First Oral Immunotherapy for Peanut Allergy Gets Closer to FDA Vote
A clinical trial for peanut allergy treatment has hit another milestone, with research suggesting graduated doses of peanut protein powder could help protect allergic children.
After learning their son Andrew had a serious peanut allergy, Jennifer and Daniel Ayala did everything they could to protect him, from becoming master label readers to sending him to birthday parties with his own treats.
Still, there were times Andrew accidentally ingested peanut, most often from an outside food that did not obviously include the allergen as an ingredient. An onslaught of “terrifying” symptoms followed, his mom says, including vomiting, swelling, turning red and breaking out in hives.
But today, the 11-year-old — whose reactions were once triggered by barely a nibble of a single peanut — can tolerate more than six whole peanuts during a supervised food challenge. Andrew was the first Michigan Medicine patient to enroll in a global clinical trial for an oral immunotherapy regimen that aims to reduce children’s sensitivity to peanut allergens.
The University of Michigan was among 66 research sites that participated in the trial, whose full findings were published in the New England Journal of Medicine in November. The study’s publication is another milestone that may pave the way for possible Food and Drug Administration approval of the first oral medication to reduce reactions among children with severe peanut allergies.
“Knowing he was going to be given peanut as part of the trial was very scary, but we felt comfortable doing it at U-M, where he could be closely monitored,” Jennifer Ayala says.
“We’ve learned a lot of lessons along the way and have been pretty successful in avoiding peanut exposure, but you always live in fear that you’re going to miss something. As Andrew gets older and more responsible for asking the right questions and making some of these decisions himself without us, it’s hard not to worry.
“This therapy brings peace of mind. He still needs to be allergy-savvy, but if there’s a mess-up, it won’t lead to those severe reactions.”
Developing peanut tolerance
Andrew was among 250 children in the yearlong trial who developed peanut tolerance after gradual exposure to carefully measured amounts of peanut protein that increased incrementally under medical supervision. Two-thirds of the 372 children who received the treatment were able to ingest 600 milligrams or more of peanut protein (about two peanuts) without an allergic reaction. They underwent six months of treatment followed by six months of maintenance therapy.
By contrast, only 4 percent of the 124 children who had been given a placebo powder could consume the same amount of peanut without a reaction.
Georgiana Sanders, M.D., the U-M site’s principal investigator for the research, emphasized that children who complete the regimen must remain on a peanut-free diet and may need to keep up maintenance therapy with daily doses of peanut protein powder.
“The goal isn’t to cure a peanut allergy but to provide a safeguard for unsuspected exposure,” says Sanders, a pediatric allergist at Michigan Medicine and a research faculty member of the university’s Mary H. Weiser Food Allergy Center. “Families will still need to take the same steps to read labels and avoid peanuts. None of these patients are going to suddenly start eating peanut butter sandwiches.
“However, this is still a significant step towards a therapy that for many patients, it increases peanut tolerance and prevents serious and life-threatening reactions to accidental ingestion.”
Sanders, a U-M associate professor of pediatrics and internal medicine, says alleviating fear is key for patients and their families.
“Until now, advising cautiousness to prevent exposure, recognizing the symptoms of an allergic reaction and carrying an epinephrine auto-injector to treat a reaction has been all we could offer families,” she says. “But some situations are out of your control, and accidents still happen. This possibility can cause a great deal of fear and anxiety. Knowing their children have some protection against an inadvertent allergic reaction lifts a huge weight off of parents’ shoulders.”
Aimmune Therapeutics designed and sponsored the double-blind, placebo-controlled trial of the drug, called AR101. A third of the participants between ages 4 and 55 — with 496 of the 551 participants ages 4 to 17 — were given a placebo, while the remaining two-thirds were given peanut protein powder in increasing amounts.
Not every enrollee had an outcome as successful as Andrew’s. Roughly 4 percent of children receiving the active drug experienced severe side effects, and 20 percent of the children in the active treatment group withdrew from the study (half of them were taken off the treatment because of adverse events).
Fourteen percent of those on active treatment received injections of epinephrine — a drug used in emergencies — compared with 6.5 percent of those on the placebo.
Still, the advancement comes amid growing need, with nearly 1 in 50 American children reportedly allergic to peanuts. Peanut allergies are thought to cause more deaths from anaphylaxis, an acute allergic reaction that can include constriction of the airways, than any other food allergy.
The Ayalas, who were often hesitant to travel because of less control over peanut exposure and more risk with outside food, are now preparing for a big family trip to Australia.
“I’m not sure we would have tried that kind of trip before. We would worry about ingesting peanut dust from the 14-hour flight or having to pack a lot of our own food,” Jennifer Ayala says.
“It’s definitely less nerve-wracking.”
She notes that following the strict daily regimen takes a lot of dedication and isn’t always easy, since patients aren’t supposed to skip any days. Participants also can’t be too active for a couple of hours after taking the peanut dose, and they need regular clinic appointments.
But Andrew, who says he often worried about his allergy at school and avoided certain restaurants his friends liked, says the new routine is worth the commitment. And he’s glad to be part of research that can help him and other kids like him.
“I hate food allergies,” he says. “I know how hard it is to live with food allergies every day, and I’m guessing others with food allergies who feel left out of things like I do feel the same way. I wanted to help other people and myself too.”