OBJECTIVES: Mavacamten is a first-in-class cardiac myosin modulator treatment for obstructive HCM, often a genetic disorder that affects patients’ quality of life. Following European guidelines first-line treatment consists of beta-blockers (BB) and/or calcium-channel blockers (CCB). The cost-effectiveness of mavacamten (+BB/CCB) compared to BB/CCB alone in symptomatic patients (New-York-Heart-Association [NYHA] class II/III) is assessed by the Commission for Economic Evaluation and Public Health (CEESP) following French health economic guidelines.

METHODS: A 4-state Markov model simulated disease severity evolution (NYHA I, II, III/IV and death) over a lifetime horizon. NYHA transition probabilities were derived from the mavacamten pivotal phase 3 EXPLORER-HCM trial (NCT03470545). Aligned with CEESP guidelines, utility scores were estimated using the EQ-5D-5L, applying French tariffs. From the National Health Insurance Database (NHID), health care resource utilization and costs were collected for obstructive HCM population according to NYHA class. A health care system (HCS) perspective was adopted as recommended by CEESP only including direct costs. Sick leaves in patients of working age were also collected in the NHID to inform a scenario with a broader societal perspective. Outcomes were incremental quality-adjusted-life-years (QALYs), incremental costs, incremental cost-utility ratio (ICUR). Robustness was tested with sensitivity and scenario analyses.

RESULTS: Within the HCS perspective, in comparison to BB/CCB alone, addition of mavacamten achieved +1.52 discounted incremental QALYs. Incremental discounted costs were €122,651 over a lifetime horizon, resulting in an ICUR of €80,799/QALY. ICUR remained below €100,000/QALY in all sensitivity analyses and 80% of the probabilistic simulations were below €97,500/QALY. In the scenario adding the loss of patient productivity, the ICUR reduced to €77,290/QALY.

CONCLUSIONS: The positive methodological assessment by CEESP underlines the robustness of this cost-effectiveness model and results to inform decision making in France. When data on productivity loss are available from reliable sources, the addition of indirect costs could broaden the economic perspective.