Cost-effectiveness of aficamten for obstructive hypertrophic cardiomyopathy: a model-based analysis from the perspective of the Chinese healthcare system.

Background: To evaluate the cost-effectiveness of aficamten plus standard of care (SoC) versus SoC alone for patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) from the perspective of the Chinese healthcare system. Methods: A four-state Markov model based on the phase III SEQUOIA-HCM trial was developed to simulate lifetime outcomes. The first 24 weeks were modeled using trial data, followed by 4-week cycles for long-term extrapolation. Based on FOREST-HCM, the incremental treatment effect of aficamten was assumed to persist through week 96 and then linearly wane to complete loss by year 3. Costs and health outcomes were discounted at 4.5% annually. Model uncertainty was assessed using one-way sensitivity analysis, probabilistic sensitivity analysis, and scenario analyses. Results: Total costs were US$143,281.22 with aficamten plus SoC and US$96,509.03 with SoC alone, with 9.696 and 7.643 QALYs, respectively. Aficamten plus SoC yielded an incremental cost of US$46,772.19 and 2.054 QALYs, corresponding to an ICER of US$22,775.17/QALY, below the WTP threshold of US$29,399.70/QALY. The probability of being cost-effective was 76.6% at the WTP threshold. Scenario analyses showed ICERs of US$19,351.77/QALY when only short-term effects were considered, US$43,752.42/QALY when treatment effects disappeared in year 5, and US$81,220.72/QALY when they disappeared in year 10. Price reductions of 22.0% and 50.5%, respectively, were required in the latter two scenarios. With a permanent discontinuation probability of 0.131% per 4-week cycle, the ICER was US$23,888.94/QALY. Conclusion: From the Chinese healthcare system perspective, aficamten plus SoC was cost-effective versus SoC alone for symptomatic oHCM under the base-case assumptions.