Early-life peanut oral immunotherapy associated with long-term ingestion and immunologic changes

Background: The IMPACT trial (NCT01867671) demonstrated strong desensitization and the potential for remission with peanut oral immunotherapy (pnOIT) in 1- to 3-year-olds. Data on long-term outcomes of early intervention oral immunotherapy (OIT) are limited. Objective: IMPACT-PLuS sought to assess the long-term efficacy, safety, and mechanistic changes related to early-life pnOIT. Methods: Participants randomized in IMPACT (n = 146) were recruited. The primary outcome was long-term efficacy, defined as ongoing peanut consumption. Secondary outcomes included safety, peanut serology, and skin prick tests. Participants were categorized according to IMPACT treatment (pnOIT, placebo) and participation in any additional peanut allergy intervention apart from guidance given at the end of the IMPACT trial. Patients were grouped as follows: group A, pnOIT with no subsequent intervention; group B, pnOIT with subsequent intervention; group C, placebo OIT with no subsequent intervention; and group D, placebo OIT with subsequent intervention. Results: Follow-up data were available for 78 of the 146 IMPACT participants (aged 9-14 years; 8-11 years after IMPACT enrollment). Fifty-eight received pnOIT in IMPACT. Overall, 80% (32/40) of group A were eating peanut at follow-up (48/58, 83%, of the entire IMPACT follow-up pnOIT group), with 35% (14/40) eating ≥1000 mg peanut. All 15 subjects from the IMPACT remission group were eating peanut at follow-up. Peanut reactions were reported by 35% (14/40) in group A, with epinephrine therapy received by 5. Compared with group C (placebo), group A had significantly lower levels of peanut and Ara h 2 IgE, and higher peanut and Ara h 2 IgG4. Conclusions: pnOIT initiated early in life can have long-term, sustainable impact, both clinically and immunologically.