ImmunoGen, develops targeted anticancer therapeutics using its Tumour-Activated Prodrug (TAP) technology, has collaborated with Genentech to create a commercial manufacturing process for Genentech's trastuzumab-DM1 TAP compound. ImmunoGen and Genentech also have agreed to amend their 2000 agreement that grants Genentech exclusive rights to use ImmunoGen's TAP technology with therapeutic antibodies to HER2. This amendment increases the total potential milestone payments to ImmunoGen under this agreement to $44 million and the royalties to ImmunoGen on HER2-targeting TAP compounds developed by Genentech, including trastuzumab-DM1.

"We're delighted that Genentech chose to access our process development expertise in order to gain a commercial-scale manufacturing process for trastuzumab-DM1," commented Mitchel Sayare, chairman and CEO. "We believe that the considerable increase in the milestone payments and royalties that ImmunoGen potentially can earn with Genentech's successful development of HER2-targeting TAP compounds reflects the value of our manufacturing expertise in this area as well as the significance of our technology," he added.

According to the release, under the process development agreement announced today, ImmunoGen and Genentech will develop a production method for Genentech to manufacture trastuzumab-DM1 at amounts up to and including commercial scale, and ImmunoGen will receive research support payments in return. ImmunoGen and Genentech also have amended the 2000 agreement that grants Genentech exclusive rights to use ImmunoGen's maytansinoid TAP technology with therapeutic antibodies to HER2. This amendment increases the potential milestone payments to ImmunoGen under this agreement by $6.5 million and the potential royalties to ImmunoGen on any HER2-targeting TAP compound that may be developed by Genentech.

A TAP compound uses a tumour-targeting antibody to deliver a potent, cell-killing agent specifically to cancer cells. During the manufacturing process, the cell-killing agent is attached to the antibody in a manner that does not significantly impact the binding properties of the antibody.

ImmunoGen's proprietary TAP technology uses tumour-targeting antibodies to deliver a potent cell-killing agent specifically to cancer cells. Four TAP compounds are in clinical testing - huN901-DM1 and huC242-DM4, which are wholly owned by ImmunoGen, and AVE9633 and trastuzumab-DM1, which are in development by the sanofi-aventis Group and Genentech, respectively.