Prolonged disease-free remission following rituximab and low-dose cyclophosphamide therapy for renal ANCA-associated vasculitis

Background. Rituximab (RTX) has been shown to be effective as an induction agent in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV), but studies have been limited by short-term follow-up. We decided to investigate the long-term efficacy and safety of an RTX-based cyclophosphamide (CYP)-sparing regimen (CycLow-Vas) for renal AAV.Methods. Consecutive patients with renal AAV presenting de novo or with a major relapse, except those with serum creatinine >500 mu mol/L, previous treatment with RTX and pulmonary haemorrhage or cerebral vasculitis, were treated with two pulses of RTX 2 weeks apart and six fortnightly doses of CYP, as well as a reducing protocol of daily oral steroids. Maintenance was with low-dose steroids and azathioprine.Results. Twenty-three patients were treated. Median follow-up was 39 months, with 17 patients reaching >2 years of follow-up. All patients achieved clinical remission within 6 weeks. Three major and two minor relapses occurred in five patients at a median of 30 months, which were treated by re-dosing with RTX for major relapses and steroid increase alone for minor relapses. Adverse events included one severe drug reaction, four non-serious and one serious infective episodes in the first 3 months, one skin malignancy at 21 months and one death at 19 months not related to treatment or disease.Conclusions. A RTX-based low-dose CYP regimen is effective at inducing long-term disease-free remission and may be the platform on which to develop a steroid-minimizing regimen to further decrease adverse events in the future.