A panel of independent advisors to the FDA voted on Friday to recommend approval of an experimental peanut allergy drug from Aimmune Therapeutics. But concern about the risks of an allergic reaction to the therapy led the committee of mostly physicians to also recommend a safety plan to ensure that clinicians, patients, and their families understand the dangers that can come with treatment.
The vote was 7-2 in favor of recommending approval based on data that Brisbane, CA-based Aimmune (NASDAQ: AIMT) presented about its therapy, Palforzia. Asked whether to recommend approval of the therapy with additional safeguards, panelists voted 8-1. Advisory panel recommendations are not binding. The FDA considers them during drug reviews but does not always follow them. A decision on Palforzia is expected in January 2020.
Palforzia is a powder made from peanut flour. Daily doses of the powder, which is consumed with food, increase over time and gradually desensitize patients to peanuts. After about six months, patients would continue taking the top daily dose in order to maintain desensitization. Aimmune developed its therapy to provide precise doses of peanut and food proteins at each step of treatment.
The Aimmune therapy is not intended to eliminate peanut allergy. Rather, the oral immunotherapy was developed to reduce the frequency and severity of life-threatening allergic reactions. Aimmune aims to address accidental exposures to peanut protein that children 4 to 17 years of age can encounter in their daily lives.
Most of the panelists at the daylong hearing said that the data presented by Aimmune showed that patients benefited from treatment with Palforzia. The two “no” votes came from Andrea Apter, a professor of allergy and immunology at the University of Pennsylvania, and John Kelso, a physician in the Scripps Clinic in San Diego. Both said not enough is known about how the drug will affect accidental exposure, which Kelso noted was not directly addressed by the controlled environment of Aimmune’s clinical trials.
But Gailen Marshall, a professor of allergy and immunology at the University of Mississippi Medical Center, noted that there’s precedent for drugs winning FDA approval based on surrogate endpoints, substitute indicators of how a drug is working that may relate to its impact on a disease. In explaining his “yes” vote, Marshall said the FDA can monitor Palforzia over time, as it has done with many new therapies.
While there was general consensus about Palforzia’s effectiveness, Aimmune’s therapy has also sparked safety concerns. FDA scientists noted that the treatment caused allergic reactions and other side effects in nearly 90 percent of patients who received it. Also, 12 patients treated with the drug developed eosinophilic esophagitis, accumulation of a type of white blood cell in the esophagus that leads to chest pain and difficulty swallowing.
Panelists recommended a Risk Evaluation and Mitigation Strategy (REMS), a safety plan that accompanies a drug and conveys the risks that come with treatment. REMS plans are worked out between the FDA and the drug company. But the panel recommended that the plan require patients to have a valid prescription for epinephrine, and that their caregivers also carry the injectable medication used to quickly treat allergic reactions. The panel also recommended that dose escalation of the Aimmune therapy be done in facilities capable of treating allergic reactions.
In a Friday afternoon research note, Piper Jaffray analyst Christopher Raymond wrote that the REMS program and recommendations of additional warnings were not a surprise, and Aimmune has already planned a strategy to manage safety risks. He added that the panel vote improves the chances of an FDA approval for Palforzia. If it reaches the market, Piper Jaffray projects the drug could generate $69 million in revenue in 2020, growing to $1.5 billion in annual sales by 2025.