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 exposed to small 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 of age 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 sends the body into shock – after accidental exposure to various food allergens.
The results of the researchers’ study of children and adolescents, presented at the annual meeting 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 patients with food allergy, this drug will be life-changing,” said Dr. Robert A. Wood, the paper’s first author and director of the Eudowood Division of Pediatric Allergy, Immunology and Rheumatology at Johns Hopkins Children’s Center.
“If you have a severe allergy to milk or eggs or something that wasn’t even part of this study — like garlic or mustard — you can never eat in a restaurant,” Dr. Wood said.
“There’s also the fear and anxiety you walk around with every day,” he added. “I have a lot of patients who are teenagers and have never been allowed to eat in a restaurant. The family has never been on a plane for fear of allergies.”
The prevalence of food allergies has been increasing over the past 20 years, although it is not clear why. About 5.5 million children and 13.6 million adults in the US have food allergies, and many are allergic to more than one food.
Almost half of people with food allergies have experienced a serious, life-threatening reaction. Food allergies are the cause of approximately 30,000 emergency room visits annually.
Dr. Ann Marqueling and Dr. Kevin Wang, of Palo Alto, Calif., has a 5-year-old son, Liam, with multiple food allergies who participated in the trial.
They have not been told whether their son was randomized to receive the drug or the dummy injections. But by the end of the treatment phase, he showed greater tolerance to traces of eggs, peanuts and tree nuts, they said. They believe he was given Xolair.
“It’s been very liberating for us, but it’s also liberating for him — we’re not hawking him all over the place for random exposures,” said Dr. Wang. “We are still cautious, but we are not wavering. Instead of being on a red alert, it’s a yellow or orange alert.”
“We’ve gotten more comfortable letting him run and explore,” Dr. Marqueling said. “We let him be a kid.”
But while some hailed Xolair’s approval as a breakthrough, experts warned it was far from a perfect solution. The drug reduces the risk of reacting to traces of allergen, but life-threatening episodes are still possible. Patients should scrupulously avoid foods that may cause a reaction.
The drug is not easy to take, it is given by injection every two to four weeks. Many people, especially children, do not like shots and are afraid of needles. And for Xolair to be effective, patients must take it regularly.
Only one other drug, Palforzia, is approved to reduce severe reactions, but it’s only for those with peanut allergies. This 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.
Xolair’s study, funded in large part by the National Institute of Allergy and Infectious Diseases, was of 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 aged 1 to 17 years, all of whom were allergic to peanuts and at least two other foods, including cashews, milk, egg, walnut, wheat and hazelnut.
To be included, they had to have an allergic reaction to 100 milligrams or less of peanut protein (less than half a peanut) and 300 milligrams or less of two other foods from a list that included milk and eggs, among others.
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 completing the treatment phase, participants were tested to see if they could tolerate trace amounts of food allergens. Of the 118 participants who received the drug, 79, or 67 percent, were able to tolerate up to 600 milligrams of peanut protein in a single dose—the equivalent of 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.
Levels of protection varied by food: 41 percent of those allergic to cashews who received the drug had no reactions when they ate up to 1,000 milligrams of cashews, for example, compared with 3 percent of those in the placebo comparison group.
Two-thirds of people with milk allergies who received the drug were able to tolerate up to 1,000 milligrams of milk protein, compared with 10 percent who were in the placebo group.
More than two-thirds of people with egg allergies could tolerate up to 1,000 milligrams of egg protein if given the drug, while no one in the placebo group could. All findings were statistically significant.
Xolair is a man-made antibody that targets immunoglobulin E (IgE), which is produced by the body’s immune system and causes allergic reactions.
The drug binds to IgE, acting “like a sponge that soaks it all up,” said Dr. Sharon Chintraja, the paper’s senior author 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 study whether Xolair could be beneficial against severe food allergies until the National Institute of Allergy and Infectious Diseases Food Allergy Research Consortium, which provided funding, approached the company in 2017, an institute spokeswoman said.
Dr. Larry Tsai, global head of respiratory, allergy and infectious disease product development at Genentech, which developed Xolair with Novartis, emphasized that the drug is not intended to treat allergies and does not.
But, he added, it might be useful for someone like his college-age daughter, who has multiple food allergies and worries about accidental exposure at a cafeteria or restaurant.
“My daughter can easily avoid eating a lobster or a handful of peanuts,” Dr. Tsai said. “What’s more worrying is if he goes out to lunch with friends and eats a sandwich that happened to be cut with a knife previously used to spread peanut butter and wasn’t washed properly – and he ends up in hospital. This is a fear patients live with.”
