AbstractIntroduction/AimsASP0367, or bocidelpar sulfate, is an orally administered small molecule that potently and selectively modulates peroxisome proliferator–activated receptor δ (PPARδ) to address mitochondrial dysfunction occurring in diseases including primary mitochondrial myopathy and Duchenne muscular dystrophy. The objectives of this first‐in‐human trial were to evaluate the safety/tolerability, pharmacokinetics, and pharmacodynamics of ASP0367 in healthy participants.MethodsIn this double‐blind phase 1 study, adult participants were randomized to single or multiple ascending oral doses of ASP0367 or placebo. The study duration was 1 and 14 days, respectively. Pharmacokinetic parameters under fed conditions were also evaluated.ResultsA total of 64 (single‐dose cohort) and 37 (multiple‐dose cohort) participants were included in the study. After single doses of 1 to 120 mg, ASP0367 was rapidly absorbed, with median time to maximum plasma concentration (tmax) of 1.50 to 2.24 hours under fasting conditions; ASP0367 concentrations declined in a multiphasic manner after reaching maximum plasma concentration. Under fed conditions, tmax was delayed 1.7 hours. After multiple once‐daily doses, mean half‐life of ASP0367 10 to 75 mg ranged from 14.1 to 17.5 hours; steady state was reached after 4 days. Negligible accumulation was observed after repeated dosing. No participants receiving ASP0367 discontinued treatment, and all treatment‐emergent adverse events were mild to moderate in severity; none were considered drug‐related. No clinically significant changes were observed on laboratory or electrocardiographic evaluation. Treatment‐ and dose‐dependent upregulation of six PPARδ target genes was observed with single and multiple doses of ASP0367.DiscussionASP0367, or bocidelpar sulfate, was well tolerated; rapid absorption, roughly dose‐proportional bioavailability, and effects on PPARδ target genes were demonstrated in healthy adult participants.