Phase 3
Completed N=251
Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy
Source: ClinicalTrials.gov NCT03470545 ↗Enrolled (actual)
251
Serious AEs
10.4%
Results posted
Oct 2021
Primary outcomePrimary: Percentage of Participants Achieving A Clinical Response — 45; 22 Participants
◆ Published Evidence
Established
96citations · ~48 / year
Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy.
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.
Linked Publications (5)
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Long-term effect of mavacamten in obstructive hypertrophic cardiomyopathy.
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The Kansas City Cardiomyopathy Questionnaire in Relation to New York Heart Association Class.
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Association Between age or Duration of Diagnosis in Obstructive Hypertrophic Cardiomyopathy and Response to Mavacamten Treatment: Exploratory Analysis of the EXPLORER-HCM Trial.
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The Psychometric Performance of the Kansas City Cardiomyopathy Questionnaire-12 in Symptomatic Obstructive Hypertrophic Cardiomyopathy.
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Association of Echocardiographic Parameters and Health Status in Patients With Obstructive Hypertrophic Cardiomyopathy: Insights From EXPLORER-HCM.
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Percentage of Participants Achieving A Clinical Response |
45; 22 | — |
| SECONDARY Changes From Baseline to Week 30 in Post Exercise in LVOT Peak Gradient. |
-47; -10 | — |
| SECONDARY Change From Baseline to Week 30 in pVO2 as Assessed by CPET |
1.4; -0.05 | — |
| SECONDARY Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 |
80; 40 | — |
| SECONDARY Change From Baseline to Week 30 in Participant-reported Health-related Quality of Life as Assessed by the KCCQ Score |
13.6; 4.2 | — |
| SECONDARY Change From Baseline to Week 30 in Participant-reported Severity of HCM Symptoms as Assessed by the HCMSQ Score |
-2.8; -0.9 | — |
Eligibility 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
Data sourced from ClinicalTrials.gov (NCT03470545) and the linked publication. Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.