Abstract
Background: Emicizumab prophylaxis in children with severe haemophilia A and high-response inhibitor is more effective in preventing spontaneous bleeding when compared with bypassing agents prophylaxis. Brazil has approved emicizumab prophylaxis for high-response inhibitor who failed immune tolerance induction.
Methods: A cost-effectiveness analysis was performed to compare emicizumab prophylaxis with bypassing agents prophylaxis in high-response inhibitor during the first 5 years of treatment after immune tolerance induction failure, from the perspective of the Brazilian Ministry of Health (payer). The analysis included a 5-year-old male with high-response inhibitor (baseline weight: 20 kg). We obtained the regimens and costs (in US dollars, adjusted for Purchasing Power Parity) from the recommendations of the Brazilian Ministry of Health and the manufacturer’s package insert and purchasing information, respectively, for both emicizumab and bypassing agents prophylaxis, and the treatment of bleeding events with bypassing agents. We retrieved information on the frequency and treatment of bleeding during prophylaxis from the literature. The sensitivity analysis considered the regimen for prophylaxis and on-demand with bypassing agents and emicizumab, the probability of using a specific type of bypassing agents, and the costs associated with emicizumab and bypassing agents. Moreover, in the sensitivity analysis for emicizumab prophylaxis, we assumed settings with waste (amount of residual emicizumab discarded based on the weight regimen and vial availability) and without waste.
Results: The cost of emicizumab prophylaxis was US$1,012,021.4/ high-response inhibitor with 1.0 bleedings/ high-response inhibitor. Bypassing agents’ prophylaxis costs US$3,659,926.2/ high-response inhibitor with 16.5 bleedings/ high-response inhibitor. The incremental cost-effectiveness ratio was US$170,832.6 per bleed averted, favoring emicizumab prophylaxis. Emicizumab prophylaxis remained dominant after sensitivity analyses. The product regimen variables for bypassing agents prophylaxis and the likelihood of bypassing agents use had a high impact on incremental cost. Waste and on-demand bypassing agents doses had a minimal impact on incremental cost.
Conclusions: In high-response inhibitor, during the first 5 years following immune tolerance induction failure, emicizumab prophylaxis was a dominant option compared to bypassing agents’ prophylaxis, as per the Brazilian setting.