The "4 plus 2" rituximab protocol makes maintenance treatment unneeded in patients with refractory ANCA-associated vasculitis: A 10 years observation study.

Background: ANCA associated vasculitides (AAV) often present with a chronic relapsing course. Relapse leads to increased immunosuppressive exposure and consequent toxicity. While two randomized controlled trials have shown rituximab (RTX) to be the most effective induction treatment in patients with relapsing disease, the optimal treatment duration and RTX dose remain debated. Whether to administer a maintenance dose to every patient, at a fixed time interval or on the basis of B cell count and ANCA titre or only when disease manifestations do occur is still debated as well.

Methods: 11 patients (5 with granulomatosis with polyangiitis, 4 with microscopic polyangiitis-MPA-, and 2 with eosinophilic granulomatosis with polyangiitis -EGPA-) intolerant or refractory to conventional therapies including cyclophosphamide were enrolled. All patients received the so called "improved 4+2" RTX scheme as a rescue therapy. Following RTX administration, immunosuppressive drugs were rapidly tapered and no immunosuppressive maintenance therapy had been given.

Results: After a mean follow-up of 85 months since the "4+2" RTX protocol: four out of 11 patients (37%, 1 EGPA and 3 MPA, all MPO-positive) remained in remission after one cycle of "4+2" RTX infusion protocol with no relapse for a median 66 months [60-108]). Seven relapsing patients were re-treated once with RTX (again as monotherapy with the same protocol) after a median of 54 months (24-96). Following re-treatment, they again showed complete remission over a median of 32 months (12-96) of observation.

Conclusion: In one of the longest-term observation (85 months) studies, sustained clinical remission without immunosuppressive maintenance therapy (and a negligible dose of prednisone since the 5month) was obtained by the "4 + 2" RTX infusion protocol in patients with ANCA-associated vasculitis intolerant or refractory to conventional therapy.