Genentech, Inc., a leading biotechnology company, and XOMA Ltd. announced that the companies have decided to terminate Phase II testing of Raptiva (efalizumab) in patients with moderate-to-severe rheumatoid arthritis (RA) based on an evaluation that suggested no overall net clinical benefit in patients receiving the study drug. This decision followed an evaluation by an independent Data Safety Monitoring Board (DSMB) that was charged with evaluating the ongoing safety and efficacy data in this exploratory trial that enrolled 240 patients.

Genentech and XOMA have instructed all sites to stop enrollment and treatment of patients in both this study and a roll-over extended treatment study.

As a targeted T-cell modulator, Raptiva is designed to block the activation of T-cells that cause psoriasis, without destroying them. Raptiva has been studied as a once-weekly therapy for the continuous treatment of moderate-to-severe plaque psoriasis. In clinical trials, Raptiva was administered via subcutaneous injection and in several of the trials was self-administered by some patients in their homes.

In December 2002, Genentech and XOMA filed a Biologics License Application (BLA) with the U.S. Food and Drug Administration (FDA) for Raptiva for the treatment of moderate-to-severe plaque psoriasis in patients 18 years or older. The BLA submission included data from over 2,100 patients treated with Raptiva.