ImmunoGen, Inc. Appoints Theresa Wingrove, Ph.D., as Vice President, Regulatory Affairs

ImmunoGen, Inc. (Nasdaq: IMGN), a biotechnology company that develops targeted antibody-based anticancer products using its antibody expertise and Targeted Antibody Payload (TAP) technology, today announced the appointment of Theresa G. Wingrove, Ph.D. as Vice President of Regulatory Affairs. Dr. Wingrove will be responsible for leading the regulatory development of the Company’s product candidates and directing the regulatory submissions prepared by ImmunoGen in support of the Company’s own programs and those of its partners. Dr. Wingrove reports to Daniel Junius, President and Chief Executive Officer.

“Theresa brings to ImmunoGen a wealth of regulatory experience in the development of new healthcare products,” commented Mr. Junius. “Her addition to our team is particularly timely in light of our programs to aggressively advance our lead compound – IMGN901 – and our expectation that we’ll double the number of compounds we have in the clinic by early 2012.”

Dr. Wingrove joins ImmunoGen with over twenty years of regulatory and clinical management experience in the healthcare industry. Before joining ImmunoGen, she was the vice president of regulatory and clinical affairs at Histogenics, where her responsibilities included authoring and gaining approval of a SPA for a Phase III trial for a novel biologic and other regulatory responsibilities in the US and Europe. Prior to that, she was the senior director of regulatory and clinical affairs at MediSpectra, where she was responsible for the full spectrum of regulatory support – from start of clinical testing through marketing approval – for a novel cancer diagnostic product. Prior to joining MediSpectra, Dr. Wingrove was at Pfizer-Infusaid for over ten years, during which time she executed the clinical and regulatory programs associated with the company’s combination products. She holds a BS in Biochemistry from Brown University and a doctorate in Biochemical Toxicology from the University of Rochester.

About ImmunoGen, Inc.

ImmunoGen, Inc. develops targeted anticancer therapeutics using the Company's expertise in tumor biology, monoclonal antibodies and potent cancer-cell killing agents. The Company's TAP technology uses monoclonal antibodies to deliver one of ImmunoGen's proprietary cancer-cell killing agents specifically to tumor cells. There are currently seven TAP compounds in the clinic, with a wealth of clinical data reported with the technology. ImmunoGen’s collaborative partners include Amgen, Bayer Schering Pharma, Biogen Idec, Biotest, Genentech (a member of the Roche Group), Novartis, and sanofi-aventis. The most advanced compound using ImmunoGen's TAP technology, trastuzumab-DM1 (T-DM1), is in Phase III testing through the Company's collaboration with Genentech. More information about ImmunoGen can be found at www.immunogen.com.

This press release includes forward-looking statements. For these statements, ImmunoGen claims the protection of the safe harbor for forward-looking statements provided by the Private Securities Litigation Reform Act of 1995. It should be noted that there are risks and uncertainties related to the development of novel anticancer products, including IMGN901 and ImmunoGen’s current preclinical candidates, including risks related to uncertainties around preclinical studies and clinical trials conducted and their timings and results. A review of these risks can be found in ImmunoGen’s Annual Report on Form 10-K for the fiscal year ended June 30, 2010 and other reports filed with the Securities and Exchange Commission.