The purpose of this study is to evaluate the effectiveness, safety, and tolerability of a 30-week course of mavacamten and the long-term effects of mavacamten in Japanese participants with symptomatic obstructive hypertrophic cardiomyopathy (HCM).

A Study of Mavacamten in Obstructive Hypertrophic Cardiomyopathy

Cardiomyopathy, Hypertrophic Obstructive

Mavacamten

A Phase 3, Open-label, Single Arm, Clinical Study to Evaluate Efficacy, Safety and Tolerability of Mavacamten in Adults With Symptomatic Obstructive Hypertrophic Cardiomyopathy

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 doppler echocardiography. Baseline is defined as the last non-missing assessment prior to the first dose of the study treatment if both the time of the measurement and the time of first dose are available otherwise it is the last non-missing assessment on or prior to the first dose of the study treatment.

The KCCQ-23 is a 23-item, self-administered questionnaire that measures the impact of a participant's cardiovascular disease or its treatment on 6 distinct domains using a 2-week recall period: symptoms/signs, physical limitation, quality of life (QoL), social limitations, self-efficacy, and symptom stability. The KCCQ 23 Clinical Summary Score (CSS) is derived from the Total Symptom Score (TSS) and the Physical Limitations (PL) score of the KCCQ 23. The CSS, TSS, and the PL score range from 0 to 100 with higher scores representing less severe symptoms and/or physical limitations. The CSS is a mean of the TSS and the PL score. Baseline is defined as the last non-missing assessment prior to the first dose of the study treatment if both the time of the measurement and the time of first dose are available otherwise it is the last non-missing assessment on or prior to the first dose of the study treatment.

The NYHA Functional Classification of Heart Failure (HF) assigns participants to 1 of 4 categories based on the participant's symptoms. Class I (No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea); Class II (Slight limitation of physical activity, Comfortable at rest, Ordinary physical activity results in fatigue, palpitation, dyspnea); Class III (Marked limitation of physical activity, Comfortable at rest, Less-than ordinary-activity causes fatigue, palpitation, or dyspnea) and Class IV (Unable to carry on any physical activity without discomfort. Symptoms of heart failure at rest. If any physical activity is undertaken, discomfort increases). Improvement is defined as participant moving to lower class category from a higher one. Baseline is defined as last non-missing measurement prior to the first dose.

Blood samples were collected for assessing the concentration of NT-proBNP. Baseline is defined as last non-missing measurement prior to the first dose.

Blood samples were collected for assessing cardiac troponins. Baseline is defined as the last non-missing assessment prior to the first dose of the study treatment if both the time of the measurement and the time of first dose are available otherwise it is the last non-missing assessment on or prior to the first dose of the study treatment.

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Safety analysis population included all participants who receive at least one dose of study drug.

Participants with symptomatic obstructive hypertrophic cardiomyopathy received oral capsule of mavacamten during the treatment period from Day 1 to Week 30. The starting dose of mavacamten was 2.5 milligram (mg) once daily. At Week 6, Week 8, Week 14, and Week 20, mavacamten dose were titrated based on the individual, transthoracic echocardiogram (TTE) response (Valsalva left ventricular outflow tract \[LVOT\] gradient and left ventricular ejection fraction LVEF). The permissible doses during the study were 1, 2.5, 5, 10, or 15 mg.

Age, Continuous

Sex: Female, Male

Japanese

Race/Ethnicity, Customized

Bristol-Myers Squibb Study Director

Intent-to-treat population. Only those participants with data available at the specified time points were analyzed.

Change From Baseline in Post-exercise Left Ventricular Outflow Tract (LVOT) Peak Gradient at Week 30

Intent to Treat Population. Only those participants with data available at the specified time points were analyzed.

Change From Baseline in Kansas City Cardiomyopathy Questionnaire 23-item Version (KCCQ-23) Clinical Summary Score (CSS) at Week 30

Percentage of Participants With at Least 1 Class Improvement in New York Heart Association (NYHA) Functional Class From Baseline to Week 30

Change From Baseline in N-terminal Pro B-type Natriuretic Peptide (NT-proBNP) at Week 30

Intent to Treat population. Only those participants with data available at the specified time points were analyzed.

A Study of Mavacamten in Obstructive Hypertrophic Cardiomyopathy

About this trial

Study ID

Status

Type

Phase

Placebo

Accepting

Trial Timing

What is this trial about?

What are the participation requirements?