Asthma drug limits serious reactions to allergy-triggering foods, study says

NEW YORK, Feb. 25 (UPI) -- A drug approved to treat allergic asthma and chronic hives can limit children's dangerous allergic responses to small amounts of allergy-triggering foods, a new study says.

Results of the research, conducted at the Stanford School of Medicine, were published Sunday in The New England Journal of Medicine.

Regular use of the injectable drug, omalizumab, marketed under the brand name Xolair, targets inflammation by binding and inactivating antibodies that cause many kinds of allergic disease.

Researchers say it could protect people from severe allergic reactions, such as difficulty breathing, if they accidentally eat a small quantity of a food that aggravates their allergies.

"Food allergy is a chronic condition driven by allergic antibodies mistakenly identifying food proteins as 'bad actors.' Important early studies had shown that omalizumab held promise for our food allergy patients," the study's senior author, Dr. R. Sharon Chinthrajah, told UPI via email.

"Our colleagues and our patients were desperate for a therapeutic option that could treat many different foods," said Chinthrajah, who is acting director of the Sean N. Parker Center for Allergy and Asthma Research at Stanford University in Palo Alto, Calif.

"Patients with multiple food allergies have an even harder burden of trying to avoid multiple foods," she said.

Based on the new study, the Food and Drug Administration on Feb. 16 approved omalizumab for decreasing risk of allergic reactions to foods in children as young as 1 year old and adults.

"We found that omalizumab injections for four months can increase the threshold for an allergic reaction to multiple foods," said Chinthrajah, who also is an associate professor at Stanford School of Medicine.

"This is a major breakthrough for food allergy, as omalizumab affords food allergy families improved quality of life and safety when doing everyday activities," such as attending parties and dining in restaurants.

Families also face economic impacts from buying more expensive items to avoid potentially life-threatening allergens, Chinthrajah said.

All study participants had severe allergies to peanuts and a minimum of two other foods. After four months of monthly or bimonthly omalizumab injections, two-thirds of the 118 participants receiving the drug safely ate small quantities of their allergy-triggering foods.

About 8% of children and 10% of U.S. adults have food allergies. While those with severe allergies are advised to completely avoid foods with their allergy triggers, common allergens such as peanuts, milk, eggs and wheat can hide in so many places.

In the study, 177 children had at least three food allergies each, of whom 38% were 1 to 5 years old; 37% were 6 to 11 years old; and 24% were 12 or older. Skin-prick testing and food challenges confirmed severe allergies. Participants reacted to less than 100 milligrams of peanut protein and less than 300 mg. of each other food.

Two-thirds of the participants were randomly assigned to receive omalizumab injections, and one-third got an injected placebo, with the injections occurring a 16-week period. They were retested during weeks 16 and 20 to determine how much of each allergy-triggering food they could safely tolerate.

Retesting showed that 79 patients (66.9%) who had taken omalizumab could handle at least 600 mg. of peanut protein, the quantity in two or three peanuts, compared with only four patients (6.8%) who received the placebo. Similar proportions of patients improved in their reactions to other foods in the study.

About 80% of patients taking omalizumab were able to ingest small amounts of at least one allergy-triggering food without inducing an allergenic reaction; 69% of patients could eat small quantities of two allergenic foods; and 47% could consume small amounts of all three allergenic foods.

No side effects occurred other than minor reactions at the injection site. And this study marks the first time the drug's safety has been evaluated in children as young as 1.

The drug also could make it safer for community physicians to manage patients with food allergies, since it can't trigger dangerous allergic reactions, as oral immunotherapy sometimes does.

More studies are needed to further understand how omalizumab could help people with food allergies, the researchers said, adding that they have a lot of unanswered questions, such as how long patients need to take the drug.

Many patients with food allergies also have other allergic conditions treated by omalizumab, such as asthma, allergic rhinitis (hay fever and allergies to environmental triggers such as mold, dogs or cats, or dust mites) or eczema, Chinthrajah noted.

The drug could be particularly useful for severe food allergies that affect young children, who tend to put things in their mouths and may not be aware of the dangers their allergies pose, researchers said.

The research was funded by the National Institute of Allergy and Infectious Diseases and the National Center for Advancing Translational Sciences, both part of the National Institutes of Health.

"Many patients with food allergies have the fear that, although they avoid the food to which they are allergic, they may inadvertently ingest a food containing the allergen," Dr. H. James Wedner, a professor of allergy and immunology at Washington University School of Medicine and Barnes-Jewish Hospital in St. Louis, who was not involved in the research, told UPI via email.

"Being treated with omalizumab gives them the confidence that they can eat food without worrying about accidental ingestion," Wedner said.

However, he added, "The study does not mean that a peanut-allergic patient, for example, can eat peanuts without concern -- only that they do not have to be concerned by an inadvertent exposure to the food."

Patients should continue to carry epinephrine at all times, as it is still possible for them to have anaphylaxis -- a severe reaction that could be fatal, Dr. Heather Cassell, an associate clinical professor and a pediatric allergist and immunologist at the University of Arizona College of Medicine-Tucson, told UPI via email.

Omalizumab is an expensive medication that requires monthly injections "but will no longer provide protection once it has been stopped," Cassell said. "This means that this medication would need to be used lifelong in order to reduce the risk of food anaphylaxis."

She added that "because of the cost and continued risk for food allergy reactions, this treatment should only be pursued after a discussion with an allergist. Every patient is different and treatment options are not one-size-fits-all."