A Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive HCM Who Are Eligible for Septal Reduction Therapy

A Randomized, Double-blind, Placebo-controlled Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy Who Are Eligible for Septal Reduction Therapy

This is a randomized, double-blind, placebo-controlled, multi-center study in the United States (U.S.) that will evaluate the effect of mavacamten treatment on reducing the number of septal reduction therapy (SRT) procedures performed in subjects with symptomatic obstructive hypertrophic cardiomyopathy (oHCM [also known as HOCM]) who are eligible for SRT based on ACCF/AHA 2011 and/or ESC 2014 guidelines.

Key Inclusion Criteria:

• At least 18 years old at screening and body weight > 45 kg at screening
• Diagnosed with oHCM consistent with current ACCF/AHA 2011 and meet their recommendations for invasive therapies
• Referred or under active consideration within the past 12 months for SRT procedure and willing to have SRT procedure
• Has documented left ventricular ejection fraction (LVEF) ≥ 60% at Screening
• Has documented oxygen saturation at rest ≥ 90% at Screening

Key Exclusion Criteria:

• Persistent or permanent atrial fibrillation and subject not on anticoagulation for ≥ 4 weeks prior to screening and/or not adequately rate controlled ≤ 6 months prior to screening
• Previously treated with invasive septal reduction (surgical myectomy or percutaneous alcohol septal ablation [ASA])
• For individuals on beta blockers, calcium channel blockers, or disopyramide, any dose adjustment of these medications < 14 days prior to screening or an anticipated change in regimen during the first 16 weeks of the study
• Any medical condition that precludes upright exercise stress testing
• Paroxysmal, intermittent atrial fibrillation with atrial fibrillation present at screening
• Prior treatment with cardiotoxic agents, such as doxorubicin or similar
• Has a history or evidence of any other clinically significant disorder, condition, or disease that would pose a risk to subject safety or interfere with the study evaluation, procedures, or completion