A slow, low-dose peanut oral immunotherapy (OIT) regimen enabled most peanut-allergic preschool children to achieve sustained unresponsiveness after three years of treatment, according to findings from the SMACHO randomized controlled trial conducted in Sweden.
The study evaluated whether gradual up-dosing combined with a relatively low maintenance dose could improve the safety profile of peanut OIT in very young children while maintaining efficacy.
Peanut allergy affects up to 2% of children in many Western countries and is associated with a risk of severe allergic reactions and reduced quality of life. Although OIT has emerged as a promising treatment strategy, concerns remain regarding treatment-related adverse events, particularly with protocols involving rapid escalation or high maintenance doses.
In the SMACHO trial, 75 peanut-allergic children aged 1-3 years were randomized in a 2:1 ratio to receive peanut OIT or continue peanut avoidance. Children assigned to OIT underwent dose increases every 4-6 weeks before reaching a maintenance dose of 285 mg peanut protein daily. After three years of therapy, participants completed a 4-6 week peanut-free period before repeat challenge testing.
The primary endpoint was sustained unresponsiveness, defined as tolerating at least 750 mg of peanut protein after the avoidance phase. Researchers found that 82% of treated children achieved this outcome. Median cumulative tolerated dose after treatment reached 5000 mg peanut protein, versus only 3 mg among children who avoided peanut.
Safety outcomes were favorable overall. Adverse reactions occurred during 0.7% of administered doses, and most events were mild. Six children experienced eight severe dose-related reactions, including breathing difficulties, reduced general wellbeing, or anaphylaxis.
The investigators concluded that slow up-dosing with a low maintenance dose may offer a safer alternative to more intensive OIT protocols and could be feasible for wider clinical implementation. Combined with early dietary peanut introduction, the approach may help reduce the future burden of peanut allergy.