By PAUL ELIAS

The Associated PressWednesday, January 18, 2006; 2:57 PM

SAN FRANCISCO -- Biotechnology company Genentech Inc. has stopped a clinical trial of a promising peanut-allergy treatment because of safety concerns raised during the human experiments, a company spokesman said Tuesday.

Genentech officials stopped the trial of the drug last month after two volunteers had a more severe allergic reaction to peanuts than expected, spokesman Neil Cohen said.

Volunteers were given peanut protein to gauge how severe their allergies were and as a way to measure the effectiveness of the experimental drug, called Xolair.

Cohen said the drug had nothing to do with the severe reactions and the South San Francisco-based Genentech and its two corporate partners intend to continue the peanut-allergy program after consulting with the Food and Drug Administration.

"We remain committed," Cohen said.

Last year, Genentech and Novartis Pharma AG agreed to pay $6.6 million to Tanox Inc. to settle a bitter legal dispute related to Xolair, which has been approved for asthma treatment. All three companies will share Xolair's profits.

Xolair is a genetically engineered protein designed to block the same molecule, which plays a crucial role in setting off both asthma and allergy attacks.

The drug doesn't cure the allergy, but is designed to allow sufferers to avoid reactions caused by accidental contact with peanuts.

Between 50 and 100 people die a year because of these allergies, and thousands more suffer severe reactions such as constricted breathing and dramatic swelling. Allergic toddlers are especially at risk because they can't consciously avoid the surprising number of foods that contain peanut ingredients.

Eds: A previous version of this story erroneously said that the company was stopping development of the drug because of safety concerns. The company is halting only the clinical trial but will continue to develop the experimental drug Xolair.