A Phase 2 Study of Mavacamten in Adults With Symptomatic Non-Obstructive Hypertrophic Cardiomyopathy (nHCM)

Key Inclusion Criteria:

Diagnosed with nHCM (hypertrophied and non-dilated left ventricle in absence of systemic or other known cause), with LV wall thickness ≥ 15mm at Screening or ≥ 13mm with a positive family history of HCM.
Age 18 and greater, Body weight > 45kg
Documented LVEF ≥ 55% at the Screening as determined by echo central lab
LVOT gradient < 30 mmHg at rest AND during Valsalva AND post-exercise
NYHA functional class II or III
Elevated NT-proBNP at rest

Key Exclusion Criteria:

History of syncope, sustained ventricular tachyarrhythmia with exercise, obstructive coronary artery disease or myocardial infarction within the past 6 months
History of resuscitated sudden cardiac arrest at any time or known appropriate implantable cardioverter defibrillator (ICD) discharge within 6 months prior to Screening
Current treatment with disopyramide or ranolazine (within 14 days prior to Screening)
Current or planned treatment during the study with a combination of beta-blockers and calcium channel blockers
Has been treated with invasive septal reduction (surgical myectomy or percutaneous alcohol septal ablation [ASA]) within 6 months prior to Screening
History of resting or post-exercise LVOT >30 mmHg unless subsequently treated by septal reduction
Has QTc Fridericia (QTcF) >480 ms or any other ECG abnormality considered by the investigator to pose a risk to participant safety (eg, second-degree atrioventricular block type II)
Has persistent or permanent atrial fibrillation not on anticoagulation for at least 4 weeks prior to Screening and/or not adequately rate-controlled within 1 year of Screening
History of clinically significant malignant disease within 10 years such as non-metastatic cutaneous squamous cell or basal cell carcinoma
History or evidence of any other clinically significant disorder, condition, or disease that, in the opinion of the investigator or MyoKardia physician, would pose a risk to subject safety or interfere with the study evaluation, procedures, or completion.