A Study to Evaluate Mavacamten in Adolescents With Symptomatic Obstructive Hypertrophic Cardiomyopathy

Change from baseline in resting LVOT gradient

Time frame: At Week 28

Change from baseline in post-exercise peak LVOT gradient

Time frame: At Week 28

Change from baseline in maximal wall thickness

Time frame: At Week 28

Change from baseline in ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e')

Time frame: At Week 28

Proportion of participants achieving an increase from baseline to Week 28 in peak oxygen uptake test (pVO2)

Time frame: From baseline up to Week 28

Proportion of participants achieving a reduction from baseline to Week 28 in maximal LVOT gradient to < 30 mmHg

Time frame: From baseline up to Week 28

Proportion of participants with at least 1 class improvement in New York Heart Association (NYHA) class from baseline to Week 28

Time frame: From baseline up to Week 28

Proportion of participants with at least 1 grade improvement in mitral regurgitation at Week 28

Time frame: From baseline up to Week 28

Number of participants with treatment-emergent adverse events (TEAEs)

Time frame: Up to Week 218