This is a multicenter study to evaluate the long-term safety and tolerability of mavacamten in participants with nHCM who completed MAVERICK-HCM through Week 24 and enroll into this study within 3 months. All participants will receive active study drug as described below, but their status (active or placebo) in the original MAVERICK-HCM study will remain blinded as the studies will be enrolling in parallel. Approximately 60 participants will be enrolled; enrollment must occur within 3 months of the participant completing MAVERICK-HCM.

You may be eligible for this study if you meet the following criteria:

• Conditions: ['Hypertrophic Cardiomyopathy', 'Obstructive Hypertrophic Cardiomyopathy', 'Non-obstructive Hypertrophic Cardiomyopathy']
• Age: 99 years or below
• Gender: All