Tuesday, Mar 17, 1998

Genentech Files Patent Infringement Suit Against Centocor's Thrombolytic Agent

South San Francisco, Calif. -- March 17, 1998 --

Genentech, Inc. (NYSE: GNE) today announced the filing of a suit for patent infringement and a declaratory judgment of patent infringement in the U.S. District Court for the Northern District of California against Centocor, Inc. of Malvern, Pennsylvania. In the suit, Genentech is seeking a permanent injunction and damages.

The suit alleges that Centocor's sale, offer for sale, use and importation of Retavase™ (Reteplase, recombinant) tissue plasminogen activator (t-PA) product in the United States infringes two newly issued Genentech patents -- U.S. Patent No. 5,728,565 and U.S. Patent No. 5,728,566, both of which relate to variant forms of t-PA. Genentech manufactures and markets Activase® (Alteplase, recombinant) t-PA product.

Genentech, which pioneered t-PA research in the 1980s, has carefully evaluated the patent situation and firmly believes that Centocor infringes these patents. "The two new patents strengthen our existing patent situation with respect to t-PA products like Retavase," said Stephen Juelsgaard, Genentech vice president and general counsel.

Centocor announced last week that it had completed its previously announced acquisition of the U.S. and Canadian product rights for Retavase from Roche Healthcare Limited, an affiliate of Roche Holding, Ltd. Roche acquired those rights as part of its recently completed purchase of Corange Ltd. (parent company of Boehringer Mannheim, the manufacturer of Retavase).

Separately, Genentech will continue its patent infringement litigations against Boehringer Mannheim relating to Retavase that are ongoing in the U.S. District Court in Boston and in Germany.

Genentech, Inc. is a leading biotechnology company that discovers, develops, manufactures and markets human pharmaceuticals for significant unmet medical needs. Eleven of the currently marketed biotechnology products stem from Genentech science. Genentech markets or promotes eight biotechnology products in the United States. The company has headquarters in South San Francisco, California and is traded on the New York Stock Exchange and Pacific Exchange under the symbol GNE.

# # #