AB0598 Rituximab Treatment in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Results from A Russian Registry (NORMA)

Background Rituximab (RTX) therapy is a treatment option in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Objectives Analysis of safety and efficacy of RTX in patients with ANCA-associated vasculitis treated in fourteen Russian clinical centers. Methods In 2011, Nasonova V.A. Research Institute of Rheumatology and Association of Rheumatologists of Russia created the NORMA project, a multicenter study whose objective is to gather information concerning the use of RTX in adult patients with systemic autoimmune diseases. Results 50 patients with ANCA-associated vasculitis treated with RTX are included in the NORMA registry (26 women and 24 men, mean age 40±15 years), including 35 patients with granulomatosis with polyangiitis, 13 with microscopic polyangiitis, 2 with eosinophilic granulomatosis with polyangiitis. 39 patients were cANCA/PR3 positive and 11 pANCA/MPO positive. 34% of patients had refractory ANCA-associated vasculitis, 36% high activity and/or signs of poor prognosis and 28% intolerance of standard agents. 25/50 patients were re-treatment at low-dose RTX (≤1000 mg) for partial responses/relapses (70%) or to maintain remission (30%). A total of 46 RTX subsequent cycles were completed, intervals between cycles averaged 6.4 months (range 4.5-11.3). Among 25 patients followed for more than 12 months, 23 complete and 2 partial responses were observed. Table 1 shows Birmingham vasculitis activity score (BVAS), CD19+ B-cells in peripheral blood and serum IgG levels at enrolment and after RTX treatment. Re-treatment was effective in controlling disease activity and did not result in progressive reduction in IgG. Ten patients (20%) had serious adverse events (including 6 infections and 3 neutropenia), all received a single cycle of RTX. Five patients died, two due to pneumonia and late onset neutropenia, two due to acute pulmonary embolism and one patient due to refractory vasculitis and pneumonia. Conclusions This uncontrolled observational study shows good tolerance and clinical efficacy of RTX in patients with ANCA-associated vasculitis and suggest, that low-dose RTX for the re-treatment is also effective. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1960