Maintenance with Rituximab in anti-neutrophil cytoplasm antibody-associated vasculitis

Granulomatosis with polyangiitis, microscopic polyangiitis and renal-limited anti-neutrophil cytoplasm antibody (ANCA) associated vasculitis are the main ANCA-associated vasculitidies (AAV). Multiple induction therapies for AAV exist and have proven successful in achieving disease remission. Azathioprine and methotrexate have been used to maintain remission of AAV, however, relapse rates and adverse effects with these medications remain high. Rituximab (RTX), a B cell depleting monoclonal antibody, was shown to be safe and effective in maintaining disease remission in AAV in early retrospective reviews. In 2014, the first randomized control trial to compare RTX and azathioprine in maintenance therapy of newly diagnosed AAV (MAINRITSAN trial), revealed that patients who received RTX after cyclophosphamide induction had higher rates of sustained remission, fewer adverse effects and, better overall survival rates as compared to azathioprine. MAINRITSAN 2 revealed that patients receiving tailored regimens of maintenance RTX received fewer infusions but did not have higher rates of relapse than patients who received fixed dose therapy. The RITAZAREM trial conveyed that patients who experienced AAV relapse after induction therapy that received induction and maintenance RTX were significantly less likely to develop a relapse at 24 months vs . patients who received maintenance therapy with azathioprine. Overall, these studies suggest that maintenance therapy with RTX represents an exceptional treatment option in patients with AAV in terms of safety and efficacy, resulting in lower relapse rates and less drug toxicity than conventional treatments. As a result, patients have fewer exposures to cytotoxic medications and thus, improved outcomes.