The IMPACT trial (2019–2023), a landmark Phase 3 study led by Dr. Stacie Jones, focused on the safety and efficacy of peanut OIT in young children aged 1 to 3 years. The study enrolled 146 children and administered increasing oral doses of peanut protein, up to a 2000 mg maintenance dose, over approximately 2.5 years. The results were significant: 71% of children in the treatment group tolerated a 5000 mg peanut protein challenge at the end of the trial, compared to only 2% in the placebo group. Importantly, 21% achieved sustained unresponsiveness, meaning they maintained tolerance to 5 grams of peanut protein upon re-challenge after stopping therapy for 26 weeks. The treatment was generally well tolerated, though some participants experienced mild-to-moderate allergic symptoms, and a few required epinephrine.
The IMPACT trial provided compelling evidence that early intervention with peanut OIT in toddlers can effectively increase tolerance and even induce longer-term immune changes in some children. It demonstrated that starting OIT during early immune system development may increase the chance of achieving lasting benefits, such as sustained unresponsiveness. While the therapy requires commitment, careful dosing, and monitoring, it represents a major advance in the management of peanut allergy. The trial also informed guidelines recommending that peanut OIT can be safely initiated in children under age 4, under the care of an allergy specialist.
https://pubmed.ncbi.nlm.nih.gov/35065784/