Mersana Therapeutics Announces Research Collaboration and Commercial License Agreement with Merck KGaA, Darmstadt, Germany to Develop Novel Immunosynthen Antibody-Drug Conjugates
December 22, 2022 – Drug Discovery –
CAMBRIDGE, Mass., Dec. 22, 2022 (GLOBE NEWSWIRE) — Mersana Therapeutics, Inc. (NASDAQ: MRSN), a clinical-stage biopharmaceutical company focused on discovering and developing a pipeline of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, today announced a research collaboration and commercial license agreement with a subsidiary of Merck KGaA, Darmstadt, Germany to discover novel Immunosynthen ADCs directed against up to two targets. Immunosynthen, Mersanaís proprietary STING-agonist ADC platform, is designed to generate systemically administered ADCs that locally activate STING signaling in both tumor-resident immune cells and in antigen-expressing tumor cells, unlocking the anti-tumor potential of innate immune stimulation.
‘Building on our deep expertise in the ADC space, we are focused on the discovery of next-generation state-of-the-art ADC drugs,’ said Paul Lyne, Head of Research Unit, Oncology, Merck KGaA, Darmstadt, Germany. ‘An approach that can directly target the tumor microenvironment with an immunomodulatory ADC has the potential to bring the benefits of this immunotherapy to a broader group of patients. This collaboration with Mersana to design novel immunostimulatory ADCs that can harness the potential of the STING pathway is an ideal complement to our innovation in this area.’
The STING pathway is a fundamental means of generating innate immune responses that can lead to anti-tumor activity and immunological memory. Mersana has generated preclinical data demonstrating Immunosynthenís ability to enable highly targeted STING activation within both tumor cells and tumor-resident myeloid cells while avoiding unwanted systemic effects.
‘We are pleased to be partnering with Merck KGaA, Darmstadt, Germany in a collaboration designed to extend the reach of our Immunosynthen platform and bring novel new product candidates forward with the potential to benefit patients,’ said Anna Protopapas, President and Chief Executive Officer of Mersana Therapeutics. ‘With three significant new collaborations signed in 2022 alone, we are demonstrating Mersanaís increasing role as a partner of choice within the ADC field.’
Under the terms of the agreement, Mersana will develop novel ADC product candidates against up to two targets utilizing its Immunosynthen platform to conjugate proprietary antibodies from Merck KGaA, Darmstadt, Germany. Mersana will be responsible for certain discovery activities, as well as limited preclinical manufacturing and supply obligations, which will be reimbursed by Merck KGaA, Darmstadt, Germany. Merck KGaA, Darmstadt, Germany will be solely responsible for in vitro and in vivo characterization, other preclinical work, and all clinical development and potential commercialization activities relating to any resulting product candidates.
Mersana will receive an upfront payment of $30 million. Mersana is also eligible to receive reimbursement of certain costs, up to $800 million in potential regulatory, development and commercial milestone payments, and tiered royalties up to the low double-digit percentages on worldwide net sales of any approved ADCs developed under the agreement.
About Mersana Therapeutics
Mersana Therapeutics is a clinical-stage biopharmaceutical company using its differentiated and proprietary ADC platforms to rapidly develop novel ADCs with optimal efficacy, safety and tolerability to meaningfully improve the lives of people fighting cancer. Mersanaís lead product candidate, upifitamab rilsodotin (UpRi), is a Dolaflexin ADC targeting NaPi2b that is being studied in UPLIFT, a single-arm registrational trial in patients with platinum-resistant ovarian cancer; UPGRADE-A, a Phase 1/2 clinical trial evaluating UpRi in combination with carboplatin; and UP-NEXT, a Phase 3 clinical trial of UpRi as monotherapy maintenance following treatment with platinum doublets in recurrent platinum-sensitive ovarian cancer. Mersana is also advancing XMT-1660, a Dolasynthen ADC targeting B7-H4, and XMT-2056, an Immunosynthen ADC targeting a novel epitope of human epidermal growth factor receptor 2 (HER2), in addition to other earlier-stage assets. In addition, multiple partners are using Mersanaís platforms to advance their ADC pipelines. Mersana routinely posts information that may be useful to investors on the ‘Investors & Media’ section of its website at www.mersana.com.

