Trial · NCT03470545
Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy
NCT03470545, Phase 3, Completed, MyoKardia, Inc.; results first posted 2021-10-04
3 sourcestrials-2026-11-12-0.4.0
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ConductScience Library. Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy. Trials, record NCT03470545. Release trials-2026-11-12-0.4.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03470545
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- Clinical Study to Evaluate Mavacamten (MYK-461) in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy
- NCT number
- NCT03470545
- Status
- Completed
- Phases
- Phase 3
- Enrollment
- 251 participants, actual
- Lead sponsor
- MyoKardia, Inc.
- Conditions
- Obstructive Hypertrophic Cardiomyopathy
- Interventions
- mavacamten, Placebo
- First posted
- 2018-03-20
- Last updated
- 2021-10-04
- Results first posted
- 2021-10-04
Source ClinicalTrials.gov
Registered outcomes6
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Percentage of Participants Achieving A Clinical Response | 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 | Changes From Baseline to Week 30 in Post Exercise in LVOT Peak Gradient. | 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. |
| Secondary | Change From Baseline to Week 30 in pVO2 as Assessed by CPET | 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. |
| Secondary | Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 | 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. |
| Secondary | Change From Baseline to Week 30 in Participant-reported Health-related Quality of Life as Assessed by the KCCQ Score | 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. |
| Secondary | Change From Baseline to Week 30 in Participant-reported Severity of HCM Symptoms as Assessed by the HCMSQ Score | 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. |
Source ClinicalTrials.gov
Outcomes6
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Percentage of Participants Achieving A Clinical Response | 30 weeks | Participants | COUNT_OF_PARTICIPANTS | |
| SECONDARY | Changes From Baseline to Week 30 in Post Exercise in LVOT Peak Gradient. | 30 weeks | mmHg | MEAN | |
| SECONDARY | Change From Baseline to Week 30 in pVO2 as Assessed by CPET | 30 weeks | mL/kg/min | MEAN | |
| SECONDARY | Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 | 30 weeks | Participants | COUNT_OF_PARTICIPANTS | |
| SECONDARY | Change From Baseline to Week 30 in Participant-reported Health-related Quality of Life as Assessed by the KCCQ Score | 30 weeks | Scores on Scale | MEAN | |
| SECONDARY | Change From Baseline to Week 30 in Participant-reported Severity of HCM Symptoms as Assessed by the HCMSQ Score | 30 weeks | Scores on Scale | MEAN |
Source ClinicalTrials.gov
Results by group12
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Percentage of Participants Achieving A Clinical Response | Mavacamten (MYK-461) | 45 | Participants | ||
| Percentage of Participants Achieving A Clinical Response | Placebo | 22 | Participants | ||
| Changes From Baseline to Week 30 in Post Exercise in LVOT Peak Gradient. | Mavacamten (MYK-461) | -47 | Standard Deviation 40.3 | mmHg | |
| Changes From Baseline to Week 30 in Post Exercise in LVOT Peak Gradient. | Placebo | -10 | Standard Deviation 29.6 | mmHg | |
| Change From Baseline to Week 30 in pVO2 as Assessed by CPET | Mavacamten (MYK-461) | 1.4 | Standard Deviation 3.12 | mL/kg/min | |
| Change From Baseline to Week 30 in pVO2 as Assessed by CPET | Placebo | -0.05 | Standard Deviation 3.02 | mL/kg/min | |
| Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 | Mavacamten (MYK-461) | 80 | Participants | ||
| Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 | Placebo | 40 | Participants | ||
| Change From Baseline to Week 30 in Participant-reported Health-related Quality of Life as Assessed by the KCCQ Score | Mavacamten (MYK-461) | 13.6 | Standard Deviation 14.42 | Scores on Scale | |
| Change From Baseline to Week 30 in Participant-reported Health-related Quality of Life as Assessed by the KCCQ Score | Placebo | 4.2 | Standard Deviation 13.68 | Scores on Scale |
1 to 10 of 12Source ClinicalTrials.gov
See all 12 results by groupParticipant flow6
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Mavacamten (MYK-461) | 123 | |
| Overall Study | STARTED | Placebo | 128 | |
| Overall Study | COMPLETED | Mavacamten (MYK-461) | 119 | |
| Overall Study | COMPLETED | Placebo | 125 | |
| Overall Study | NOT COMPLETED | Mavacamten (MYK-461) | 4 | |
| Overall Study | NOT COMPLETED | Placebo | 3 |
Source ClinicalTrials.gov
Adverse events88
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Atrial Fibrillation | Cardiac disorders | Mavacamten (MYK-461) | 10 | 123 | |
| other | Atrial Fibrillation | Cardiac disorders | Placebo | 10 | 128 | |
| other | Palpitations | Cardiac disorders | Mavacamten (MYK-461) | 7 | 123 | |
| other | Palpitations | Cardiac disorders | Placebo | 10 | 128 | |
| other | Angina pectoris | Cardiac disorders | Mavacamten (MYK-461) | 3 | 123 | |
| other | Angina pectoris | Cardiac disorders | Placebo | 7 | 128 | |
| other | Dyspnoea | Respiratory, thoracic and mediastinal disorders | Mavacamten (MYK-461) | 18 | 123 | |
| other | Dyspnoea | Respiratory, thoracic and mediastinal disorders | Placebo | 13 | 128 | |
| other | Cough | Respiratory, thoracic and mediastinal disorders | Mavacamten (MYK-461) | 10 | 123 | |
| other | Cough | Respiratory, thoracic and mediastinal disorders | Placebo | 4 | 128 |
1 to 10 of 88Source ClinicalTrials.gov
See all 88 adverse eventsAdverse event totals6
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Mavacamten (MYK-461) | 0 | 123 |
| Total, all-cause mortality | Placebo | 1 | 128 |
| Total, other adverse events | Mavacamten (MYK-461) | 108 | 123 |
| Total, other adverse events | Placebo | 104 | 128 |
| Total, serious adverse events | Mavacamten (MYK-461) | 14 | 123 |
| Total, serious adverse events | Placebo | 12 | 128 |
Source ClinicalTrials.gov
Papers19
The papers the trial lists on ClinicalTrials.gov.
Grants0
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
None in this release.
Trial comparisons4
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
| Comparison | Source |
|---|---|
| Mavacamten (MYK-461) vs Placebo: Proportion of Participants With at Least 1 Class Improvement in NYHA Functional Class From Baseline to Week 30 | Trial comparisons |
| Mavacamten (MYK-461) vs Placebo: deaths from any cause | Trial comparisons |
| Mavacamten (MYK-461) vs Placebo: Percentage of Participants Achieving A Clinical Response | Trial comparisons |
| Mavacamten (MYK-461) vs Placebo: serious adverse events | Trial comparisons |
Tests0
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
None in this release.
Source
- Release
- trials-2026-11-12-0.4.0
- Release manifest SHA-256
- 0f4a8d8c48aee2a7573ae0fa94ecbeab70c1adbe449bbc95c424bc7d3e97b9d4
- Registry capture
- 2026-11-12
- Results copy, AACT
- 2026-03-23
- NIH clinical studies file
- 2026-11-13
Source ClinicalTrials.gov
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNone stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
GET https://conductscience.org/api/trials/v1/NCT03470545
GET https://conductscience.org/api/trials/v1/NCT03470545/events?page=2