A comparison of rituximab with cyclophosphamide in terms of efficacy and complications as induction therapy for treating granulomatosis with polyangiitis: A three-center study

Objective: Granulomatosis with polyangiitis (GPA), formerly known as Wegner’s granulomatosis, is a rare vasculitic syndrome classified under Anti-Neutrophilic Cytoplasmic Autoantibody (ANCA)-associated vasculitides, which is fatal if untreated. The mainstay of treatment consists of immunosuppression using a combination of corticosteroids with either rituximab (RTX) or cyclophosphamide (CYC). We aimed to compare the 4-year clinical outcomes between patients with GPA receiving CYC and RTX as remission induction. Methods: In this retrospective cohort, we used patient data from 92 patients with GPA at two large teaching hospitals and a private clinic in Isfahan, Iran. The patients were classified based on the medication they received for remission induction into RTX and CYC groups. The main outcomes were rate of death and relapse, disease activity assessed based on the Birmingham Vasculitis Activity Score (BVAS), disease-related complications, laboratory markers, and adverse-drug-reactions. Results: Fifty-three (57.6%) patients received CYC, whereas 39 (42.4%) received RTX. The mean duration of follow-up was 3.6 (±2) years. Most of patients (70%) had a successful remission, while 20.7% experienced a relapse and 8.7% of patients died. The rate of death and relapse did not differ between the RTX and CYC groups. Disease-related complications involved an insignificantly higher proportion of patients in the CYC (12/53) group than the RTX (4/39) group. Patients in both groups showed a significant decrease in BVAS during follow-ups irrespective of the medication exposure. The rate of adverse events was similarly low (n = 1) in both groups. Conclusion: RTX and CYC were similar in inducing remission and reducing adverse clinical outcomes among patients with GPA with acceptable side effect profiles.