Genetic Engineering Brings Hay Fever Relief

Study finds omalizumab safe, effective

TUESDAY, Dec. 18, 2001 (HealthDayNews) -- A new genetically engineered treatment for allergy worked well against hay fever in a carefully controlled study, researchers report. But its developers say the drug probably will not be on the market until the 2003 season at best.

The drug is omalizumab, a molecule engineered to block the activity of immunoglobulin E (IgE), the immune system antibody that causes the itch, red eyes, runny nose and other symptoms of hay fever and other allergies.

It was tested successfully in a manufacturer-sponsored study of 536 patients who had severe seasonal allergic rhinitis (hay fever), says a report in the Dec. 19 issue of the Journal of the American Medical Association.

The patients, all of whom had long histories of hay fever, got injections every two to four weeks of either 150 milligrams or 300 milligrams during the hay fever season, and their experiences were compared to patients who got dummy injections.

"The patients who got the highest dose as a group did very well," says the leader of the study group, Dr. Thomas B. Casale, director of clinical research at Creighton University in Omaha. "They never got an increase in symptoms when the pollen count went up, and their quality of life was improved."

Side effects were minimal, Casale adds, with swelling and discomfort at the injection site less than that experienced with standard allergy shots.

On the basis of this study, he says, omalizumab seems suitable for "people with mild to moderate symptoms and proven evidence of allergy who have no favorable response to antihistamines, with or without nasal corticosteroids. That would be a fairly large number of people."

The treatment "is effective in that it blocks the action of IgE," says Dr. Marshall Plaut, chief of the allergic mechanisms section at the National Institute of Allergy and Infectious Diseases.

But there still are a number of questions, he says.

"It hasn't been around long, so the short- and long-term safety effects are unknown," Plaut says. "And we don't know what the relative cost would be."

The two companies that developed omalizumab, Genentech in the United States and Novartis in Switzerland, were hoping for Food and Drug Administration approval in time for the 2002 hay fever season. But in July, the FDA requested more information about the safety of the medication.

That information has been submitted, says Shelley Schneiderman, a Genentech spokeswoman, and the hope is that omalizumab will be available in 2003 -- but not for hay fever. Instead, approval is being sought for treatment of asthma, a more serious condition. If that approval is given, approval for hay fever treatment will be sought, she says.

The two companies sponsored the study, and Casale and several co-authors have served as consultants for them.

An estimated 40 million Americans have hay fever, and 17 million are estimated to have asthma. An uncounted number have other allergies.

One major advantage of omalizumab is that by blocking IgE, it can provide relief from any allergy, Casale says.

"It wouldn't matter what you were allergic to," he says. "That differs from traditional allergy shots, where we inject what you are allergic to -- cat, dog or whatever."

"Because it targets IgE, which appears to be the proximate cause of all allergic diseases, it could have a wide-ranging effect," Plaut adds.

What To Do

With the new treatment still on the horizon, people with hay fever and other allergies will have to stick with whatever their doctor says is most effective for them among current treatments.

For information about hay fever, asthma and other allergies, consult the Asthma and Allergy Foundation of America and the National Institute of Allergy and Infectious Diseases.

SOURCES: Interviews with Thomas B. Casale, M.D., director of clinical research, Creighton University, Omaha, Neb.; Marshall Plaut, M.D., chief, allergic mechanisms section, National Institute of Allergy and Infectious Diseases, Bethesda, Md.; Shelley Schneiderman, spokeswoman, Genentech, Inc., South San Francisco, Calif.; Dec. 19, 2001, Journal of the American Medical Association
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