ImmunoGen, Inc. is focused on the development of antibody-based anticancer therapeutics. It develops, targeted therapeutics for the treatment of cancer using cancer biology, monoclonal antibodies, highly-potent cytotoxic (cell-killing), agents, and the design of linkers that enable these agents to be stably attached to the antibodies while in the blood stream and released in their fully active form after delivery to a cancer cell. An anticancer compound made using the Company’s Targeted Antibody Payload (TAP), technology consists of a monoclonal antibody that binds specifically to an antigen target found on cancer cells with multiple copies of one of its cell-killing agents attached using one of its linkers. As of June 30, 2009, there were six TAP compounds in clinical trials through its programs and those of several of its collaborators. As of June 30, 2009, collaborators included Amgen, Bayer HealthCare, Biogen Idec, Biotest, Genentech and sanofi-aventis.