Gradual Tapering or Discontinuation of Beta-Blockers After Stabilization With Mavacamten Therapy

This multicenter, randomized, open-label, parallel-group, non-inferiority trial will evaluate whether sequential tapering and discontinuation of beta-blockers is non-inferior to maintenance of the baseline stable beta-blocker dose in adult patients with obstructive hypertrophic cardiomyopathy (oHCM) who have achieved predefined clinical and hemodynamic stability during mavacamten treatment. Eligible participants will be randomly assigned in a 1:1 ratio to a sequential tapering and discontinuation group or a baseline stable-dose maintenance group. In the tapering group, the beta-blocker dose will be reduced stepwise approximately every 4 weeks, with complete discontinuation planned at Week 12 if predefined safety and stability criteria are met. Participants will be followed through Week 24. The primary objective is to compare the proportion of participants who maintain clinical and hemodynamic stability without protocol-defined treatment failure through Week 24. The feasibility and safety of complete beta-blocker discontinuation will also be evaluated.

Inclusion Criteria: 1. Age 18 to 75 years. 2. Diagnosis of obstructive hypertrophic cardiomyopathy (oHCM). 3. Receiving mavacamten for ≥12 weeks at screening, with the current maintenance dose stable for ≥8 weeks; after completion of the 4-week run-in period, the total duration of mavacamten treatment at randomization should generally be ≥16 weeks. 4. Receiving one and only one beta-blocker continuously for at least 4 weeks before randomization, with the beta-blocker type, dosing frequency, and daily dose remaining stable, and without concomitant use of a non-dihydropyridine calcium channel blocker. 5. The last qualified echocardiographic assessment before randomization shows a resting left ventricular outflow tract (LVOT) peak gradient \