METHODS: ARC004 is a multicenter, open-label extension study of peanut OIT that follows a pivotal randomized controlled trial where all subjects received six months of daily maintenance. ARC004 is designed to offer extended maintenance (EM) OIT, with some subjects receiving daily regimens and others conditionally receiving incrementally lengthened dosing intervals [e.g., every other day (QOD), twice weekly (BIW), and weekly (QW)]. Stringent stopping criteria are in place in this ongoing exploratory study to ensure safety; continued effectiveness, as measured by double-blinded, placebo-controlled peanut challenges will be assessed at study completion.
RESULTS: At the time of this writing, 258 subjects have been enrolled, of which 190 received active treatment in the prior study and began EM in ARC004. 120 continued daily dosing. 50 additional subjects began QOD dosing regimens for four weeks, and advanced to BIW for 24 additional weeks as tolerated. Of these, 13 of 13 successfully tolerated QOD dosing and advanced to BIW; 35 (70%) currently remain in QOD and 2 (4%) withdrew consent, unrelated to adverse events. No subjects have yet reached QW dosing.
CONCLUSIONS: ARC004 is an ongoing, novel study that will produce critically-needed hypothesis-generating data concerning the safety and efficacy of non-daily EM regimens in peanut OIT. Although patients have thus far tolerated alternative dosing intervals, analysis of continued effectiveness is pending.