OBJECTIVES: Mavacamten is a first-in-class cardiac myosin modulator for HOCM, which is a genetic disorder of the cardiac sarcomere. This study assessed the cost effectiveness of mavacamten in addition to standard of care (SoC) compared with SoC alone, as well as disopyramide, myectomy, and septal ablation each in addition to SoC.

METHODS: A semi-Markov model was used over a lifetime time horizon from a healthcare sector perspective and the cycle length was 4 weeks. Patient utilities were estimated via New York Heart Association functional classes (NYHA) but assuming mortality was the same across all classes. Evidence from clinical trials, related literature and expert experience were the basis for model inputs. A placeholder price for Mavacamten ($75,000/year) was used in the cost estimates. Both costs and outcomes were discounted at a rate of 3%. Cost per quality adjusted life year (QALY) gained, cost per life year (LY) gained, cost per equal value LY gained (evLYG), and cost per additional year in NYHA class I were the outcomes of interest. Sensitivity and scenario analyses were conducted to test the robustness of the model.

RESULTS: In comparison to SoC alone and disopyramide (with SoC), the cost/QALY gained by mavacamten was $1.2 and $1.5 million respectively. Compared with myectomy and septal ablation, mavacamten resulted in fewer QALYs, slightly more LYs gained, and incremental costs of $5.6 and $7 million per LY respectively. Mavacamten produced additional NYHA I years compared to SoC and disopyramide at costs over $200,000/NYHA I year. Sensitivity and scenario analyses results supported the robustness of the findings.

CONCLUSION: The actual cost-effectiveness of mavacamten will depend on its price. At the placeholder price, the incremental cost effectiveness ratios of mavacamten over SoC and disopyramide are well beyond standard threshold levels. Also, mavacamten is dominated by septal reduction procedures in terms of QALYs.