CoFAR investigators previously reported 52-week outcomes from a randomized, controlled trial of peanut EPIT, observing modest and statistically significant induction of desensitization, highest in children ages 4-11 years.

To evaluate changes in efficacy, safety, and mechanistic parameters following extended open-label peanut EPIT.

Peanut-allergic participants (4-25 years) received 52 weeks of placebo (PLB), Viaskin Peanut 100 mcg (VP100) or 250 mcg (VP250), then crossover to VP250 for placebo (PLB-VP250) and VP100 (VP100-VP250) participants and continuation of treatment for VP250 participants (total=130 weeks of active EPIT). Efficacy was assessed by DBPCFC (5044 mg peanut protein) and adherence, safety and mechanistic parameters were evaluated.

At week 130, desensitization success was achieved in 1/20 (5%) PLB-VP250, 5/24 (20.8%) VP100-VP250, and 9/25 (36%) VP250 participants with median successfully consumed dose (SCD) change from baseline of 11.5 mg, 141.5 mg, and 400 mg, respectively. Median age (years) for week 130 desensitization success was 6.2 years (IQR:5.2,9.1) versus 9.4 years (IQR:7.6,12.8) for failures (p<0.001). Adherence was 96%. Adverse reactions were predominantly local patch-site reactions. Significant increases in peanut- and Ara h2-specific IgG4 observed at week 52 persisted to week 130. By a post-hoc analysis, there were no statistically significant increases from week 52 to week 130 in either desensitization success or SCD.

Extended treatment with VP250 was well-tolerated and desensitization observed at week 52 persisted between weeks 52 and 130. Treatment success was observed predominantly in younger participants with younger age at initiation of active therapy an important predictor of success.