April 24, 2024

Drug dramatically reduces children’s reactions to trace food allergens

A drug used for decades to treat allergic asthma and hives significantly reduced the risk of life-threatening reactions in children with severe food allergies who were exposed to trace amounts of peanuts, cashews, milk and eggs, researchers reported Sunday.

The drug, Xolair, is already approved by the Food and Drug Administration for adults and children over 1 year old with food allergies. It is the first treatment to dramatically reduce the risk of serious reactions – such as anaphylaxis, a life-threatening allergic reaction that causes the body to go into shock – after accidental exposure to various food allergens.

The results of the researchers’ study, presented at the annual conference of the American Academy of Allergy, Asthma and Immunology in Washington, were published in The New England Journal of Medicine.

“For a certain population of food allergy patients, this drug will be life-changing,” says Dr. Robert A. Wood, the paper’s first author and director of the Eudowood Division of Pediatric Allergy, Immunology and Rheumatology at the Johns Hopkins Children’s Center.

“If you have a severe milk or egg allergy, or something that wasn’t even part of this study — like garlic or mustard — you can never eat in a restaurant,” said Dr. Wood.

“There’s also the fear and anxiety that you walk with every day,” he added. “I have a lot of patients who are teenagers and have never had the opportunity to eat in a restaurant. The family has never boarded a plane because of the fear of the allergy.”

Food allergies have become increasingly common over the past two decades, although it is not clear why. About 5.5 million children and 13.6 million American adults have food allergies, and many are allergic to more than one food.

Nearly half of people with food allergies have experienced a severe, life-threatening reaction. Food allergies are the cause of an estimated 30,000 emergency room visits per year.

Dr. Ann Marqueling and Dr. Kevin Wang, of Palo Alto, California, has a 5-year-old son, Liam, with multiple food allergies who participated in the trial.

They were not told whether their son was randomized to receive the drug or dummy injections. But toward the end of the treatment phase, he showed more tolerance to trace amounts of eggs, peanuts and tree nuts, they said. They believe he got Xolair.

“It’s been very liberating for us, but it’s also liberating for him. We’re not watching him everywhere like a hawk because of the accidental exposures,” said Dr. Cheek. “We are still vigilant, but we are not sitting still. Instead of us being on red alert, it is a yellow or orange alert.”

“We felt more comfortable letting him run around and explore,” said Dr. Marqueling. “We let him be a kid.”

But while some saw Xolair’s approval as a breakthrough, experts warned it was far from a perfect solution. The drug reduces the risk of a reaction to traces of an allergen, but life-threatening episodes are still possible. Patients should still painstakingly avoid foods that could cause a reaction.

The drug is not easy to take and is given by injection every two to four weeks. Many people, especially children, do not like injections and are afraid of needles. And for Xolair to be effective, patients must take it regularly.

Only one other drug, Palforzia, is approved for reducing severe reactions, but this is only for people with a peanut allergy. It is an oral immunotherapy regimen that works by gradually exposing children to small amounts of peanut protein until they can safely eat the equivalent of two peanuts. Those taking Palforzia should also continue to avoid peanuts.

The Xolair study, funded largely by the National Institute of Allergy and Infectious Diseases, was the kind considered the gold standard in medicine: a double-blind, randomized, placebo-controlled clinical trial.

It was conducted at 10 medical centers in the United States and included 177 children and adolescents between the ages of 1 and 17, all of whom were allergic to peanuts and at least two other foods, including cashews, milk, eggs, walnuts, wheat and hazelnuts.

To be included, they had to have an allergic reaction to 100 milligrams or less of peanut protein (less than half a peanut) and to 300 milligrams or less of two other foods from a list that included milk and eggs.

The participants were randomly assigned to receive injections of Xolair or a placebo every two to four weeks for 16 to 20 weeks. (Dosing frequency was based on individual characteristics, including weight.)

After the treatment phase was completed, participants were tested to see if they could tolerate trace amounts of food allergens. Of the 118 participants given the drug, 79, or 67 percent, could tolerate up to 600 milligrams of peanut protein in a single dose — equivalent to just over half a teaspoon of peanut butter, or about two and a half peanuts — without serious symptoms .

Only four of the 59 participants who received the placebo injections, or 7 percent, were able to do so.

The level of protection varied by food: For example, 41 percent of those allergic to cashews who received the drug had no reactions when they ate up to 1,000 milligrams of cashews, compared with 3 percent of those in the placebo comparison group.

Two-thirds of people with a milk allergy who took the drug could tolerate up to 1,000 milligrams of milk protein, compared with 10 percent of the placebo group.

More than two-thirds of people with an egg allergy could tolerate up to 1,000 milligrams of egg protein if they were given the drug, while no one in the placebo group could. All findings were statistically significant.

Xolair is a man-made antibody directed against immunoglobulin E (IgE), which is produced by the body’s immune system and causes allergic reactions.

The drug binds to IgE and acts “like a sponge that soaks everything up,” says Dr. Sharon Chinthrajah, senior author of the paper and acting director of the Sean N. Parker Center for Allergy and Asthma Research at Stanford University .

Although the drug has been approved for other uses for two decades, Genentech did not investigate whether Xolair might be beneficial against severe food allergies until the National Institute of Allergy and Infectious Diseases’ Consortium for Food Allergy Research, which provided funding, approached the company to 2017, an institute spokeswoman said.

Dr. Larry Tsai, global head of respiratory, allergy and infectious disease product development at Genentech, which co-developed Xolair with Novartis, emphasized that the drug was not intended to cure allergies and does not do so.

But, he added, it could be helpful for someone like his own daughter who works at the university, who has multiple food allergies and worries about accidental exposure in a cafeteria or restaurant.

“My daughter can easily avoid eating a lobster or a handful of peanuts,” said Dr. Tsai. “What’s more worrying is that if she goes to lunch with friends and eats a sandwich that happens to have been cut with a knife previously used to spread peanut butter and not thoroughly washed – and she ends up in a hospital. That is a fear that patients live with.”

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