Single-dose rituximab plus glucocorticoid versus cyclophosphamide plus glucocorticoid in patients with newly diagnosed acquired hemophilia A: A multicenter, open-label, randomized noninferiority trial

Acquired hemophilia A (AHA) is a rare but serious bleeding disorder. Randomized controlled trial (RCT) comparing the efficacy of immunosuppression therapy for AHA lacks. We conducted the first multicenter RCT aiming to establish whether the single-dose rituximab combination regimen was noninferior to the cyclophosphamide combination regimen. From 2017 to 2022, 63 patients with newly diagnosed AHA from five centers were randomly assigned 1:1 to receive glucocorticoid (methylprednisolone 0.8 mg/kg per day for the first 3 weeks and then tapered) plus single-dose rituximab (375 mg/m(2); n = 31) or plus cyclophosphamide (2 mg/kg per day until inhibitor becomes negative, for a maximum of 5 weeks; n = 32). The primary outcome was complete remission (CR, defined as FVIII activity >= 50 IU/dL, FVIII inhibitor undetectable, immunosuppression tapered and no bleeding for 24 h without bypassing agents) rate measured within 8 weeks. The noninferiority margin was an absolute difference of 20%. Twenty-four (77.4%) patients in the rituximab group and 22 (68.8%) patients in the cyclophosphamide group achieved CR, which showed the noninferiority of the single-dose rituximab-based regimen (absolute difference = -8.67%, lower limit of the 95% confidence interval = -13.11%; Pnoninferiority = 0.005). No difference was found in the incidence of treatment-related adverse events. Single-dose rituximab plus glucocorticoid regimen showed similar efficacy and safety, without a reported risk of secondary malignancies or reproductive toxicity seen in cyclophosphamide, it might be recommended as a first-line therapy for AHA, especially in China where there is a young age trend in AHA patients.