European Phase 3 Trial of Aimmune Therapeutics’ AR101 Meets Primary Endpoint

Aimmune Therapeutics announced that its phase 3 European clinical trial of AR101 for the treatment of peanut allergy, known as ARTEMIS (AR101 Trial in Europe Measuring oral Immunotherapy Success), met its primary efficacy endpoint. Topline data show that the proportion of AR101-treated patients who tolerated a 1,000-mg dose of peanut protein (2,043 mg cumulative) in a blinded exit challenge after approximately nine months of AR101 treatment was significantly higher (p<0.00001) than in the placebo group. Specifically, the median tolerated dose of peanut protein for AR101-treated patients improved 100-fold, from 10 mg at baseline to 1,000 mg at exit. The trial also greatly exceeded a 15% lower-bound of the 95% confidence interval (CI) of the difference between treatment arms for all endpoints.

In addition, the safety profile and completion rate observed in ARTEMIS are consistent with the results seen in previous AR101 clinical trials. Notably, no cases of anaphylaxis or of eosinophilic esophagitis (EoE) were observed. Aimmune plans to present full results in an oral presentation at the European Academy of Allergy and Clinical Immunology (EAACI) Congress in early June.

“We are very pleased with the results of the ARTEMIS trial, which demonstrate that AR101 significantly improved the ability of patients to tolerate the 1,000-mg dose of peanut protein in the exit food challenge, which correlates to at least three or four peanuts. This level of protection provides ample buffer beyond a typical bite of a peanut-containing food in the real world,” said Jayson Dallas, M.D., President and CEO of Aimmune. “AR101 has the potential to become the first approved therapy for peanut allergy in both the United States and Europe, where up to two percent of children in many countries are affected. If approved, AR101 could significantly reduce their risk of severe, potentially life-threatening reactions to peanut exposures and provide peace of mind to them and their families.”

The ARTEMIS findings reinforce the results from the highest level tested in Aimmune’s landmark phase 3 PALISADE trial, which found that 50.3% of AR101-treated patients tolerated a single highest dose of 1,000 mg of peanut protein (2,043 mg cumulative) after approximately six months of dose escalation followed by six months at a daily therapeutic dose of 300 mg, compared to 2.4% of placebo patients (p<0.00001). Full results from the PALISADE trial were published in November 2018 in the New England Journal of Medicine.

“The ARTEMIS data demonstrate that most patients exceeded what we consider to be protective levels well before a full year of treatment. It’s gratifying to see how these data build upon the insights gained throughout the entire AR101 program regarding the desensitization process and the ability of our patients to tolerate relatively large challenge-doses of peanut protein,” said Daniel Adelman, M.D., Chief Medical Officer of Aimmune. “When added to our prior experiences with AR101, these data enable us to better define the time course of the desensitization and on-going immunomodulation processes as treatment continues.”

The randomized, double-blind, placebo-controlled phase 3 ARTEMIS clinical trial enrolled 175 children and adolescents ages 4 to 17 from 18 sites in France, Germany, Ireland, Italy, Spain, Sweden and the United Kingdom. Patients underwent approximately six months of dose escalation and then three months at a daily therapeutic dose of AR101 at 300 mg or placebo, followed by an exit double-blind, placebo-controlled food challenge. The primary efficacy endpoint was patients’ ability to tolerate a 1,000-mg single dose of peanut protein, the equivalent of approximately three to four peanut kernels (2,043 mg cumulative, equivalent to seven or eight peanut kernels).

Based on these positive results, Aimmune intends to submit a marketing authorization application (MAA) for AR101 to the European Medicines Agency (EMA) in mid-2019. Aimmune submitted a biologics license application (BLA) for AR101 to the U.S. Food and Drug Administration (FDA) in December 2018, and its review by the agency began following the end of the U.S. government shutdown in January 2019. The FDA informed Aimmune that the BLA will be reviewed under a 12-month target review period, as measured from the January 2019 start date. Consequently, review of the BLA may take until late January 2020.