Company Warns of Cancer Drug Deaths

Friday, May 5th 2000, 12:00 am

By: News On 6

SAN FRANCISCO (AP) â€” Pharmaceutical maker Genentech Inc. has warned doctors that the breast cancer drug Herceptin is linked to 15 deaths and 47 other adverse reactions in patients.

In a letter to doctors sent Thursday, the company said the adverse effects included allergic shock and extreme respiratory distress.

``We sent the letter to oncologists to heighten their awareness and educate them about infrequent adverse events that can occur in certain patients,'' Genentech spokesman Neil Cohen said.

An estimated 23,000 patients have been treated with Herceptin.

Severe reactions to Herceptin had not occurred in clinical trials before the drug gained Food and Drug Administration approval in 1998, Cohen said.

But sometimes reactions can't be foreseen in trials, he said.

``A lot of times you might see some safety issues once the drug gets put into a larger patient population,'' Cohen said.

Cohen said he didn't know when the company first heard of the deaths and reactions, but analysis had confirmed the link to Herceptin.

In nine of the 15 deaths, symptoms arose within 24 hours of the time Herceptin was administered, according to the letter.

Genentech is working with the FDA to have the drug's label amended to reflect the new risks, Cohen said.

Herceptin is used to treat breast cancer patients that have too many copies of the HER2 gene. A healthy version of this gene produces a protein that signals cells to grow and multiply normally. But in women with too much HER2, the breast cells reproduce out of control and spread throughout the body. Herceptin, an antibody, blocks excess HER2, shrinking and eliminating tumors.

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On the Net:

Genentech Inc.: http://www.genentech.com

Food and Drug Administration: http://www.fda.gov