Experimental allergy shot attaches to antibody

May 17, 1999
Web posted at: 5:57 p.m. EDT (2157 GMT)

(CNN) -- A new experimental allergy shot breaks the chain of reaction that triggers an allergic attack by targeting a key antibody, according to research presented at the 20th Annual Nordic Congress on the Study of Allergy in Olso, Norway.

"It's one of the first new therapies we've had for the treatment of allergies in a long time," said Dr. Thomas Casale, head investigator for the U.S. trial of the shot.

Scientists at Genentech Inc. in San Francisco developed a genetically engineered antibody that attaches itself to IgE, the antibody in the bloodstream that releases histamines when triggered by an allergen such as pollen or mold.

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It is the histamines that set off allergic reactions, including runny noses and watery eyes. The anti-IgE blocks release of the histamine early in the process before symptoms kick in.

The study of 251 adults found those given the shot once a month cut their allergy symptoms by almost half and their need for other allergy medications by two-thirds.

"With this therapy, it really doesn't matter what you are allergic to; by taking care of the IgE in your body and getting rid of it from the circulation, you will effectively treat the symptoms of allergies," said Casale, director of the Nebraska Medical Research Institute.

It is estimated one in five Americans suffers from allergies.

Traditional allergy shot treatment injects the body with substances a patient is allergic to. Antihistamine pills treat symptoms of allergies after histamines have been released.

"In all the studies that have been done to date, there have been very few side effects" with the anti-IgE, Casale said. "It appears to be a relatively safe therapy where patients only have to come in to see a physician every two to four weeks for an injection."

Genentech and Novartis Pharma AG are collaborating on phase III clinical development of the drug. Food and Drug Administration approval could take one to two years, and price has not been determined.