By Lisa Seachrist

Washington Editor

WASHINGTON - Genentech Inc.'s humanized monoclonal antibody designed to disrupt the allergic process and offerrelief to seasonal allergy sufferers posted positive results in a pivotal Phase II/III clinical trial in patients with hay fever.

The South San Francisco-based firm studied 536 hay fever sufferers at the beginning of allergy season and found that treatingthem with rhuMAB-E25, a recombinant humanized monoclonal antibody aimed at immunoglobulin E (IgE), decreased theseverity and occurrence of sneezing, runny and stuffy nose, and watery, itchy eyes.

The randomized, double-blind, placebo-controlled study evaluated three doses of the injectable drug over a 12-week period,beginning two weeks prior to the start of ragweed pollen season, in patients with moderate or severe ragweed allergy.

Preliminary results of the study show a dose-related decrease in nasal and ocular symptoms and severity.

At the highest dose, a 300 mg injection delivered every two to four weeks as needed, the researchers noted a 50 percentdecrease in the number of days a patient required additional "rescue" medicines (antihistamines and decongestants), compared toplacebo. Patients in the 50 mg and 150 mg dosing groups also needed less rescue medication than the placebo group. The onlynotable side effect of the injections was a drug-related rash.

RhuMAB-E25 is designed to combat allergies by binding to IgE, one of five kinds of immunoglobulin that send antibodies toattack antigens causing an allergic reaction, thus preventing the release of inflammatory mediators including histamine,prostaglandins and leukotrienes.

Genentech and collaborators Novartis Pharma AG, of Basel, Switzerland, and Tanox Biosystems Inc., of Houston, are alsotesting the therapy in patients with allergic asthma. A Phase II study in allergic asthma showed positive results last year. PhaseIII study results for both indications are expected in 1999.

"We are looking forward to filing for regulatory approval sometime in the year 2000," said Michelle Truelson, manager ofcorporate communications at Genentech. "We hope to be launching the product in 2001."

The results were presented at a meeting of the American College of Allergy, Asthma and Immunology, in Philadelphia.

Genentech's stock (NYSE:GNE) closed at $71.937, down $1.062.