ImmunoGen, Inc. Announces Presentations at the 22nd EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics

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 that several ImmunoGen poster presentations will be made at the 22nd EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics to be held in Berlin, Germany, November 16-19, 2010.

“Our presentations at this Symposium reflect our expanding product pipeline and technology portfolio,” commented John Lambert, Ph.D., Executive Vice President and Chief Scientific Officer. “We’ll be reporting additional clinical data for our IMGN388 compound as well as preclinical data generated in our development of IMGN853, a TAP compound that targets Folate Receptor 1. We’ll also be presenting data on one of our linkers that enhances the effectiveness of TAP compounds against cancers with multi-drug resistance.”

On Nov. 17 from 12-2:20 pm CET/6:00-8:20 am ET:

• “Antibody-maytansinoid conjugates targeting Folate Receptor 1 for cancer therapy” (Abstract #236, Poster board #193).
• “Negatively-charged sulfonate group in linker improves potency of antibody-maytansinoid conjugates against multidrug-resistant cancer cells” (Abstract #235, Poster board #192).

On Nov. 19 from 8-9:30 am CET/2:00-3:30 am ET:

• “A Phase I Study of IMGN388, an antibody drug conjugate targeting av Integrin, in patients with solid tumors” (Abstract #472, Poster board #008).

Data on TAP compounds in development by ImmunoGen partners also will be presented at this conference.

About the Topics of the Presentations

ImmunoGen develops targeted anticancer compounds using its TAP technology and also conducts research to continue to expand the utility of this technology. A TAP compound consists of a tumor-targeting antibody with one of the Company’s proprietary cancer-cell killing agents attached using an engineered ImmunoGen linker. The antibody serves to target the TAP compound specifically to cancer cells, and the cell-killing agent serves to kill these cells. The linker controls the release and activation of the cell-killing agent inside the cancer cell.

IMGN388 and IMGN853 are TAP compounds in development by ImmunoGen. IMGN388 targets αv integrin and is in Phase I testing for the treatment of solid tumors. IMGN853 targets the Folate Receptor 1 found on ovarian cancer and other epithelial malignancies. It is in preclinical testing. The linker being discussed is an example of the technology created by the Company to enable the development of highly effective TAP compounds for cancers with multi-drug resistance.

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 IMGN388 and IMGN853, that include risks related to uncertainties around preclinical and clinical studies conducted and their 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.