B-cell therapy in antineutrophil cytoplasmic antibody-associated vasculitis.

Until recently, standard of care for patients with generalized or severe antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has consisted of an induction regimen with cyclophosphamide (CYC) and corticosteroids followed by maintenance treatment with azathioprine. This regimen is associated with significant toxicity resulting in considerable morbidity and mortality whereas relapses are still not infrequent. In two controlled trials, the Rituximab in ANCA-associated Vasculitis study (RAVE) and the RITUXVAS trial of the European Vasculitis Study Group (EUVAS), rituximab (RTX) proved non-inferior to CYC for induction of remission. In addition, outcome at 18 months for the RAVE trial and 12 months for the RITUXVAS trial showed that RTX without maintenance treatment was as efficacious as CYC followed by azathioprine maintenance. To prevent relapses, which occur particularly in patients positive for PR3-ANCA, 500 mg RTX given every 6 months was shown to be superior to azathioprine in a French study. Thus, RTX is a new and promising therapeutic armamentarium for AAV although long-term safety has still to be established.