Monday, Jul 20, 1998

U.S. Stroke Study Halted Due to Lack of Clinical Benefit Observed in Patients Treated After Three Hours

South San Francisco, Calif. -- July 20, 1998 --

Genentech announced today that the Data Safety Monitoring Board (DSMB) of its U.S. trial ATLANTIS (Alteplase ThromboLysis for Acute Noninterventional Therapy in Ischemic Stroke), recommended termination of the study. ATLANTIS, sponsored by Genentech, is a placebo-controlled, double-blinded pivotal study observing Activase® (Alteplase, recombinant) in acute ischemic stroke patients three to five hours from symptom onset.

"The decision was based upon an interim analysis of the trial which revealed an extremely small statistical chance to demonstrate a net clinical benefit by fully enrolling the trial with an additional 500 patients as originally planned," said J. Donald Easton M.D., chairman of the DSMB and professor of neurology at Brown University.

The DSMB, consisting of a group of independent medical and statistical experts, is primarily responsible for monitoring accrued safety and efficacy data for ATLANTIS as well as all available data. At the time of interim analysis, it's the responsibility of the DSMB to recommend that the trial either stop or continue.

"As a result of the DSMB's recommendation, Genentech will not file for a label extension for Activase in acute ischemic stroke beyond the currently approved three hour window," said Susan Hellmann, M.D., M.P.H., Genentech's senior vice president of Development and chief medical officer. "Activase continues to be a safe and effective therapy when given to eligible patients within three hours of symptom onset -- emphasizing the importance of treating patients early in addition to educating the public about recognizing the symptoms of stroke and seeking prompt medical attention."

Genentech continues to work with organizations such as the American Heart Association and National Stroke Association to educate people about the signs and symptoms of stroke and the importance of getting to the emergency room quickly.

Activase -- a tissue plasminogen activator (t-PA) -- is the only FDA-approved treatment in the U.S. for acute ischemic stroke or brain attack. It currently is indicated for use in eligible adult patients within three hours of symptom onset, and only after a CT scan rules out a hemorrhagic stroke or bleeding in the brain. Since Activase was approved for acute ischemic stroke in 1996, more than 10,000 patients have been treated in the U.S.

The pivotal U.S. NINDS study of Activase for stroke, published in December 1995, found that out of every 100 patients treated within three hours of symptom onset as compared to placebo, at least 11 more patients demonstrated a favorable outcome at three months, with minimal or no disability. The most common serious side effect from therapy was symptomatic intracranial hemorrhage, which occurred in 6.4 percent of treated patient versus 0.6 percent of patients in the placebo group.

New estimates predict that in the U.S. alone, stroke will occur in as many as 700,000 people each year, causing moderate to severe disability in up to 40 percent of its victims. About 80 percent of all strokes are ischemic -- caused by blood clots which result in insufficient blood circulation to a portion of the brain. Stroke is the leading cause of disability among U.S. adults, robbing many of memory, mobility and speech. Symptoms of stroke include weakness or numbness on one side of the face or body, difficulty speaking or understanding speech, sudden vision loss or blurred vision or sudden, severe headache.

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, six of which Genentech markets or promotes directly in the United States.

The company has headquarters in South San Francisco, California, and is traded on the New York and Pacific Stock Exchanges under the symbol GNE.

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