Continuous and Daily Oral Immunotherapy for Peanut Allergy: Results from a 2-Year Open-Label Follow-On Study

BACKGROUND: The randomized, controlled PALISADE trial demonstrated the benefit of daily oral immunotherapy with Peanut (Arachis Hypogaea) allergen powder-dnfp (PTAH, formerly AR101) in peanut-allergic children and adolescents. OBJECTIVE: ARC004, the open-label follow-on study to PALISADE, used 5 dosing cohorts to explore PTAH treatment beyond 1 year and alternative dosing regimens in peanut-allergic individuals. METHODS: Active arm (PTAH-continuing) PALISADE participants who tolerated 300-mg peanut protein at the exit double-blind placebo-controlled food challenge and placebo arm (PTAH-naive) participants could enter ARC004. PTAHcontinuing participants were assigned to receive daily (cohorts 1and 3A) or non-daily (cohorts 2, 3B, and 3C) dosing regimens; PTAH-naive participants were built up to 300 mg/d PTAH, followed by maintenance dosing. At study completion, partici-pants underwent an exit double-blind placebo-controlled food challenge with doses up to 2000 mg peanut protein. Data were assessed using descriptive statistics. RESULTS: Overall, 358 (87.5%) eligible participants (4-17 years) entered ARC004 (PTAH-continuing, n = 256; PTAH-naive, n = 102). Among PTAH-continuing participants, exposure-adjusted adverse event rates were 12.94 to 17.54/ participant-year and 25.95 to 42.49/participant-year in daily and non-daily dosing cohorts, respectively; most participants (83%) experienced mild or moderate adverse events. Daily dosing cohorts appeared to have higher desensitization rates than nonedaily dosing cohorts. Of all PTAH-continuing cohorts, cohort 3A had the longest daily dosing duration and the highest desensitization rates. Changes in immune markers with PTAH continuation demonstrated ongoing immunomodulation. Outcomes in PTAH-naive participants mirrored those of the PALISADE active arm. CONCLUSIONS: Continued daily PTAH treatment beyond 1 year showed sustained safety and efficacy. Ongoing immunomodulation was observed during the second year of treatment.(C) 2020 The Authors. Published by Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).