Mersana Therapeutics, Inc. is a clinical-stage biopharmaceutical company, which is focused on the development of antibody-drug conjugates (ADCs), which offer a clinically meaningful benefit for cancer patients with significant unmet needs. It has developed two proprietary and differentiated ADC platforms: Dolasynthen and Immunosynthen. Dolasynthen is a cytotoxic ADC platform that is designed to generate site-specific, homogeneous ADCs. Immunosynthen is its proprietary stimulator of interferon genes (STING)-agonist platform that is designed to generate systemically administered ADCs that locally activate STING signaling in both antigen-expressing tumor cells and in tumor-resident immune cells. The Company's pipeline includes Emi-Le (emiltatug ledadotin; 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).