Efficacy and safety of rimegepant for the acute treatment of migraine in Japan: A dose-ranging, double-blind, randomized controlled trial

Abstract

Objective: The objectives of this study were to compare the efficacy, including dose response, and safety of rimegepant, an orally administered small-molecule calcitonin gene-related peptide receptor antagonist, with placebo for the acute treatment of migraine in Japan.

Background: There is a substantial unmet need for the acute treatment of migraine in Japan due to undesirable attributes of existing acute treatments.

Methods: In this Phase 2/3, double-blind, randomized trial, adults with a ≥1-year history of migraine were recruited to 50 study centers in Japan. Participants were randomly assigned to receive rimegepant 25 mg, rimegepant 75 mg, or placebo and instructed to treat a single migraine attack of moderate or severe pain intensity. The randomization was stratified by preventive migraine medication use (yes or no). The primary endpoint was the proportion of participants with pain freedom at 2 h post-dose. Formal hypothesis testing was conducted for rimegepant 75 mg versus placebo. Safety was assessed based on adverse events (AEs).

Results: The study was conducted from August 9, 2022, through January 19, 2024. A total of 706 treated participants were evaluable for efficacy (rimegepant 25 mg, n = 238; rimegepant 75 mg, n = 238; placebo, n = 230) and safety (rimegepant 25 mg, n = 239; rimegepant 75 mg, n = 238; placebo, n = 229). Response rates for pain freedom at 2 h post-dose were 21.0% (rimegepant 25 mg), 32.4% (rimegepant 75 mg), and 13.0% (placebo): percentage difference rimegepant 75 mg versus placebo was 19.4% (95% confidence interval 12.0-26.8%, p < 0.001). On-treatment AEs were reported by 7.1% (rimegepant 25 mg), 9.2% (rimegepant 75 mg), and 6.6% (placebo) of treated participants; all were mild or moderate in intensity and most were not considered related to the study drug.

Conclusion: Rimegepant 75 mg demonstrated efficacy superior to placebo for the acute treatment of migraine, with a favorable safety profile, in participants in Japan. A dose-response relationship was observed for rimegepant (NCT05399459).

Plain language summary: This randomized trial was designed to test the effectiveness and safety of rimegepant for the acute treatment of migraine among adults in Japan. Results indicated that rimegepant was more effective than placebo, and the 75 mg dose was observed to be more effective than the 25 mg dose. These results are similar to previous findings from clinical studies in other countries, and suggest that rimegepant can help patients with migraine in Japan.

Keywords: acute treatment; calcitonin gene‐related peptide receptor antagonist; headache; migraine; pain; rimegepant.