Rituximab for anti-neutrophil cytoplasmic antibodies-associated vasculitis: experience of a single center and systematic review of non-randomized studies.

Rituximab (RTX) is becoming a standard treatment for patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) but heterogeneity exists regarding its use. We present our uncontrolled experience with RTX in patients with refractory AAV and also the results of a systematic review of non-randomized studies on RTX in AAV patients. We retrospectively reviewed the records of AAV patients treated with RTX following an inadequate response to immunosuppressives between 2011 and 2015. The systematic review covered all English articles listed in PubMed until June 2017. There were 25 AAV patients (21 GPA, four unclassified) treated with RTX (median 2, IQR 1-3 courses; median follow-up 24, IQR 17-50 months). The kidney and the lung were the most commonly affected organs, observed in 14 and 16 patients, respectively. Complete remission rate was 72% at month 6 and 88% at month 12. Two patients had died and three serious adverse events occurred. The systematic review included 56 studies on 1422 patients with the majority being on refractory or relapsing disease. There was wide variability regarding disease characteristics, endpoints, concomitant immunosuppressives and RTX schedule. Most studies reported > 80% complete or partial remission rates with the lowest response (37.5%) for granulomatous lesions. The relapse rate was 30%. Infections and infusion reactions were the main adverse events. Our experience with RTX in refractory AAV is in line with the literature in terms of efficacy and safety. The systematic review underlines many uncertainties on its optimal use.