Clinical Trials

Inclusion Criteria                   

• Diagnosed with HCM (hypertrophied and non-dilated left ventricle in absence of systemic or other known cause), with LV wall thickness ≥ 15 mm at time of initial diagnosis or ≥ 13 mm with a positive family history of HCM
• Age 18-70
• BMI 18-37kg/m2
• Documented LVEF ≥ 55% at the screening visit as determined by the investigator and the investigational site's echocardiography laboratory
• Resting LVOT gradient ≥ 30 mg Hg and post-exercise peak LVOT gradient ≥ 50 mm Hg
• NYHA functional class II or higher

Exclusion Criteria

• History of sustained ventricular tachyarrhythmia
• History of syncope with exercise within past 6 months
• Active infection
• Persistent atrial fibrillation or atrial fibrillation at screening
• Has QTc Fridericia (QTcF) > 500 ms, or any other ECG abnormality considered by the investigator to pose a risk to subject safety (e.g. second degree atrioventricular block type II)
• Aortic stenosis or fixed subaortic obstruction
• History of LV systolic dysfunction (LVEF < 45%) at any time during their clinical course
• History of coronary artery disease
• 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
• Ongoing therapy with beta blockers, calcium channel blockers, or disopyramide
  • Subjects not on beta blockers, or on a stable dose of beta blockers and will require ongoing therapy can enroll in part B of study
  • Subjects in part A are required to washout from current treatment for atleast 14 days prior to screening
• Prior treatment with cardiotoxic agents such as doxorubicin or similar, or current treatment with antiarrhythmic drugs that have negative inotropic activity, e.g. flecainide or propafenone
• Prior participation in a clinical trial with MYK-461 not eligible for part B of study
• Use of estrogen based hormonal contraception as highly effective contraceptive