An investigational topical treatment for peanut allergy in children has shown promising long-term efficacy.
In the study, the initial protocol escalated the oral challenge of peanut protein until hypersensitivity symptoms were elicited. After 3 years of treatment, 75.9% of children aged 4 to 11 had increased the “eliciting dose” (ED) of peanut protein.
The primary efficacy outcome was the difference in responder rate with active treatment versus placebo, with a caveat that the lower boundary to the 95% confidence interval had to be no lower than ≥15 percentage points. Responders were those who maximally tolerated peanut protein at a dose of 300 mg at 12 months if baseline tolerance was ≤10 mg, or 1,000 mg if baseline tolerance was >10-300 mg.
Although there was a significant difference in responder rate, the risk difference missed the prespecified statistical component.
All participants who reached an eliciting dose ≥1000mg at month 36 were eligible to continue the study for an additional two months without treatment while maintaining a peanut-free diet. A double-blind, placebo-controlled food challenge to determine the 'eliciting dose' (ED) was then given at month 38. The analysis revealed that 77.8 per cent maintained desensitisation with an ED ≥1,000mg.