Objectives The RITUXVAS trial reported similar remission induction rates and safety between rituximab and cyclophosphamide based regimens for antineutrophil cytoplasm antibody (ANCA)-associated vasculitis at 12 months; however, immunosuppression maintenance requirements and longer-term outcomes after rituximab in ANCA-associated renal vasculitis are unknown.

Methods Forty-four patients with newly diagnosed ANCA-associated vasculitis and renal involvement were randomised, 3:1, to glucocorticoids plus either rituximab (375 mg/m²/week×4) with two intravenous cyclophosphamide pulses (n=33, rituximab group), or intravenous cyclophosphamide for 3–6 months followed by azathioprine (n=11, control group).

Results The primary end point at 24 months was a composite of death, end-stage renal disease and relapse, which occurred in 14/33 in the rituximab group (42%) and 4/11 in the control group (36%) (p=1.00). After remission induction treatment all patients in the rituximab group achieved complete B cell depletion and during subsequent follow-up, 23/33 (70%) had B cell return. Relapses occurred in seven in the rituximab group (21%) and two in the control group (18%) (p=1.00). All relapses in the rituximab group occurred after B cell return.

Conclusions At 24 months, rates of the composite outcome of death, end-stage renal disease and relapse did not differ between groups. In the rituximab group, B cell return was associated with relapse.

Trial registration number ISRCTN28528813.