A new skin patch for treating peanut allergies has been getting a lot of online attention over the past few days, and it’s no wonder. For the estimated 3.2 million Americans who are allergic to peanuts, the options are pretty slim when it comes to treatment. In fact, no drugs have been approved by the US Food and Drug Administration to treat life-threatening peanut allergies. But that might soon change.
A couple of companies are developing therapies designed to blunt dangerous allergic reactions by slowly reducing an allergic person’s sensitivity to peanut protein. These drugs are early in development and still need to be heavily tested, but at this stage they’re looking promising. Both received “breakthrough therapy designation” from the FDA, which means the therapies meet what the FDA calls an otherwise “unmet medical need.”
Allergies occur when the immune system responds to harmless proteins just like it would to a dangerous invader like a parasite. It may sound counterintuitive to treat food allergies by exposing people to the very protein they’re allergic to, but at times, tiny amounts of the allergen can actually teach the immune system to stay calm in its presence. That’s the premise behind allergy shots: they deliver small amounts of the proteins in pollen, pet dander, or insect stings, so the allergic body gets used to them.
The reason doctors don’t do peanut allergy shots is that reactions to peanuts can be extremely severe. When allergic people eat the legume, they might experience anything from nausea and vomiting to hives and potentially fatal anaphylaxis, a reaction that can squeeze your airways shut.
Companies have tried to capitalize on the anxiety this severe reaction can cause. After a recent study showed that children who eat peanuts when they’re very young are less likely to develop allergies to them, one company began selling very expensive peanut butter to worried parents. And the pharmaceutical company Mylan came under heavy fire earlier this year for hiking the price of life-saving EpiPens, epinephrine injections that temporarily interrupt an allergic reaction, giving the patient more time to get to a hospital.
Right now, though, the only way to manage peanut allergies is to avoid the food. But food labels aren’t always reliable, and there’s always the chance of exposure. That’s where the new treatments step in. The French company DBV Technologies is developing a skin patch, called Viaskin Peanut, that slowly releases small amounts of peanut protein through the skin. Every 24 hours, the old patch is removed and a new one is applied in a new spot.
In a recent year-long study, about half of the participants using Viaskin were able to eat either a little more than five grams of peanut protein, or 10 times more peanut protein than they could when the study started. (The study was funded by the NIH with additional funds from DBV, but the study was independent.) In comparison, only about 12 percent of the people using the placebo patches could eat that much peanut protein after a year. Children between the ages of 4 and 11 responded the best to the therapy, according to the findings published last week in the Journal of Allergy and Clinical Immunology.
The patch wasn’t without side effects. Nearly 80 percent of the study participants in the treatment group got rashes underneath the patch. But only one person specifically withdrew because of the skin irritation. “One of the things we were a little bit surprised about, but also very excited about, was that adherence was very high,” says the study’s lead author Stacie Jones, an allergist at Arkansas Children’s Hospital. “We had more than 97 percent of the participants across all the treatment groups that stayed with the study and changed the patch every 24 hours.”
The other treatment undergoing clinical trials is the oral capsule AR101, manufactured by California-based company Aimmune. The capsule contains peanut protein that is dissolved in food and taken daily. The premise is similar to Viaskin’s: delivering small doses of peanut protein over time might train the immune system to ignore the protein, instead of react. The two key differences are that people take AR101 by mouth and the dose slowly increases over the span of 20 weeks.
In one small clinical trial conducted by Aimmune, 23 participants received AR101 daily for 22 weeks. Six patients dropped out because of gut-related side effects. But, at the end of the study, 78 percent of the participants could eat about one gram of peanut, 10 times more than they could when they started. Nobody taking the placebo was able to eat as much.
Though both treatments look promising, there’s still a long way to go, says Gerald Nepom, an immunologist at the Benaroya Research Institute in Washington State. Neither the patch nor the pill are FDA-approved yet, but both have recently wrapped up Phase II clinical trials that assessed the efficacy and safety of the treatments. And both products will now be tested in larger Phase III trials, with about 500 patients already screened by DBV and 500 expected to enroll for Aimmune. Results won’t be in until the second half of 2017. And, as a word of caution, these late-stage trials are when most drug candidates fail, according to Nature.
It’ll be especially important to test the treatments’ safety and efficacy in large groups of people. That’s because giving allergy sufferers a false sense of security could be dangerous, says Mary Rozenman, Aimmune’s senior vice president for corporate development and strategy. “We wouldn’t want anyone to have a sense of protection who wasn’t really protected,” she says.
In the future, these therapies might need to be combined with immunosuppressant drugs that help the body tolerate peanut protein, Nepom says. With recent advances in lab techniques that give scientists a more detailed view into how the immune system is responding to allergens, Nepom thinks that we may be seeing more treatment options for allergic people soon.
“Now, there are really good new methodologies for interrogating the immune system and the response to peanut,” he says. “So I’m pretty optimistic actually that things are going to move a lot faster now.”