A Two-Stage Adaptive Design in Phase 2 Clinical Trials for Acute Treatment of Migraine

In the development of acute migraine treatments, traditional phase 2 dose-finding trial designs are particularly challenging when a wide dose range needs to be investigated. In this article, an adaptive two-stage dose-finding design is introduced. The proposed design combines traditional phase 2a and 2b to serve the dual purpose of proof of concept and dose finding through the use of an unblinded interim analysis that provides an opportunity for adaptation. The design has a fixed total sample size but includes provisions for discontinuation of less effective doses at the interim analysis to allow for the allocation of patients into a more promising range of doses. The interim adaptation is designed to increase the amount of information collected on more effective doses and increase study power as compared to a traditional nonadaptive dose-finding design. On the other hand, despite the interim look and adaptation of the design, conventional statistical analyses of the final data can still be used for the final analysis and provide proper inferences with adequately controlled type I error and an ignorable amount of bias.