A Phase 1, Randomized, Placebo‐Controlled, Multiple‐Dose, Double‐Blind Study to Evaluate and Compare the Pharmacokinetics and Safety of Rimegepant in Healthy Adult Japanese and Caucasian Individuals

This Phase 1, randomized, placebo-controlled, double-blind study assessed the pharmacokinetic profile of rimegepant (25, 75, or 150 mg once daily for 14 days) in healthy Japanese and Caucasian adults. Exposures were modestly increased in Japanese participants compared with Caucasian participants following a single dose of rimegepant (Day 1); fold-change (expressed as geometric mean ratio) for Japanese versus Caucasian participants ranged 1.13-1.55 for maximum plasma concentration (C_max) and 1.22-1.48 for area under the concentration-time curve to one dosing interval (AUC_tau) across all doses. Generally, rimegepant exposures were also similar or slightly higher in Japanese participants compared with Caucasian participants at steady state (Day 14); fold-change for Japanese versus Caucasian participants ranged 0.97-1.30 for C_max,ss and 1.10-1.38 for AUC_tau,ss across all doses. Analysis of dose-normalized exposures confirmed higher rimegepant exposure in Japanese participants than Caucasian participants. These effects were due to differences in body weight in Japanese and Caucasian participants since post hoc analyses, where exposure parameters were normalized to body weight and to a 75-mg dose of rimegepant, showed that differences in C_max and AUC_tau between the ethnic groups were <20% following a single dose (Day 1) and <5% at steady state (Day 14). Greater than dose-proportional increases in rimegepant exposure were observed in both Japanese and Caucasian participants. Overall, rimegepant demonstrated a favorable safety profile similar to placebo in both Japanese and Caucasian participants, with no serious or severe adverse events and no clinically relevant findings regarding laboratory tests, vital signs, electrocardiograms, Sheehan-Suicidality Tracking Scale scores, or physical examinations observed.