AIMS: Efficacy, safety, and pharmacokinetics of the selective PPARα modulator pemafibrate as once-daily extended-release (XR) tablets were compared with those of twice-daily immediate-release (IR) tablets in patients with hypertriglyceridemia. METHODS: A multicenter, randomized, single-blind, active-controlled crossover, phase 2 clinical pharmacology study was performed in patients with hypertriglyceridemia. Patients were randomly assigned to IR 0.2 mg/day, XR 0.4 mg/day, or XR 0.8 mg/day before/after meals (fasted/fed) and treated for a total of eight weeks. The primary endpoint was percentage change in fasting serum triglycerides (TG). RESULTS: Of 63 randomized patients, 60 received the study drug. Patients were 78.3% male, mean age (±SD) 57.5±9.8 years, BMI 25.5±3.7 kg/m CONCLUSIONS: In patients with hypertriglyceridemia, XR substantially lowered TG at all doses, with maximum effectiveness at 0.4 mg/day, the dose approved in Japan, to a level comparable to IR 0.2 mg/day. There were no safety concerns up to 0.8 mg/day.