ADC Therapeutics SA 6-K, filed Sep 8, 2020

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORTOF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDERTHE SECURITIES EXCHANGE ACT OF 1934

For the month of September, 2020.

Commission File Number: 001-39071

ADC Therapeutics SA

(Exact name of registrant as specifiedin its charter)

Biopôle

Routede la Corniche 3B

1066 Epalinges

Switzerland

(Address of principal executive office)

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

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

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.

EXHIBITINDEX

Exhibit 99.1

ADCTherapeutics****Gives Notice of PartialWaiver of Restrictions

Pursuantto FINRA Rule 5131

Lausanne, Switzerland, September4, 2020 – ADC Therapeutics SA (NYSE: ADCT), today gave notice that Morgan Stanley & Co. LLC and BofA Securities, Inc., the lead book-running managers in the Company’s recent initial public offering, are releasing a lock-up restriction with respect to 105,000 common shares held by A.T. Holdings II Sàrl, an affiliate of Peter B. Corr and Stephen Evans-Freke who are members of the Company’s board of directors, as part of a block trade of common shares to HPWH TH AG. Both A.T. Holdings II Sàrl and HPWH TH AG are long-term investors who continue to hold significant interests in the Company and are represented on the Company’s board of directors. The release will take effect on September 10, 2020, and the shares may be sold on or after such date.

This press release is not an offer for sale of the securities in the United States or in any other jurisdiction where such offer is prohibited, and such securities may not be offered or sold in the United States absent registration or an exemption from registration under the United States Securities Act of 1933, as amended.

About ADC Therapeutics

ADC Therapeutics SA (NYSE:ADCT) is a late clinical-stage oncology-focused biotechnology company pioneering the development and commercialization of highly potent and targeted antibody drug conjugates (ADCs) for patients with hematological malignancies and solid tumors. The Company develops ADCs by applying its decades of experience in this field and using next-generation pyrrolobenzodiazepine (PBD) technology to which ADC Therapeutics has proprietary rights for its targets. Strategic target selection for PBD-based ADCs and substantial investment in early clinical development have enabled ADC Therapeutics to build a deep clinical and research pipeline of therapies for the treatment of hematological and solid tumor cancers. The Company has multiple PBD-based ADCs in ongoing clinical trials, ranging from first in human to pivotal Phase 2 clinical trials, in the USA and Europe, and numerous preclinical ADCs in development.

Loncastuximab tesirine (Lonca, formerly ADCT-402), the Company’s lead product candidate, has been evaluated in a 145-patient pivotal Phase 2 clinical trial for the treatment of relapsed or refractory diffuse large B-cell lymphoma (DLBCL) that showed a 48.3% overall response rate (ORR), which exceeded the target primary endpoint. Camidanlumab tesirine (Cami, formerly ADCT-301), the Company’s second lead product candidate, is being evaluated in a 100-patient pivotal Phase 2 clinical trial for the treatment of relapsed or refractory Hodgkin lymphoma (HL) after having shown an 86.5% ORR in HL patients in a Phase 1 clinical trial. The Company is also evaluating Cami as a novel immuno-oncology approach for the treatment of various advanced solid tumors.

ADC Therapeutics is based in Lausanne (Biopôle), Switzerland and has operations in London, the San Francisco Bay Area and New Jersey. For more information, please visit https://adctherapeutics.com/ and follow the Company on Twitter and LinkedIn.

Forward-LookingStatements

This press release contains statements that constitute forward-looking statements. All statements other than statements of historical facts contained in this press release, including statements regarding our future results of operations and financial position, business strategy, product

candidates, research pipeline, ongoing and planned preclinical studies and clinical trials, regulatory submissions and approvals, research and development costs, timing and likelihood of success, as well as plans and objectives of management for future operations are forward-looking statements. Forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to our management. Such statements are subject to risks and uncertainties, and actual results may differ materially from those expressed or implied in the forward-looking statements due to various factors, including those described in our filings with the U.S. Securities and Exchange Commission. No assurance can be given that such future results will be achieved. Such forward-looking statements contained in this document speak only as of the date of this press release. We expressly disclaim any obligation or undertaking to update these forward-looking statements contained in this press release to reflect any change in our expectations or any change in events, conditions, or circumstances on which such statements are based unless required to do so by applicable law. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

CONTACTS:

Investors

Amanda Hamilton

ADC Therapeutics

amanda.hamilton@adctherapeutics.com

Tel.: +1 917-288-7023

EU Media

Alexandre Müller

Dynamics Group

amu@dynamicsgroup.ch

Tel: +41 (0) 43 268 3231

USA Media

Annie Starr

6 Degrees

astarr@6degreespr.com

Tel.: +1 973-415-8838