A phase 1, randomized, double-blind, crossover study compared the cardiac repolarization effect of therapeutic (100 mg) and supratherapeutic (400 mg) ubrogepant doses versus placebo, with moxifloxacin 400 mg as open-label, active control. Healthy adults were randomized to 1 of 12 treatment sequences, with inter-treatment 7-day washouts. QT interval corrected for heart rate (Fridericia correction; QTcF) was measured at baseline (predose) and for 25 hours postdose on days 1, 8, 15, and 22. The primary outcome was the largest time-matched mean difference from baseline in QTcF interval change (ΔΔQTcF). The largest upper 2-sided 90% CI limit for each ΔΔQTcF was compared with a 10 msec threshold to evaluate QT effect of ubrogepant. Other outcomes included adverse event (AE) incidence, plasma concentrations of study medications, and frequency of extreme QTcF interval values.