8-K

Cullinan Therapeutics, Inc. (CGEM)

8-K 2025-06-04 For: 2025-06-04
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Added on April 04, 2026

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 04, 2025

CULLINAN THERAPEUTICS, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware 001-39856 81-3879991
(State or Other Jurisdiction<br>of Incorporation) (Commission File Number) (IRS Employer<br>Identification No.)
One Main Street<br><br>Suite 1350
Cambridge, Massachusetts 02142
(Address of Principal Executive Offices) (Zip Code)
Registrant’s Telephone Number, Including Area Code: 617 410-4650
---

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class Trading<br>Symbol(s) Name of each exchange on which registered
Common Stock, $0.0001 par value per share CGEM The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement.

On June 4, 2025, Cullinan Therapeutics, Inc. (the “Company”) and Chongqing Genrix Biopharmaceutical Co., Ltd. (“Genrix”) entered into a License Agreement (the “License Agreement”), pursuant to which Genrix granted to the Company a global (ex-greater China), exclusive license to develop and commercialize velinotamig, a BCMAxCD3 bispecific T cell engager, in all fields of use.

Under the terms of the License Agreement, the Company is obligated to pay Genrix an upfront license fee of $20 million due upon signing. Genrix will be eligible to receive up to $292 million in milestone payments based on the achievement of development and regulatory milestones. Genrix is also eligible to receive up to an additional $400 million in net sales-based milestones as well as tiered royalties ranging from mid-single digit to mid-teens, as a percentage of net sales of licensed products.

Unless earlier terminated, the License Agreement will continue in effect on a country-by-country basis until the expiration of the Company’s royalty obligations in such country.

The License Agreement may be terminated by either party for a material breach by the other party, subject to notice and cure provisions, or in the event of the other party’s insolvency. Additionally, subject to a notice period, the Company may terminate the License Agreement for convenience. In the License Agreement, each party made customary representations and warranties and agreed to customary covenants, including, without limitation, with respect to indemnification, for transactions of this type.

The License Agreement became effective immediately upon execution.

A copy of the License Agreement will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2025.

Item 7.01 Regulation FD Disclosure.

On June 4, 2025, the Company issued a press release announcing it entered into the License Agreement and made available on its website a copy of a corporate presentation to be shared with investors and others from time to time, copies of which are being furnished as Exhibits 99.1 and 99.2 to this Current Report on Form 8-K. The information in this Item 7.01 and Exhibits 99.1 and 99.2 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act or the Exchange Act, except as expressly set forth by specific reference in such filing.

Forward-Looking Statements

This Current Report on Form 8-K contains forward-looking statements, including express or implied statements regarding the Company’s beliefs and expectations regarding velinotamig, potential milestone and royalty payments, as well as royalties on net sales of licensed products, if any. Any forward-looking statements in this Current Report on Form 8-K are based on management’s current expectations and beliefs of future events and are subject to known and unknown risks and uncertainties that may cause the Company’s actual results, performance or achievements to be materially different from any expressed or implied by the forward-looking statements. These risks include, but are not limited to, the risks and uncertainties discussed in the Company’s filings with the Securities and Exchange Commission (“SEC”), including under the caption “Risk Factors” in the Company’s most recent Annual Report on Form 10-K and subsequent filings with the SEC. While the Company may elect to update such forward-looking statements in the future, it disclaims any obligation to do so, even if subsequent events cause its views to change, except to the extent required by law. These forward-looking statements should not be relied upon as representing the Company’s views as of any date subsequent to the date of this Current Report on Form 8-K. Moreover, except as required by law, neither the Company nor any other person assumes responsibility for the accuracy and completeness of the forward-looking statements included in this Current Report on Form 8-K. Any forward-looking statement included in this Current Report on Form 8-K speaks only as of the date on which it was made.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit No. Description
99.1 Press release issued by Cullinan Therapeutics, Inc. on June 4, 2025, furnished herewith
99.2 Corporate Presentation of Cullinan Therapeutics, Inc. dated June 4, 2025, furnished herewith
104 Cover page from this Current Report on Form 8-K, formatted in Inline XBRL

SIGNATURES

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 hereunto duly authorized.

CULLINAN THERAPEUTICS, INC.
Date: June 4, 2025 By: /s/ Mary Kay Fenton
Mary Kay Fenton<br>Chief Financial Officer

EX-99.1

Exhibit 99.1

Cullinan Therapeutics Licenses Rights to Velinotamig, a Clinical-Stage BCMA-Directed Bispecific T Cell Engager, from Genrix Bio for Development in Autoimmune Diseases

Advances Cullinan’s leadership in T cell engager (TCE) development for autoimmune diseases with both a CD19 TCE and BCMA TCE in its pipeline

Strengthens Cullinan portfolio of autoimmune programs with the opportunity to address a broader range of diseases while maintaining cash runway into 2028

Company to host conference call today at 4:30 pm ET

CAMBRIDGE, Mass., (June 4, 2024) (GLOBE NEWSWIRE) -- Cullinan Therapeutics, Inc. (Nasdaq: CGEM; “Cullinan”), a biopharmaceutical company focused on developing modality-agnostic targeted therapies, today announced that it has entered into an agreement with Genrix Bio for a global (ex-Greater China), all indication, exclusive license to velinotamig, a BCMAxCD3 bispecific T cell engager. Velinotamig has demonstrated potential best-in-class efficacy at the Phase 2 target dose in nearly 50 patients with relapsed/refractory (r/r) multiple myeloma (MM). Cullinan will develop velinotamig in autoimmune diseases.

“We believe T cell engagers represent the next wave of innovation in autoimmune diseases, and we are excited to build upon our core T cell engager expertise and extensive KOL relationships to develop another potential best-in-class, clinical-stage program. Accumulated data supports BCMA as a promising target in autoimmune diseases, offering a precise and potentially disease-modifying approach by eliminating the entirety of the self-reactive plasma cells that result in certain autoimmune diseases, especially those diseases driven by long-lived plasma cells,” said Nadim Ahmed, Chief Executive Officer of Cullinan Therapeutics. “Adding a BCMAxCD3 bispecific T cell engager to our pipeline complements our rapid global clinical development of CLN-978, enabling us to address the needs of more patients across a broader range of autoimmune diseases than with either molecule alone.”

Genrix plans to initiate a Phase 1 study in China by the end of this year in patients with autoimmune diseases. Cullinan intends to use the data generated to accelerate global clinical development of the program. Following the completion of the Genrix Bio Phase 1 study, Cullinan will conduct all further development of velinotamig in autoimmune diseases.

“With our planned Phase 1 study of velinotamig in autoimmune diseases, we will be able to quickly leverage our experience in autoimmune diseases to complete the study in China expeditiously,” said Dr. Liu Zhigang, Chairman, Chief Executive Officer, and Chief Science Officer of Genrix Biopharmaceutical “Cullinan is a proven leader in developing T cell engagers and we are confident in the company’s ability to carry the program forward to address the needs of patients with autoimmune diseases.”

Under the agreement, Cullinan will pay Genrix Bio an upfront license fee of $20 million for exclusive rights to develop and commercialize velinotamig in all disease areas globally outside of Greater China. In the future, Genrix will also be eligible to receive up to $292 million in development and regulatory milestones plus up to an additional $400M in sales-based milestones, as well as tiered royalties from mid-single digits up to the mid- teens on potential ex-Greater China net sales.

Importantly, with refinement of the clinical oncology pipeline, Cullinan reiterates its existing guidance to have cash resources into 2028 based on its current operating plan.

Cullinan Therapeutics Conference Call Information

Cullinan Therapeutics will host a conference call today, June 4, at 4:30 pm ET. Investors, analysts and the general public are invited to listen to a live webcast of the call. A link to join the call and to find related materials will be available under the Events and Presentations section of the Company’s investor relations website at https://cullinantherapeutics.com/events-and-presentations/

About Velinotamig

Velinotamig is a bispecific antibody that can simultaneously bind to the BCMA and CD3 antigens, redirecting cytotoxic T cells to target BCMA-expressing cells. Velinotamig has high affinity for BCMA and lower affinity for CD3. Affinity for BCMA is two orders of magnitude higher than for CD3, ensuring that the bispecific antibody recruits and activates T cells while minimizing non-specific T cell activation and reducing the toxicity mediated by the CD3 antibody.

Genrix Bio received approval from the National Medical Products Administration (NMPA) in January 2022 to conduct clinical trials for the indication of multiple myeloma. Velinotamig received Breakthrough Therapy Designation by the Center for Drug Evaluation (CDE) for the treatment of relapsed and refractory multiple myeloma.

About Cullinan Therapeutics

Cullinan Therapeutics, Inc. (Nasdaq: CGEM) is a biopharmaceutical company dedicated to creating new standards of care for patients. Cullinan has strategically built a diversified portfolio of clinical-stage assets that inhibit key drivers of disease or harness the immune system to eliminate diseased cells in both autoimmune diseases and cancer. Cullinan’s portfolio encompasses a wide range of modalities, each with the potential to be best and/or first in class. Anchored in a deep understanding of oncology, immunology, and translational medicine, we create differentiated ideas, identify the most appropriate targets, and select the optimal modality to develop transformative therapeutics across a wide variety of autoimmune and cancer indications. We push conventional boundaries from candidate selection to differentiated therapeutic, applying rigorous go/no go criteria at each stage of development to fast-track only the most promising molecules to the clinic and, ultimately, commercialization. With deep scientific expertise, our teams exercise creativity and urgency to deliver on our promise to bring new therapeutic solutions to patients. Learn more about Cullinan at https://cullinantherapeutics.com/, and follow us on LinkedIn and X.

About Genrix Bio

Genrix Bio (Stock Code: 688443), founded in 2015, is an innovative biopharmaceutical company driven by advanced antibody drug discovery technology to address critical clinical needs. With antibody drug R&D centers in Beijing, Shanghai, and Chongqing, we are committed to the development of monoclonal and bispecific antibodies for autoimmune diseases, infectious diseases, and oncology. Our capabilities span across antibody molecular discovery, process development and quality research, clinical trials, and large-scale commercialization. Upholding the philosophy of "to deliver affordable and reliable new medicines for patients," we strive to address the clinical needs of a wider population. Learn more about Genrix Bio at https://www.genrixbio.com/#/home

Forward Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, express or implied statements regarding Cullinan’s beliefs and expectations regarding the potential benefits of, and plans relating to, the license agreement between Cullinan and Genrix Bio, including anticipated milestone payments under the license agreement, as well as royalties on net sales; the therapeutic potential of velinotamig; the timing of planned clinical development of velinotamig; our expectations regarding our cash resources; and other statements that are not historical facts. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “hope,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “target,” “should,” “would,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

Any forward-looking statements in this press release are based on management's current expectations and beliefs of future events and are subject to known and unknown risks and uncertainties that may cause our actual results, performance or achievements to be materially different from any expressed or implied by the forward-looking statements. These risks include, but are not limited to, the following: uncertainty regarding the timing and results of regulatory submissions; the success of our clinical trials and preclinical studies; risks related to our ability to protect and maintain our intellectual property position; risks related to manufacturing, supply, and distribution of our product candidates; the risk that any one or more of our product candidates, including those that are co-developed, will not be successfully developed and commercialized; the risk that the results of preclinical studies or clinical studies will not be predictive of future results in connection with future studies; the effect of changes in global economic conditions, including uncertainties related to international trade policies, tariffs and supply chain dynamics on our business and operations; and the success of any collaboration, partnership, license or similar agreements. These and other important risks and uncertainties discussed in our filings with the Securities and Exchange Commission, including under the caption “Risk Factors” in our most recent Annual Report on Form 10-K and subsequent filings with the SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change, except to the extent required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release. Moreover, except as required by law, neither Cullinan nor any other person assumes responsibility for the accuracy and completeness of the

forward-looking statements included in this press release. Any forward-looking statement included in this press release speaks only as of the date on which it was made.

Contacts:

Investors Nick Smith +1 401.241.3516 nsmith@cullinantx.com

Media  Rose Weldon +1 215.801.7644 rweldon@cullinantx.com

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June 2025 Cullinan Therapeutics Licensing of velinotamig (BCMAxCD3) from Genrix Bio Exhibit 99.2

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Important Notice and Disclaimers This presentation contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, express or implied statements regarding Cullinan’s beliefs and expectations regarding the potential benefits of, and plans relating to, the license agreement between Cullinan and Genrix, including anticipated milestone payments under the license agreement; the therapeutic potential of Velinotamig; the timing of planned clinical development of Velinotamig; our expectations regarding our cash resources; and other statements that are not historical facts. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “hope,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “target,” “should,” “would,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this presentation are based on management's current expectations and beliefs of future events and are subject to known and unknown risks and uncertainties that may cause our actual results, performance or achievements to be materially different from any expressed or implied by the forward-looking statements. These risks include, but are not limited to, the following: uncertainty regarding the timing and results of regulatory submissions; the success of our clinical trials and preclinical studies; risks related to our ability to protect and maintain our intellectual property position; risks related to manufacturing, supply, and distribution of our product candidates; the risk that any one or more of our product candidates, including those that are co-developed, will not be successfully developed and commercialized; the risk that the results of preclinical studies or clinical studies will not be predictive of future results in connection with future studies; the effect of changes in global economic conditions, including uncertainties related to international trade policies, tariffs and supply chain dynamics on our business and operations; and the success of any collaboration, partnership, license or similar agreements. These and other important risks and uncertainties discussed in our filings with the Securities and Exchange Commission, including under the caption “Risk Factors” in our most recent Annual Report on Form 10-K and subsequent filings with the SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this presentation. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change, except to the extent required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this presentation. Moreover, except as required by law, neither Cullinan nor any other person assumes responsibility for the accuracy and completeness of the forward-looking statements included in this presentation. Any forward-looking statement included in this presentation speaks only as of the date on which it was made. Certain information contained in this presentation relates to or is based on studies, publications, surveys and other data obtained from third-party sources and our own internal estimates and research. While we believe these third-party sources to be reliable as of the date of this presentation, we have not independently verified, and make no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. In addition, all of the market data included in this presentation involves a number of assumptions and limitations, and there can be no guarantee as to the accuracy or reliability of such assumptions. Finally, while we believe our own internal research is reliable, such research has not been verified by any independent source.

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Agenda Introduction Nadim Ahmed BCMA & Velinotamig Overview Jeff Jones Deal Terms & Financial Context Mary Kay Fenton Strategic Perspective & Next Steps Nadim Ahmed Q&A Nadim Ahmed Chief Executive Officer Jeff Jones, MD, MBA Chief Medical Officer Mary Kay Fenton Chief Financial Officer 3 © CULLINAN THERAPEUTICS, INC. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY PRESENTERS

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CULLINAN THERAPEUTICS Our Mission: Create new standards of care for patients Cullinan Therapeutics is entering into an agreement with Genrix Bio for a global (ex-Greater China*), all indication, exclusive license agreement for velinotimag. Velinotamig is a BCMAxCD3 bispecific T cell engager (TCE) with best-in-class potential. Genrix Bio will execute a planned Phase 1 study in China in patients with autoimmune diseases; Genrix Bio plans to initiate the study later this year. Cullinan plans to utilize the data generated to accelerate global clinical development of velinotamig in autoimmune diseases. Adding a BCMAxCD3 bispecific T cell engager (plasma cell depleter) to our pipeline will complement CLN-978 (B cell depleter) and creates the opportunity to impact more patients across a broader range of autoimmune diseases than either molecule alone, while utilizing our core expertise with TCEs. We are leveraging the strength of our balance sheet to expand and strengthen our portfolio of high-opportunity and high-impact autoimmune programs in a capital efficient manner while creating additional near-term and long-term value-driving catalysts. Importantly, as a result of refining our oncology pipeline, we can reiterate our existing guidance to have cash resources into 2028 based on our current operating plan. © CULLINAN THERAPEUTICS, INC. ALL RIGHTS RESERVED. *Greater China, including the Hong Kong Special Administrative Region, Macao Special Administrative Region and Taiwan

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Combined ~41.6M patients globally Source: SLE: Tian J, Zhang D, Yao X, Huang Y, Lu Q. Global epidemiology of systemic lupus erythematosus: a comprehensive systematic analysis and modelling study. Ann Rheum Dis. Published online October 14, 2022. RA: Rheumatoid arthritis: Key Facts. WHO. Published online June 28, 2023. MG: Dresser L, Wlodarski R, Rezania K, Soliven B. Myasthenia Gravis: Epidemiology, Pathophysiology and Clinical Manifestations. J Clin Med. 2021 May 21;10(11):2235. SS: Tian J, Kang S, Zhang D, Huang Y, Zhao M, Gui X, Yao X, Lu Q. Global, regional, and national incidence and prevalence of systemic sclerosis. Clin Immunol. 2023 Mar;248:109267. MN: Ronco, P., Beck, L., Debiec, H. et al. Membranous nephropathy. Nat Rev Dis Primers 7, 69 (2021). ITP: Affected Populations. Immune Thrombocytopenia. National Organization for Rare Disorders. Last updated 2022. MS: MS Prevalence. National MS Society. IIM: Khoo, T., Lilleker, J.B., Thong, B.YH. et al. Epidemiology of the idiopathic inflammatory myopathies. Nat Rev Rheumatol 19, 695–712 (2023). NMOSD: Bagherieh S, Afshari-Safavi A, Vaheb S, Kiani M, Ghaffary EM, Barzegar M, Shaygannejad V, Zabeti A, Mirmosayyeb O. Worldwide prevalence of neuromyelitis optica spectrum disorder (NMOSD) and neuromyelitis optica (NMO): a systematic review and meta-analysis. Neurol Sci. 2023 Jun;44(6):1905-1915. AHA: Hansen D.L., Möller S., Andersen K., Gaist D., Frederiksen H. Increasing Incidence and Prevalence of Acquired Hemolytic Anemias in Denmark, 1980–2016. Clin. Epidemiol. 2020;12:497–508. ANCAV: Redondo-Rodriguez R, Mena-Vázquez N, Cabezas-Lucena AM, Manrique-Arija S, Mucientes A, Fernández-Nebro A. Systematic Review and Metaanalysis of Worldwide Incidence and Prevalence of Antineutrophil Cytoplasmic Antibody (ANCA) Associated Vasculitis. J Clin Med. 2022 May 4;11(9):2573. Sjogren’s: Epidemiology. Sjogren Syndrome. Medscape. Last updated: March 24, 2023. PV: Rosi-Schumacher M, Baker J, Waris J, Seiffert-Sinha K, Sinha AA. Worldwide epidemiologic factors in pemphigus vulgaris and bullous pemphigoid. Front Immunol. 2023 Apr 25;14:1159351. Graves’/TED: Girgis CM, Champion BL, Wall JR. Current concepts in graves' disease. Ther Adv Endocrinol Metab. 2011;2(3):135-144. doi:10.1177/2042018811408488 OPPORTUNITY TO ADDRESS AUTOIMMUNE DISEASES THROUGH B CELL AND LONG-LIVED PLASMA CELL DEPLETION Multiple Sclerosis Rheumatoid Arthritis Systemic Sclerosis Membranous Nephropathy Idiopathic Thrombocytopenia Purpura Sjögren’s Disease ANCA+ Vasculitis Pemphigus Vulgaris Autoimmune Hemolytic Anemia Idiopathic Inflammatory Myopathies Systemic Lupus Erythematous Myasthenia Gravis NMOSD Growing global prevalence of autoimmune diseases underscores need for treatments that deliver durable remissions Thyroid Eye Disease Graves Disease

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© CULLINAN THERAPEUTICS, INC. ALL RIGHTS RESERVED. Plasma cell depletion may be important for disease modification of autoimmune diseases driven by long-lived plasma cells BCMA B cell dysfunction is central to the pathogenesis of many autoimmune diseases, and broadly and deeply depleting these cells by targeting CD19 appears necessary to affect an immune system reset Autoantibodies central to the pathogenesis of other autoimmune diseases are predominantly produced by plasma cells, particularly long-lived plasma cells, so depleting these cells by targeting BCMA could potentially improve outcomes1,2,3 Stem cell Pro-B cell Pre-B cell Immature B cell Naïve B cell Memory B cell Plasmablast Short-lived plasma cell Long-lived plasma cell 1 Dong N., Zhang H., Song J., et al. B-cell maturation antigen expression and clinical features of plasmablastic lymphoma. EJHaem. 2024 Jan 18;5(1):285-289. doi: 10.1002/jha2.807. PMID: 38406544; PMCID: PMC10887266 2 Pillarisetti K., Powers G., Luistro L., et al. Teclistamab is an active T cell-redirecting bispecific antibody against B-cell maturation antigen for multiple myeloma. Blood Adv. 2020 Sep 22;4(18):4538-4549. doi: 10.1182/bloodadvances.2020002393. PMID: 32956453; PMCID: PMC7509877 3 Tian D.S., Qin C., Dong M.H., et al. cell lineage reconstitution underlies CAR-T cell therapeutic efficacy in patients with refractory myasthenia gravis. EMBO Mol Med. 2024 Apr;16(4):966-987. doi: 10.1038/s44321-024-00043-z. Epub 2024 Feb 26. PMID: 38409527; PMCID: PMC11018773 CD19

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Established MOA and validated target: clinical data for teclistamab, a BCMAxCD3 bispecific T cell engager, in autoimmune diseases SLE = Systemic Lupus Erythematosus; RA = Rheumatoid Arthritis; SjD = Sjögren’s Disease; IIM = Idiopathic Inflammatory Myositis; SSc = Systemic Sclerosis Hagen M et al. NEJM. 2024. BCMA X CD3 TCE IN RA, SjD, IIM, SSc Clinical effect, profound decrease in autoantibodies and IgG levels in four patients with autoimmune diseases that were multi-drug resistant (n=4) In patients who failed conventional therapies, teclistamab improved disease activity Short-term treatment resulted in rapid onset of clinical effect Results demonstrate the promise of targeting the plasma cell compartment in autoimmune patients with a BCMA TCE BCMA X CD3 TCE IN SLE Plasma cell depletion and drug free remission in severe, refractory SLE (n=1) Alexander T et al. NEJM. 2024.

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VELINOTAMIG BISPECIFIC BCMAXCD3 T CELL ENGAGER VELINOTAMIG A HIGHLY SELECTIVE, DIFFERENTIATED MOLECULE Binds to the BCMA and CD3 antigens, redirecting cytotoxic T cells to target BCMA-expressing cells High affinity for BCMA and lower affinity for CD3: affinity for BCMA is two orders of magnitude higher than for CD3, promoting recruitment and activation of T cells while minimizing non-specific T cell activation A rigid hinge region enhances synapse formation between T cells and target cells to eliminates BCMA+ plasma cells Similar structure as classic monoclonal antibody and possible lower immunogenicity by using common light chain; subcutaneous administration (in development) is feasible Velinotamig: a BCMAxCD3 bispecific T cell engager with clinical evidence of robust plasma cell depletion common light chain anti-BCMA anti-CD3 rigid hinge region knob into hole

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Velinotamig current clinical development status in China GR1803-001: A (follow-up) completed Phase 1 study in patients with relapsed/refractory multiple myeloma GR1803-002: A Phase 2 pivotal study in patients with relapsed/refractory multiple myeloma GR1803-003: A Phase 2 pivotal study in patients with relapsed/refractory multiple myeloma with extramedullary lesions Velinotamig received Breakthrough Therapy Designation by the Center for Drug Evaluation (CDE) for the treatment of relapsed/refractory multiple myeloma. PLANNED CLINICAL TRIAL IN AUTOIMMUNE DISEASES Genrix Bio plans to conduct a Phase 1 study in China in patients with autoimmune diseases beginning later this year. Cullinan expects the data generated to accelerate the global clinical development of velinotamig in autoimmune diseases. Following the completion of the Genrix Bio Phase 1 study, Cullinan will conduct all further development of velinotamig in autoimmune diseases COMPLETED/ ONGOING CLINICAL TRIALS IN MULTIPLE MYELOMA

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Agreement builds upon accumulated data, leveraging Genrix Bio’s established expertise and KOL network to accelerate clinical development Genrix Bio has an existing network of leading autoimmune clinical investigators in China, allowing for rapid study start-up and patient accrual for the planned Phase 1 study in autoimmune diseases* Genrix Bio is an established clinical innovator in autoimmune diseases, with one approved product (xeligekimab, an anti-IL17 mAb) and several late-stage autoimmune disease trials currently ongoing Genrix Bio has established expertise in immune modulation, with a robust portfolio of late-stage assets across autoimmune diseases and oncology This licensing agreement expands Cullinan’s ability to bring high-impact therapies to more people with autoimmune diseases, leveraging expertise in immune modulation and TCEs to accelerate the advancement of paradigm shifting molecules *Following the completion of the Genrix Bio Phase 1 study, Cullinan will conduct all further development of velinotamig in autoimmune diseases.

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Velinotamig has demonstrated meaningful efficacy in late-line patients with relapsed/refractory multiple myeloma: Phase 1 results at RP2D target dose Approved moleculesb (in U.S. and or EU) Velinotamiga (n=48) Elranatamab1,2 (n=97) Teclistamab3,4,5 (n=110) Linvoseltamab6 (n=117) ORR (sCR + CR + VGPR + PR) 85.4% 57.7% 61.8% 70.9% ≥VGPR (sCR + CR + VGPR) 66.7% 51.5% 57.3% 63.2% CR (sCR + CR) 33.3% 25.8% 28.2% 49.6% MRD-neg rate (in all patients) 39.6% n/a 26.7% n/a Proportion of EMD patients in study 50.0% 34.0% 25.5% 16.2% ORR in EMD 79.2% 36.4% 35.7% 52.6% Higher ORR rate observed relative to approved BCMA TCEs Higher ORR in patients with extramedullary disease (EMD), a particularly poor prognosis subset of MM patients Similar CR and ≥VGPR rate versus the majority of approved BCMA TCEs, despite a larger proportion of EMD patients https://labeling.pfizer.com/ShowLabeling.aspx?id=19669#ID_b883b50f-6abb-40b6-ab24-68b9b6e74ac3 Lesokhin AM, Tomasson MH, Arnulf B, et al. Elranatamab in relapsed or refractory multiple myeloma: phase 2 MagnetisMM-3 trial results. Nat Med. 2023;29:2259-2267. doi:10.1038/s41591-023-02528-9 https://www.janssenlabels.com/package-insert/product-monograph/prescribing-information/TECVAYLI-pi.pdf https://www.jnjmedicalconnect.com/products/tecvayli/medical-content/tecvayli-use-in-patients-with-extramedullary-disease Moreau P, Garfall A, van de Donk C, et al. Teclistamab in relapsed or refractory multiple myeloma. N Engl J Med. 2022;387:495-505 Naresh Bumma et al. Linvoseltamab for Treatment of Relapsed/Refractory Multiple Myeloma. JCO 42, 2702-2712(2024). DOI:10.1200/JCO.24.01008 Data from trial: Phase 1 clinical study of the safety, pharmacokinetics, immunogenicity and preliminary efficacy of single and multiple administrations of GR1803 (velinotamig) in patients with relapsed/refractory multiple myeloma. Velinotamig data as of July 31, 2024 cutoff date; includes patients who have received the target dose of 180 ug/kg, which was explored with (n=25) and without a step-up priming regimen (n=23). The recommended Phase 2 dose (RP2D) for further development includes a step-up priming regimen. Data provided for context only; direct comparisons between molecules can not be made in the absence of head-to-head clinical trials.

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Overview of velinotamig safety data at RP2D target dose Any grade ≥Grade3 Velinotamig (n=48)* Cytokine release syndrome 89.6% 6.3% Infection 81.3% 50.0% ICANS 0% 0% Neutrophil count decreased 89.6% 64.6% Platelet count decreased 79.2% 39.6% White blood cell count decreased 89.6% 35.4% Lymphocyte count decreased 62.5% 60.4% Opportunities to further mitigate CRS are being implemented: Alternative step-up dosing regimen Introduction of subcutaneous formulation No ICANS of any grade at the RP2D Augmented supportive care measures to reduce the risk of infection will be implemented in autoimmune studies *Data from trial: Phase 1 clinical study of the safety, pharmacokinetics, immunogenicity and preliminary efficacy of single and multiple administrations of GR1803 (velinotamig) in patients with relapsed/refractory multiple myeloma. Velinotamig data as of July 31, 2024 cutoff date; includes patients who have received the target dose of 180 ug/kg, which was explored with (n=25) and without a step-up priming regimen (n=23). The recommended Phase 2 dose (RP2D) for further development includes a step-up priming regimen.

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Enthusiasm for CLN-978 from global network of investigators, leading KOLs and patient advocacy groups provides momentum for velinotamig development VELINOTAMIG AUTOIMMUNE DISEASES Plans to initiate a Phase 1 trial Aim: Evaluate the safety, PK, PD, and potential effectiveness of velinotamig CLN-978 RHEUMATOID ARTHRITIS (RA) Phase 1 trial Aim: Evaluate the safety, PK, PD, and potential effectiveness of CLN-978 CLN-978 Phase 1 trial Aim: Evaluate the safety, PK, PD, and potential effectiveness of CLN-978 SJÖGREN’S DISEASE (SjD) CLN-978 Phase 1 trial Aim: Evaluate the safety, PK, PD, and potential effectiveness of CLN-978 SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) Expansion into autoimmune diseases HREC approval to start SLE trial in Australia  EMA approval to initiate RA trial  Expansion into SjD  Cullinan licenses velinotamig from Genrix Bio SLE US IND filing April 2024 September October April 2025 June © CULLINAN THERAPEUTICS, INC. ALL RIGHTS RESERVED. SLE US IND clearance And with pioneering researchers… In collaboration with patient advocacy groups…

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Deal provides favorable upfront economics for Cullinan for an asset with meaningful efficacy and safety data and best-in-class potential Coupled with refining our oncology pipeline, Cullinan can reiterate existing guidance to have cash resources into 2028​ based on current operating plan Upfront license fee: Cullinan will pay Genrix Bio $20 million for exclusive rights to develop and commercialize velinotamig in all disease areas globally outside of Greater China* Future milestone payments: Genrix Bio will be eligible to receive future payments up to: $292 million associated with development and regulatory milestones $400 million associated with sales-based milestones Royalties: Genrix Bio will be eligible to receive tiered royalties from mid-single digits up to the mid-teens on potential ex-Greater China* commercial sales *Greater China, including the Hong Kong Special Administrative Region, Macao Special Administrative Region and Taiwan

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Next steps: Focused on rapid initiation of global regulatory and clinical development plans Execute parallel development for CLN-978 and velinotimag across both B-cell and plasma cell mediated autoimmune diseases Genrix Bio initiates Phase 1 study, characterizing the safety and tolerability profile of velinotimag in autoimmune diseases* Activate existing autoimmune investigator and KOL network for clinical development Prepare for global regulatory interactions *Following the completion of the Genrix Bio Phase 1 study, Cullinan will conduct all further development of velinotamig in autoimmune diseases.

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Velinotamig agreement illustrates strategy of aligning the right target with the best modality while utilizing our core expertise in T cell engagers Leveraging our extensive investigator and KOL network, we will continue to be a leader in developing and advancing T cell engagers in the clinic in autoimmune diseases TCEs represent the next wave of innovation in autoimmune diseases Velinotamig has demonstrated meaningful efficacy in patients with r/r multiple myeloma, including depletion of plasma cells in the tissues of patients with extramedullary disease, a poor prognosis population Velinotamig has best-in-class potential Genrix Bio plans to expeditiously initiate a Phase 1 study in China in patients with autoimmune diseases* later this year allowing us the opportunity to accelerate our global clinical development plans for velinotamig Rapid initiation of global regulatory and clinical development plans Adding velinotamig, a BCMAxCD3 bispecific T cell engager, to our pipeline will complement CLN-978 and creates the opportunity for us to address the needs of patients across a broader range of autoimmune diseases Pursuing comprehensive B cell and plasma cell depletion We are strengthening our portfolio of high-opportunity and high-impact autoimmune programs, while creating additional near-term and long-term value-driving catalysts and maintaining cash runway into 2028 *Following the completion of the Genrix Bio Phase 1 study, Cullinan will conduct all further development of velinotamig in autoimmune diseases.

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CULLINAN THERAPEUTICS Q&A Nadim Ahmed Chief Executive Officer Jeff Jones, MD, MBA Chief Medical Officer Mary Kay Fenton Chief Financial Officer © CULLINAN THERAPEUTICS, INC. ALL RIGHTS RESERVED.