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 1–3-year-olds. Data on long-term outcomes of early intervention OIT are limited. Objective The objective of this study (IMPACT-PLuS) was 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 based on IMPACT treatment (pnOIT, placebo) and participation in any additional peanut allergy intervention apart from guidance given at the end of the IMPACT trial (Group A: pnOIT- no subsequent intervention; Group B: pnOIT- subsequent intervention; Group C: placebo OIT- no subsequent intervention; Group D: placebo OIT- subsequent intervention). Results Follow-up data were available for 78 of the 146 IMPACT participants, age range 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 (83% (48/58) of the entire IMPACT follow-up pnOIT group), with 35% (14/40) eating ≥1000mg peanut. All (15/15) from the IMPACT remission group were eating peanut at follow-up. Peanut reactions were reported by 35% (14/40) in Group A, epinephrine use by 5. Compared with Group C (placebo-treated), Group A had significantly lower levels of peanut and Ara h2 IgE, and higher peanut and Ara h2 IgG4. Conclusions This study suggests that pnOIT initiated early in life can have long-term, sustainable impact both clinically and immunologically.