Sensitivity to peanuts is one of the most dangerous food allergies. Even the smallest traces can cause severe allergic reactions, which can be fatal. The allergy is also relatively common; an estimated 250,000 children in England alone are allergic to peanuts, with rates are on the rise. Peanut allergies are also highly persistent and four out of five children with peanut allergies remain allergic into adulthood.
There is currently no cure for peanut allergy and symptoms can only be treated with emergency epinephrine, which can be difficult to administer and often requires more than one injection. Now, in a landmark trial, Aimmune Therapeutics’ drug AR101 has successfully generated tolerance to peanuts in 500 children.
The drug, which is taken orally, contains a range of proteins found in peanuts in order to ‘train’ the immune system to accept them. This is in line with emerging evidence which suggests that early exposure may prevent peanut allergies from developing. In the UK, the government recommend the introduction of peanuts into the diet of infants with other allergies or eczema at 4 – 6 months to prevent development of an allergy.
This trial included 496 highly allergic children aged 4–17, including several with severe allergies to peanuts. Of these, 370 received the drug while 124 received placebo. After one year of treatment, they completed a food trial to assess their reaction to peanuts. This is the biggest peanut allergy trial ever conducted and the first to use independent assessors, who were not involved in the care of the participants and were blinded to the different treatments.
While only 4% of the placebo group were able to tolerate a 60 mg dose of peanut protein at the end of the trial, almost 70% of the treated group coped with this amount, which is equivalent to two to four whole peanuts. Almost all of the treatment group (96.3%) tolerated half of this dose, while half tolerated the much higher 1000mg dose.
However, there is a risk associated with this approach and 12% of participants withdrew due to adverse effects including hypersensitivity (a common and expected side effect of immunotherapy), gastrointestinal and respiratory problems. Ten patients experienced serious adverse effects, although none were life threatening.
“Although the treatment will not eliminate the allergy, it should provide a ‘comfortable margin’ in case of accidental exposure”, says trial coordinator and Professor of Paediatrics, Dr Wesley Burks. “It’s great to have patients go from managing to tolerate at most the amount of peanut protein in a tenth of a peanut without reacting to successfully eating the equivalent of between two to four peanuts with nothing more than mild, transient symptoms, if any at all,” he added.
The company currently has three phase three clinical trials underway for AR101 across the US, Canada and Europe. The drug already has Food and Drug Administration (FDA) Breakthrough Therapy Designation for peanut-allergic patients aged 4 – 17 and the company plan to submit an application to market the drug in the US by the end of this year, followed soon after by an application to the European Medicines Agency (EMA).