Sesen Bio, Inc. is a late-stage clinical company, which engages in the development of targeted fusion protein therapeutics. It offers Vicineum and Proxinium, which target tumor cell surface antigens that allow for rapid internalization into the targeted cancer cell and also have limited expression on normal cells. The company was founded by Reza Dana, K. Christopher Garcia, Gregory L. Verdine, Casey T. Weaver, and K. Dane Wittrup on February 25, 2008 and is headquartered in Cambridge, MA.