Combining Low-Dose Rituximab and Bortezomib as Immunosuppressive Therapy for Acquired Hemophilia A: 6 Case Series.

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by autoantibodies against factor VIII. Persistently positive inhibitor titers increase the risk of bleeding. Upfront combined regimen with multiple mechanisms has the potential to shorten remission time to lower bleeding risk and reduce immunosuppressor exposure time. We administered lowered dose of rituximab and bortezomib in combination with corticosteroids and cyclophosphamide (rituximab: 100 mg weekly × 4 or 500 mg once in week 1, bortezomib: 0.65 mg/m2 once in week 1, prednisone: 1 mg/kg daily, cyclophosphamide: 11.5-2 mg/kg daily). We retrospectively analyzed 6 cases (male = 3, female = 3, median age = 51 years) treated on this therapeutic regimen. All patients achieved complete remission (range from19 to 66 days); adverse event: infection (1/6). This is the first time that this regimen has been reported for treating AHA. It has shown good therapeutic efficacy and the potential to shorten the time to CR. The incidence of adverse events is within a reasonable range. This regimen is feasible and offers a new alternative treatment for AHA.