ImmunoGen, Inc. Announces Conference Call to Discuss its Third 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, April 29, 2010 to discuss the Company’s financial results for the three-month period ended March 31, 2010 – the third 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 4862730. 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 May 6, 2010.

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 potent cancer-cell killing agents specifically to tumor 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.