ImmunoGen, Inc. Announces Conference Call to Discuss its First Quarter Fiscal Year 2010 Financial Results

ImmunoGen, Inc. (Nasdaq:IMGN), a biotechnology company that develops targeted anticancer products, today announced that will host a conference call at 4:30 pm ET on Thursday, October 29, 2009 to discuss the Company’s financial results for the three-month period ended September 30, 2009 – the first quarter of ImmunoGen’s 2010 fiscal year. Management also will provide an update on the Company.

To access the live call by phone, dial 913-312-6698. Passcode is 6451192. The call also may be accessed through the Investor Information section of the Company’s website, www.immunogen.com. Following the live webcast, a replay of the call will be available at the same location through November 5, 2009.

About ImmunoGen, Inc.

ImmunoGen, Inc. develops targeted anticancer therapeutics using its expertise in cancer biology, monoclonal antibodies and the creation and attachment of potent cell-killing agents. The Company’s Targeted Antibody Payload (TAP) technology uses antibodies to deliver one of ImmunoGen’s proprietary cell-killing agents specifically to cancer targets. In addition to the Company’s product pipeline, compounds utilizing the TAP technology are in clinical testing through ImmunoGen’s collaborations with Genentech (a wholly-owned member of the Roche Group), sanofi-aventis, Biogen Idec and Biotest. The most advanced compound, trastuzumab-DM1 (T-DM1), is in Phase III testing being conducted by Genentech and Roche. Other ImmunoGen collaborative partners include Bayer HealthCare and Amgen. More information about ImmunoGen can be found at www.immunogen.com.