Mersana Therapeutics, Inc.

The company is a clinical-stage biopharmaceutical company focused on developing antibody-drug conjugates (ADCs) for cancer patients. It utilizes two proprietary ADC platforms: Dolasynthen and Immunosynthen. Dolasynthen is a cytotoxic ADC platform designed to create site-specific, homogeneous ADCs with optimized drug-to-antibody ratios (DARs) and a proprietary auristatin payload that has clinically avoided severe neutropenia, peripheral neuropathy, and ocular toxicity. Immunosynthen is a STING (stimulator of interferon genes)-agonist platform designed for systemically administered ADCs that locally activate STING signaling in tumor cells and immune cells. The company has two clinical-stage product candidates. Emiltatug ledadotin (XMT-1660), or Emi-Le, is a B7-H4-targeting Dolasynthen ADC with a DAR of 6, currently in a Phase 1 clinical trial for patients with breast, endometrial, and ovarian cancers, as well as adenoid cystic carcinoma type 1 (ACC-1). XMT-2056 is a systemically-administered Immunosynthen ADC targeting a novel human epidermal growth factor receptor 2 (HER2) epitope with a DAR of 8, in a Phase 1 clinical trial for patients with HER2-expressing advanced or recurrent solid tumors, including breast, gastric, colorectal, and non-small cell lung cancers. The company also has strategic collaborations with Janssen Biotech, Inc. (Johnson & Johnson) and Ares Trading S.A. (an affiliate of Merck KGaA, Darmstadt, Germany) for the discovery, development, and commercialization of additional ADC product candidates using its Dolasynthen and Immunosynthen platforms, respectively. It has also granted GlaxoSmithKline Intellectual Property.