Interaction Between Baseline Participant Factors and Treatment Effects Following Peanut Oral Immunotherapy

BACKGROUND:The PPOIT-003 multi-center randomized trial found that both Probiotic Peanut Oral ImmunoTherapy (PPOIT) and peanut OIT alone (OIT) were effective compared to placebo at inducing clinical remission following 18 months of treatment, and improving health-related quality of life (HRQL) at 12-months post-treatment. Understanding treatment effect modifiers can optimize outcomes through precision care. OBJECTIVES:This post hoc study aims to examine baseline clinical and demographic participant factors that modified treatment effects. METHODS:Study sample included 201 children (1-10 years) with challenge-confirmed peanut allergy. Exposure variables were baseline clinical and demographic factors. Outcomes were remission (double blind placebo-controlled food challenge, cumulative 4950mg peanut protein, at 8-weeks post-treatment) and HRQL (change in Food Allergy Quality of Life Questionnaire-Parent Form score). Interactions between baseline factors and treatment effects on remission and HRQL were explored with regression models. RESULTS:A higher degree of peanut sensitivity (large peanut SPT, high peanut sIgE, low reaction eliciting dose at study entry challenge), and other concurrent allergic conditions (multiple food allergies, asthma or wheeze) were associated with decreased likelihood of attaining remission following both PPOIT and OIT treatment. History of anaphylaxis was associated with reduced likelihood of remission after PPOIT compared to OIT. For the HRQL outcome, there was evidence that sex, history of anaphylaxis and age modified treatment effects. CONCLUSIONS:Baseline participant factors modify PPOIT and OIT effects on remission and HRQL. Considering modifiers of treatment effect during participant selection may optimize treatment success and clinical trial design toward specific outcomes, such as achievement of remission.