- Question
- Does treatment with aficamten, a selective cardiac myosin inhibitor, improve exercise capacity as measured by peak oxygen uptake in adults with symptomatic obstructive hypertrophic cardiomyopathy?
- Design
- Phase 3, multicenter, randomized, double-blind, placebo-controlled trial enrolling 282 patients with 24 weeks of treatment.
- Population
- Adults with symptomatic obstructive hypertrophic cardiomyopathy; mean age 59.1 years, 59.2% men, baseline mean resting left ventricular outflow tract gradient of 55.1 mm Hg and mean left ventricular ejection fraction of 74.8%.
- Intervention
- Oral aficamten starting at 5 mg with a maximum of 20 mg, dose-adjusted according to echocardiography results, for 24 weeks (142 patients).
- Control
- Placebo with the same dose-adjustment scheme and duration (140 patients).
- Primary outcome
- Change from baseline to week 24 in peak oxygen uptake, assessed by cardiopulmonary exercise testing.
- Results
- The mean change in peak oxygen uptake was 1.8 ml/kg/min (95% CI, 1.2 to 2.3) with aficamten and 0.0 ml/kg/min (95% CI, -0.5 to 0.5) with placebo; the between-group difference was 1.7 ml/kg/min (95% CI, 1.0 to 2.4; P<0.001). All 10 prespecified secondary end points improved significantly with aficamten versus placebo.
- Safety
- The incidence of adverse events appeared similar in the two groups.
- Conclusion
- Among patients with symptomatic obstructive hypertrophic cardiomyopathy, aficamten produced a significantly greater improvement in peak oxygen uptake than placebo.
- Why it matters
- It provided phase 3 evidence that a second cardiac myosin inhibitor, with echocardiography-guided dose titration, improves functional capacity and symptoms in this disease, broadening the treatment options aimed at outflow tract obstruction.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 14, 2026