Real-world safety and effectiveness of recombinant porcine sequence factor VIII in acquired haemophilia A: A non-interventional, post-authorization safety study

Abstract

Introduction: Recombinant porcine factor VIII (rpFVIII, susoctocog alfa) is indicated for the treatment of bleeding episodes in adults with acquired haemophilia A (AHA).

Aim: To provide long-term real-world safety and effectiveness data for rpFVIII in the management of AHA bleeding episodes.

Methods: US PASS (NCT02610127) was a multicentre, uncontrolled, open-label, post-marketing safety surveillance study conducted in adults with AHA. Data were collected retrospectively or prospectively for 180 days after rpFVIII treatment. The primary outcome was the incidence of treatment-related serious adverse events (SAEs). Secondary outcomes included haemostatic effectiveness of rpFVIII and rpFVIII utilization.

Results: Fifty-three patients were enrolled from December 2015 to June 2019 (prospective, n = 30; retrospective, n = 23). Six patients experienced seven treatment-related SAEs (incidence 12.0%). The most common treatment-related SAE was FVIII inhibition (inhibiting antibodies to rpFVIII; incidence 8.0%, 95% CI: 2.2-19.2). Five patients reported seven thromboembolic events; one was an SAE and possibly related to rpFVIII. Of bleeding events treated with rpFVIII, 80.3% (57/71) of bleeds resolved with rpFVIII. The median (range) dose of rpFVIII per infusion was 50 (10-300) units/kg, with a median (range) of 6.0 (1-140) infusions and a median (range) time from bleed onset to bleed resolution of 14.0 (2.0-132.7) days.

Conclusion: In this real-world study of rpFVIII for AHA, no new safety signals were identified compared with previous clinical trial findings. Eighty percent of bleeds resolved with rpFVIII treatment.

Keywords: acquired haemophilia A; effectiveness; long-term data; real-world study; recombinant porcine FVIII; safety.