Real-world use of recombinant porcine sequence factor VIII in the treatment of acquired hemophilia A: EU PASS.

Background: Recombinant porcine factor VIII (rpFVIII; susoctocog alfa) is indicated for the treatment of bleeding events (BEs) in adults with acquired hemophilia A (AHA).

Objectives: To assess the safety, utilization, and effectiveness of rpFVIII in clinical practice.

Design: EU post-authorization safety study (PASS) (NCT03199794) was a multicenter, noninterventional, post-authorization safety study conducted in adults with AHA.

Methods: Data were collected retrospectively or prospectively for up to 180 days after the last rpFVIII dose. The primary objective was safety, as assessed by adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) (e.g. immunogenicity, hypersensitivity reactions, thromboembolic events). Secondary endpoints included immunogenicity, rpFVIII hemostatic effectiveness, and rpFVIII utilization.

Results: Fifty patients were enrolled; 31 completed the study. The median (range) follow-up for patients who completed or discontinued the study was 178 (26-371) days. The median (range) first dose of rpFVIII was 54.0 (11-200) U/kg. Thirty patients reported 46 SAEs; 5 SAEs were considered probably related to rpFVIII, of which 1 was lack of rpFVIII efficacy, and 4 were AESIs: drug resistance due to FVIII inhibition (one patient), antibody test positive for anti-pFVIII inhibitors (one patient), and anti-pFVIII inhibitors (two patients). No hypersensitivity reactions or thromboembolic events were reported. Of the 50 initial BEs, 37 resolved [in a median (interquartile range) of 8.0 (4.0-16.0) days].

Conclusion: Results from this real-world study support the use of rpFVIII for AHA, aligning with findings from the clinical trial of rpFVIII (NCT01178294) in the treatment of BEs in adults with AHA.

Trial Registration: EUPAS16055; NCT03199794.