Rituximab as maintenance therapy for anti-neutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND AND OBJECTIVES: Ongoing randomized trials seek to validate the efficacy of rituximab as an induction agent for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). However, no studies directly address the role of rituximab as maintenance therapy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This retrospective study reports the authors' experience with continuous rituximab administration in 39 patients in complete or partial remission at the time of rituximab initiation. All 39 patients had at least 1 year of follow-up, and 20 had 2 years of follow-up.
RESULTS: Disease activity, as measured by a modified Birmingham Vasculitis Activity Score, decreased from a median of 1 at baseline to 0 at 12 (P < 0.001) and 24 months (P = 0.02). Three patients experienced nonorgan-threatening flares during 708 patient-months of follow-up. Each flare occurred after at least 20 months of follow-up. The percentage of patients on cytotoxic immunosuppression decreased from 87% at baseline to 41% at 12 months (P < 0.001) and 30% at 24 months (P = 0.002). The percentage of patients on prednisone decreased from 92% at baseline to 59% at 12 months (P < 0.001) and 55% at 24 months (P = 0.02). Two patients developed late-onset neutropenia; both responded to treatment with recombinant granulocyte colony-stimulating factor.
CONCLUSIONS: The successful use of continuous anti-B cell therapy in patients with AAV in complete or partial remission is reported. This extends the potential role of rituximab beyond induction to include maintenance therapy. However, more data are required regarding the delayed adverse effects of rituximab.