ImmunoGen, Inc. Announces Start of SAR566658 Clinical Testing

ImmunoGen, Inc. Announces Start of SAR566658 Clinical Testing
-- Company Remains on Track for Achieving 12 Novel Anticancer Agents in Clinic by End of 2011 through ImmunoGen and Partner Programs --

WALTHAM, Mass., Sep 21, 2010 (BUSINESS WIRE) -- ImmunoGen, Inc. /quotes/comstock/15*!imgn/quotes/nls/imgn (IMGN 5.54, +0.03, +0.54%) , a biotechnology company that develops targeted antibody-based anticancer products, today announced the start of clinical testing with SAR566658. Eight compounds are now in the clinic through ImmunoGen's product programs and those of its partners, consistent with Company expectations of as many as 12 such compounds being in the clinic by late 2011 and marked, sustained pipeline growth thereafter.

SAR566658 is a potential treatment for many ovarian, breast, cervical, lung and pancreatic cancers. It was developed under a research collaboration between the Company and sanofi-aventis. SAR566658 utilizes ImmunoGen's Targeted Antibody Payload (TAP) technology with the CA6-binding antibody, huDS6, created by East Carolina University and humanized with ImmunoGen's proprietary resurfacing technology. Sanofi-aventis has begun clinical evaluation of SAR566658, triggering a $1 million milestone payment to ImmunoGen.

"The development and advancement of this highly promising compound reflects the vision and successful collaboration of multiple parties," commented John Lambert, PhD, Executive Vice President and Chief Scientific Officer of ImmunoGen.

About the Research Collaboration between ImmunoGen and sanofi-aventis

In 2003, ImmunoGen and sanofi-aventis (then Aventis) entered into a five-year research collaboration to develop novel antibody-based anticancer drugs using ImmunoGen's antibody expertise. These included both therapeutic antibody compounds and TAP compounds, in which the antibody is conjugated to one of ImmunoGen's proprietary highly potent cancer-cell killing agents. Two TAP compounds, SAR3419 and SAR566658, and one therapeutic antibody compound, SAR650984, are now in clinical testing through this collaboration. For each compound developed in the collaboration, ImmunoGen is entitled to receive milestone payments plus royalties on the sales of any resulting product; ImmunoGen also has certain co-promotion rights. Sanofi-aventis is responsible for product development, clinical testing, manufacturing and marketing.

About ImmunoGen's Proprietary Technology

ImmunoGen has comprehensive capabilities to develop highly effective, well-tolerated antibody-based anticancer compounds. In addition to the Company's established antibody-development capabilities, ImmunoGen's proprietary resurfacing technology has been used to humanize numerous antibodies that have advanced into clinical testing.

The Company's TAP technology uses tumor-targeting antibodies to deliver one of ImmunoGen's highly potent cancer-cell killing agents (e.g., DM1, DM4) specifically to tumors. The Company's proprietary cancer-cell killing agents are many-fold more potent than standard chemotherapeutics and were developed by ImmunoGen scientists specifically for targeted delivery to tumors. ImmunoGen also has engineered linkage technology that keeps the cancer-cell killing agent attached to the antibody until it reaches the cancer cell and then controls the release of the agent inside the cell.

Seven TAP compounds are now in clinical testing: trastuzumab-DM1 (T-DM1), in global development by Roche; IMGN901 and IMGN388, in development by ImmunoGen; SAR3419 and SAR566658, in development by sanofi-aventis; and BIIB015 and BT-062, in development by Biogen Idec and Biotest, respectively. The Company expects 3 - 4 additional TAP compounds to enter clinical testing by the end of 2011. The therapeutic antibody compound, SAR650984, entered clinical testing earlier this year.

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 TAP technology uses antibodies to deliver one of ImmunoGen's proprietary cancer-cell killing agents specifically to tumor targets. In addition to the Company's product pipeline, compounds are in clinical testing through ImmunoGen's collaborations with Genentech (a member of the Roche Group), sanofi-aventis, Biogen Idec and Biotest. The most advanced TAP compound, T-DM1, is in Phase III testing. Other ImmunoGen collaborative partners include Bayer Schering HealthCare and Amgen. More information about ImmunoGen can be found at