A-SURE: intra-patient comparison of prophylactic effectiveness of a recombinant factor VIII Fc fusion protein versus standard half-life factor VIII in hemophilia A

Background: Despite recent advances, factor replacement therapy remains a cornerstone in hemophilia A treatment. Efmoroctocog alfa, a recombinant FVIII Fc fusion protein (rFVIIIFc), has an extended half-life allowing higher FVIII levels and less frequent dosing than standard half-life (SHL) products, without increasing factor consumption. Methods: A-SURE was a 24-month prospective, non-interventional study assessing real-world effectiveness of rFVIIIFc prophylaxis. This post-hoc, intra-patient analysis included patients with hemophilia A (PwHA) who switched from SHL FVIII to rFVIIIFc prophylaxis. Effectiveness endpoints included annualised bleeding rate (ABR), annualised joint bleeding rate (AjBR), weekly injection frequency and weekly factor consumption. Results: Of 131 PwHA eligible for analysis, mean ABR and AjBR decreased from 3.7 and 2.4 to 1.8 and 1.1, respectively, after switching (mean [95% confidence interval (CI)] change of −1.9 [−3.0, −0.8] and −1.2 [−2.0, −0.5]). Mean weekly injection frequency decreased from 3.1 to 2.3 (mean [95% CI] change of −0.8 [−1.0, −0.7]); weekly factor consumption reduced from 89.7 to 84.1 international units (IU)/kg, respectively (mean [95% CI] change of −5.7 [−10.7, −0.6]). These trends were consistent across age groups. Conclusion: This intra-patient comparison demonstrates switching from SHL FVIII to rFVIIIFc prophylaxis reduces frequency of bleeds, injection frequency, and factor consumption, complementing previously reported data from A-SURE. Trial registration:.