OBJECTIVES : The HAVEN 1 trial showed that emicizumab prophylaxis reduced bleeding rates and improved health-related quality of life (HRQoL), when compared with bypassing agents (BPA) on-demand and prophylaxis, among patients with hemophilia A with inhibitors (HAwI). The objective of this study was to evaluate the cost-effectiveness of emicizumab versus BPAs in the Brazilian Public Healthcare System (SUS) perspective.

METHODS : A probabilistic two state transition (Alive with HAwI; Death) Markov model was populated using treated bleed rates and utilities from HAVEN 1 trial. The study cohort was composed with male patients with two years old at diagnosis and followed in a lifetime horizon. General population mortality was adjusted by disease severity. Treatment discontinuation was not considered and patients treated with on-demand regimens were assumed to undergo two arthroplasties over lifetime. Direct medical costs included drug acquisition, arthroplasty, hospitalization and adverse events management. Costs were extracted from official sources. All costs were based on the 2019 SUS perspective (1 BRL = 0.27 USD) and a 5% discount rate was applied for costs and effectiveness. Validity of the results were evaluated on sensitivity analyses.

RESULTS : Overall, emicizumab prophylaxis improved QALY gained in 3.70 and averted 273 bleed events, with a cost decrease of 2,45 million BRL (661,000 USD), thus, being dominant over BPA prophylaxis. Emicizumab also averted 405 bleed events with an ICER 29,046 BRL (7,842 USD) versus BPA on-demand. The result was driven mostly by the reduction in breakthrough bleed costs and utility. All probabilistic iterations were located on the I and II cost-effectiveness plane quadrants versus BPA on-demand and BPA prophylaxis respectively, demonstrating the model robustness and emicizumab superiority in effectiveness.

CONCLUSIONS : Once-weekly subcutaneous emicizumab prophylaxis was dominant over intravenous BPA prophylaxis in treating patients with HAwI under SUS perspective, offering higher effectiveness and lower costs, and can be considered cost-effective over BPA on-demand.