Acquired haemophilia and haemostatic control with recombinant porcine factor VIII: case series

Abstract

Background: Acquired haemophilia A (AHA) is a rare acquired bleeding disorder that can present with life-threatening bleeding.

Aims: To describe recent Australian use of recombinant porcine factor VIII (rpFVIII) replacement therapy as a haemostatic agent in patients with acquired haemophilia.

Methods: Four patients with acquired haemophilia treated in three different institutions around Australia in the past 12 months were included in the study. Haemostatic efficacy of Obizur (Takeda) was assigned by the treating haematologist according to previously published criteria.

Results: Six bleeds were treated with rpFVIII, three of which were initially refractory to treatment with recombinant VIIa. rpFVIII was rated efficacious in 100% of bleeds by 24 h. rpFVIII loading dose was 100 U/kg (100-120 U kg^-1 ) and this increased the factor VIII level (via one-stage FVIII assay) from <1-1.2% to 54-306% taken 0.5-1.5 h post-infusion. Subsequent doses ranged from 40 to 60 U/kg twice daily or daily for 3 to 13 days. No rpFVIII related adverse events occurred. Three of the four patients achieved complete remission and were weaned from immunosuppression. One patient died prior to achieving partial remission, secondary to an arterial ischaemic event.

Conclusion: This case series demonstrates that recombinant porcine FVIII is efficacious to treat acute bleeds in acquired haemophilia, including in those who are refractory to bypassing agents. Doses of rpFVIII were able to be titrated based on FVIII level and clinical response.

Keywords: acquired haemophilia; bypassing agent; factor VIII; recombinant FVIIa; recombinant porcine factor VIII.