• KCCQ CSS \< 85.

• NYHA functional class II or III

• A diagnosis of HCM consistent with the current American College of Cardiology Foundation/American Heart Association and European Society of Cardiology guideline definition: unexplained left ventricular (LV) hypertrophy with nondilated ventricular chambers in the absence of other cardiac (eg, hypertension, aortic stenosis) or systemic disease with maximal LV wall thickness ≥ 15 millimeters (mm), or ≥ 13 mm with positive family history of HCM.

• For obstructive hypertrophic cardiomyopathy (oHCM), left ventricular outflow tract (LVOT) peak gradient ≥ 30 millimetre of mercury (mm Hg) during screening as assessed by echocardiography at rest or during a valsalva maneuver.

• For nonobstructive hypertrophic cardiomyopathy (nHCM), LVOT peak gradient \< 30 mm Hg during screening as assessed by echocardiography at rest and \< 30 mm Hg during a valsalva maneuver.

• Screening left ventricular ejection fraction (LVEF) ≥ 50%, except for those on a cardiac myosin inhibitor (screening LVEF ≥ 55%).

• For participants on a cardiac myosin inhibitor, the dose must be stable at least 3 months prior to screening. Participants on cardiac myosin inhibitor should not be scheduled for up-titration during the trial.

• Stable doses of background therapy (ie, β-blockers, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, diuretics) for at least 1 month prior to screening.