BACKGROUND: Peanut allergy is a common, life-threatening food allergy in children. We evaluated whether dupilumab, which blocks the activity of interleukin (IL)-4/IL-13, enhances the efficacy of oral immunotherapy (OIT) AR101 in pediatric patients with peanut allergy. METHODS: A Phase II, multicenter, randomized, double-blind study was conducted in the USA (NCT03682770) in pediatric patients (6-≤ 17 years old) with confirmed peanut allergy. Patients were randomized 2:1 to receive dupilumab + OIT or placebo + OIT during a 28-40-week up-dosing period. Patients in the dupilumab + OIT group were re-randomized 1:1 and received dupilumab + OIT or placebo + OIT during 24-week OIT maintenance, undergoing a 2044 mg (cumulative) of peanut protein double-blind, placebo-controlled food challenge (DBPCFC) following up-dosing, maintenance, and at 12-week post-treatment follow-up. RESULTS: The study enrolled 148 patients, 123 of whom were included in the modified full analysis set, with a mean age of 11.1 years. Dupilumab + OIT treatment (n = 84) led to a 20.2% increase (p <
0.05) in the number of patients who passed a DBPCFC to 2044 mg (cumulative) of peanut protein following the up-dosing period versus placebo (OIT alone, n = 39). Following the OIT maintenance period, continuous dupilumab treatment improved the number of patients who passed a DBPCFC to 2044 mg (cumulative) of peanut protein versus patients continuously on OIT alone (16.6% difference [95% CI -9.7, 42.8], p = 0.2123). Safety was consistent with known dupilumab safety profile. CONCLUSIONS: Dupilumab provided a modest increase efficacy of OIT in children and adolescents with peanut allergy, though it did not provide protection against OIT-related anaphylaxis. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03793608.