BACKGROUND: Prophylaxis goals for patients with severe hemophilia A encompass advancement toward the hemophilia-free mind (freedom from bleeding, pain, arthropathy, and treatment burden). Efanesoctocog alfa, the first ultra-long half-life factor VIII agent that enables once-weekly prophylaxis, shows a 77% improvement in annualized bleeding rate compared with standard-care factor VIII prophylaxis.

OBJECTIVE: To evaluate the conventional and distributional cost-effectiveness of prophylaxis with efanesoctocog alfa versus standard-care factor VIII (standard half-life and extended half-life) in the United States.

DESIGN: Markov model.

DATA SOURCES: XTEND-1 study and other published sources.

TARGET POPULATION: Patients with severe hemophilia A.

TIME HORIZON: Lifetime.

PERSPECTIVE: U.S. health system and societal.

INTERVENTION: Prophylaxis with efanesoctocog alfa versus standard-care factor VIII.

OUTCOME MEASURES: Incremental cost-effectiveness ratio (ICER; cost per quality-adjusted life-year [QALY]) and threshold inequality aversion parameter (equity weight).

RESULTS OF BASE-CASE ANALYSIS: Efanesoctocog alfa and standard-care factor VIII accrued 19.7 and 14.6 discounted lifetime QALYs at costs of $22.1 million and $11.2 million, respectively, with an ICER of $2.13 million per QALY. The distributional cost-effectiveness analysis (DCEA)-derived threshold equity weight was 6.9, exceeding commonly used U.S. equity standards. Results were consistent across all scenario analyses.

RESULTS OF SENSITIVITY ANALYSIS: Only the price of efanesoctocog alfa could change the conclusion. Efanesoctocog alfa needs to be priced at less than 53% of its current price for conventional cost-effectiveness and less than 59% for distributional cost-effectiveness. Standard-care factor VIII was favored in 100% of 10 000 probabilistic iterations.

LIMITATION: Benchmark equity weights (as opposed to hemophilia-specific weights) to interpret DCEA results.

CONCLUSION: Prophylaxis with efanesoctocog alfa is not conventionally or distributionally cost-effective for severe hemophilia A in the United States at current pricing and equity weight thresholds.

PRIMARY FUNDING SOURCE: National Institutes of Health; National Heart, Lung, and Blood Institute.