Tuesday, Feb 9, 1999

Genentech Issued New t-PA Patent and Files Patent Infringement Suit Against Centocor's Thrombolytic Agent

South San Francisco, Calif. -- February 9, 1999 --

Genentech, Inc. (NYSE: GNE) today announced that it was issued U.S. Patent No. 5,869,314, relating to variant forms of tissue plasminogen activator (t-PA), and that it filed another suit against Centocor, Inc. of Malvern, Pennsylvania for infringement of this new patent.

The newly issued patent is the latest in a series of Genentech patents covering the thrombolytic agent t-PA and its variants. In particular, this new patent claims a particular aspect of Genentech's t-PA research, t-PA deletion variants having characteristics different from another thrombolytic agent, urokinase.

Last year, Genentech brought suit against Centocor in the U.S. District Court for the Northern District of California alleging infringement of two related Genentech patents, U.S. Patent Nos. 5,728,565 and 5,728,566. That suit is still pending. In the earlier lawsuit, Centocor made certain allegations challenging the validity and enforceability of Genentech's patents. Genentech specifically brought those allegations to the attention of the U.S. Patent Office, and notwithstanding those allegations, the U.S. Patent Office decided to issue the new patent.

The suit against Centocor today was filed in the same court as the earlier lawsuit and alleges that Centocor is infringing the new patent by selling, offering for sale, using and importing Retavase™(Reteplase, recombinant) t-PA product in the United States. Retavase is a deletion variant of t-PA that is produced by deleting various amino acids that are present in the naturally occurring form of t-PA.

Genentech, which pioneered t-PA research in the 1980's, manufactures and markets its own t-PA product under the trade name Activase®(Alteplase, recombinant).

Genentech, Inc. is a leading biotechnology company that discovers, develops, manufactures, and markets human pharmaceuticals for significant unmet medical needs. Twelve of the currently marketed biotechnology products stem from Genentech science. Genentech markets seven biotechnology products directly 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.

# # #