Research & Innovation


Clinical Trials

SLUHN 2018-33

A Randomized, Double-blind, Placebo-controlled, Concentration-guided, Exploratory Study of Mavacamten (MYK-461) in Patients with Symptomatic Non-obstructive Hypertrophic Cardiomyopathy (nHCM) and Preserved Left Ventricular Ejection Fraction

Physician & Study Coordinator

Study Coordinator

Susan Hahn




Synopsis: The purpose of this study is to compare the effect of the investigational drug, mavacamten, (MYK-461),to a placebo (an inactive substance) in patients with Non-obstructive Hypertrophic Cardiomyopathy (nHCM).  This study is being done to test whether that mavacamten is safe, and can be tolerated in nHCM and to study whether it helps to improve symptoms or ability to exercise. 

Mavacamten is an investigational drug. This means that it has not been approved by the Food and Drug Administration (FDA) or any regulatory agency for routine clinical use, including the treatment of nHCM. Mavacamten and the matching placebo are referred to as “study drugs(s)” in this consent form.

MyoKardia Inc. is the sponsor of this study, also referred to as “MyoKardia.” MyoKardia is providing the study drug and is compensating the study doctor and site staff to conduct the study.



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


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.