The Food and Drug Administration (FDA) in the US has approved the allergen powder, Palforzia, an oral immunotherapy to mitigate allergic reactions which includes anaphylaxis, caused by the accidental peanut exposure in patients with a confirmed peanut allergy.
The efficacy of the allergen powder was established in a randomised, double-blind trial with 496 children (aged 4 to 17 years) of which 372 received the allergen powder, were given a maintenance dose of 300mg/day (after a dose titration phase) for total of 24 weeks.
The primary outcome measure was the proportion of participants who could ingest a challenge dose of 600mg (roughly two peanuts) of peanut protein without dose-limiting symptoms at the trial end. A secondary outcome was the proportion of participants tolerating and 300 and 100mg dose also at the study end. The results showed that 62.7% of those given Palforzia tolerated a dose of 300mg of peanut protein with no more than mild symptoms, compared to 4% in the placebo group. For the secondary outcome, 76.6% and 50.3% tolerated a 300 and 100mg dose respectively compared with 8.1% and 2.4% in the placebo group.
Palforzia must be taken continuously and is indicted for children aged 4-17 years and in those 18 years and over. However, patients still need to practice allergy avoidance and carry an adrenalin injector.
Peanut allergen powder (Palforzia). JAMA 2020;324(2):192-3.