An experimental treatment aimed at helping people with severe peanut allergy recently scored a clinical win, putting it in line to possibly become the first drug to provide meaningful protection against accidental exposure.
Based on the positive results, Aimmune Therapeutics expects to seek U.S. approval for its preventative peanut allergy therapy by the end of the year, with a European filing in 2019, the company said. The company’s lead product, AR101, is a capsule filled with a precise, measured quantity of peanut flour. The capsules are opened and mixed into food. The idea is simple: Expose people to small, escalating doses of ingestible peanut protein over time with the goal of desensitizing them enough to prevent severe reactions.
Aimmune is trying to standardize a peanut allergy protection method already tried on an ad hoc basis. AR101 proved highly effective in a phase 3 clinical trial known as PALISADE. The results: 67 percent of patients ages 4 to 17 tolerated at least a 600-mg dose of peanut protein at the end of the study, compared with 4 percent of placebo patients.
Six hundred milligrams of peanut protein is roughly the equivalent of two peanuts or a child-sized bite from a peanut butter sandwich. The patients entered the study not being able to tolerate exposure to 10 percent of a single peanut. To meet the FDA requirements for approval, AR101 had to beat placebo by a biostatistical cushion of at least 15 percent. Aimmune cleared this statistical hurdle easily with a 53 percent difference.
There were some safety concerns in the study. Twenty percent of the AR101 patients and 6.5 percent of the placebo patients discontinued from the trial. Among AR101 patients, 12 percent discontinued due to adverse events, including gastrointestinal side effects. Ten AR101 patients, or just under 3 percent, left the study because of systemic allergic hypersensitivity reactions. Of these, seven patients were deemed by their doctors to have experienced potentially serious allergic reactions known as anaphylaxis, including one severe case.
Anyone with school age children knows peanut allergy is a serious and prevalent health problem. It’s estimated that between 1.5 million to 2 million people under 18 in the U.S. have peanut allergy. Apart from scrupulous peanut avoidance, there are no approved treatments for people at risk for severe allergic reaction if exposed to even trace amounts of peanut protein.
There is no cure for peanut allergy. A “peace of mind” treatment would still be beneficial, however, and offers the possibility of reassurance to parents and patients that accidental reactions would be less likely to occur.
Dr. Kenneth Backman of Allergy & Asthma Care comments: "Oral immunotherapy, or desensitization, to foods has been studied for some time and remains experimental. There are many different protocols and doses in use among different investigators, and some centers have offered the treatment in unapproved, off-label protocols that remain unproven in safety and efficacy. They often use nonstandard doses of peanut protein, such as peanut M&Ms, which due to marked variability of peanut content can cause unexpected severe reactions. While there is the potential for adverse reactions, this study is promising and offers hope that we will be able to offer an FDA approved, carefully controlled, safe and effective treatment to help reduce the risk of accidental food reactions. We look forward to further studies and FDA action."