Assessing the Impact of Introducing Mavacamten for the Treatment of Obstructive HCM on the Modelled System and Societal Level Burden in China

OBJECTIVES: Obstructive hypertrophic cardiomyopathy (HCM) is rare cardiovascular condition (estimated around ten thousand patients in China), with patients experiencing a high symptomatic burden. This study aims to assess the economic impact of mavacamten (a first-in-class cardiac myosin inhibitor) + beta-blockers or calcium channel blockers (BB/CCBs) versus BB/CCBs monotherapy to patients.

METHODS: A 5-state (New York Heart Association [NYHA] functional class I, II, III, IV, and death) Markov cost-effectiveness model was developed with a Chinese societal perspective. Patients initially enter the model in either NYHA II or III, as per the baseline population of the EXPLORER-CN trial (NCT05174416). During each cycle, patients can transition between different NYHA functional classes, dependent on trial-based transition probabilities and long-term extrapolation assumptions. Patients can reach the death state in each cycle based on all-cause, disease specific and surgical intervention mortality rates. Treatment sequencing is modelled based on clinical guidelines and local clinical insights stratified by NYHA functional class, driven by lack of response, serious adverse events or meeting the criteria for septal reduction therapy (SRT). The model incorporates cost data from healthcare provider surveys and real-world data.

RESULTS: Over a lifetime horizon (up to aged 100), patients in the mavacamten + BB/CCBs arm (vs BB/CCB) experienced a larger per-patient cost savings when considering costs of healthcare resources excluding treatment acquisition costs (¥320,683 and ¥835,973, respectively). Additional cost-savings were achieved when considering SRT costs (¥26,952 vs. ¥86,204), terminal care costs (¥6,462 vs. ¥8,585), and total indirect costs (¥127,642 vs. ¥720,284) encompassing caregiver and productivity loss costs.

CONCLUSIONS: Mavacamten not only offers significant clinical value but has the potential to yield substantial economic benefits across multiple cost components compared to the current standard of care.