A low-dose rituximab regimen for first-line treatment of acquired haemophilia A

Abstract

A low-dose rituximab regimen for first-line treatment of acquired haemophilia A.

Introduction: Acquired haemophilia A (AHA) is a rare disease caused by the development of autoantibodies against FVIII. Diagnosis involves confirmation of FVIII deficiency and the presence of an inhibitor via the Bethesda assay. Severe bleeding is often managed with bypassing agents such as recombinant factor VII. This is then followed by eradication of the inhibitor with immunosuppression which typically includes a corticosteroid backbone.

Aim: Review the current management and outcomes of AHA in Queensland, Australia. Determine the incidence, demographics and clinical characteristics of AHA patients.

Methods: Retrospective case series of AHA diagnosed between May 2014 and August 2018. Data were derived from the Australian Bleeding Disorders Registry and state-wide pathology database. Data collection proforma was completed by the treating haematologist and reviewed/compiled centrally.

Results: 24 patients were identified (incidence 1 in 1.27 million). The median age was 76.5 years. Median follow-up was 20 months. Index bleed was atraumatic and skin/soft tissue in the majority of patients. Recombinant FVIIa was the most commonly used haemostatic therapy and effective in 85% of patients. Immunosuppression and steroid usage were uniform. Upfront second agent was used in 75% of patients and was most commonly rituximab. 87.5% of patients achieved a complete remission in a median time of 48 days. Low-dose rituximab was frequently used and equally as efficacious as standard dose.

Conclusion: Immunosuppression with combination therapy, notably rituximab, appears to be non-inferior and has a favourable side effect profile.

Keywords: acquired haemophilia; bypassing agents; factor VIII; immunosuppression; inhibitors; rituximab.