Analysis of Wegener's Granulomatosis Responses to Rituximab: Current Evidence and Therapeutic Prospects

Available data on small numbers of patients with refractory and/or relapsing Wegener's granulomatosis support very good overall outcomes with rituximab, an anti-CD20 biotherapy targeting B cells, in combination with ongoing immunosuppressants, apparently independently of antineutrophil cytoplasm antibody (ANCA) status. However, clearly dissociated responses were observed, with constitutional and vasculitis-related symptoms often achieving complete responses within days or weeks, and granulomatous-related manifestations regressing more slowly over a few weeks to several months or not at all, particularly for orbital pseudotumors. Tolerance was good with few side effects, and when relapses occurred, more often after 12 months, a second or even a third rituximab cycle was almost always able to obtain another complete remission. Randomized trials are needed to define rituximab's best place, compared to cyclophosphamide, in initial and maintenance regimens; to determine optimally combined drugs, considering the various responses of granulomatous-related manifestations; and to delineate the role of circulating B-cell monitoring for pre-emptive management decisions. This promising biotherapy opens the way for other therapeutic agents targeting B lymphocytes and to improve our understanding of the pathophysiology of ANCA-associated vasculitis.