SILVER SPRING, Md. — The FDA’s Allergenic Products Advisory Committee voted Friday to recommend that Palforzia (formerly called AR101), a standardized peanut protein mixture, be approved for reducing incidence and severity of peanut allergy in pediatric patients.
Panel members voted 7-2 that the clinical trial’s efficacy data were adequate to justify approval, and 8-1 that the product is sufficiently safe. The latter vote was conditioned on the FDA’s requirement of a Risk Evaluation and Mitigation Strategy, or REMS, under which physicians would have to certify that patients prescribed Palforzia also have a valid prescription for an epinephrine autoinjector, in case of systemic allergic reactions while on treatment.
Palforzia is a powder containing 12 “Ara h” peanut proteins thought to be the principal allergens in peanuts. It will come packaged in pull-apart capsules or sachets, to be mixed into age-appropriate foods such as applesauce or pudding.
Manufacturer Aimmune Therapeutics is seeking approval to market the product for peanut-allergic individuals age 4-17.
Clinical studies showed substantial efficacy in cutting incidence and severity of allergic reactions, including anaphylaxis, according to an FDA staff review prepared for the committee. But the document also noted that half of participants developed reactions to Palforzia itself, a few needing epinephrine treatment.
Oral immunotherapy for peanut and other allergies have been in development for more than a decade. When some of the first data were presented in 2009, it set off a scramble — among clinicians as well as researchers — to make it a viable treatment in routine practice. But concerns about the consistency of store-bought peanut products gave impetus to commercial developers such as Aimmune to create pharmaceutical grade products that could be used in standardized dosing protocols.
In Palforzia’s clinical trials, patients were dosed under supervision in precise steps over a period of weeks, then kept for 6 months on a set maintenance dose. It’s likely that patients will need to stay on therapy indefinitely, particularly in light of a study coincidentally released Friday: it found that, in patients treated to a point where they could eat peanuts without incident, withdrawal of treatment (not with Palforzia, but a different product) led to waning tolerance over time.
Clinical data with Palforzia also indicated risk of allergic reactions with treatment. Four serious events related to the product were seen, among more than 700 patients treated. In addition, epinephrine use was roughly four times more common with Palforzia, and most doses were given outside of clinical settings.