Will the Peanut Allergy Ever be a Thing of the Past?

If you have school age kids in your life, you’ve probably noticed a lot has changed since you were their age. Smart screens and computer science courses are making chalkboards and writing in cursive obsolete. Another thing that’s missing: the classic PB & J. In fact, some schools have banned peanuts entirely due to allergies. 

Peanut allergies have tripled since the 1990s, and some kids are so sensitive that just one bite of a food made with peanuts is enough to trigger a bad reaction. When a kid has an allergic reaction to food, their body’s defenses mistake a harmless food for something dangerous, and launches an immune response (Figure 1). Severe food allergies can cause someone’s airway to close, making it hard to breath. EpiPens® (easy-to-use, injectable adrenaline) can reopen airways temporarily, but even if you have an EpiPen® on hand and you administer correctly, you still need to rush to the emergency room. The only way to prevent an allergic reaction is to avoid contact with peanuts – hence, the bans. 

Although there is no cure for food allergies, a new treatment might reduce the severity of allergic reactions: oral immunotherapy (OIT). 

So what is OIT? 

Immunotherapy works by targeting the immune system, our body’s defense against viruses, bacteria, or anything else that might make us sick. One common type of immunotherapy that you may have heard of is cancer immunotherapy, which directs the immune system to kill cancer cells. OIT works differently. It’s not a drug that targets the immune system directly; rather, it’s a treatment program designed to train the immune system to stop reacting to food. 

OIT is based on tolerance: the idea that if you have repeated contact with something, it will have less of an effect on you over time. You’ve probably experienced this in your life – maybe a small cup of coffee used to give you the jitters, but now it takes a few cups just to wake you up in the morning. Through OIT, people with peanut allergies can build up their tolerance the same way. They start by consuming a miniscule amount of peanut and gradually increase the dose. 

OIT doesn’t cure a food allergy – it just increases how much peanut it takes to cause a severe reaction. That goal is to decrease someone’s sensitivity to the point where the patient is “bite-proof” – where accidently biting into a peanut-laden food won’t cause a life-threatening reaction. 

Immunotherapy isn’t new – Leonhard Noon first documented this back in 1911, when he used small doses of pollen to treat hayfever. It was rumored that King Mithridates VI (135-65 BCE) built up a tolerance to poisons to thwart assassination. Recently, scientists have tested variations of immunotherapy, such as ones that use injections or patches instead of oral administration. 

peanut oral immunotherapy

Only a few certified allergists offer OIT for food allergies. OIT isn’t as simple as mixing a bit of peanut powder into your morning orange juice. The amount of peanut protein you consume needs to be carefully measured and administered in a doctor’s office. Even if the dosing is right, patients can experience symptoms of a mild allergic reaction. A patient might also react strongly to a dose and require emergency treatment. There is currently no FDA-approved treatment for OIT, so the regimen varies among doctors. Some allergy specialists prepare pills for their patients using store-bought peanut flour, but others refuse to offer this kind of home-made treatment. For one thing, the exact concentration of peanut allergen (the particular protein molecule causing the reaction) in the flour is unknown, making it hard to control the dose. Because it’s not an approved treatment, doctors are liable for any adverse effects. OIT has the potential to reduce unexpected allergic reactions, but realistically the treatment needs to be standardized and FDA-approved before it gets widespread acceptance and use.

Enter: AR101

Even though it is still awaiting FDA approval, there has been a lot of buzz over Aimmune’s new OIT drug AR101, aka Palforzia™. So far, it has made it through clinical trials and was recommended for FDA approval by a panel of experts. The FDA usually agrees with its advisory panel, and an official decision is expected in early 2020. If approved, AR101 would be the first FDA-approved drug for preventing allergic reactions to peanuts. 

The pill contains carefully standardized, medical-grade peanut allergen so doctors know exactly what dose they are administering. In clinical trials, the allergic response to peanuts decreased in about 80% of patients. Most were able to tolerate about two peanuts by the end of their yearlong study, which is pretty great considering, previously, a bit of peanut dust could have been lethal. OIT has the potential to reduce unexpected allergic reactions, but realistically the treatment needs to be standardized and FDA-approved before it gets widespread acceptance and use. If approved, AR101 would be the first FDA-approved drug for preventing allergic reactions to peanuts.

Controversy

To recap, we have more than one million kids in the US with peanut allergies and zero cures. AR101 has the potential to protect against severe reactions to peanuts, but experts still disagree on its safety. A number of kids  dropped out of the clinical trials for AR101 because of its side effects. Because the OIT involves consuming peanuts, participants were more likely to experience an allergic reaction during the course of the study. People must also follow strict rules when taking the drug to reduce the chance that they will have allergic reactions to the OIT doses, including: not taking a dose a few hours before or after sleep, no exercising within 3-4 hours of a dose, and no showering/bathing within 3-4 hours of a dose

These rules make it difficult for patients to maintain their normal schedule. One study also found that patients who discontinued OIT saw their allergies return. To keep up their tolerance, patients will likely need to continue consuming peanuts regularly. That could mean taking AR101 indefinitely, but we don’t yet know how safe that is.

Despite all this, the public largely supports allergy treatments. In fact, in addition to listening to the experts regarding AR101, the FDA also heard from patients and their families. Many of them said that the risks and restrictions are worth it. It’s easy, for example, for a kid to slip up and take a bite of a friend’s ice cream without making sure it is peanut-free. According to families, fearing an unexpected allergic reaction is way more stressful than seeing their child react to a pill taken under supervision.

What about other allergies?

The peanut allergy tends to steal the spotlight because it’s very common and tends to be more severe than other allergies, but OIT can work for other foods too! Clinical trials have looked at OIT in other common allergies, like eggs and other nuts besides peanuts. (Technically a peanut is a legume, not a nut, but I digress). 

Warning – Don’t try this at home!

You may be thinking, ‘Wait – can’t I just do this at home with a jar of Skippy?’ I’m not a doctor (well, not that kind of doctor), but my answer is PLEASE DON’T TRY THIS AT HOME.  Like I’ve said – OIT is really risky and experts do not recommend tackling a serious food allergy for your next DIY project.

Disclaimer: This article is not an endorsement of Aimmune, Mylan (the maker of Epipens), or any of their associated brands or products. Neither the author nor the Illinois Science Council has received any form of compensation form Aimmune or Mylan in relation to this article.

Danika is a postdoctoral researcher at UIC. Her research focuses on the connection between the innate immune system and intestinal health. Find her on LinkedIn.