Mersana Therapeutics, Inc., a clinical stage biopharmaceutical company, develops antibody drug conjugates (ADC) for cancer patients with unmet needs. The company develops XMT-1660, a B7-H4-targeted Dolasynthen ADC candidate; and XMT-2056, an immunosynthen ADC. It has research and development collaborations with Janssen Biotech, Inc., Ares Trading S.A., Merck KGaA, and Asana BioSciences, LLC for the development of ADC product candidates. The company was formerly known as Nanopharma Corp. and changed its name to Mersana Therapeutics, Inc. in November 2005. Mersana Therapeutics, Inc. was incorporated in 2001 and is headquartered in Cambridge, Massachusetts.