Dose-finding Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of CK-3773274 in Adults With Hypertrophic Cardiomyopathy

This was a Phase 2, multi-center, randomized, placebo-controlled, double-blind, dose-finding study in participants with symptomatic HCM. The study consisted of 4 cohorts. For Cohorts 1 and 2, participants with obstructive HCM (oHCM) and not receiving disopyramide were randomized 2:1 to active or placebo treatment and received up to 3 escalating doses of aficamten (5, 10, and 15 mg once daily in Cohort 1 and 10, 20, and 30 mg once daily in Cohort 2) or placebo based on site-read echocardiographic guidance. Cohort 3 consisted of participants with oHCM whose background HCM therapy included disopyramide. All participants in Cohort 3 received up to 3 escalating doses of aficamten (5, 10, and 15 mg once daily) based on echocardiographic guidance. Cohort 4 consisted of participants with non-obstructive HCM (nHCM) on standard of care background therapy. Cohort 4 participants received up to 3 doses of aficamten (5, 10, and 15 mg once daily), titrated based on site-read echocardiographic guidance. In all 4 cohorts, treatment duration was 10 weeks with a 4-week follow-up period after the last dose.