FDA Approves AR101 as First Peanut Allergy Immunotherapy

The US Food and Drug Administration (FDA) has approved the first immunotherapy indicated for a food allergy.

AR101 (Palforzia), an oral peanut-protein immunotherapy from Aimmune Therapeutics, has been approved for the reduction of allergic reaction incidence and severity in patients aged 4-17 years old with a peanut allergy.

The indication was granted on the strength of a Biologics License Application (BLA) which included findings from 7 clinical trials and the 7-2 committee vote-support from the Allergenic Products Advisory Committee (APAC) in September 2019.

The phase 3 PALISADE trial, a double-blind, randomized study including 551 patients aged 4-55 years old with peanut allergy, showed two-thirds (67.2%) of allergen-treated patients aged 4-17 years old were capable of ingesting at least 600 mg of peanut protein without dose-limiting symptoms at 24 weeks.

Treated adult patients did not achieve statistically significant differences in efficacy endpoints.

Investigators evaluated 2 datasets to assess the safety of the therapy among patients 4-17 years old: the controlled safety population of 1001 patients and the integrated population of 812 patients.

Patients treated with AR101 in the pediatric safety population reported an increased rate of systemic allergic reactions (9.4%) than placebo-treated patients (3.8%).

During maintenance, 8.7% of treated patients reported a systemic allergic reaction, compared to just 1.7% of placebo patients. Another 7.7% of treated patients used epinephrine; just 3.4% of placebo patients did.

Investigators also observed a proportion of treated patients discontinuing care due to adverse events (9% of pediatric, 14.3% of adult patients in PALISADE). In the controlled safety population, 3 treated patients developed treatment-emergent eosinophilic esophagitis (EoE), as well as some treated patients in follow-up studies.

In new study comparison data presented at the American College of Allergy, Asthma & Immunology (ACAAI) 2019 Scientific Meeting in Houston last November, investigators noted that 14% of patients in the PALISADE trial were administered epinephrine to relieve treatment-emergency adverse events (TEAEs) during a dose-escalation treatment stage that raised patient tolerance from 10 mg to 1000 mg peanut.

In an interview with HCPLive® while at ACAAI 2019, Douglas Mack, MD, a pediatric allergist at McMaster University, explained that a driving factor as to why food-allergic patient families are reticent of oral immunotherapies was the lack of a regulated product.

With that having changed today, the next major focus in ensuring families that peanut allergen exposure—for the right patients—could be a worthwhile benefit to reducing burdens and reactions associated with peanut allergy.

“This is not a curative procedure, that I'm aware of. And it's quite possibly long-term,” Mack said. “So when you look at that, and then you look at the possibility that there is risk involved here, you do have to prepare these families for this. And I think that this is what myself and my colleagues were talking about in the session today: this takes time.”

In a statement accompanying the approval, Jayson Dallas, MD, president and chief executive officer of Aimmune, called the approval a defining moment for both the company and the peanut allergy community.

“Our commercial field team is ready to begin engaging with allergists to help them prepare to safely incorporate PALFORZIA into their practices and, with approval in hand, our payer team can also immediately begin work to secure formulary access to PALFORZIA," Dallas said. "We view this approval as just the beginning for Aimmune, and it underscores our continued commitment to bringing innovative treatments to people with potentially life-threatening food allergies.”

AR101 previously received Breakthrough Therapy Designation as well as Fast Track Designation from the FDA.