Hope for peanut allergies
Pills, patches, drops and even nuts themselves are being studied
Every year, Americans make 30,000 emergency room visits because of food allergies, according to the Food and Drug Administration.
Even touching a surface that previously held peanuts can trigger anaphylaxis, a life-threatening allergic reaction. When a peanut-allergic person starts feeling their throat close up, they stab themselves with an epinephrine, or adrenaline, device and then head to the ER for a few hours of monitoring. What if there were another way? Researchers, doctors and pharmaceutical companies are trying to make people less allergic to peanuts. A peanut pill and a patch could be widely available by the end of 2019. In the meantime, a small number of private-practice allergists have been offering oral immunotherapy, in which you gradually eat more peanut products under a doctor’s supervision.
Right now, the majority of allergists only prescribe patients an epinephrine device and tell them to strictly avoid peanut protein, in hopes of warding off reactions such as hives, swelling, blood pressure loss and difficulty breathing. The FDA has not approved any treatments for peanut allergies, which affect 2 percent of children today.
This spring, Aimmune Therapeutics announced that it had wrapped up a 10-nation trial for its “peanut pill,” AR101.
“Our hope all the time is to make a cure, to make this go away permanently and never have to worry about it,” said Dr. Edwin Kim, a researcher at the Food Allergy Institute at UNC-Chapel Hill, one of the trial sites. Kim is the father of a peanut-allergic child. “These kids don’t want to think about it. They don’t want to have to worry about it. They want to be normal.”
For decades, people with hay fever or other environmental allergies have received allergy shots. Allergists inject a patient with increasing amounts of serum derived from whatever the patient is allergic to, building up his or her tolerance for the allergen. After several years, the shots are no longer needed.
“What we found out in the ’80s and ’90s was that doing something similar, like putting peanuts into an allergy shot, wasn’t effective,” Kim said. “That’s where the idea of oral immunotherapy was born, since eating the food is how your body learns to tolerate it.”
Oral immunotherapy, or OIT, works the same way the allergy shots do. Start with a very small amount of the food, check to make sure the patient doesn’t have any reactions and then gradually increase that amount in a process called updosing.
Dr. Wesley Burks at Duke University first demonstrated how to increase patients’ tolerance to peanuts in 2009. His 29 patients started with mixing a few crumbs of peanut flour into applesauce or pudding, then updosed for months by eating a little more each day to build up tolerance for the allergen.
Once they passed a “food challenge” of eating about 16 peanuts at once, the patients entered maintenance, which meant they ate eight peanuts a day for years afterward.
Every OIT study since then has followed a similar updose and maintenance pattern, with some including the food challenge.
In 2011, a parent-run nonprofit brought together various experts to figure out how to cure food allergies. Aimmune formed from that meeting.
By 2013, the company created AR101, capsules of proprietary peanut flour that come with a standardized updose and maintenance schedule.
By the end of this year, Aimmune will apply to the FDA for a license to sell AR101 in the U.S., said Dr. Daniel Adelman, Aimmune’s chief medical officer.
At the same time, another company hopes to offer a “peanut patch,” called Viaskin, which patients will wear for increasing amounts of time to updose and then will wear all the time for maintenance.
At the Food Allergy Institute at UNC, researchers are also working on peanut “drops” held under the tongue, Kim said. No pharmaceutical company has picked up the drops yet, so they will not be available for consumers for at least several more years.
If they pass, AR101 and Viaskin will be the first FDA-approved products to treat peanut allergies.
“The reason you have FDA approval of drugs is because they have oversight of manufacturing processes — there’s a reason for regulation,” said allergist Dr. Laurie McWilliams, who does not offer private practice OIT. “That keeps drugs at the level they should be. What if you get a different dose on a different day because that peanut doesn’t have the same high amount of protein content?”
Kim, the allergist and parent from UNC, said the pill was the most effective but also the least convenient treatment. The patch is less effective but has a short updose period and hassle-free application.
“In a perfect world it would be great to have multiple treatments,” Kim said. “Every child varies. Maybe the child is higher-risk, and even if there’s a little more difficulty doing the treatment it’s worth it for those. Maybe for other families it’s all about convenience, and they need protection but they’re pretty good at avoidance.
“I’d love for there to be options. That would give more power to the allergist and to the families as well.”
The success of the peanut pill may spread the popularity of private practice OIT, McWilliams said.
“They might say the peanut product isn’t different from what’s in the grocery store, and they’ll go grind it up,” McWilliams said.
Beyond peanut, Aimmune is working on trials for egg and walnut allergies. The company behind the peanut patch also is developing patches for milk and egg allergies.