Drug: Palforzia (AR101)
Used for: peanut allergy
Est. 2024 sales: $1.28 billion
Aimmune is taking a big swing with its immunotherapy Palforzia (AR101) in a food allergy field where avoidance is the norm. Despite skepticism from some market watchers, the FDA's approval could put Palforzia on the path to blockbuster status in the next few years.
Palforzia could hit an estimated $1.28 billion in sales by 2024, according to EvaluatePharma, as a peanut allergy immunotherapy that works by desensitizing patients through gradual doses of peanut protein.
On Friday, the FDA approved Palforzia as a treatment for peanut allergy reactions, including anaphylaxis. In September, an FDA advisory committee panel voted 7-2 to recommend approval of the drug.
In a note to investors in March 2019, Credit Suisse analyst Vamil Divan, M.D., said physicians were largely positive on the clinical need for Palforzia but raised concerns about the drug's commercial chances.
"We believe there are more investor questions on the commercial opportunity for the product given the need for frequent office visits and GI side effects during the up-dosing period," Divan wrote. "However, we see significant interest in the product from physicians and patients/parents, a side effect profile that appears manageable and a commercial opportunity that can be addressed through a targeted sales force."
In its recommendation, the FDA's advisory committee voted 8-1 in favor of a safety plan called a Risk Evaluation and Mitigation Strategy, or REMS, proposed by the agency, to support the use of Palforzia in children aged 4 to 17.
This plan mandated that any patient potentially prescribed Palforzia has a valid prescription for injectable epinephrine, caregivers/patients attest to carrying injectable epinephrine while taking Palforzia and the initial dose escalation and the first dose of each up-dosing level must be given at a certified site capable of treating systemic allergic reactions.
The FDA based its review on Palforzia's yearlong Palisade trial, which tested the treatment against placebo in 555 patients aged 4 to 55. The vast majority of them were children and adolescents, the age group for which Aimmune sought approval.
At the start of the trial, patients could not tolerate 100 mg or less of peanut protein—a fraction of a single peanut, which weighs in at about 300 mg. Patients were given a higher dose of the treatment every two weeks until they reached a maintenance dose of 300 mg. After one year of treatment, 67% of patients in the intent-to-treat population could tolerate 600 mg of peanut protein, about two peanuts or a small bite of a peanut butter sandwich, compared to 4% of patients who received placebo.
In early 2019, a government shutdown delayed the FDA's review of Palforzia as a direct consequence of a “lapse in appropriations." In other words, the gap hampered the agency’s ability to raise further funding through user fees, the drugmaker said.
Editor's Note: This story has been updated to reflect the FDA's approval of Palforzia on Friday, Jan. 31.