Exploring Durable Remission With Rituximab in Antineutrophil Cytoplasmic Antibody(ANCA)-Associated Vasculitis

Overview

Most recent insights in the treatment for patients with ANCA-associated vasculitis (AAV) have demonstrated that 'tailored' maintenance treatment with rituximab (RTX) is effective to achieve durable remission of disease. As such, RTX re-treatment can be tailored on the basis of relevant clinical and immunological parameters in AAV patients. Now, the present study intends to evaluate whether combining rituximab with cyclophosphamide is superior to current standard of care with rituximab only to induce a favorable clinical and immunological state in AAV patients and can thereby reduce the number of tailored re-treatments with rituximab.

Objectives: The primary objective is to prove that the combination of RTX and low-dose CYC reduces the number of RTX infusions needed to maintain clinical remission over 2 years. The secondary objectives are measurements for minimal residual auto-immunity (MRA) such as time to ANCA seronegativity, proportion of seronegativity, time to ANCA return, proportion of ANCA return, duration of B-cell depletion and the composition of the memory B-cell and plasma cell populations. Other secondary objectives are the potential association between MRA and disease flares, and the evaluation of (severe) adverse events, cost-effectiveness and quality of life Study design: open-label, multicenter, 1:1 randomized, prospective study Study population: Adult AAV patients with a clinical diagnosis of granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) who have 'generalised disease' and a positive ANCA-test for anti-PR3 or anti-MPO. Intervention: In addition to standard of care corticosteroid therapy, AAV patients will be randomized to receive either standard induction therapy with 2 infusions of RTX 1000 mg or induction therapy combining 2 infusions of RTX 1000 mg with 6 infusions of low dose intravenous cyclophosphamide 500mg. Thereafter, as part of standard of care patients will receive tailored RTX re-treatment as maintenance therapy. Main study parameters: AAV patients will be evaluated for the cumulative number of events for tailored RTX retreatments needed to maintain clinical remission over 2 years. Also, AAV patients will be evaluated for MRA by prospectively and consecutively studying ANCA levels and B-cell depletion by standard flowcytometry at predefined timepoints. Additionally, the study will perform safety and toxicity monitoring according to WHO toxicity criteria and evaluate the clinical response, the number of moderate and severe flares during study follow-up, the cost-effectiveness, and the quality of life of patients. Study duration: 2 years