How it works and what it costs

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Kevin Wang and Annie Marqueling’s son Liam was 8 months old when he broke out in hives all over his body after eating a few bits of a scrambled egg. An allergy test revealed Liam was allergic to eggs, as well as peanuts and tree nuts, and for the next year, the entire family avoided foods that could trigger a dangerous reaction. 

“We had to pay special attention to every single item that we brought to the house because it could potentially be a life-threatening allergen for him,” Wang said. “There’s multiple times where we’ve had to reach out and take a cookie before he takes a bite because we were unsure of the contents.”

Then, two years ago, Wang and Marqueling, who live in Palo Alto, California, found out about a clinical trial for a decades-old drug called omalizumab. The injectable drug was approved in 2003 under the name Xolair for chronic hives and allergic asthma, but now there was evidence it could also protect against severe allergic reactions to food

They enrolled Liam in the trial.

Liam with his parents Annie and Kevin on his 5th birthday.
Liam with his parents Annie and Kevin on his 5th birthday.Courtesy Annie Marqueling

The results were published Sunday in the New England Journal of Medicine. In order to participate in the clinical trial, patients had to be allergic to peanuts along with two other foods. After four months, many of the participants were able to tolerate small amounts of the foods they were allergic to, meaning an accidental exposure was no longer a life-threatening event.

Senior study author Dr. Sharon Chinthrajah, an associate professor of medicine and pediatrics at and acting director of the Sean Parker Center for Allergy and Asthma Research at Stanford University, noted that Xolair is not a cure, and patients still need to avoid the foods they are allergic to. “But it is a tremendous layer of safety,” she said.

“This therapy offers injections and offers an umbrella, a safety protection, to go out and live your lives normally to not be as afraid of accidental exposures and everyday living,” Chinthrajah said.

Earlier this month, the Food and Drug Administration expanded the approval for Xolair for certain kids and adults with food allergies, based on the results of the clinical trial. 

“The very same day the FDA approved the drug, we were writing prescriptions for our food allergy patients,” Chinthrajah said.

A badly needed safety net

Just over 6% of people in the U.S., including 6% of kids, have a food allergy, according to the Centers for Disease Control and Prevention. About 40% of kids who have food allergies have a reaction to more than one food, according to a study in the Annals of Allergy, Asthma & Immunology

Until now, only one medication, called Palforzia, has been available to protect against acute allergic reactions to food, and the drug only works for peanuts. In addition to peanuts, Xolair works for other common food allergies, including eggs, milk and wheat. 

In the clinical trial, Chinthrajah and her team recruited 180 people across 10 hospitals in the U.S. who were allergic to peanuts and at least two of the following foods: cashews, milk, eggs, walnuts, wheat or hazelnuts. The participants ranged in age from 1 to 55 years — about 40% were younger than 6 and most were younger than 18 — and 118 of them received a monthly or biweekly dose of Xolair. The rest got a placebo. The first 60 people to finish the initial stage of the trial — 59 of whom were younger than 18 — were extended for another 24 weeks. 

By the end of the initial four-month period, about 80% of people who got the drug were able to eat small amounts of one of the foods they were allergic to without triggering their normal reaction. About two-thirds were able to tolerate two to three peanuts, “which is much larger than an average accidental exposure,” Chinthrajah said. 

Nearly 70% could eat small amounts of two of their three allergic foods without a reaction. Nearly half could tolerate small amounts of all three. 

“One of the biggest things for kids and even adults living with food allergies is fear of accidental exposure,” said Dr. Ruchi Gupta, the founding director of the Center for Food Allergy & Asthma Research at Northwestern University Feinberg School of Medicine in Chicago. “This gives peace of mind at least for those small amounts that they may come into contact with.” 

When a person with a food allergy eats that food — or sometimes even comes into contact with it — their immune system releases a flood of antibodies called IgE. These antibodies attach themselves to certain cells, triggering a systemwide reaction. Xolair is an antibody drug that acts as a sponge, binding to IgE antibodies and preventing them from latching onto these cells.

“The drug’s ability to do this is finite,” however, Gupta said. For that reason, the drug is meant to prevent reactions to small accidental exposures to allergic foods rather than allowing a person to indulge in them.

Marqueling and Wang don’t know whether Liam, now 5, got the actual drug or the placebo during the clinical trial. 

Now, however, he can tolerate small amounts of peanuts and tree nuts, so they believe it was the real thing.  

The trial has changed their experience as parents.

“We have this extra layer of comfort knowing that he is protected in these accidental exposures that mom and dad can’t always be around for,” Wang said. 

Expanding access

Xolair isn’t meant for everyone with food allergies. It only works for people whose food allergies are Type I, meaning the person always produces IgE antibodies when they are exposed to the food they are allergic to, and it isn’t always effective — 20% of the people in the study were not able to tolerate even small amounts of their trigger foods even when taking the medication.

All experts stressed that people taking the drug should still be cautious. 

“I think it will help mitigate fear and anxiety, but definitely still avoid the allergen and carry an EpiPen,” said Dr. Asal Gharib Naderi, an allergist and immunologist at Keck Medicine at the University of Southern California who wasn’t involved with the trial. 

In rare instances, people can go into anaphylactic shock after taking Xolair, but Gharib Naderi said this typically happens when people are starting on the drug, usually within the first three doses. These early doses are given in a doctor’s office, where the patient can be monitored for a reaction. Later doses can be taken at home.

A spokesperson for drugmaker Genentech said the estimated monthly list price of Xolair is around $2,900 for children and $5,000 for adults. The actual out-of-pocket cost to patients is typically lower, the spokesperson said, based on insurance and other financial assistance programs.

While Xolair could previously be prescribed off-label for food allergies, insurance companies rarely cover off-label uses. With the FDA’s expanded approval, doctors hope insurance companies will be more likely to cover it for food allergies. 

“I don’t want a drug like this to increase the disparities we already see in food allergies,” Gupta said. “There are quite a few more treatments on the heels of Xolair, and we need to make sure those are accessible.”

It’s currently unclear how long someone would need to be on Xolair for food allergies, but that is the subject of additional research.

“This could potentially be a lifelong therapy,” Chinthrajah said.

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