Mavacamten in Patients With Hypertrophic Cardiomyopathy Referred for Septal Reduction: Week 128 Results From...

Area of Science:

• Cardiology
• Pharmacology
• Clinical Trials

Background:

• Obstructive hypertrophic cardiomyopathy (HCM) is a severe condition requiring treatment for symptomatic patients.
• Septal reduction therapy (SRT) is an option for patients with obstructive HCM.
• Mavacamten has shown short-term efficacy in reducing the need for SRT in obstructive HCM.

Purpose of the Study:

• To evaluate the longer-term effects of mavacamten in patients with obstructive HCM.
• To assess the proportion of patients who avoided SRT at 128 weeks.
• To determine the safety and efficacy of long-term mavacamten treatment.

Main Methods:

• A double-blind, randomized, placebo-controlled trial (VALOR-HCM) involving symptomatic obstructive HCM patients eligible for SRT.
• Patients received mavacamten or placebo for up to 128 weeks, with dose titration based on echocardiographic parameters.
• The primary endpoint was the proportion of patients proceeding with SRT or remaining guideline-eligible at week 128.

Main Results:

• At 128 weeks, 15.7% of patients met the composite endpoint (underwent SRT, were SRT-eligible, or SRT-status unevaluable).
• 80.5% of patients showed at least one New York Heart Association class improvement, with sustained reduction in left ventricular outflow tract gradients.
• 13.8% of patients experienced left ventricular ejection fraction <50%, and 10.2% developed new-onset atrial fibrillation.

Conclusions:

• Long-term mavacamten treatment in obstructive HCM patients resulted in sustained freedom from SRT at 128 weeks.
• Nearly 90% of patients remained on mavacamten, demonstrating sustained clinical benefit.
• Mavacamten offers a promising long-term therapeutic option for severely symptomatic obstructive HCM.