Longer‐Term Safety and Efficacy Measures of AR101 Oral Immunotherapy for Peanut Allergy: Results from a Phase 3 Follow‐On Study: 776

Abstract

Tara F. Carr, MD FAAAAI, Wayne G. Shreffler, MD PhD FAAAAI, Noelle M. Griffin, PhD, Karin Ros en, MD, PhD, Rezi Zawadzki, DrPH, John Matthews, MB BS BSc, Daniel C. Adelman, MD, and Stacie M. Jones, MD; Asthma and Airway Disease Research Center, University of Arizona, Tucson, AZ, Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, Aimmune Therapeutics, Brisbane, CA, UAMS/Arkansas Children’s Hospital, Little Rock, AR. RATIONALE: Of subjects who completed the phase 3 study of the experimental treatment AR101 for peanut allergy (PALISADE), 76% of AR101-treated subjects vs 5.4% of placebo-treated tolerated >_600mg of peanut protein at exit double-blind, placebo-controlled food challenge (DBPCFC). Adverse events (AEs) were mostly mild-to-moderate in severity. The ability to tolerate doses >1000 mg and safety beyond the initial maintenance period has not been established and initial findings from the ongoing study are reported. METHODS: PALISADE completers were eligible to enter the follow-on study and continue AR101 daily maintenance for 6 months before the next DBPCFC, which included an additional 2000 mg challenge dose. AEs and discontinuations were recorded and compared to the prior 6-month maintenance period. RESULTS: 117 of 316 (37%) AR101-treated PALISADE subjects enrolled in the daily maintenance regimen; the remainder were assigned to other dosing regimens (not included in this analysis). 100 (85%) subjects have completed the DBPCFC to date. AEs, regardless of causality, were similar during both maintenance periods (PALISADE 88% vs follow-on 81.2%). Three subjects (2.6%) discontinued due to AEs, 2 were treatmentrelated (1 EoE, 1 mild systemic reaction). The median tolerated dose was 1000mg with 49% of subjects to date being able to tolerate the highest challenge dose of 2000mg. Of the subjects who tolerated <1000 mg at PALISADE exit, 64% (27/42) could tolerate a higher challenge dose after extended maintenance. CONCLUSIONS: 300 mg daily of AR101 was well tolerated in the ongoing follow-on study; the majority of subjects could tolerate higher challenge amounts (1000 mg and 2000 mg) of peanut protein after additional maintenance.