Post Hoc Analyses of A-SURE and PREVENT Confirm the Effectiveness of rFVIIIFc Prophylaxis Across All Ages, BMIs, Severities, and Inhibitor Histories

Objective To assess the effectiveness of recombinant factor VIII Fc fusion protein (efmoroctocog alfa; referred to herein as rFVIIIFc) prophylaxis in people with hemophilia A (PwHA) stratified by age, body mass index (BMI), disease severity, and inhibitor history included in the A-SURE (NCT02976753) and PREVENT (NCT03055611) real-world studies. Methods PwHA receiving at least one prescription of rFVIIIFc and ≥3 months of follow-up during the prospective periods were included. Post hoc analyses were performed for the overall analysis population and subgroups based on age, BMI, disease severity, and those with and without previous inhibitors. Effectiveness endpoints were annualized bleeding rate (ABR), annualized joint bleeding rate (AjBR), injection frequency, and factor consumption in the prospective period. Results Overall, 333 PwHA were analyzed. ABRs and AjBRs, generally, were low across the different subgroups (range of medians, 0.0-0.6 for both ABRs and AjBRs, except for ABRs in PwHA aged ≥65 years). Injection frequencies ( n injections/week) were comparable across subgroups (range of medians, 2.0-2.3), and factor consumption was generally similar (range of medians, 68.3-100.0 international units/kg/week), although with slightly higher factor consumption in pediatric PwHA and lower consumption in the overweight or obese BMI groups. Conclusion These post hoc analyses support the effectiveness and, therefore, use of rFVIIIFc prophylaxis in PwHA across all ages, BMI categories, severities, and for those with a history of inhibitors.