Mavacamten (Camzyos™; MYK-461) is an oral small-molecule cardiac myosin inhibitor developed by MyoKardia, Inc., a wholly owned subsidiary of Bristol Myers Squibb, for the treatment of hypertrophic cardiomyopathy (HCM) and diseases of diastolic dysfunction. Mavacamten is an allosteric and reversible inhibitor selective for cardiac myosin. Mavacamten modulates the number of myosin heads that can enter “on actin” (power-generating) states, thus reducing the probability of force-producing (systolic) and residual (diastolic) cross-bridge formation. Excess myosin actin cross-bridge formation and dysregulation of the super-relaxed state are mechanistic hallmarks of HCM. Mavacamten shifts the overall myosin population towards an energy-sparing, recruitable, super-relaxed state. In HCM patients, myosin inhibition with mavacamten reduces dynamic LVOT obstruction and improves cardiac filling pressures. In April 2022, mavacamten was approved for use in the USA in the treatment of adults with symptomatic New York Heart Association (NYHA) class II-III obstructive HCM to improve functional capacity and symptoms.