Two-year post-treatment outcomes following peanut oral immunotherapy in the Probiotic and Peanut Oral Immunotherapy-003 Long-Term (PPOIT-003LT) study

Background: Few studies have examined long-term outcomes following oral immunotherapy (OIT); none have examined long-term risks and benefits associated with distinct clinical outcomes (desensitization, remission). Methods: Participants completing the probiotic and peanut oral immunotherapy (PPOIT) -003 randomized trial were enrolled in a follow-on study, PPOIT-003LT. Peanut ingestion, reactions, and health-related quality of life (HRQOL) were monitored prospectively. Outcomes at 1-year and 2-years post-treatment were examined by treatment group and by post-OIT clinical outcome (remission, desensitization without remission [DWR], allergic). Results: 86% (151/176) of eligible children enrolled. Post-treatment peanut ingestion at 2-years post-treatment were similar for PPOIT (86.7%) and OIT (78.7%) groups, both higher than placebo (10.3%). Reactions reduced over time for all treatment and clinical outcome groups (PPOIT 31.7% to 23.3%, OIT 37.7% to 19.7%, placebo 13.8% to 6.9%; remission 27.5% to 15.9%; DWR 57.9% to 36.8%; allergic 11.6% to 7%). At 2-years post-treatment, similar proportions of remission and allergic participants reported reactions (RD 0.09 (95%CI -0.03, 0.20), p = .127), whereas more DWR participants reported reactions than remission (remission vs DWR: RD -0.21 (95%CI -0.39; -0.03), p = .02) and allergic (DWR vs allergic: RD 0.30 (95%CI 0.13, 0.47), p = .001) participants. At 2-years post-treatment, 0% remission versus 5.3% DWR versus 2.3% allergic participants reported adrenaline injector usage. Remission participants had significantly greater HRQOL improvement (adjusted for baseline) compared with both DWR (MD -0.54 (95%CI -0.99, -0.10), p = .017) and allergic (MD -0.82 (95%CI -1.25, -0.38), p < .001). Conclusion: By 2-years post-treatment, remission participants reported fewer reactions, less severe reactions and greater HRQOL improvement compared with DWR and allergic participants, indicating that remission is the patient-preferred treatment outcome over desensitization or remaining allergic.