Try the modernized ClinicalTrials.gov beta website. Learn more about the modernization effort.
Working…
ClinicalTrials.gov
ClinicalTrials.gov Menu

Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy (EXPLORER-HCM)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT03470545
Recruitment Status : Completed
First Posted : March 20, 2018
Results First Posted : October 4, 2021
Last Update Posted : October 4, 2021
Sponsor:
Information provided by (Responsible Party):
MyoKardia, Inc.

Brief Summary:
This is a multicenter, international, double-blind study of the administration of mavacamten in participants with symptomatic obstructive HCM (oHCM). Approximately 220 participants will be randomized to receive placebo or mavacamten.

Condition or disease Intervention/treatment Phase
Obstructive Hypertrophic Cardiomyopathy Drug: mavacamten Drug: Placebo Phase 3

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 251 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomized, Double Blind, Placebo Controlled Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy
Actual Study Start Date : May 29, 2018
Actual Primary Completion Date : March 14, 2020
Actual Study Completion Date : May 6, 2020


Arm Intervention/treatment
Experimental: mavacamten (MYK-461) Drug: mavacamten
mavacamten capsules
Other Name: MYK-461

Placebo Comparator: Placebo Drug: Placebo
placebo oral capsule




Primary Outcome Measures :
  1. Percentage of Participants Achieving A Clinical Response [ Time Frame: 30 weeks ]
    A positive clinical response (value="YES") is defined as having achieved either an improvement of at least 1.5 mL/kg/min in peak oxygen consumption (pVO2) as determined by cardiopulmonary exercise testing (CPET) and a reduction of one or more class in New York Heart Association (NYHA) functional classification (e.g.I, II, III, or IV) -OR- an improvement of 3.0 mL/kg/min or more in pVO2 with no worsening in NYHA Functional Class.


Secondary Outcome Measures :
  1. Changes From Baseline to Week 30 in Post Exercise in LVOT Peak Gradient. [ Time Frame: 30 weeks ]
    The post-exercise LVOT gradient was measured from echocardiograms obtained at baseline and week 30 following a study-specified exercise protocol and read by the Cardiovascular Imaging Core Laboratory (CICL, Boston MA). Change from baseline was determined as per the study statistical analysis plan and compared between treatment arms.

  2. Change From Baseline to Week 30 in pVO2 as Assessed by CPET [ Time Frame: 30 weeks ]
    Cardiopulmonary exercise testing (CPET) was performed at baseline and week 30 following a study-specified protocol and peak oxygen consumption (pVO2) was determined by the Cardiovascular Metabolic Disease Research Institute (CMDRI, Palo Alto, CA). Change from baseline was determined as per the study statistical analysis plan and compared between treatment arms.

  3. Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 [ Time Frame: 30 weeks ]
    New York Heart Association (NYHA) functional classification was determined by the principal investigator at baseline and at specified timepoints in the study. At baseline, all subjects were NYHA Class II or III. For the secondary outcome, NYHA class at Week 30 was compared to baseline and the proportion of subjects with an improvement of at least one class was determined, and the difference between treatment groups was analyzed. The proportion was also multiplied by 100 to provide the result as a percent.

  4. Change From Baseline to Week 30 in Participant-reported Health-related Quality of Life as Assessed by the KCCQ Score [ Time Frame: 30 weeks ]
    The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a patient reported outcome instrument with minimum score = 0 and maximum score = 100 where higher score indicates better health status. There are no units to the score. The instrument utilizes a recall period of 2 weeks over which patients describe the frequency and severity of their symptoms, their physical and social limitations, and how they perceive their heart failure symptoms to affect their quality of life. The KCCQ clinical summary (KCCQ-CS) score, a prespecified secondary outcome of EXPLORER-HCM, combines the physical limitation and total symptom scores.

  5. Change From Baseline to Week 30 in Participant-reported Severity of HCM Symptoms as Assessed by the HCMSQ Score [ Time Frame: 30 weeks ]
    The Hypertrophic Cardiomyopathy Symptom Questionnaire (HCMSQ) is a patient reported outcome instrument that is a daily self-administered 11-item questionnaire. The HCMSQ assesses the core symptoms of HCM (tiredness/fatigue, heart palpitations, chest pain, dizziness, and shortness of breath). The Shortness of Breath domain score, a pre-specified secondary outcome of EXPLORER-HCM, assesses the frequency and severity of shortness of breath. The minimum score = 0 and maximum score = 18 where lower score indicates better health status. There are no units to the score.



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Key Inclusion Criteria:

  • Age 18 and greater, body weight ≥ 45kg
  • Has adequate acoustic windows to enable accurate transthoracic echocardiograms (TTEs)
  • Diagnosed with oHCM consistent with current American College of Cardiology Foundation/American Heart Association and European Society of Cardiology guidelines and satisfy both criteria:
  • Has documented left ventricular ejection fraction (LVEF) ≥55%
  • NYHA Class II or III
  • Has documented oxygen saturation at rest ≥90% at Screening
  • Is able to perform an upright CPET and has a respiratory exchange ratio (RER) ≥1.0 at Screening per central reading

Key Exclusion Criteria:

  • Known infiltrative or storage disorder causing cardiac hypertrophy that mimics oHCM, such as Fabry disease, amyloidosis, or Noonan syndrome with LV hypertrophy
  • History of syncope or sustained ventricular tachyarrhythmia with exercise within 6 months prior to Screening
  • History of resuscitated sudden cardiac arrest (at any time) or known history of appropriate implantable cardioverter defibrillator (ICD) discharge for life-threatening ventricular arrhythmia within 6 months prior to Screening
  • Paroxysmal, intermittent atrial fibrillation with atrial fibrillation present at Screening
  • Persistent or permanent atrial fibrillation not on anticoagulation for at least 4 weeks prior to Screening and/or not adequately rate controlled within 6 months prior to Screening
  • Treatment (within 14 days prior to Screening) or planned treatment during the study with disopyramide or ranolazine
  • Treatment (within 14 days prior to Screening) or planned treatment during the study with a combination of β-blockers and calcium channel blockers
  • LVOT gradient with Valsalva maneuver <30 mmHg at Screening
  • Has been successfully treated with invasive septal reduction (surgical myectomy or percutaneous alcohol septal ablation [ASA]) within 6 months prior to Screening or plans to have either of these treatments during the study
  • ICD placement within 2 months prior to Screening or planned ICD placement during the study
  • Has a history or evidence of any other clinically significant disorder, condition, or disease that, in the opinion of the investigator, would pose a risk to participant safety or interfere with the study evaluation, procedures, or completion
  • Prior treatment with cardiotoxic agents such as doxorubicin or similar

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03470545


Locations
Show Show 71 study locations
Sponsors and Collaborators
MyoKardia, Inc.
Investigators
Layout table for investigator information
Study Director: Medical Information Team MyoKardia, Inc.
  Study Documents (Full-Text)

Documents provided by MyoKardia, Inc.:
Study Protocol  [PDF] October 4, 2019
Statistical Analysis Plan  [PDF] April 21, 2020

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Layout table for additonal information
Responsible Party: MyoKardia, Inc.
ClinicalTrials.gov Identifier: NCT03470545    
Other Study ID Numbers: MYK-461-005
First Posted: March 20, 2018    Key Record Dates
Results First Posted: October 4, 2021
Last Update Posted: October 4, 2021
Last Verified: May 2020

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by MyoKardia, Inc.:
Symptomatic, left ventricular outflow tract gradient
Additional relevant MeSH terms:
Layout table for MeSH terms
Cardiomyopathies
Cardiomyopathy, Hypertrophic
Hypertrophy
Heart Diseases
Cardiovascular Diseases
Pathological Conditions, Anatomical
Aortic Stenosis, Subvalvular
Aortic Valve Stenosis
Aortic Valve Disease
Heart Valve Diseases