On July 31, 2003, we announced that ImmunoGen and Aventis entered into a collaboration to discover, develop, and commercialize novel antibody-based anticancer products. ImmunoGen and Aventis will collaborate to create these products using targets provided by both companies. Aventis is the seventh largest pharmaceutical company in the world and a global leader in oncology.

Under this agreement, ImmunoGen received an upfront payment of $12 million and is to receive more than $50 million in committed research funding over a three-year period. Aventis can extend the research collaboration for one to two years. Extension of the collaboration could bring the total committed funding to ImmunoGen up to $99 million.

Additionally, for each product within the collaboration, ImmunoGen is to receive milestone payments upon specified development and regulatory achievements. The potential milestone payments – per product – total between $21.5 million and $30 million depending on the product. ImmunoGen is to receive royalties on the sales of each collaboration product commercialized. Aventis is responsible for product development, manufacturing, and commercialization, and will cover all such costs for the life of the product.

The agreement grants Aventis the worldwide commercialization rights to the new product candidates created by the collaboration and to three early-stage product candidates in ImmunoGen’s research pipeline: huMy9-6-DM1, our anti-IGF-IR antibody, and our product candidate for certain B-cell blood cancers including non-Hodgkin’s lymphoma. ImmunoGen has an option to certain co-promotion rights in the United States on a product-by-product basis.

We expect this collaboration with Aventis to yield substantially more products that provide a return to ImmunoGen than we could have achieved on our own. Additionally, it enables us to expand our activities in the development of naked (unconjugated) antibody therapeutics and to enhance our TAP effector molecule program. We plan to continue to use partnerships – including out-licensing our TAP technology – to provide ImmunoGen with additional cash and to broaden our product opportunities.