News

CAMBRIDGE, Mass., Jan. 23 /PRNewswire-FirstCall/ -- ImmunoGen, Inc. (Nasdaq: IMGN) today announced that the U.S. Patent and Trademark Office has issued to the Company a patent covering novel taxane compounds and their use as effector molecules in ImmunoGen's Tumor-Activated Prodrug (TAP) technology. The taxane family, which includes Taxol^® and Taxotere^®, is a key category of chemotherapeutic agents used in the treatment of several different types of cancer, including breast, ovarian and lung cancer.

The Company's TAP technology is designed to deliver a highly potent cytotoxic agent (the effector molecule) to cancer cells with minimal harm to healthy tissue. Each TAP product is composed of effector molecules bound to a selective, cancer-targeting monoclonal antibody. Once the antibody has bound to the cancer cell, the TAP is internalized into the cell, the effector molecules are released and the cancer cell is killed.

The issued patent, U.S. Patent 6,340,701, covers the composition of matter of specific linkable taxane compounds. It also covers new cancer-killing products composed of these taxanes linked to cell-binding agents such as monoclonal antibodies.

"Taxane chemotherapeutics have had significant commercial success. These agents work by a mechanism of action that is effective in the treatment of several types of cancer that do not respond well to other classes of chemotherapeutics," said Mitchel Sayare, Ph.D., Chairman and CEO of ImmunoGen, Inc. "The claims in this patent provide us protection on use of this technology in our future products for these types of cancer. They also offer protection to partners who license this technology for use in their own taxane-based TAP products."

Data reported at the 2001 AACR-NCI-EORTC cancer research conference in October showed that ImmunoGen's taxane-based TAP technology provides exceptional anti-tumor activity. In a well-accepted animal model for evaluation of anti-cancer agents -- mice with xenograft implants of human A-431 cell line tumors -- the taxane-based TAP conjugate provided efficacy superior to that of the established standard, naked anti-EGF receptor antibody used in combination with doxorubicin. While the maximum tolerated dose of this standard therapy only delayed tumor progression, the taxane-based TAP conjugate achieved tumor regressions at doses well below its maximum tolerated dose.

Walter Blattler, Ph.D., Executive Vice President, Science and Technology, ImmunoGen, Inc., stated, "ImmunoGen now has key intellectual property protection in three major categories of chemotherapeutics -- the maytansinoid derivative DM1, the CC-1065 analog DC1 and now taxane derivatives. Having such an array of agents, each with a different mechanism of action, enables TAP products to be developed for many different types of cancers with the most appropriate effector molecule selected for each cancer target."

About ImmunoGen, Inc.

ImmunoGen, Inc. develops innovative biopharmaceuticals, primarily for cancer treatment. The Company's TAP technology couples highly potent cytotoxic agents with tumor-targeting antibodies to create effective new treatments for cancer with minimal damage to normal tissue. The Company has partnerships with GlaxoSmithKline, Genentech, British Biotech, Abgenix, Millennium, Boehringer Ingelheim, MorphoSys, Avalon Pharmaceuticals and Raven Biotechnologies. Two TAP products are currently in clinical trials, with additional products expected to start trials in 2002.

This press release includes forward-looking statements based on management's current expectations. Factors that could cause future results to differ materially from such expectations include, but are not limited to: the success of the Company's research strategy; the applicability of the discoveries made therein; the difficulties inherent in the development of pharmaceuticals, including uncertainties as to the timing and results of preclinical studies; delayed achievements of milestones; reliance on collaborators; uncertainty as to whether the Company's potential products will succeed in entering human clinical trials and uncertainty as to the results of such trials; uncertainty as to whether adequate reimbursement for these products will exist from the government, private healthcare insurers and third-party payors; and the uncertainties as to the extent of future government regulation of the pharmaceutical business.

Taxol^® is a registered trademark of Bristol-Myers Squibb Company. Taxotere^® is a registered trademark of Aventis.

Contacts:

ImmunoGen, Inc.

Investors
Carol Hausner
Senior Director, Investor Relations and Corporate Communications
Tel: (617) 995-2500
info@immunogen.com

Media
Pete Holmberg
Rx Communications Group, LLC
Tel: (917) 501-7434
pholmberg@rxir.com

SOURCE ImmunoGen, Inc.