37 PM 13 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:37 PM 41 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:37 PM 6 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 26 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 14 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 13 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 14 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 44 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 31 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 12 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 41 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 14 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:37:38 PM 13 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:38:15 PM 88 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:38:15 PM 27 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:38:15 PM 26 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:38:15 PM 26 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:38:15 PM 26 1218.50 TQEX
GENMAB A/S 11-Apr-2025 12:38:15 PM 86 1218.50 CEUX
GENMAB A/S 11-Apr-2025 12:40:11 PM 85 1219.50 CEUX
GENMAB A/S 11-Apr-2025 12:40:12 PM 30 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:12 PM 41 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:14 PM 35 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:14 PM 30 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:14 PM 65 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:19 PM 35 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:19 PM 65 1219.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:20 PM 85 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:40:20 PM 31 1218.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:20 PM 5 1218.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:20 PM 45 1218.00 XCSE
GENMAB A/S 11-Apr-2025 12:40:20 PM 61 1218.50 CEUX
GENMAB A/S 11-Apr-2025 12:40:20 PM 25 1218.50 CEUX
GENMAB A/S 11-Apr-2025 12:40:20 PM 39 1217.50 CEUX
GENMAB A/S 11-Apr-2025 12:40:22 PM 81 1217.50 XCSE
GENMAB A/S 11-Apr-2025 12:40:22 PM 46 1217.50 CEUX

88

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 12:42:47 PM 59 1217.00 XCSE
GENMAB A/S 11-Apr-2025 12:43:35 PM 2 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:43:35 PM 13 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:43:35 PM 13 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:43:35 PM 69 1218.50 XCSE
GENMAB A/S 11-Apr-2025 12:45:42 PM 19 1224.00 XCSE
GENMAB A/S 11-Apr-2025 12:45:42 PM 15 1224.00 TQEX
GENMAB A/S 11-Apr-2025 12:45:42 PM 13 1224.00 TQEX
GENMAB A/S 11-Apr-2025 12:46:20 PM 81 1223.50 XCSE
GENMAB A/S 11-Apr-2025 12:46:20 PM 60 1223.00 XCSE
GENMAB A/S 11-Apr-2025 12:46:20 PM 35 1223.50 XCSE
GENMAB A/S 11-Apr-2025 12:46:20 PM 16 1223.50 XCSE
GENMAB A/S 11-Apr-2025 12:46:20 PM 28 1223.00 TQEX
GENMAB A/S 11-Apr-2025 12:46:20 PM 26 1223.50 AQEU
GENMAB A/S 11-Apr-2025 12:49:41 PM 27 1224.00 AQEU
GENMAB A/S 11-Apr-2025 12:49:42 PM 17 1225.50 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 71 1225.50 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 16 1226.00 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 30 1226.00 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 41 1226.00 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 4 1226.00 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 20 1226.00 XCSE
GENMAB A/S 11-Apr-2025 12:49:42 PM 25 1225.50 TQEX
GENMAB A/S 11-Apr-2025 12:49:42 PM 84 1225.50 CEUX
GENMAB A/S 11-Apr-2025 12:49:59 PM 39 1225.00 AQEU
GENMAB A/S 11-Apr-2025 12:51:03 PM 81 1224.50 XCSE
GENMAB A/S 11-Apr-2025 12:51:03 PM 84 1224.50 CEUX
GENMAB A/S 11-Apr-2025 12:52:46 PM 9 1225.50 XCSE
GENMAB A/S 11-Apr-2025 12:52:46 PM 14 1225.50 XCSE
GENMAB A/S 11-Apr-2025 12:52:46 PM 59 1225.50 XCSE
GENMAB A/S 11-Apr-2025 12:52:49 PM 26 1225.00 TQEX
GENMAB A/S 11-Apr-2025 12:52:49 PM 87 1225.00 CEUX
GENMAB A/S 11-Apr-2025 12:54:46 PM 7 1228.00 XCSE
GENMAB A/S 11-Apr-2025 12:54:46 PM 12 1228.00 XCSE
GENMAB A/S 11-Apr-2025 12:54:46 PM 13 1228.00 XCSE
GENMAB A/S 11-Apr-2025 12:54:46 PM 58 1228.00 XCSE
GENMAB A/S 11-Apr-2025 12:54:46 PM 21 1228.00 XCSE
GENMAB A/S 11-Apr-2025 12:55:19 PM 43 1226.50 XCSE
GENMAB A/S 11-Apr-2025 12:55:19 PM 45 1226.50 XCSE
GENMAB A/S 11-Apr-2025 12:55:19 PM 88 1226.50 CEUX
GENMAB A/S 11-Apr-2025 12:55:24 PM 86 1225.50 XCSE
GENMAB A/S 11-Apr-2025 12:55:24 PM 24 1225.50 AQEU
GENMAB A/S 11-Apr-2025 12:55:30 PM 14 1225.50 XCSE

89

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 12:58:05 PM 84 1227.00 XCSE
GENMAB A/S 11-Apr-2025 12:58:05 PM 25 1227.00 TQEX
GENMAB A/S 11-Apr-2025 12:58:05 PM 82 1227.00 CEUX
GENMAB A/S 11-Apr-2025 13:02:02 PM 47 1231.00 XCSE
GENMAB A/S 11-Apr-2025 13:02:14 PM 27 1232.00 XCSE
GENMAB A/S 11-Apr-2025 13:02:14 PM 14 1232.00 XCSE
GENMAB A/S 11-Apr-2025 13:02:14 PM 14 1232.00 XCSE
GENMAB A/S 11-Apr-2025 13:02:14 PM 14 1232.00 XCSE
GENMAB A/S 11-Apr-2025 13:02:14 PM 42 1232.00 XCSE
GENMAB A/S 11-Apr-2025 13:02:14 PM 84 1231.00 CEUX
GENMAB A/S 11-Apr-2025 13:02:26 PM 14 1231.50 XCSE
GENMAB A/S 11-Apr-2025 13:02:26 PM 16 1231.50 XCSE
GENMAB A/S 11-Apr-2025 13:03:03 PM 81 1231.50 XCSE
GENMAB A/S 11-Apr-2025 13:03:03 PM 24 1231.50 TQEX
GENMAB A/S 11-Apr-2025 13:05:11 PM 36 1233.50 CEUX
GENMAB A/S 11-Apr-2025 13:05:12 PM 85 1233.50 XCSE
GENMAB A/S 11-Apr-2025 13:05:12 PM 12 1233.50 XCSE
GENMAB A/S 11-Apr-2025 13:05:13 PM 32 1233.50 CEUX
GENMAB A/S 11-Apr-2025 13:05:30 PM 87 1232.50 XCSE
GENMAB A/S 11-Apr-2025 13:05:30 PM 41 1233.00 XCSE
GENMAB A/S 11-Apr-2025 13:05:30 PM 30 1233.00 XCSE
GENMAB A/S 11-Apr-2025 13:05:30 PM 40 1233.00 XCSE
GENMAB A/S 11-Apr-2025 13:05:30 PM 25 1233.00 TQEX
GENMAB A/S 11-Apr-2025 13:05:30 PM 88 1233.00 CEUX
GENMAB A/S 11-Apr-2025 13:05:30 PM 83 1233.00 CEUX
GENMAB A/S 11-Apr-2025 13:05:32 PM 83 1232.50 XCSE
GENMAB A/S 11-Apr-2025 13:05:32 PM 79 1232.50 XCSE
GENMAB A/S 11-Apr-2025 13:06:20 PM 85 1232.00 CEUX
GENMAB A/S 11-Apr-2025 13:07:09 PM 87 1231.50 XCSE
GENMAB A/S 11-Apr-2025 13:07:09 PM 55 1230.00 XCSE
GENMAB A/S 11-Apr-2025 13:07:09 PM 26 1230.00 XCSE
GENMAB A/S 11-Apr-2025 13:07:09 PM 30 1230.50 AQEU
GENMAB A/S 11-Apr-2025 13:07:09 PM 84 1231.00 CEUX
GENMAB A/S 11-Apr-2025 13:07:09 PM 88 1229.50 CEUX
GENMAB A/S 11-Apr-2025 13:07:41 PM 28 1229.00 XCSE
GENMAB A/S 11-Apr-2025 13:10:29 PM 37 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:10:29 PM 33 1228.00 CEUX
GENMAB A/S 11-Apr-2025 13:10:29 PM 49 1228.00 CEUX
GENMAB A/S 11-Apr-2025 13:10:34 PM 46 1227.00 XCSE
GENMAB A/S 11-Apr-2025 13:10:35 PM 52 1226.50 CEUX
GENMAB A/S 11-Apr-2025 13:12:40 PM 24 1226.00 XCSE
GENMAB A/S 11-Apr-2025 13:12:55 PM 84 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:15:42 PM 39 1229.50 XCSE

90

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 13:15:42 PM 46 1229.50 XCSE
GENMAB A/S 11-Apr-2025 13:15:42 PM 30 1229.50 TQEX
GENMAB A/S 11-Apr-2025 13:15:42 PM 27 1229.50 AQEU
GENMAB A/S 11-Apr-2025 13:15:44 PM 41 1229.00 CEUX
GENMAB A/S 11-Apr-2025 13:15:44 PM 27 1229.00 CEUX
GENMAB A/S 11-Apr-2025 13:16:01 PM 81 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:16:01 PM 24 1228.50 TQEX
GENMAB A/S 11-Apr-2025 13:16:01 PM 66 1228.00 CEUX
GENMAB A/S 11-Apr-2025 13:16:27 PM 41 1228.00 CEUX
GENMAB A/S 11-Apr-2025 13:16:56 PM 88 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:17:39 PM 22 1227.00 CEUX
GENMAB A/S 11-Apr-2025 13:20:53 PM 33 1230.50 TQEX
GENMAB A/S 11-Apr-2025 13:20:53 PM 82 1230.50 CEUX
GENMAB A/S 11-Apr-2025 13:21:07 PM 23 1231.00 XCSE
GENMAB A/S 11-Apr-2025 13:21:07 PM 41 1231.00 XCSE
GENMAB A/S 11-Apr-2025 13:21:07 PM 47 1231.00 XCSE
GENMAB A/S 11-Apr-2025 13:23:03 PM 81 1231.00 XCSE
GENMAB A/S 11-Apr-2025 13:23:03 PM 30 1230.50 AQEU
GENMAB A/S 11-Apr-2025 13:23:03 PM 64 1231.00 CEUX
GENMAB A/S 11-Apr-2025 13:23:12 PM 86 1230.00 XCSE
GENMAB A/S 11-Apr-2025 13:23:12 PM 53 1230.00 CEUX
GENMAB A/S 11-Apr-2025 13:24:12 PM 3 1229.00 CEUX
GENMAB A/S 11-Apr-2025 13:24:12 PM 27 1229.00 CEUX
GENMAB A/S 11-Apr-2025 13:24:12 PM 35 1229.00 CEUX
GENMAB A/S 11-Apr-2025 13:24:13 PM 81 1229.00 XCSE
GENMAB A/S 11-Apr-2025 13:24:21 PM 81 1230.00 XCSE
GENMAB A/S 11-Apr-2025 13:24:21 PM 26 1230.00 TQEX
GENMAB A/S 11-Apr-2025 13:24:21 PM 29 1230.00 AQEU
GENMAB A/S 11-Apr-2025 13:24:21 PM 24 1230.00 CEUX
GENMAB A/S 11-Apr-2025 13:25:05 PM 85 1229.00 XCSE
GENMAB A/S 11-Apr-2025 13:25:05 PM 27 1229.00 CEUX
GENMAB A/S 11-Apr-2025 13:26:15 PM 25 1228.50 CEUX
GENMAB A/S 11-Apr-2025 13:26:55 PM 24 1228.50 CEUX
GENMAB A/S 11-Apr-2025 13:28:42 PM 24 1228.50 TQEX
GENMAB A/S 11-Apr-2025 13:28:42 PM 37 1228.50 CEUX
GENMAB A/S 11-Apr-2025 13:29:18 PM 10 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:29:18 PM 72 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:29:18 PM 36 1228.00 AQEU
GENMAB A/S 11-Apr-2025 13:29:18 PM 44 1227.50 CEUX
GENMAB A/S 11-Apr-2025 13:29:19 PM 82 1226.50 XCSE
GENMAB A/S 11-Apr-2025 13:29:19 PM 25 1226.50 AQEU
GENMAB A/S 11-Apr-2025 13:29:19 PM 26 1226.00 CEUX
GENMAB A/S 11-Apr-2025 13:29:41 PM 34 1226.00 XCSE

91

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 13:29:41 PM 49 1226.00 XCSE
GENMAB A/S 11-Apr-2025 13:34:15 PM 3 1227.00 XCSE
GENMAB A/S 11-Apr-2025 13:34:15 PM 2 1227.00 XCSE
GENMAB A/S 11-Apr-2025 13:34:15 PM 2 1227.00 XCSE
GENMAB A/S 11-Apr-2025 13:35:56 PM 3 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:35:56 PM 41 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:35:56 PM 14 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:35:56 PM 58 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:39:41 PM 25 1228.00 TQEX
GENMAB A/S 11-Apr-2025 13:39:41 PM 86 1227.50 CEUX
GENMAB A/S 11-Apr-2025 13:40:44 PM 29 1227.50 TQEX
GENMAB A/S 11-Apr-2025 13:40:44 PM 5 1227.50 AQEU
GENMAB A/S 11-Apr-2025 13:43:06 PM 86 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:43:06 PM 42 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:43:06 PM 69 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:43:06 PM 24 1228.00 TQEX
GENMAB A/S 11-Apr-2025 13:43:06 PM 20 1227.50 AQEU
GENMAB A/S 11-Apr-2025 13:43:06 PM 81 1228.00 CEUX
GENMAB A/S 11-Apr-2025 13:43:47 PM 85 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:43:47 PM 42 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:43:47 PM 69 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:45:24 PM 82 1227.00 XCSE
GENMAB A/S 11-Apr-2025 13:45:24 PM 44 1227.00 XCSE
GENMAB A/S 11-Apr-2025 13:45:24 PM 37 1227.50 AQEU
GENMAB A/S 11-Apr-2025 13:45:24 PM 82 1227.50 CEUX
GENMAB A/S 11-Apr-2025 13:46:28 PM 15 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:46:28 PM 12 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:46:28 PM 13 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:46:28 PM 12 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:46:28 PM 16 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:46:29 PM 13 1227.00 AQEU
GENMAB A/S 11-Apr-2025 13:47:03 PM 27 1227.00 AQEU
GENMAB A/S 11-Apr-2025 13:47:36 PM 13 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:47:36 PM 14 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:47:36 PM 19 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:47:36 PM 39 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:48:30 PM 85 1226.50 CEUX
GENMAB A/S 11-Apr-2025 13:48:31 PM 82 1226.00 XCSE
GENMAB A/S 11-Apr-2025 13:50:03 PM 25 1225.50 TQEX
GENMAB A/S 11-Apr-2025 13:50:03 PM 28 1225.50 CEUX
GENMAB A/S 11-Apr-2025 13:50:16 PM 1 1225.50 XCSE
GENMAB A/S 11-Apr-2025 13:50:16 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 13:50:29 PM 13 1225.50 XCSE

92

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 13:50:42 PM 25 1225.00 AQEU
GENMAB A/S 11-Apr-2025 13:50:43 PM 24 1225.00 XCSE
GENMAB A/S 11-Apr-2025 13:50:43 PM 1 1225.00 AQEU
GENMAB A/S 11-Apr-2025 13:52:27 PM 11 1226.50 CEUX
GENMAB A/S 11-Apr-2025 13:55:31 PM 24 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:55:31 PM 57 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:55:41 PM 21 1228.00 AQEU
GENMAB A/S 11-Apr-2025 13:55:41 PM 4 1228.00 AQEU
GENMAB A/S 11-Apr-2025 13:57:14 PM 14 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:45 PM 28 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:45 PM 9 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:45 PM 12 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:45 PM 14 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:45 PM 4 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:46 PM 12 1228.00 XCSE
GENMAB A/S 11-Apr-2025 13:57:56 PM 12 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:56 PM 13 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:56 PM 68 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:56 PM 13 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:56 PM 25 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:58 PM 14 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:58 PM 13 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:58 PM 14 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:59 PM 13 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:59 PM 12 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:57:59 PM 13 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:58:16 PM 12 1228.50 XCSE
GENMAB A/S 11-Apr-2025 13:59:06 PM 34 1229.00 XCSE
GENMAB A/S 11-Apr-2025 13:59:06 PM 37 1229.00 XCSE
GENMAB A/S 11-Apr-2025 13:59:06 PM 9 1229.00 XCSE
GENMAB A/S 11-Apr-2025 13:59:06 PM 24 1228.00 TQEX
GENMAB A/S 11-Apr-2025 13:59:23 PM 56 1227.50 XCSE
GENMAB A/S 11-Apr-2025 13:59:23 PM 85 1227.50 CEUX
GENMAB A/S 11-Apr-2025 13:59:23 PM 25 1227.50 CEUX
GENMAB A/S 11-Apr-2025 13:59:23 PM 7 1227.50 CEUX
GENMAB A/S 11-Apr-2025 13:59:26 PM 58 1226.50 XCSE
GENMAB A/S 11-Apr-2025 13:59:26 PM 1 1226.50 XCSE
GENMAB A/S 11-Apr-2025 13:59:26 PM 1 1226.50 CEUX
GENMAB A/S 11-Apr-2025 13:59:27 PM 26 1226.50 CEUX
GENMAB A/S 11-Apr-2025 14:00:00 PM 24 1226.50 XCSE
GENMAB A/S 11-Apr-2025 14:00:00 PM 41 1226.50 CEUX
GENMAB A/S 11-Apr-2025 14:00:00 PM 2 1226.50 CEUX
GENMAB A/S 11-Apr-2025 14:00:05 PM 25 1225.50 XCSE

93

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 14:01:28 PM 63 1225.50 XCSE
GENMAB A/S 11-Apr-2025 14:01:28 PM 82 1225.50 CEUX
GENMAB A/S 11-Apr-2025 14:02:20 PM 24 1225.00 TQEX
GENMAB A/S 11-Apr-2025 14:02:22 PM 85 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:02:29 PM 29 1224.00 CEUX
GENMAB A/S 11-Apr-2025 14:02:29 PM 55 1224.00 CEUX
GENMAB A/S 11-Apr-2025 14:04:24 PM 82 1224.50 CEUX
GENMAB A/S 11-Apr-2025 14:05:43 PM 15 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:05:43 PM 41 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:05:43 PM 37 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:06:16 PM 16 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:06:16 PM 60 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:06:16 PM 5 1224.50 XCSE
GENMAB A/S 11-Apr-2025 14:07:46 PM 16 1225.50 XCSE
GENMAB A/S 11-Apr-2025 14:07:46 PM 24 1225.50 TQEX
GENMAB A/S 11-Apr-2025 14:09:31 PM 87 1225.00 XCSE
GENMAB A/S 11-Apr-2025 14:09:31 PM 77 1225.00 XCSE
GENMAB A/S 11-Apr-2025 14:09:31 PM 34 1225.50 XCSE
GENMAB A/S 11-Apr-2025 14:09:42 PM 85 1225.00 XCSE
GENMAB A/S 11-Apr-2025 14:10:24 PM 21 1224.50 CEUX
GENMAB A/S 11-Apr-2025 14:10:39 PM 25 1224.50 CEUX
GENMAB A/S 11-Apr-2025 14:11:02 PM 36 1224.50 CEUX
GENMAB A/S 11-Apr-2025 14:11:24 PM 88 1224.00 XCSE
GENMAB A/S 11-Apr-2025 14:11:24 PM 24 1224.00 TQEX
GENMAB A/S 11-Apr-2025 14:11:24 PM 26 1224.00 AQEU
GENMAB A/S 11-Apr-2025 14:11:26 PM 3 1223.50 CEUX
GENMAB A/S 11-Apr-2025 14:11:28 PM 9 1223.50 CEUX
GENMAB A/S 11-Apr-2025 14:11:28 PM 10 1223.50 CEUX
GENMAB A/S 11-Apr-2025 14:11:28 PM 64 1223.50 CEUX
GENMAB A/S 11-Apr-2025 14:12:19 PM 81 1223.00 XCSE
GENMAB A/S 11-Apr-2025 14:12:20 PM 9 1222.50 CEUX
GENMAB A/S 11-Apr-2025 14:12:20 PM 77 1222.50 CEUX
GENMAB A/S 11-Apr-2025 14:15:41 PM 45 1223.00 XCSE
GENMAB A/S 11-Apr-2025 14:15:41 PM 24 1223.00 TQEX
GENMAB A/S 11-Apr-2025 14:15:41 PM 35 1223.00 CEUX
GENMAB A/S 11-Apr-2025 14:15:41 PM 38 1223.00 CEUX
GENMAB A/S 11-Apr-2025 14:15:57 PM 57 1222.50 XCSE
GENMAB A/S 11-Apr-2025 14:15:57 PM 25 1222.50 XCSE
GENMAB A/S 11-Apr-2025 14:16:18 PM 4 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:16:18 PM 25 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:16:18 PM 11 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:16:57 PM 82 1221.50 XCSE
GENMAB A/S 11-Apr-2025 14:18:41 PM 85 1222.00 XCSE

94

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 14:18:41 PM 34 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:18:41 PM 44 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:18:42 PM 17 1221.50 TQEX
GENMAB A/S 11-Apr-2025 14:18:49 PM 7 1221.50 TQEX
GENMAB A/S 11-Apr-2025 14:19:24 PM 84 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:19:24 PM 88 1221.00 CEUX
GENMAB A/S 11-Apr-2025 14:19:50 PM 85 1220.00 XCSE
GENMAB A/S 11-Apr-2025 14:19:50 PM 15 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:19:50 PM 71 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:21:10 PM 2 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:22:07 PM 25 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:23:15 PM 49 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:23:15 PM 34 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:23:15 PM 24 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:25:03 PM 10 1221.00 CEUX
GENMAB A/S 11-Apr-2025 14:25:15 PM 12 1221.50 XCSE
GENMAB A/S 11-Apr-2025 14:25:32 PM 38 1221.50 XCSE
GENMAB A/S 11-Apr-2025 14:25:32 PM 43 1221.00 CEUX
GENMAB A/S 11-Apr-2025 14:25:48 PM 14 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:25:48 PM 10 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:25:56 PM 59 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:28:13 PM 41 1221.50 XCSE
GENMAB A/S 11-Apr-2025 14:28:13 PM 40 1221.50 XCSE
GENMAB A/S 11-Apr-2025 14:28:13 PM 30 1221.50 XCSE
GENMAB A/S 11-Apr-2025 14:28:13 PM 13 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:28:13 PM 24 1221.00 TQEX
GENMAB A/S 11-Apr-2025 14:28:13 PM 37 1221.00 AQEU
GENMAB A/S 11-Apr-2025 14:28:13 PM 52 1221.00 CEUX
GENMAB A/S 11-Apr-2025 14:29:41 PM 74 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:29:41 PM 21 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:29:41 PM 28 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:29:44 PM 3 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:29:44 PM 60 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:29:44 PM 19 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:29:44 PM 11 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:29:44 PM 12 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:29:44 PM 19 1219.50 AQEU
GENMAB A/S 11-Apr-2025 14:29:44 PM 7 1219.50 AQEU
GENMAB A/S 11-Apr-2025 14:31:30 PM 1 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:31:36 PM 47 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:31:36 PM 29 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:31:52 PM 49 1219.00 CEUX
GENMAB A/S 11-Apr-2025 14:32:01 PM 87 1218.50 XCSE

95

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 14:32:04 PM 11 1218.00 AQEU
GENMAB A/S 11-Apr-2025 14:34:52 PM 22 1219.50 CEUX
GENMAB A/S 11-Apr-2025 14:35:29 PM 85 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:35:29 PM 24 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:35:29 PM 63 1219.50 CEUX
GENMAB A/S 11-Apr-2025 14:35:49 PM 45 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:37:49 PM 36 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:37:49 PM 35 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:37:49 PM 38 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:37:57 PM 17 1219.00 TQEX
GENMAB A/S 11-Apr-2025 14:38:01 PM 7 1219.00 TQEX
GENMAB A/S 11-Apr-2025 14:38:36 PM 45 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:38:36 PM 15 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:38:36 PM 15 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:39:46 PM 12 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:39:46 PM 23 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:39:46 PM 14 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:39:46 PM 13 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:40:03 PM 88 1218.50 XCSE
GENMAB A/S 11-Apr-2025 14:40:03 PM 3 1218.00 AQEU
GENMAB A/S 11-Apr-2025 14:40:03 PM 88 1218.50 CEUX
GENMAB A/S 11-Apr-2025 14:40:06 PM 1 1218.00 AQEU
GENMAB A/S 11-Apr-2025 14:41:19 PM 56 1219.00 CEUX
GENMAB A/S 11-Apr-2025 14:41:20 PM 25 1219.00 CEUX
GENMAB A/S 11-Apr-2025 14:44:29 PM 38 1219.00 XCSE
GENMAB A/S 11-Apr-2025 14:44:29 PM 35 1219.00 XCSE
GENMAB A/S 11-Apr-2025 14:44:29 PM 13 1219.00 XCSE
GENMAB A/S 11-Apr-2025 14:44:45 PM 38 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:46:52 PM 7 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:46:52 PM 21 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:46:52 PM 53 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:46:52 PM 28 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:46:52 PM 48 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:48:11 PM 14 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:48:11 PM 13 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:48:12 PM 12 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:48:12 PM 12 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:48:15 PM 12 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:48:15 PM 56 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:48:15 PM 18 1220.50 XCSE
GENMAB A/S 11-Apr-2025 14:48:15 PM 12 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:48:15 PM 74 1221.00 XCSE
GENMAB A/S 11-Apr-2025 14:48:15 PM 25 1221.00 XCSE

96

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 14:48:15 PM 10 1220.50 CEUX
GENMAB A/S 11-Apr-2025 14:48:34 PM 10 1220.50 CEUX
GENMAB A/S 11-Apr-2025 14:48:34 PM 5 1220.50 CEUX
GENMAB A/S 11-Apr-2025 14:48:44 PM 10 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:48:44 PM 77 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:48:44 PM 12 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:48:44 PM 5 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:48:44 PM 7 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:48:44 PM 5 1219.50 TQEX
GENMAB A/S 11-Apr-2025 14:48:44 PM 25 1220.00 AQEU
GENMAB A/S 11-Apr-2025 14:48:44 PM 62 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:48:44 PM 20 1220.00 CEUX
GENMAB A/S 11-Apr-2025 14:50:07 PM 29 1219.00 AQEU
GENMAB A/S 11-Apr-2025 14:50:35 PM 5 1218.50 TQEX
GENMAB A/S 11-Apr-2025 14:50:35 PM 19 1218.50 TQEX
GENMAB A/S 11-Apr-2025 14:50:35 PM 83 1218.50 CEUX
GENMAB A/S 11-Apr-2025 14:50:38 PM 72 1218.00 XCSE
GENMAB A/S 11-Apr-2025 14:50:38 PM 9 1218.00 XCSE
GENMAB A/S 11-Apr-2025 14:52:05 PM 81 1219.50 XCSE
GENMAB A/S 11-Apr-2025 14:53:37 PM 81 1219.00 XCSE
GENMAB A/S 11-Apr-2025 14:53:37 PM 36 1219.50 CEUX
GENMAB A/S 11-Apr-2025 14:54:34 PM 12 1219.50 CEUX
GENMAB A/S 11-Apr-2025 14:56:09 PM 8 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:56:09 PM 6 1222.00 CEUX
GENMAB A/S 11-Apr-2025 14:56:10 PM 8 1222.00 CEUX
GENMAB A/S 11-Apr-2025 15:00:18 PM 22 1222.50 TQEX
GENMAB A/S 11-Apr-2025 15:00:44 PM 86 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:00:44 PM 27 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:00:44 PM 37 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:00:44 PM 47 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:00:44 PM 22 1222.50 TQEX
GENMAB A/S 11-Apr-2025 15:00:44 PM 24 1222.50 AQEU
GENMAB A/S 11-Apr-2025 15:00:44 PM 81 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:00:44 PM 3 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:00:44 PM 20 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:01:36 PM 7 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:01:36 PM 8 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:01:36 PM 8 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:01:56 PM 68 1224.50 XCSE
GENMAB A/S 11-Apr-2025 15:01:56 PM 12 1224.50 XCSE
GENMAB A/S 11-Apr-2025 15:01:56 PM 14 1224.50 XCSE
GENMAB A/S 11-Apr-2025 15:01:56 PM 27 1223.50 TQEX
GENMAB A/S 11-Apr-2025 15:01:56 PM 36 1224.50 CEUX

97

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:01:56 PM 11 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:01:56 PM 75 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:01:57 PM 5 1223.50 TQEX
GENMAB A/S 11-Apr-2025 15:02:11 PM 82 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 45 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 29 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 37 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 14 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 74 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 23 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 87 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:11 PM 32 1222.50 TQEX
GENMAB A/S 11-Apr-2025 15:02:11 PM 87 1223.00 CEUX
GENMAB A/S 11-Apr-2025 15:02:56 PM 3 1222.00 CEUX
GENMAB A/S 11-Apr-2025 15:02:57 PM 4 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:02:57 PM 3 1221.50 TQEX
GENMAB A/S 11-Apr-2025 15:03:55 PM 9 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:04:39 PM 85 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:04:39 PM 111 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:04:39 PM 84 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:04:39 PM 21 1221.50 TQEX
GENMAB A/S 11-Apr-2025 15:04:39 PM 111 1222.00 CEUX
GENMAB A/S 11-Apr-2025 15:04:39 PM 35 1221.50 CEUX
GENMAB A/S 11-Apr-2025 15:04:39 PM 50 1221.50 CEUX
GENMAB A/S 11-Apr-2025 15:04:48 PM 85 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:04:48 PM 85 1220.00 CEUX
GENMAB A/S 11-Apr-2025 15:04:49 PM 82 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:04:49 PM 30 1219.50 AQEU
GENMAB A/S 11-Apr-2025 15:05:05 PM 82 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:05:05 PM 46 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:05:05 PM 11 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:05:05 PM 2 1220.50 TQEX
GENMAB A/S 11-Apr-2025 15:05:05 PM 84 1220.00 CEUX
GENMAB A/S 11-Apr-2025 15:05:08 PM 15 1220.50 TQEX
GENMAB A/S 11-Apr-2025 15:05:31 PM 2 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:06:23 PM 23 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:06:23 PM 46 1220.00 CEUX
GENMAB A/S 11-Apr-2025 15:08:04 PM 82 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:08:04 PM 64 1218.00 XCSE
GENMAB A/S 11-Apr-2025 15:08:04 PM 85 1219.00 CEUX
GENMAB A/S 11-Apr-2025 15:08:18 PM 85 1218.00 CEUX
GENMAB A/S 11-Apr-2025 15:08:19 PM 16 1217.50 TQEX
GENMAB A/S 11-Apr-2025 15:09:40 PM 56 1218.50 XCSE

98

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:09:40 PM 28 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:09:40 PM 71 1218.50 CEUX
GENMAB A/S 11-Apr-2025 15:13:08 PM 24 1219.00 TQEX
GENMAB A/S 11-Apr-2025 15:13:09 PM 3 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:13:09 PM 25 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:13:09 PM 42 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:13:26 PM 5 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:13:26 PM 17 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:13:26 PM 61 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:16:20 PM 25 1219.00 TQEX
GENMAB A/S 11-Apr-2025 15:18:03 PM 81 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 30 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 52 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 12 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 13 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 4 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 8 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 47 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 14 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 30 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 12 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 85 1217.50 XCSE
GENMAB A/S 11-Apr-2025 15:18:03 PM 24 1218.00 TQEX
GENMAB A/S 11-Apr-2025 15:18:03 PM 37 1218.50 CEUX
GENMAB A/S 11-Apr-2025 15:18:03 PM 61 1217.50 CEUX
GENMAB A/S 11-Apr-2025 15:18:06 PM 24 1217.00 TQEX
GENMAB A/S 11-Apr-2025 15:22:15 PM 13 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:22:15 PM 10 1218.50 XCSE
GENMAB A/S 11-Apr-2025 15:22:15 PM 5 1218.50 CEUX
GENMAB A/S 11-Apr-2025 15:22:35 PM 14 1218.00 XCSE
GENMAB A/S 11-Apr-2025 15:22:35 PM 14 1218.00 XCSE
GENMAB A/S 11-Apr-2025 15:22:35 PM 43 1217.50 XCSE
GENMAB A/S 11-Apr-2025 15:22:35 PM 36 1218.00 CEUX
GENMAB A/S 11-Apr-2025 15:22:53 PM 46 1218.00 XCSE
GENMAB A/S 11-Apr-2025 15:22:53 PM 36 1218.00 CEUX
GENMAB A/S 11-Apr-2025 15:22:53 PM 1 1218.00 CEUX
GENMAB A/S 11-Apr-2025 15:22:54 PM 45 1217.50 XCSE
GENMAB A/S 11-Apr-2025 15:22:54 PM 25 1217.50 TQEX
GENMAB A/S 11-Apr-2025 15:22:54 PM 73 1217.50 CEUX
GENMAB A/S 11-Apr-2025 15:22:54 PM 8 1217.50 CEUX
GENMAB A/S 11-Apr-2025 15:23:01 PM 38 1217.50 XCSE
GENMAB A/S 11-Apr-2025 15:23:01 PM 19 1217.50 XCSE
GENMAB A/S 11-Apr-2025 15:25:34 PM 36 1218.50 CEUX

99

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:25:48 PM 12 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:25:48 PM 5 1219.00 CEUX
GENMAB A/S 11-Apr-2025 15:25:56 PM 13 1219.00 XCSE
GENMAB A/S 11-Apr-2025 15:26:47 PM 14 1219.50 XCSE
GENMAB A/S 11-Apr-2025 15:29:14 PM 38 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:29:14 PM 13 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:29:14 PM 14 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:29:14 PM 14 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:29:14 PM 13 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:29:15 PM 13 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:29:15 PM 9 1220.00 XCSE
GENMAB A/S 11-Apr-2025 15:30:07 PM 14 1220.50 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 8 1220.50 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 8 1220.50 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 6 1220.50 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 2 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 8 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 26 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:30:07 PM 7 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:30:08 PM 20 1220.50 CEUX
GENMAB A/S 11-Apr-2025 15:30:54 PM 11 1222.00 CEUX
GENMAB A/S 11-Apr-2025 15:30:58 PM 13 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:30:59 PM 22 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:32:57 PM 87 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:32:57 PM 111 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:32:57 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:32:57 PM 31 1223.50 TQEX
GENMAB A/S 11-Apr-2025 15:32:57 PM 26 1223.50 AQEU
GENMAB A/S 11-Apr-2025 15:32:57 PM 68 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:32:57 PM 15 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:33:00 PM 48 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:35:02 PM 88 1224.50 XCSE
GENMAB A/S 11-Apr-2025 15:35:02 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:02 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:02 PM 30 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:02 PM 32 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:02 PM 23 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:02 PM 28 1225.00 TQEX
GENMAB A/S 11-Apr-2025 15:35:02 PM 33 1224.50 AQEU
GENMAB A/S 11-Apr-2025 15:35:02 PM 81 1224.50 CEUX
GENMAB A/S 11-Apr-2025 15:35:03 PM 29 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:03 PM 3 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:03 PM 30 1225.00 XCSE

100

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:35:03 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:03 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:03 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:03 PM 10 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:08 PM 10 1225.00 CEUX
GENMAB A/S 11-Apr-2025 15:35:08 PM 10 1225.00 CEUX
GENMAB A/S 11-Apr-2025 15:35:09 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:09 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:09 PM 40 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:09 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:10 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:16 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 15:35:17 PM 14 1224.50 XCSE
GENMAB A/S 11-Apr-2025 15:35:17 PM 82 1224.50 CEUX
GENMAB A/S 11-Apr-2025 15:35:56 PM 86 1224.50 XCSE
GENMAB A/S 11-Apr-2025 15:35:56 PM 32 1224.50 TQEX
GENMAB A/S 11-Apr-2025 15:35:59 PM 72 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:35:59 PM 14 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:35:59 PM 24 1223.50 TQEX
GENMAB A/S 11-Apr-2025 15:35:59 PM 87 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:36:01 PM 27 1223.50 AQEU
GENMAB A/S 11-Apr-2025 15:36:07 PM 9 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:07 PM 18 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:08 PM 12 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:14 PM 12 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:14 PM 15 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:14 PM 13 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:14 PM 12 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:14 PM 30 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:36:14 PM 46 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:37:44 PM 68 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:37:44 PM 23 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:37:44 PM 16 1223.50 AQEU
GENMAB A/S 11-Apr-2025 15:37:58 PM 19 1223.50 AQEU
GENMAB A/S 11-Apr-2025 15:37:59 PM 11 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:37:59 PM 14 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:37:59 PM 25 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:37:59 PM 13 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:37:59 PM 13 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:37:59 PM 14 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:38:06 PM 26 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:38:06 PM 8 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:38:06 PM 14 1223.50 XCSE

101

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:38:06 PM 14 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:38:06 PM 14 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:38:06 PM 35 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:38:06 PM 3 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:38:44 PM 18 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:38:58 PM 27 1223.50 AQEU
GENMAB A/S 11-Apr-2025 15:38:58 PM 50 1223.00 CEUX
GENMAB A/S 11-Apr-2025 15:38:58 PM 60 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:38:58 PM 23 1223.50 CEUX
GENMAB A/S 11-Apr-2025 15:38:59 PM 5 1223.50 AQEU
GENMAB A/S 11-Apr-2025 15:39:56 PM 19 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:39:56 PM 28 1223.00 TQEX
GENMAB A/S 11-Apr-2025 15:41:20 PM 67 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:41:20 PM 3 1222.50 AQEU
GENMAB A/S 11-Apr-2025 15:41:20 PM 19 1222.50 AQEU
GENMAB A/S 11-Apr-2025 15:41:20 PM 3 1222.50 AQEU
GENMAB A/S 11-Apr-2025 15:41:20 PM 11 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:41:20 PM 77 1222.50 CEUX
GENMAB A/S 11-Apr-2025 15:41:38 PM 86 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 26 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 14 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 14 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 88 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:44:00 PM 24 1221.50 TQEX
GENMAB A/S 11-Apr-2025 15:44:00 PM 85 1222.00 CEUX
GENMAB A/S 11-Apr-2025 15:44:28 PM 5 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:44:28 PM 28 1221.50 AQEU
GENMAB A/S 11-Apr-2025 15:45:31 PM 32 1221.50 CEUX
GENMAB A/S 11-Apr-2025 15:45:32 PM 15 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:33 PM 28 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:33 PM 12 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:33 PM 38 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:34 PM 9 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:34 PM 17 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:45:35 PM 28 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:35 PM 14 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:35 PM 13 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:35 PM 12 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:35 PM 13 1221.50 XCSE

102

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:45:35 PM 31 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:45:46 PM 17 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:45:55 PM 47 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:46:45 PM 46 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:46:45 PM 14 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:46:45 PM 24 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:46:45 PM 70 1220.50 XCSE
GENMAB A/S 11-Apr-2025 15:46:45 PM 17 1220.50 XCSE
GENMAB A/S 11-Apr-2025 15:47:06 PM 26 1222.00 TQEX
GENMAB A/S 11-Apr-2025 15:47:06 PM 83 1222.00 CEUX
GENMAB A/S 11-Apr-2025 15:47:41 PM 86 1221.50 XCSE
GENMAB A/S 11-Apr-2025 15:47:41 PM 15 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:47:41 PM 14 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:47:41 PM 3 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:48:02 PM 27 1221.00 AQEU
GENMAB A/S 11-Apr-2025 15:48:02 PM 82 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:48:07 PM 79 1220.50 XCSE
GENMAB A/S 11-Apr-2025 15:48:07 PM 9 1220.50 XCSE
GENMAB A/S 11-Apr-2025 15:50:01 PM 88 1221.00 XCSE
GENMAB A/S 11-Apr-2025 15:50:01 PM 85 1221.00 CEUX
GENMAB A/S 11-Apr-2025 15:51:30 PM 52 1222.00 XCSE
GENMAB A/S 11-Apr-2025 15:51:30 PM 53 1221.50 CEUX
GENMAB A/S 11-Apr-2025 15:51:30 PM 33 1221.50 CEUX
GENMAB A/S 11-Apr-2025 15:51:41 PM 12 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:52:05 PM 12 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:52:05 PM 5 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:52:05 PM 24 1224.00 TQEX
GENMAB A/S 11-Apr-2025 15:52:05 PM 85 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:53:48 PM 18 1224.00 AQEU
GENMAB A/S 11-Apr-2025 15:53:49 PM 2 1224.00 AQEU
GENMAB A/S 11-Apr-2025 15:54:05 PM 7 1224.00 AQEU
GENMAB A/S 11-Apr-2025 15:54:23 PM 11 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:55:21 PM 24 1224.00 TQEX
GENMAB A/S 11-Apr-2025 15:55:21 PM 30 1224.00 AQEU
GENMAB A/S 11-Apr-2025 15:55:21 PM 86 1224.00 CEUX
GENMAB A/S 11-Apr-2025 15:56:00 PM 30 1224.00 XCSE
GENMAB A/S 11-Apr-2025 15:56:11 PM 86 1223.50 XCSE
GENMAB A/S 11-Apr-2025 15:56:11 PM 30 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:56:11 PM 30 1223.00 XCSE
GENMAB A/S 11-Apr-2025 15:56:11 PM 25 1223.00 TQEX
GENMAB A/S 11-Apr-2025 15:56:11 PM 24 1223.00 AQEU
GENMAB A/S 11-Apr-2025 15:56:11 PM 85 1223.00 CEUX
GENMAB A/S 11-Apr-2025 15:56:12 PM 46 1223.00 XCSE

103

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 15:56:12 PM 88 1222.50 XCSE
GENMAB A/S 11-Apr-2025 15:59:25 PM 13 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:00:16 PM 86 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:00:16 PM 10 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:00:16 PM 11 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:00:16 PM 33 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:01:41 PM 39 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:41 PM 20 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:01:41 PM 36 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:01:42 PM 17 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:42 PM 35 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:42 PM 39 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:42 PM 15 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:56 PM 31 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:56 PM 14 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:01:56 PM 82 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:01:56 PM 32 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:01:58 PM 10 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:02:20 PM 21 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:02:21 PM 37 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:02:21 PM 30 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:02:21 PM 24 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:02:21 PM 1 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:02:21 PM 82 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:04:34 PM 5 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:04:34 PM 22 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:04:34 PM 5 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:04:39 PM 88 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:04:39 PM 34 1225.00 TQEX
GENMAB A/S 11-Apr-2025 16:04:39 PM 34 1225.00 AQEU
GENMAB A/S 11-Apr-2025 16:04:39 PM 82 1224.50 CEUX
GENMAB A/S 11-Apr-2025 16:04:40 PM 15 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:05:12 PM 24 1224.00 TQEX
GENMAB A/S 11-Apr-2025 16:05:24 PM 15 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:03 PM 30 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:50 PM 45 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:50 PM 39 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:50 PM 27 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:54 PM 7 1224.00 AQEU
GENMAB A/S 11-Apr-2025 16:07:57 PM 24 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:57 PM 83 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:57 PM 20 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:07:57 PM 29 1224.50 TQEX

104

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:07:57 PM 84 1224.50 CEUX
GENMAB A/S 11-Apr-2025 16:08:24 PM 32 1224.50 CEUX
GENMAB A/S 11-Apr-2025 16:08:25 PM 47 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:34 PM 46 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:34 PM 22 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:41 PM 39 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:41 PM 21 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:41 PM 39 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:42 PM 46 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:42 PM 16 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:42 PM 15 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:08:42 PM 13 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:09:01 PM 39 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:09:01 PM 14 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:09:01 PM 48 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:09:01 PM 39 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:09:01 PM 21 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:09:01 PM 22 1224.00 AQEU
GENMAB A/S 11-Apr-2025 16:09:01 PM 32 1224.00 CEUX
GENMAB A/S 11-Apr-2025 16:09:09 PM 83 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:09:09 PM 84 1223.50 CEUX
GENMAB A/S 11-Apr-2025 16:09:35 PM 84 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:09:35 PM 2 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:09:35 PM 8 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:09:35 PM 84 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:10:23 PM 43 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:10:23 PM 42 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:10:41 PM 25 1223.00 AQEU
GENMAB A/S 11-Apr-2025 16:10:41 PM 88 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:10:55 PM 24 1222.50 TQEX
GENMAB A/S 11-Apr-2025 16:12:16 PM 12 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:12:16 PM 13 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:12:16 PM 14 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:12:16 PM 39 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:12:16 PM 19 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:13:06 PM 82 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:13:06 PM 18 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:13:06 PM 86 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:13:13 PM 22 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:13:43 PM 2 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:13:53 PM 12 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:14:39 PM 7 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:14:55 PM 82 1222.00 XCSE

105

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:14:55 PM 35 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:14:55 PM 30 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:14:55 PM 82 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:14:56 PM 86 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:14:56 PM 28 1221.00 TQEX
GENMAB A/S 11-Apr-2025 16:14:56 PM 25 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:14:56 PM 87 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:16:32 PM 42 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:16:32 PM 15 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:16:32 PM 39 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:16:32 PM 13 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:16:32 PM 2 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:16:32 PM 83 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:16:33 PM 26 1220.50 AQEU
GENMAB A/S 11-Apr-2025 16:17:44 PM 83 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:17:44 PM 60 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:17:44 PM 14 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:17:44 PM 30 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:17:44 PM 7 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:17:44 PM 86 1219.50 XCSE
GENMAB A/S 11-Apr-2025 16:17:44 PM 27 1220.50 TQEX
GENMAB A/S 11-Apr-2025 16:17:44 PM 86 1220.50 CEUX
GENMAB A/S 11-Apr-2025 16:18:52 PM 83 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:18:52 PM 80 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:18:53 PM 53 1220.00 XCSE
GENMAB A/S 11-Apr-2025 16:18:53 PM 35 1220.00 XCSE
GENMAB A/S 11-Apr-2025 16:18:56 PM 26 1220.50 AQEU
GENMAB A/S 11-Apr-2025 16:19:41 PM 81 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:20:19 PM 68 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:20:19 PM 20 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:20:21 PM 81 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:20:23 PM 17 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:20:23 PM 70 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:20:24 PM 7 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:20:24 PM 18 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:20:24 PM 61 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:22:07 PM 84 1220.50 CEUX
GENMAB A/S 11-Apr-2025 16:22:26 PM 30 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:22:26 PM 14 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:22:36 PM 13 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:22:36 PM 38 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:22:36 PM 13 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:22:36 PM 14 1221.00 XCSE

106

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:23:25 PM 75 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:23:25 PM 14 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:23:25 PM 16 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:25:00 PM 36 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:25:00 PM 5 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:25:02 PM 33 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:25:24 PM 12 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:25:24 PM 18 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:25:24 PM 2 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:25:55 PM 39 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:25:55 PM 14 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:25:55 PM 18 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:25:55 PM 32 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:26:46 PM 14 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:26:46 PM 12 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:26:46 PM 12 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:26:46 PM 49 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:26:46 PM 12 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:26:46 PM 14 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:26:46 PM 5 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:26:46 PM 37 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:26:46 PM 8 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:26:47 PM 9 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:26:47 PM 12 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:26:59 PM 45 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:26:59 PM 18 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:27:50 PM 3 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:27:50 PM 2 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:27:50 PM 8 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:27:50 PM 18 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:27:52 PM 39 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:27:54 PM 3 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:27:54 PM 36 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:27:54 PM 17 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:27:54 PM 6 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:28:11 PM 86 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:28:11 PM 3 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:28:11 PM 8 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:28:11 PM 36 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:28:13 PM 29 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:28:13 PM 36 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:28:13 PM 75 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:28:36 PM 3 1222.00 TQEX

107

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:28:36 PM 81 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:28:38 PM 31 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:28:46 PM 46 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:28:46 PM 13 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:28:48 PM 100 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:00 PM 13 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:00 PM 26 1224.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:00 PM 31 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:00 PM 7 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:00 PM 82 1224.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:01 PM 70 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:01 PM 25 1223.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:01 PM 2 1223.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:01 PM 10 1223.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:01 PM 2 1223.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:01 PM 70 1224.00 AQEU
GENMAB A/S 11-Apr-2025 16:30:01 PM 15 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:01 PM 2 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:01 PM 10 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:01 PM 8 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:01 PM 51 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:02 PM 84 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 2 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 3 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 46 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 2 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 3 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 8 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:02 PM 1 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:02 PM 7 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:02 PM 10 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:02 PM 3 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:02 PM 9 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:30:02 PM 45 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:30:02 PM 9 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:30:03 PM 15 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:04 PM 21 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:04 PM 49 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:04 PM 18 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:05 PM 10 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:05 PM 17 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:05 PM 12 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:05 PM 11 1224.00 XCSE

108

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:30:05 PM 69 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:05 PM 21 1224.00 AQEU
GENMAB A/S 11-Apr-2025 16:30:05 PM 23 1224.00 AQEU
GENMAB A/S 11-Apr-2025 16:30:06 PM 47 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:06 PM 21 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 3 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 3 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 8 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 19 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 30 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 8 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 3 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 19 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:12 PM 8 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:13 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:13 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:13 PM 3 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:13 PM 10 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:13 PM 2 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:13 PM 7 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:28 PM 6 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:28 PM 6 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:28 PM 10 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:28 PM 3 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:35 PM 30 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:35 PM 49 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:35 PM 32 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:35 PM 10 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:30:35 PM 2 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:35 PM 4 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:35 PM 2 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:35 PM 2 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:35 PM 2 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:35 PM 8 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:41 PM 84 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 49 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 30 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 3 1223.00 XCSE

109

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:30:41 PM 4 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 2 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 2 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 9 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 2 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 4 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 2 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 2 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 2 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:41 PM 24 1223.00 AQEU
GENMAB A/S 11-Apr-2025 16:30:41 PM 41 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:30:54 PM 13 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:54 PM 49 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:54 PM 14 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:54 PM 30 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:30:55 PM 81 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:02 PM 33 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:02 PM 12 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:02 PM 3 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:03 PM 36 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:03 PM 43 1223.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:04 PM 3 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:04 PM 2 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:04 PM 83 1223.00 CEUX
GENMAB A/S 11-Apr-2025 16:31:09 PM 87 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:09 PM 24 1222.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:11 PM 84 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:31:21 PM 30 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:21 PM 58 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:21 PM 7 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:21 PM 1 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:21 PM 1 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:21 PM 48 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:31:37 PM 15 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:31:38 PM 14 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:31:38 PM 6 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:31:42 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:43 PM 4 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:43 PM 3 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:43 PM 2 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:43 PM 2 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:47 PM 87 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:47 PM 2 1221.50 TQEX

110

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:31:47 PM 2 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:47 PM 4 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:47 PM 31 1222.00 AQEU
GENMAB A/S 11-Apr-2025 16:31:55 PM 35 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 23 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 26 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 3 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 11 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 2 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 5 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 2 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 32 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 11 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 45 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:31:55 PM 12 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:55 PM 3 1220.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:55 PM 5 1220.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:55 PM 15 1220.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:55 PM 2 1220.50 TQEX
GENMAB A/S 11-Apr-2025 16:31:55 PM 17 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:31:55 PM 86 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:31:55 PM 20 1220.50 CEUX
GENMAB A/S 11-Apr-2025 16:31:55 PM 38 1220.50 CEUX
GENMAB A/S 11-Apr-2025 16:31:55 PM 7 1220.50 CEUX
GENMAB A/S 11-Apr-2025 16:31:55 PM 18 1220.50 CEUX
GENMAB A/S 11-Apr-2025 16:32:22 PM 16 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:32:22 PM 25 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:32:22 PM 25 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:32:22 PM 5 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:32:22 PM 13 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:32:26 PM 15 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:32:26 PM 14 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:32:26 PM 12 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:32:27 PM 13 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:32:27 PM 49 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:32:27 PM 12 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:32:30 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:30 PM 3 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:30 PM 5 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:32:30 PM 9 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:32:30 PM 5 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:32:30 PM 2 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:32:30 PM 3 1222.00 TQEX

111

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:32:32 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 4 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 6 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 3 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 3 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:32 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:37 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:37 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:37 PM 48 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:32:37 PM 1 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:32:50 PM 3 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:32:50 PM 7 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:33:15 PM 36 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 30 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 15 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 7 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 13 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 7 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 8 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 23 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:15 PM 4 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:15 PM 2 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:15 PM 4 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:15 PM 3 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:15 PM 4 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:15 PM 2 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:15 PM 4 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:33:15 PM 7 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:33:15 PM 8 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:33:15 PM 35 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:33:15 PM 4 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:33:15 PM 5 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:33:23 PM 7 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:33:23 PM 36 1221.50 AQEU
GENMAB A/S 11-Apr-2025 16:33:23 PM 66 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:33:24 PM 21 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:33:24 PM 30 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:33:24 PM 77 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:33:25 PM 9 1221.00 XCSE

112

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:33:48 PM 14 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:34:14 PM 43 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:14 PM 5 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:14 PM 49 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:14 PM 12 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:14 PM 2 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:14 PM 32 1221.50 TQEX
GENMAB A/S 11-Apr-2025 16:34:14 PM 86 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:34:14 PM 36 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:34:14 PM 20 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:34:14 PM 36 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:34:14 PM 7 1222.00 CEUX
GENMAB A/S 11-Apr-2025 16:34:15 PM 49 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:34:16 PM 88 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:17 PM 15 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:17 PM 10 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:17 PM 7 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:21 PM 27 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:24 PM 15 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:34:37 PM 13 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:34:37 PM 7 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:34:37 PM 32 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:34:48 PM 15 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:34:51 PM 8 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:34:53 PM 10 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:12 PM 13 1225.50 CEUX
GENMAB A/S 11-Apr-2025 16:35:15 PM 84 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:15 PM 14 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:15 PM 14 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:15 PM 12 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:15 PM 34 1225.50 TQEX
GENMAB A/S 11-Apr-2025 16:35:15 PM 2 1226.00 AQEU
GENMAB A/S 11-Apr-2025 16:35:15 PM 22 1226.00 AQEU
GENMAB A/S 11-Apr-2025 16:35:15 PM 68 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:15 PM 14 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:16 PM 14 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 49 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 14 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 13 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 21 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 29 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 12 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 49 1226.00 XCSE

113

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:35:16 PM 13 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 8 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 82 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:16 PM 32 1225.50 CEUX
GENMAB A/S 11-Apr-2025 16:35:20 PM 30 1225.50 TQEX
GENMAB A/S 11-Apr-2025 16:35:26 PM 46 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:26 PM 49 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:26 PM 12 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:26 PM 4 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:34 PM 6 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:34 PM 10 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:34 PM 26 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:34 PM 5 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:39 PM 82 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:35:51 PM 86 1224.50 CEUX
GENMAB A/S 11-Apr-2025 16:35:52 PM 82 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:35:52 PM 27 1223.50 TQEX
GENMAB A/S 11-Apr-2025 16:35:52 PM 81 1223.50 CEUX
GENMAB A/S 11-Apr-2025 16:36:16 PM 6 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:36:16 PM 29 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:36:16 PM 29 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:36:25 PM 19 1224.50 XCSE
GENMAB A/S 11-Apr-2025 16:36:25 PM 87 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:36:31 PM 85 1223.50 CEUX
GENMAB A/S 11-Apr-2025 16:36:35 PM 24 1223.00 AQEU
GENMAB A/S 11-Apr-2025 16:37:48 PM 86 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 5 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 15 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 12 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 10 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 49 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 10 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 10 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:37:48 PM 3 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:37:48 PM 2 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:37:48 PM 35 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:37:48 PM 5 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:37:48 PM 5 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:37:48 PM 37 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:37:54 PM 20 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:37:54 PM 6 1222.00 TQEX
GENMAB A/S 11-Apr-2025 16:38:01 PM 85 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 3 1221.00 XCSE

114

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:38:01 PM 15 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 5 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 14 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 6 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 36 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 28 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:01 PM 15 1221.00 TQEX
GENMAB A/S 11-Apr-2025 16:38:01 PM 13 1221.00 TQEX
GENMAB A/S 11-Apr-2025 16:38:01 PM 13 1221.00 AQEU
GENMAB A/S 11-Apr-2025 16:38:01 PM 12 1221.00 AQEU
GENMAB A/S 11-Apr-2025 16:38:01 PM 82 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:38:10 PM 84 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:38:26 PM 67 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:26 PM 49 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:38:26 PM 15 1222.00 XCSE
GENMAB A/S 11-Apr-2025 16:38:26 PM 20 1221.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:52 PM 53 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:38:52 PM 34 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:39:31 PM 21 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:39:31 PM 24 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:39:31 PM 32 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:01 PM 84 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:01 PM 60 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:01 PM 15 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:01 PM 13 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:01 PM 23 1226.50 XCSE
GENMAB A/S 11-Apr-2025 16:40:01 PM 28 1226.00 AQEU
GENMAB A/S 11-Apr-2025 16:40:01 PM 30 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:40:01 PM 51 1226.00 CEUX
GENMAB A/S 11-Apr-2025 16:40:03 PM 88 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:03 PM 88 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:40:04 PM 24 1224.50 TQEX
GENMAB A/S 11-Apr-2025 16:40:05 PM 5 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:48 PM 29 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:48 PM 50 1224.00 XCSE
GENMAB A/S 11-Apr-2025 16:40:48 PM 4 1223.50 AQEU
GENMAB A/S 11-Apr-2025 16:40:48 PM 81 1224.00 CEUX
GENMAB A/S 11-Apr-2025 16:40:51 PM 21 1223.50 AQEU
GENMAB A/S 11-Apr-2025 16:40:54 PM 3 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:40:54 PM 80 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:40:54 PM 24 1223.50 TQEX
GENMAB A/S 11-Apr-2025 16:40:54 PM 26 1223.50 CEUX
GENMAB A/S 11-Apr-2025 16:40:54 PM 15 1223.50 CEUX

115

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:40:54 PM 40 1223.50 CEUX
GENMAB A/S 11-Apr-2025 16:41:03 PM 27 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:41:03 PM 35 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:41:03 PM 23 1223.50 XCSE
GENMAB A/S 11-Apr-2025 16:41:11 PM 1 1223.00 AQEU
GENMAB A/S 11-Apr-2025 16:41:11 PM 23 1223.00 AQEU
GENMAB A/S 11-Apr-2025 16:41:11 PM 2 1223.00 AQEU
GENMAB A/S 11-Apr-2025 16:41:36 PM 47 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:41:36 PM 18 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:41:36 PM 5 1223.00 XCSE
GENMAB A/S 11-Apr-2025 16:41:37 PM 34 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:41:54 PM 2 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:41:57 PM 49 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:41:57 PM 56 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:41:57 PM 32 1222.50 CEUX
GENMAB A/S 11-Apr-2025 16:42:14 PM 24 1221.00 TQEX
GENMAB A/S 11-Apr-2025 16:42:14 PM 83 1221.00 CEUX
GENMAB A/S 11-Apr-2025 16:42:15 PM 87 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:42:15 PM 10 1220.50 XCSE
GENMAB A/S 11-Apr-2025 16:42:15 PM 30 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:42:15 PM 4 1221.00 XCSE
GENMAB A/S 11-Apr-2025 16:42:15 PM 10 1220.50 TQEX
GENMAB A/S 11-Apr-2025 16:42:27 PM 84 1221.50 CEUX
GENMAB A/S 11-Apr-2025 16:42:44 PM 10 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:42:50 PM 1 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:42:50 PM 6 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:42:50 PM 25 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:42:50 PM 40 1222.50 XCSE
GENMAB A/S 11-Apr-2025 16:43:05 PM 11 1223.50 AQEU
GENMAB A/S 11-Apr-2025 16:43:45 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:45 PM 49 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:45 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:45 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:45 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 49 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 14 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 8 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:46 PM 18 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:59 PM 2 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:59 PM 49 1225.00 XCSE

116

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:43:59 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:59 PM 12 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:43:59 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:44:06 PM 10 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:44:06 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:44:06 PM 9 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:44:28 PM 2 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:44:28 PM 5 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:44:29 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:44:29 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:44:34 PM 6 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:44:34 PM 18 1225.00 CEUX
GENMAB A/S 11-Apr-2025 16:44:38 PM 19 1225.50 CEUX
GENMAB A/S 11-Apr-2025 16:44:42 PM 62 1225.50 CEUX
GENMAB A/S 11-Apr-2025 16:44:58 PM 13 1225.50 XCSE
GENMAB A/S 11-Apr-2025 16:44:58 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 16:44:58 PM 14 1225.50 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 1 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 12 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 13 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 13 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 46 1225.50 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 14 1225.50 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 83 1225.00 XCSE
GENMAB A/S 11-Apr-2025 16:45:00 PM 2 1225.50 CEUX
GENMAB A/S 11-Apr-2025 16:45:00 PM 83 1225.50 CEUX
GENMAB A/S 11-Apr-2025 16:45:26 PM 14 1226.00 XCSE
GENMAB A/S 11-Apr-2025 16:45:46 PM 13 1226.50 XCSE
GENMAB A/S 11-Apr-2025 16:45:47 PM 75 1226.50 XCSE
GENMAB A/S 11-Apr-2025 16:45:49 PM 10 1226.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:07 PM 84 1227.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 30 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 14 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 49 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 13 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 5 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 85 1227.50 XCSE
GENMAB A/S 11-Apr-2025 16:46:40 PM 24 1228.00 AQEU
GENMAB A/S 11-Apr-2025 16:46:40 PM 85 1228.00 CEUX
GENMAB A/S 11-Apr-2025 16:46:40 PM 36 1228.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:06 PM 9 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:47:21 PM 4 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:47:39 PM 20 1230.50 AQEU

117

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:47:39 PM 24 1230.50 AQEU
GENMAB A/S 11-Apr-2025 16:47:39 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 84 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:47:58 PM 10 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:47:58 PM 22 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:47:58 PM 3 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:47:58 PM 7 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:47:58 PM 3 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:47:58 PM 13 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:47:58 PM 24 1230.50 AQEU
GENMAB A/S 11-Apr-2025 16:47:58 PM 13 1231.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 2 1231.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 4 1231.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 2 1231.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 6 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 9 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 11 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 6 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:47:58 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:48:02 PM 24 1230.50 TQEX
GENMAB A/S 11-Apr-2025 16:48:05 PM 10 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:48:05 PM 20 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:48:11 PM 3 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:48:11 PM 75 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:48:31 PM 87 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 49 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 11 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 49 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:48:53 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:00 PM 31 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:00 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:00 PM 49 1231.00 XCSE

118

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:49:00 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:16 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:16 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:16 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:23 PM 81 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:37 PM 17 1231.50 CEUX
GENMAB A/S 11-Apr-2025 16:49:40 PM 36 1231.50 CEUX
GENMAB A/S 11-Apr-2025 16:49:41 PM 36 1231.50 CEUX
GENMAB A/S 11-Apr-2025 16:49:43 PM 36 1231.50 CEUX
GENMAB A/S 11-Apr-2025 16:49:46 PM 17 1231.50 XCSE
GENMAB A/S 11-Apr-2025 16:49:48 PM 20 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:48 PM 7 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:48 PM 36 1232.00 CEUX
GENMAB A/S 11-Apr-2025 16:49:52 PM 30 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:52 PM 14 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:52 PM 13 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:52 PM 36 1232.00 CEUX
GENMAB A/S 11-Apr-2025 16:49:54 PM 4 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:54 PM 6 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:49:54 PM 19 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:49:54 PM 25 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:49:54 PM 3 1232.00 CEUX
GENMAB A/S 11-Apr-2025 16:49:54 PM 12 1232.00 CEUX
GENMAB A/S 11-Apr-2025 16:49:54 PM 86 1232.00 CEUX
GENMAB A/S 11-Apr-2025 16:49:55 PM 5 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:55 PM 2 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:49:59 PM 26 1231.50 AQEU
GENMAB A/S 11-Apr-2025 16:50:01 PM 1 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:01 PM 81 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:01 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:01 PM 24 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:01 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:01 PM 9 1231.00 TQEX
GENMAB A/S 11-Apr-2025 16:50:01 PM 37 1231.00 TQEX
GENMAB A/S 11-Apr-2025 16:50:01 PM 84 1231.00 CEUX
GENMAB A/S 11-Apr-2025 16:50:25 PM 25 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:25 PM 63 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:50:25 PM 37 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:50:25 PM 82 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:50:39 PM 17 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:39 PM 5 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:39 PM 49 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:39 PM 40 1229.50 XCSE

119

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:50:43 PM 14 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:44 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:44 PM 29 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:46 PM 3 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:46 PM 43 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:46 PM 4 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:46 PM 4 1228.50 TQEX
GENMAB A/S 11-Apr-2025 16:50:46 PM 5 1228.50 TQEX
GENMAB A/S 11-Apr-2025 16:50:46 PM 33 1229.00 AQEU
GENMAB A/S 11-Apr-2025 16:50:46 PM 8 1228.50 CEUX
GENMAB A/S 11-Apr-2025 16:50:49 PM 32 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:50:49 PM 74 1228.50 CEUX
GENMAB A/S 11-Apr-2025 16:50:54 PM 9 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:51:08 PM 14 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:51:14 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:51:14 PM 49 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:51:14 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:51:21 PM 1 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:51:21 PM 16 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 20 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 4 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 5 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 2 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 21 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 4 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:21 PM 10 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:36 PM 23 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:51:52 PM 12 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:51:52 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:51:52 PM 14 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:51:52 PM 83 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:03 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:52:03 PM 12 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:52:03 PM 14 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:52:04 PM 2 1229.50 AQEU
GENMAB A/S 11-Apr-2025 16:52:04 PM 24 1229.50 AQEU
GENMAB A/S 11-Apr-2025 16:52:05 PM 63 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:07 PM 1 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:38 PM 6 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:52:48 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:52 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:52 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:52 PM 13 1230.50 XCSE

120

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:52:52 PM 8 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:52 PM 49 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:53 PM 9 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:53 PM 49 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:53 PM 17 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:56 PM 15 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:52:56 PM 88 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:52:58 PM 67 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:53:05 PM 2 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:05 PM 3 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:05 PM 5 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:10 PM 31 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:53:10 PM 26 1228.50 XCSE
GENMAB A/S 11-Apr-2025 16:53:10 PM 3 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:10 PM 2 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:10 PM 9 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:10 PM 61 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:53:20 PM 10 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:20 PM 10 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:53 PM 6 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:53:53 PM 79 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:53:53 PM 24 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:53:53 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:53:53 PM 6 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:53:53 PM 6 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:53:53 PM 6 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:54:06 PM 32 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:54:48 PM 30 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 40 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 1 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 6 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 40 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 16:54:48 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:54:48 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:54:48 PM 6 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:54:48 PM 39 1230.50 CEUX
GENMAB A/S 11-Apr-2025 16:55:04 PM 25 1230.00 AQEU

121

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:55:07 PM 6 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:55:14 PM 83 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 47 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 50 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 4 1230.00 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 47 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 11 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 84 1229.00 XCSE
GENMAB A/S 11-Apr-2025 16:55:14 PM 28 1230.00 TQEX
GENMAB A/S 11-Apr-2025 16:55:14 PM 5 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:55:14 PM 84 1230.00 CEUX
GENMAB A/S 11-Apr-2025 16:55:14 PM 10 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:55:14 PM 13 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:55:14 PM 13 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:55:19 PM 48 1229.00 CEUX
GENMAB A/S 11-Apr-2025 16:55:40 PM 87 1229.50 XCSE
GENMAB A/S 11-Apr-2025 16:55:40 PM 24 1229.00 TQEX
GENMAB A/S 11-Apr-2025 16:55:40 PM 58 1229.50 CEUX
GENMAB A/S 11-Apr-2025 16:55:40 PM 23 1229.50 CEUX
GENMAB A/S 11-Apr-2025 16:55:40 PM 27 1229.00 AQEU
GENMAB A/S 11-Apr-2025 16:57:12 PM 45 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:12 PM 40 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:12 PM 15 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:12 PM 11 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:12 PM 40 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:12 PM 20 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:12 PM 4 1233.00 CEUX
GENMAB A/S 11-Apr-2025 16:57:15 PM 84 1233.00 XCSE
GENMAB A/S 11-Apr-2025 16:57:15 PM 2 1233.00 TQEX
GENMAB A/S 11-Apr-2025 16:57:32 PM 4 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:32 PM 81 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:32 PM 68 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:57:32 PM 4 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:57:32 PM 13 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:57:33 PM 2 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:33 PM 2 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:33 PM 3 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:33 PM 22 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:33 PM 3 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:33 PM 2 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:33 PM 5 1233.00 TQEX
GENMAB A/S 11-Apr-2025 16:57:33 PM 15 1233.50 CEUX

122

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:57:33 PM 3 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:57:33 PM 2 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:57:33 PM 3 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:57:56 PM 2 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:57:56 PM 1 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:58:25 PM 1 1233.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:25 PM 5 1233.50 XCSE
GENMAB A/S 11-Apr-2025 16:58:25 PM 4 1233.00 TQEX
GENMAB A/S 11-Apr-2025 16:58:25 PM 3 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:58:27 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 37 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 13 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 30 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 30 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:27 PM 15 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 14 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 12 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 13 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 30 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 37 1234.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 86 1233.00 XCSE
GENMAB A/S 11-Apr-2025 16:58:28 PM 17 1233.00 TQEX
GENMAB A/S 11-Apr-2025 16:58:28 PM 3 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:58:28 PM 3 1233.00 AQEU
GENMAB A/S 11-Apr-2025 16:58:28 PM 5 1233.00 AQEU
GENMAB A/S 11-Apr-2025 16:58:29 PM 8 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:58:29 PM 7 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:58:29 PM 7 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:58:49 PM 19 1233.00 AQEU
GENMAB A/S 11-Apr-2025 16:59:00 PM 8 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:00 PM 8 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:00 PM 7 1233.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:00 PM 31 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:16 PM 6 1232.50 XCSE
GENMAB A/S 11-Apr-2025 16:59:16 PM 4 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.00 TQEX

123

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 4 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 1 1232.00 TQEX
GENMAB A/S 11-Apr-2025 16:59:16 PM 51 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:16 PM 3 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:16 PM 4 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:16 PM 2 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:16 PM 2 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:32 PM 3 1232.50 XCSE
GENMAB A/S 11-Apr-2025 16:59:32 PM 3 1232.50 CEUX
GENMAB A/S 11-Apr-2025 16:59:47 PM 10 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:59:47 PM 30 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:59:47 PM 10 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:59:48 PM 38 1232.00 XCSE
GENMAB A/S 11-Apr-2025 16:59:56 PM 81 1231.50 XCSE
GENMAB A/S 11-Apr-2025 16:59:56 PM 81 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:00:00 PM 3 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:00 PM 25 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:00 PM 50 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:00 PM 24 1231.00 TQEX
GENMAB A/S 11-Apr-2025 17:00:01 PM 8 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:03 PM 4 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:00:04 PM 3 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:04 PM 2 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:00:04 PM 4 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:00:04 PM 2 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:00:04 PM 6 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:00:05 PM 9 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:00:16 PM 4 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:16 PM 13 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:16 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:19 PM 3 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:19 PM 3 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:19 PM 12 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:22 PM 85 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:29 PM 4 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:30 PM 3 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:31 PM 2 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:49 PM 2 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:00:49 PM 21 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:00:49 PM 4 1231.00 XCSE

124

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:00:49 PM 5 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:51 PM 46 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 41 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 15 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 15 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 50 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 7 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 24 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:00:51 PM 2 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:00:51 PM 2 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:00:51 PM 2 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:00:51 PM 2 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:00:51 PM 5 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:00:51 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:00:51 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:00:51 PM 5 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:10 PM 3 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:01:17 PM 2 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:01:38 PM 2 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:01:38 PM 2 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:01:38 PM 5 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:01:38 PM 5 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:01:38 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:01:38 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:38 PM 2 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:42 PM 68 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:42 PM 1 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:42 PM 2 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:42 PM 1 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:42 PM 6 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:01:48 PM 11 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:48 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:48 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:48 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:49 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:49 PM 20 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:49 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:01:49 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:02 PM 24 1230.00 TQEX
GENMAB A/S 11-Apr-2025 17:02:02 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:02:02 PM 20 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:02:02 PM 86 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:02:03 PM 47 1230.50 XCSE

125

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:02:03 PM 40 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:03 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:03 PM 11 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:03 PM 46 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:03 PM 20 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:02:11 PM 40 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:11 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:11 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:02:11 PM 2 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:02:12 PM 2 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:02:41 PM 34 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:02:52 PM 3 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:02:52 PM 20 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:10 PM 1 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 84 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 25 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 21 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 30 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 35 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 5 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 37 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 21 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 82 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:10 PM 15 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:03:10 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:03:10 PM 5 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:10 PM 5 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:10 PM 71 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 5 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:03:13 PM 2 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:03:13 PM 4 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:03:13 PM 3 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:03:13 PM 7 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 8 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 8 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 4 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:13 PM 3 1230.00 AQEU

126

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:03:13 PM 9 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:03:25 PM 20 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:31 PM 84 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:31 PM 84 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:47 PM 36 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:58 PM 13 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:58 PM 12 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:58 PM 13 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:58 PM 21 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:03:58 PM 3 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:03:58 PM 2 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:03:58 PM 5 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:04:07 PM 5 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:07 PM 6 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:07 PM 4 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:07 PM 21 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:07 PM 7 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:07 PM 3 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:07 PM 15 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:04:07 PM 3 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:04:07 PM 19 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:04:07 PM 3 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:04:11 PM 5 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:11 PM 2 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:28 PM 47 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:28 PM 31 1232.50 CEUX
GENMAB A/S 11-Apr-2025 17:04:28 PM 2 1232.50 CEUX
GENMAB A/S 11-Apr-2025 17:04:41 PM 36 1232.50 CEUX
GENMAB A/S 11-Apr-2025 17:04:42 PM 7 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:42 PM 81 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:04:42 PM 27 1232.50 TQEX
GENMAB A/S 11-Apr-2025 17:04:42 PM 33 1232.50 AQEU
GENMAB A/S 11-Apr-2025 17:04:44 PM 36 1232.50 CEUX
GENMAB A/S 11-Apr-2025 17:04:44 PM 1 1232.50 AQEU
GENMAB A/S 11-Apr-2025 17:05:31 PM 30 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 30 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 40 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 3 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 15 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 11 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:37 PM 81 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:05:37 PM 36 1232.50 CEUX

127

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:05:37 PM 1 1232.50 AQEU
GENMAB A/S 11-Apr-2025 17:05:38 PM 30 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:38 PM 15 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:38 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:05:47 PM 4 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:06:10 PM 85 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:06:10 PM 82 1234.00 CEUX
GENMAB A/S 11-Apr-2025 17:07:00 PM 83 1235.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:00 PM 12 1235.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:00 PM 2 1235.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:00 PM 32 1235.50 TQEX
GENMAB A/S 11-Apr-2025 17:07:00 PM 3 1235.50 TQEX
GENMAB A/S 11-Apr-2025 17:07:03 PM 41 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:07:03 PM 70 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:07:27 PM 86 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:07:54 PM 12 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:54 PM 14 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:54 PM 14 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:54 PM 36 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:07:54 PM 47 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:07:54 PM 36 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:07:54 PM 4 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:07:54 PM 6 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:07:54 PM 8 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:07:57 PM 3 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:57 PM 13 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:57 PM 13 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 13 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 13 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 40 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 33 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 13 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 13 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 40 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 30 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:58 PM 3 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:59 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:59 PM 40 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:59 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:59 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:07:59 PM 86 1238.50 XCSE

128

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:07:59 PM 24 1238.50 TQEX
GENMAB A/S 11-Apr-2025 17:08:39 PM 2 1239.00 AQEU
GENMAB A/S 11-Apr-2025 17:08:42 PM 41 1239.00 AQEU
GENMAB A/S 11-Apr-2025 17:09:02 PM 44 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 44 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 2 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 15 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 25 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 25 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 15 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 5 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 20 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 4 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:02 PM 24 1238.50 TQEX
GENMAB A/S 11-Apr-2025 17:09:02 PM 36 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:09:02 PM 10 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:09:03 PM 78 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:09:13 PM 31 1238.00 TQEX
GENMAB A/S 11-Apr-2025 17:09:14 PM 16 1237.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 72 1237.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 40 1238.00 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 21 1238.00 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 12 1238.00 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 23 1238.00 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 15 1238.00 XCSE
GENMAB A/S 11-Apr-2025 17:09:14 PM 14 1237.50 AQEU
GENMAB A/S 11-Apr-2025 17:09:14 PM 24 1237.50 AQEU
GENMAB A/S 11-Apr-2025 17:09:15 PM 2 1237.50 CEUX
GENMAB A/S 11-Apr-2025 17:09:31 PM 85 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:09:37 PM 28 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:09:37 PM 3 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:09:46 PM 83 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:09:53 PM 5 1239.50 TQEX
GENMAB A/S 11-Apr-2025 17:09:53 PM 5 1239.50 TQEX
GENMAB A/S 11-Apr-2025 17:09:53 PM 6 1239.50 TQEX
GENMAB A/S 11-Apr-2025 17:09:53 PM 10 1239.50 TQEX
GENMAB A/S 11-Apr-2025 17:10:21 PM 5 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:10:21 PM 3 1239.50 CEUX
GENMAB A/S 11-Apr-2025 17:10:23 PM 85 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:10:24 PM 83 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:10:24 PM 8 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:10:24 PM 20 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:10:25 PM 21 1239.00 XCSE

129

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:10:25 PM 12 1239.00 XCSE
GENMAB A/S 11-Apr-2025 17:10:25 PM 41 1239.00 XCSE
GENMAB A/S 11-Apr-2025 17:10:46 PM 37 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:10:46 PM 40 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:10:46 PM 14 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:10:46 PM 14 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:10:46 PM 6 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:06 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:06 PM 4 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:06 PM 40 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:06 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:06 PM 12 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:06 PM 31 1239.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:07 PM 52 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:07 PM 36 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:08 PM 17 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:08 PM 4 1239.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:09 PM 31 1238.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:09 PM 36 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:11:09 PM 15 1238.50 CEUX
GENMAB A/S 11-Apr-2025 17:11:09 PM 5 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:09 PM 5 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:09 PM 4 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:09 PM 71 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:22 PM 3 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:22 PM 3 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:22 PM 2 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:22 PM 3 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:24 PM 2 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:31 PM 3 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:31 PM 2 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:32 PM 64 1238.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:35 PM 82 1237.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:35 PM 4 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:35 PM 4 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:35 PM 7 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:35 PM 2 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:35 PM 5 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:35 PM 2 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:35 PM 2 1237.50 TQEX
GENMAB A/S 11-Apr-2025 17:11:40 PM 10 1237.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:42 PM 73 1237.00 CEUX
GENMAB A/S 11-Apr-2025 17:11:43 PM 2 1236.50 XCSE

130

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:11:43 PM 2 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 2 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 4 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 4 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 3 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 5 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 2 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 7 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 5 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:43 PM 26 1237.00 AQEU
GENMAB A/S 11-Apr-2025 17:11:48 PM 48 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:11:48 PM 3 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:11:48 PM 2 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:11:48 PM 5 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:11:48 PM 2 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:01 PM 81 1236.50 XCSE
GENMAB A/S 11-Apr-2025 17:12:01 PM 8 1236.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:01 PM 14 1236.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:01 PM 3 1236.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:01 PM 57 1236.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:01 PM 24 1236.50 AQEU
GENMAB A/S 11-Apr-2025 17:12:26 PM 58 1235.50 XCSE
GENMAB A/S 11-Apr-2025 17:12:26 PM 5 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:26 PM 71 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:29 PM 2 1235.00 AQEU
GENMAB A/S 11-Apr-2025 17:12:30 PM 2 1235.00 AQEU
GENMAB A/S 11-Apr-2025 17:12:32 PM 20 1235.00 AQEU
GENMAB A/S 11-Apr-2025 17:12:35 PM 1 1235.00 AQEU
GENMAB A/S 11-Apr-2025 17:12:48 PM 19 1235.00 XCSE
GENMAB A/S 11-Apr-2025 17:12:48 PM 69 1235.00 XCSE
GENMAB A/S 11-Apr-2025 17:12:56 PM 7 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:12:56 PM 53 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:12:56 PM 27 1234.50 TQEX
GENMAB A/S 11-Apr-2025 17:12:56 PM 7 1234.50 CEUX
GENMAB A/S 11-Apr-2025 17:12:56 PM 74 1234.50 CEUX
GENMAB A/S 11-Apr-2025 17:13:45 PM 14 1237.00 XCSE
GENMAB A/S 11-Apr-2025 17:13:45 PM 14 1237.00 XCSE
GENMAB A/S 11-Apr-2025 17:13:45 PM 12 1237.00 XCSE
GENMAB A/S 11-Apr-2025 17:13:45 PM 20 1237.00 XCSE
GENMAB A/S 11-Apr-2025 17:13:45 PM 34 1237.00 XCSE
GENMAB A/S 11-Apr-2025 17:13:46 PM 27 1236.50 TQEX
GENMAB A/S 11-Apr-2025 17:14:05 PM 85 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:05 PM 10 1235.00 XCSE

131

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:14:05 PM 7 1235.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:05 PM 65 1235.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:05 PM 84 1236.00 CEUX
GENMAB A/S 11-Apr-2025 17:14:47 PM 67 1235.50 XCSE
GENMAB A/S 11-Apr-2025 17:14:47 PM 40 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:47 PM 13 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:47 PM 12 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:47 PM 13 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:47 PM 2 1236.00 XCSE
GENMAB A/S 11-Apr-2025 17:14:47 PM 25 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:14:47 PM 25 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:14:47 PM 10 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:14:47 PM 5 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:14:47 PM 16 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:15:10 PM 85 1235.50 XCSE
GENMAB A/S 11-Apr-2025 17:15:10 PM 69 1235.50 CEUX
GENMAB A/S 11-Apr-2025 17:15:18 PM 4 1235.00 TQEX
GENMAB A/S 11-Apr-2025 17:15:21 PM 10 1235.00 TQEX
GENMAB A/S 11-Apr-2025 17:15:21 PM 2 1235.00 TQEX
GENMAB A/S 11-Apr-2025 17:15:21 PM 10 1235.00 TQEX
GENMAB A/S 11-Apr-2025 17:15:21 PM 5 1235.00 TQEX
GENMAB A/S 11-Apr-2025 17:15:21 PM 9 1235.00 TQEX
GENMAB A/S 11-Apr-2025 17:15:26 PM 2 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 2 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 4 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 7 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 2 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 8 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 4 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 4 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 54 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 1 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:15:26 PM 63 1234.50 CEUX
GENMAB A/S 11-Apr-2025 17:16:23 PM 87 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 36 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 3 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 5 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 3 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 4 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 5 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 3 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 59 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:16:23 PM 62 1234.00 CEUX

132

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:16:23 PM 37 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:16:48 PM 4 1233.50 TQEX
GENMAB A/S 11-Apr-2025 17:16:48 PM 4 1233.50 TQEX
GENMAB A/S 11-Apr-2025 17:17:01 PM 85 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:17:01 PM 40 1234.50 XCSE
GENMAB A/S 11-Apr-2025 17:17:01 PM 2 1234.50 XCSE
GENMAB A/S 11-Apr-2025 17:17:01 PM 12 1234.50 XCSE
GENMAB A/S 11-Apr-2025 17:17:01 PM 14 1234.50 XCSE
GENMAB A/S 11-Apr-2025 17:17:01 PM 14 1234.50 XCSE
GENMAB A/S 11-Apr-2025 17:17:01 PM 68 1234.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:01 PM 11 1234.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:10 PM 88 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:17:10 PM 55 1234.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:10 PM 24 1234.00 AQEU
GENMAB A/S 11-Apr-2025 17:17:19 PM 73 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:17:19 PM 3 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:19 PM 11 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:19 PM 2 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:19 PM 2 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:19 PM 7 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:45 PM 64 1234.00 XCSE
GENMAB A/S 11-Apr-2025 17:17:45 PM 10 1233.00 TQEX
GENMAB A/S 11-Apr-2025 17:17:45 PM 18 1233.00 TQEX
GENMAB A/S 11-Apr-2025 17:17:45 PM 52 1234.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:45 PM 3 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:45 PM 9 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:45 PM 19 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:45 PM 3 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:17:59 PM 9 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:18:00 PM 74 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:18:21 PM 4 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:18:21 PM 4 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:18:41 PM 69 1233.00 XCSE
GENMAB A/S 11-Apr-2025 17:18:41 PM 40 1233.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:04 PM 6 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:04 PM 2 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:04 PM 7 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:04 PM 8 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:04 PM 5 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:04 PM 8 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:04 PM 18 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:04 PM 2 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:04 PM 2 1232.00 CEUX

133

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:19:04 PM 21 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:04 PM 6 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:05 PM 28 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:27 PM 3 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:28 PM 2 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:19:28 PM 2 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:19:36 PM 40 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:36 PM 23 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:43 PM 27 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:43 PM 7 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:19:43 PM 18 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:19:43 PM 7 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:19:43 PM 7 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:19:46 PM 36 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:19:46 PM 45 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:19:46 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:46 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:19:46 PM 15 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:20:05 PM 3 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:05 PM 10 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:06 PM 40 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:20:26 PM 74 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:20:26 PM 30 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:20:26 PM 31 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:20:26 PM 32 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 1 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 5 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 2 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 3 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 2 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 4 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 5 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:26 PM 2 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:27 PM 83 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:20:45 PM 10 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:45 PM 3 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:45 PM 2 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:20:47 PM 10 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:20:47 PM 33 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:21:07 PM 84 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:21:07 PM 64 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:07 PM 4 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:07 PM 2 1226.50 CEUX

134

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:21:07 PM 2 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:07 PM 2 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:07 PM 18 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:07 PM 5 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:07 PM 8 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:10 PM 20 1226.50 CEUX
GENMAB A/S 11-Apr-2025 17:21:12 PM 50 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:21:14 PM 1 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:21:14 PM 20 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:21:59 PM 30 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:22:07 PM 25 1226.50 AQEU
GENMAB A/S 11-Apr-2025 17:22:12 PM 3 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:12 PM 5 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:12 PM 25 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:12 PM 8 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:12 PM 7 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:12 PM 36 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:22:12 PM 5 1225.50 TQEX
GENMAB A/S 11-Apr-2025 17:22:12 PM 15 1226.00 CEUX
GENMAB A/S 11-Apr-2025 17:22:12 PM 53 1226.00 CEUX
GENMAB A/S 11-Apr-2025 17:22:24 PM 4 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:22:24 PM 20 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:22:26 PM 35 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:48 PM 30 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:48 PM 37 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:48 PM 40 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:48 PM 4 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:22:48 PM 67 1225.00 CEUX
GENMAB A/S 11-Apr-2025 17:22:59 PM 24 1224.50 XCSE
GENMAB A/S 11-Apr-2025 17:23:26 PM 30 1223.50 XCSE
GENMAB A/S 11-Apr-2025 17:23:26 PM 31 1223.50 XCSE
GENMAB A/S 11-Apr-2025 17:23:26 PM 24 1223.50 XCSE
GENMAB A/S 11-Apr-2025 17:23:26 PM 4 1223.50 CEUX
GENMAB A/S 11-Apr-2025 17:23:26 PM 59 1223.50 CEUX
GENMAB A/S 11-Apr-2025 17:23:26 PM 11 1222.50 CEUX
GENMAB A/S 11-Apr-2025 17:23:26 PM 6 1222.50 CEUX
GENMAB A/S 11-Apr-2025 17:23:40 PM 15 1223.00 XCSE
GENMAB A/S 11-Apr-2025 17:23:40 PM 16 1223.00 XCSE
GENMAB A/S 11-Apr-2025 17:23:40 PM 4 1223.00 XCSE
GENMAB A/S 11-Apr-2025 17:23:40 PM 50 1223.00 XCSE
GENMAB A/S 11-Apr-2025 17:23:40 PM 6 1222.50 CEUX
GENMAB A/S 11-Apr-2025 17:23:40 PM 5 1222.50 CEUX
GENMAB A/S 11-Apr-2025 17:23:55 PM 85 1224.00 XCSE

135

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:24:00 PM 32 1224.50 TQEX
GENMAB A/S 11-Apr-2025 17:24:01 PM 78 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:24:08 PM 56 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:24:13 PM 40 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:24:46 PM 13 1224.50 XCSE
GENMAB A/S 11-Apr-2025 17:24:47 PM 72 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:24:47 PM 11 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:24:47 PM 27 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:25:00 PM 70 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:19 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:19 PM 40 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:19 PM 5 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:26 PM 13 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:26 PM 40 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:28 PM 58 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:36 PM 5 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:36 PM 40 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:46 PM 86 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:25:50 PM 25 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:50 PM 5 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:50 PM 5 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:50 PM 3 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 3 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 4 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 22 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 3 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:25:50 PM 2 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:26:00 PM 81 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 73 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 25 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 25 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 3 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 15 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 4 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 5 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 3 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:29 PM 31 1224.50 XCSE

136

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:26:29 PM 61 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:29 PM 24 1224.00 AQEU
GENMAB A/S 11-Apr-2025 17:26:52 PM 10 1224.50 TQEX
GENMAB A/S 11-Apr-2025 17:26:52 PM 5 1224.50 TQEX
GENMAB A/S 11-Apr-2025 17:26:52 PM 5 1224.50 TQEX
GENMAB A/S 11-Apr-2025 17:26:52 PM 6 1224.50 TQEX
GENMAB A/S 11-Apr-2025 17:26:52 PM 8 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:52 PM 6 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:52 PM 15 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:53 PM 1 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:53 PM 39 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:53 PM 1 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:26:53 PM 28 1224.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:53 PM 11 1223.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:53 PM 6 1223.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:53 PM 24 1223.50 CEUX
GENMAB A/S 11-Apr-2025 17:26:53 PM 38 1223.50 CEUX
GENMAB A/S 11-Apr-2025 17:27:14 PM 82 1224.00 XCSE
GENMAB A/S 11-Apr-2025 17:27:14 PM 2 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:27:14 PM 2 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:27:14 PM 2 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:27:14 PM 7 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:27:14 PM 2 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:27:14 PM 13 1224.00 TQEX
GENMAB A/S 11-Apr-2025 17:27:27 PM 5 1225.00 CEUX
GENMAB A/S 11-Apr-2025 17:27:27 PM 6 1225.00 CEUX
GENMAB A/S 11-Apr-2025 17:27:39 PM 33 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:27:39 PM 15 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:27:39 PM 1 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:27:39 PM 36 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:27:39 PM 7 1225.00 CEUX
GENMAB A/S 11-Apr-2025 17:27:39 PM 9 1225.00 CEUX
GENMAB A/S 11-Apr-2025 17:27:39 PM 17 1225.00 CEUX
GENMAB A/S 11-Apr-2025 17:28:04 PM 13 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:04 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:04 PM 30 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:27 PM 11 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:28:27 PM 39 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:28:49 PM 10 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:49 PM 23 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:49 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:49 PM 14 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:49 PM 12 1225.50 XCSE

137

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:28:49 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:49 PM 13 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:49 PM 65 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:28:58 PM 56 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:28:58 PM 22 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:58 PM 40 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:58 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:58 PM 14 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:58 PM 12 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:28:58 PM 11 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:29:19 PM 24 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:29:19 PM 2 1225.00 TQEX
GENMAB A/S 11-Apr-2025 17:29:19 PM 2 1225.00 TQEX
GENMAB A/S 11-Apr-2025 17:29:19 PM 20 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:29:19 PM 16 1225.00 AQEU
GENMAB A/S 11-Apr-2025 17:29:30 PM 48 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:29:33 PM 40 1225.50 XCSE
GENMAB A/S 11-Apr-2025 17:29:33 PM 19 1225.00 TQEX
GENMAB A/S 11-Apr-2025 17:29:33 PM 3 1225.00 TQEX
GENMAB A/S 11-Apr-2025 17:29:33 PM 12 1225.00 TQEX
GENMAB A/S 11-Apr-2025 17:29:33 PM 25 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:29:33 PM 3 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:29:33 PM 34 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:29:33 PM 3 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:29:51 PM 1 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:29:51 PM 5 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:29:56 PM 45 1226.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:01 PM 45 1225.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:01 PM 58 1225.50 CEUX
GENMAB A/S 11-Apr-2025 17:30:26 PM 13 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:26 PM 24 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:26 PM 40 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:26 PM 13 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:26 PM 12 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:46 PM 4 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:46 PM 12 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:46 PM 12 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:30:46 PM 13 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:31:02 PM 88 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:31:12 PM 32 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 85 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:31:26 PM 3 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 2 1226.50 TQEX

138

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:31:26 PM 3 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 2 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 2 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 4 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 11 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 9 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 3 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 4 1226.50 TQEX
GENMAB A/S 11-Apr-2025 17:31:26 PM 2 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 7 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 5 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 20 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 2 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 3 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:26 PM 2 1227.00 CEUX
GENMAB A/S 11-Apr-2025 17:31:27 PM 36 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:31:46 PM 5 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:31:48 PM 3 1227.00 XCSE
GENMAB A/S 11-Apr-2025 17:32:10 PM 36 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:32:11 PM 7 1228.50 AQEU
GENMAB A/S 11-Apr-2025 17:32:13 PM 36 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:32:13 PM 17 1228.50 AQEU
GENMAB A/S 11-Apr-2025 17:32:31 PM 40 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:31 PM 30 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:33 PM 53 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:52 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:52 PM 40 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:52 PM 12 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:32:52 PM 36 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:32:52 PM 4 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:32:52 PM 10 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:32:52 PM 2 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:32:52 PM 3 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:32:54 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 40 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 14 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 40 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:32:54 PM 13 1229.50 XCSE

139

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:32:58 PM 73 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:32:58 PM 28 1229.00 AQEU
GENMAB A/S 11-Apr-2025 17:33:14 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:33:25 PM 2 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:33:30 PM 37 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 48 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 2 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 4 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 3 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 7 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 8 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 2 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 4 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 3 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 8 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 4 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 20 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 20 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 26 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:33:30 PM 12 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:33:30 PM 13 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:33:30 PM 7 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:33:30 PM 4 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:33:30 PM 32 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:33:50 PM 6 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:04 PM 82 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:34:05 PM 12 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:05 PM 40 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:05 PM 13 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:05 PM 14 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:05 PM 13 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:05 PM 18 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:34:14 PM 50 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:34:14 PM 2 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:34:14 PM 2 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:34:42 PM 40 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:34:42 PM 37 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:34:42 PM 10 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:09 PM 39 1231.50 TQEX
GENMAB A/S 11-Apr-2025 17:35:16 PM 36 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:35:16 PM 16 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:35:28 PM 21 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:35:48 PM 14 1232.50 XCSE

140

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:35:48 PM 40 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:48 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:48 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:49 PM 14 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:49 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:49 PM 13 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:49 PM 14 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:49 PM 13 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:49 PM 68 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:35:49 PM 19 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:35:52 PM 14 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:52 PM 40 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:54 PM 40 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:54 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:54 PM 12 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:54 PM 87 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:35:59 PM 40 1232.50 XCSE
GENMAB A/S 11-Apr-2025 17:35:59 PM 33 1232.00 CEUX
GENMAB A/S 11-Apr-2025 17:36:12 PM 28 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 58 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 5 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 5 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 12 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 3 1231.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 40 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 14 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:36:12 PM 13 1232.00 XCSE
GENMAB A/S 11-Apr-2025 17:36:13 PM 28 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:36:22 PM 58 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:36:22 PM 4 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:36:22 PM 20 1231.50 CEUX
GENMAB A/S 11-Apr-2025 17:36:22 PM 28 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:36:24 PM 18 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 10 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 39 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 46 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 23 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 8 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:37:04 PM 19 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:37:04 PM 5 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:37:04 PM 55 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:37:21 PM 52 1229.50 CEUX

141

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:37:22 PM 31 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:37:22 PM 4 1228.50 TQEX
GENMAB A/S 11-Apr-2025 17:37:22 PM 3 1228.50 TQEX
GENMAB A/S 11-Apr-2025 17:37:22 PM 17 1228.50 TQEX
GENMAB A/S 11-Apr-2025 17:37:22 PM 4 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:37:22 PM 3 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:37:22 PM 8 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:37:22 PM 9 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:37:22 PM 24 1229.00 AQEU
GENMAB A/S 11-Apr-2025 17:38:41 PM 86 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 3 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 5 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 46 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 15 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 25 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 7 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 10 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:38:41 PM 30 1229.00 TQEX
GENMAB A/S 11-Apr-2025 17:38:41 PM 30 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 4 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 36 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 15 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 36 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 4 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 5 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 7 1229.50 CEUX
GENMAB A/S 11-Apr-2025 17:38:41 PM 3 1229.00 AQEU
GENMAB A/S 11-Apr-2025 17:38:41 PM 5 1229.00 AQEU
GENMAB A/S 11-Apr-2025 17:38:41 PM 16 1229.00 AQEU
GENMAB A/S 11-Apr-2025 17:38:52 PM 21 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:38:52 PM 18 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:38:53 PM 21 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 25 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 3 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 4 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 46 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:53 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:38:55 PM 4 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:08 PM 5 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:39:11 PM 32 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:39:11 PM 9 1230.50 AQEU

142

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:39:11 PM 11 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:39:31 PM 75 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 5 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 37 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 45 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:31 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:39:31 PM 50 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:39:31 PM 3 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:39:31 PM 20 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:39:31 PM 1 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:39:31 PM 8 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:39:35 PM 10 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:35 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:35 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:35 PM 46 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:39:35 PM 9 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:01 PM 3 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:01 PM 36 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:01 PM 46 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:40:01 PM 8 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:40:01 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:40:01 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:01 PM 28 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:01 PM 4 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:40:01 PM 3 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:40:02 PM 31 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:40:06 PM 7 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:06 PM 2 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:06 PM 3 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:06 PM 3 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:06 PM 2 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:40:30 PM 6 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:30 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:30 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:30 PM 46 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:40:30 PM 33 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:41:00 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:41:00 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:41:00 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:41:00 PM 3 1230.50 XCSE

143

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:41:00 PM 4 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:41:00 PM 20 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:41:00 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:15 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:41:15 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:22 PM 46 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:41:22 PM 12 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:24 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:41:24 PM 5 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:24 PM 7 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:27 PM 4 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:31 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:32 PM 24 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:35 PM 32 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:41:43 PM 24 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:41:43 PM 29 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:42:14 PM 19 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:42:18 PM 27 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:42:46 PM 4 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 58 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 5 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 46 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:42:46 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:42:46 PM 25 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:42:46 PM 67 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:07 PM 30 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:07 PM 14 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:07 PM 13 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:07 PM 5 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:07 PM 14 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:07 PM 35 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:07 PM 3 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:07 PM 3 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:07 PM 25 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:07 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:07 PM 20 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:07 PM 7 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:07 PM 7 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:07 PM 16 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:09 PM 82 1229.00 XCSE

144

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:43:34 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:34 PM 21 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:35 PM 19 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:35 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:41 PM 2 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:41 PM 36 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:41 PM 7 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:41 PM 7 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:47 PM 1 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:48 PM 22 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:50 PM 36 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:43:55 PM 85 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 46 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 15 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 14 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 12 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 14 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 10 1230.00 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 81 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:43:55 PM 7 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:55 PM 20 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:55 PM 1 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:55 PM 12 1229.50 TQEX
GENMAB A/S 11-Apr-2025 17:43:59 PM 4 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:00 PM 1 1230.00 AQEU
GENMAB A/S 11-Apr-2025 17:44:18 PM 111 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:44:18 PM 85 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:44:18 PM 7 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:18 PM 7 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:18 PM 8 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:19 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:19 PM 21 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:19 PM 8 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:19 PM 7 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:20 PM 1 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:22 PM 32 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:34 PM 111 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:44:34 PM 84 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:44:35 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:35 PM 7 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:35 PM 7 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:35 PM 32 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:44:37 PM 13 1230.50 XCSE

145

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:44:37 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:45:09 PM 111 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:45:10 PM 71 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:45:16 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:45:22 PM 20 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:45:22 PM 15 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:45:22 PM 3 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:45:22 PM 5 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:45:22 PM 24 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:45:37 PM 24 1231.00 TQEX
GENMAB A/S 11-Apr-2025 17:45:37 PM 58 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:45:37 PM 24 1231.00 AQEU
GENMAB A/S 11-Apr-2025 17:46:05 PM 17 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:46:05 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:46:05 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:46:05 PM 12 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:46:05 PM 25 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:46:05 PM 46 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:46:05 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:46:14 PM 16 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:01 PM 86 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:01 PM 46 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:01 PM 11 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:01 PM 14 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:01 PM 13 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:01 PM 27 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:01 PM 27 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:47:01 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:02 PM 82 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:07 PM 4 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:23 PM 85 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:23 PM 58 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:23 PM 26 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:23 PM 19 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:25 PM 88 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:25 PM 88 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:47:25 PM 31 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:47:25 PM 8 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:25 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:43 PM 22 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 13 1230.50 XCSE

146

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:47:43 PM 46 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 6 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 31 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 13 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 14 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 29 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 12 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 34 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:43 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:47:43 PM 8 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:47:43 PM 7 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:47:43 PM 50 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:47:54 PM 54 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:47:54 PM 26 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:47:54 PM 50 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:47:54 PM 38 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:48:00 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:01 PM 58 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:48:01 PM 13 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:01 PM 7 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:01 PM 20 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:01 PM 8 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:01 PM 8 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:04 PM 12 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:04 PM 6 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:09 PM 25 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:48:20 PM 88 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:48:31 PM 21 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:48:31 PM 36 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:48:31 PM 8 1230.50 AQEU
GENMAB A/S 11-Apr-2025 17:48:44 PM 76 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:48:44 PM 88 1231.00 XCSE
GENMAB A/S 11-Apr-2025 17:48:44 PM 10 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:44 PM 18 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:45 PM 7 1230.50 XCSE
GENMAB A/S 11-Apr-2025 17:48:45 PM 36 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:46 PM 32 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:54 PM 11 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:54 PM 20 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:48:54 PM 2 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:49:04 PM 11 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:49:04 PM 20 1231.00 CEUX
GENMAB A/S 11-Apr-2025 17:49:12 PM 25 1230.50 XCSE

147

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:49:12 PM 26 1230.50 TQEX
GENMAB A/S 11-Apr-2025 17:49:12 PM 55 1230.50 CEUX
GENMAB A/S 11-Apr-2025 17:49:31 PM 52 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:31 PM 3 1229.00 TQEX
GENMAB A/S 11-Apr-2025 17:49:31 PM 3 1229.00 TQEX
GENMAB A/S 11-Apr-2025 17:49:31 PM 2 1229.00 TQEX
GENMAB A/S 11-Apr-2025 17:49:31 PM 4 1229.00 TQEX
GENMAB A/S 11-Apr-2025 17:49:31 PM 18 1229.00 TQEX
GENMAB A/S 11-Apr-2025 17:49:31 PM 4 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:49:32 PM 30 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:32 PM 60 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:47 PM 46 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:47 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:47 PM 14 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:47 PM 12 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:49:47 PM 19 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:50:12 PM 1 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:50:12 PM 20 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:50:12 PM 24 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:50:13 PM 36 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:50:13 PM 36 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:51:07 PM 24 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:51:07 PM 30 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:51:12 PM 22 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:51:12 PM 26 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:51:12 PM 46 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:51:12 PM 17 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:51:12 PM 33 1228.00 CEUX
GENMAB A/S 11-Apr-2025 17:51:12 PM 6 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:51:12 PM 7 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:51:50 PM 2 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:51:50 PM 24 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:51:50 PM 2 1228.00 CEUX
GENMAB A/S 11-Apr-2025 17:51:50 PM 6 1228.00 CEUX
GENMAB A/S 11-Apr-2025 17:51:50 PM 16 1228.00 CEUX
GENMAB A/S 11-Apr-2025 17:52:10 PM 24 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:52:10 PM 29 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:52:10 PM 15 1227.50 TQEX
GENMAB A/S 11-Apr-2025 17:52:10 PM 36 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:10 PM 7 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:10 PM 25 1227.50 AQEU
GENMAB A/S 11-Apr-2025 17:52:11 PM 29 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:52:11 PM 36 1227.50 CEUX

148

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:52:11 PM 4 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:12 PM 5 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:15 PM 14 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:16 PM 36 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:39 PM 84 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 36 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 29 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 13 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 14 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 13 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 6 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:39 PM 15 1228.00 TQEX
GENMAB A/S 11-Apr-2025 17:52:39 PM 5 1228.00 TQEX
GENMAB A/S 11-Apr-2025 17:52:39 PM 4 1228.00 TQEX
GENMAB A/S 11-Apr-2025 17:52:39 PM 39 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:39 PM 1 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:39 PM 41 1227.50 CEUX
GENMAB A/S 11-Apr-2025 17:52:40 PM 14 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:40 PM 15 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:40 PM 46 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:40 PM 36 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:52:40 PM 76 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:52:40 PM 7 1227.50 XCSE
GENMAB A/S 11-Apr-2025 17:53:10 PM 17 1228.00 CEUX
GENMAB A/S 11-Apr-2025 17:53:11 PM 27 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:11 PM 50 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:11 PM 4 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:11 PM 11 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:12 PM 88 1228.50 TQEX
GENMAB A/S 11-Apr-2025 17:53:12 PM 82 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:27 PM 111 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:53:27 PM 22 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:29 PM 13 1228.50 TQEX
GENMAB A/S 11-Apr-2025 17:53:33 PM 83 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:53:33 PM 36 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:33 PM 25 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:53:49 PM 86 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:10 PM 17 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:10 PM 2 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:10 PM 20 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:10 PM 10 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:10 PM 3 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:10 PM 17 1230.00 CEUX

149

Exhibit 99.1(b)

APPENDIX Share buy-back programme - Specification for April 10 – April 11, 2025

Graphic

GENMAB A/S 11-Apr-2025 17:54:11 PM 12 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:11 PM 12 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:11 PM 20 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:11 PM 6 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:11 PM 7 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:11 PM 8 1230.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:19 PM 60 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 4 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 24 1229.00 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 46 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 17 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 13 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:19 PM 22 1229.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:29 PM 15 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:29 PM 10 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:31 PM 42 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:34 PM 29 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:36 PM 6 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:36 PM 27 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:36 PM 3 1229.00 CEUX
GENMAB A/S 11-Apr-2025 17:54:42 PM 111 1228.50 XCSE
GENMAB A/S 11-Apr-2025 17:54:42 PM 85 1228.00 XCSE
GENMAB A/S 11-Apr-2025 17:54:44 PM 8 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:44 PM 8 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:44 PM 8 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:44 PM 11 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:44 PM 15 1228.50 CEUX
GENMAB A/S 11-Apr-2025 17:54:50 PM 2 1228.00 AQEU

150