Two-year post-treatment outcomes following peanut oral immunotherapy.

Abstract

Background: The PPOIT-003 Phase 2b randomized trial showed that both probiotic peanut oral immunotherapy (PPOIT) and peanut oral immunotherapy (OIT) were highly effective at inducing sustained unresponsiveness (SU) and desensitization compared to placebo. Upon completion of the PPOIT-003 trial, subjects were eligible to enroll in the PPOIT-003LT follow-on study, investigating longitudinal trends in peanut ingestion, reactions, and health-related quality of life (HRQOL). Here, we present PPOIT-003LT outcomes at 1- and 2-years post-treatment, by clinical allergy status. Method(s): Participants received the following post-treatment peanut ingestion advice: SU, ad libitum intake; Full desensitization without SU (DWSU), 1-2 peanuts daily; Persistent allergy (PA), strict avoidance. Peanut intake and reactions were monitored prospectively. HRQOL was assessed by Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF). Result(s): 86% (151/176) of eligible children enrolled (n=69 SU, n=38 DWSU, n=44 PA). At 1-year and 2-years post-treatment, 99% and 96% SU participants ate peanut ad libitum, whilst 97% and 89% DWSU participants ate 1-2 peanuts daily. The proportion of participants reporting any reactions reduced over time in all groups: SU 28% in the 1st-year post-treatment, 16% in the 2nd-year post-treatment; DWSU 58% and 37%; PA 12% and 7%. In the 1st-year post-treatment, more SU participants reported reactions compared to PA (Risk Difference 0.16 [95% CI 0.02, 0.30], p=0.029); however by the 2nd-year post-treatment, similar proportions of SU and PA participants reported reactions (RD 0.09 [95% CI -0.03, 0.20], p=0.127), suggesting that SU participants were no worse off than allergic participants. More DWSU participants reported reactions compared with PA during both the 1st-year and 2nd-year post-treatment (RD 0.46 [95% CI 0.28, 0.65], p<0.001; RD 0.30 [95% CI 0.13, 0.47], p=0.001). In the 2nd-year post-treatment, no SU participants reported moderate reactions, severe reactions, or adrenaline injector usage, vs 14%, 10% and 5% of DWSU participants. SU participants had significantly greater improvement in HRQOL (adjusted for baseline) compared with DWSU participants (MD -0.54 [95% CI -0.99, -0.10), p=0.017] and PA participants (MD -0.82 [95% CI -1.25, -0.38], p<0.001). Conclusion(s): SU participants reported fewer reactions, less severe reactions and greater HRQOL improvement compared with DWSU and PA participants, suggesting that SU is a preferred treatment outcome over both desensitization or remaining allergic.