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

Abstract

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:ClinicalTrials.gov identifier: NCT02976753.

Keywords: Hemophilia A; annualised bleeding rate; extended half-life; factor consumption; injection frequency; real-world; recombinant FVIII Fc fusion protein; standard half-life.