Mycophenolate Mofetil Versus Cyclophosphamide for the Induction of Remission in Nonlife-Threatening Relapses of Antineutrophil Cytoplasmic Antibody–Associated Vasculitis: Randomized, Controlled Trial

Background and objectives Cyclophosphamide has been the mainstay of treatment of ANCA-associated vasculitis. However, cyclophosphamide has unfavorable side effects and alternatives are needed. Evidence suggests that mycophenolate mofetil can induce sustained remission in nonlife-threatening disease. The purpose of this study was to compare the efficacy and safety of mycophenolate mofetil versus cyclophosphamide for the induction treatment of nonlife-threatening relapses of proteinase 3-ANCA– and myeloperoxidase-ANCA–associated vasculitis. Design, setting, participants, & measurements We conducted a multicenter randomized, controlled trial. Participants with a first or second relapse of ANCA-associated vasculitis were randomized to induction treatment with cyclophosphamide or mycophenolate mofetil both in combination with glucocorticoids. Maintenance therapy consisted of azathioprine in both arms. Primary outcome was remission at 6 months, and secondary outcomes included disease-free survival at 2 and 4 years. Results Eighty-four participants were enrolled, of whom 41 received mycophenolate mofetil and 43 received cyclophosphamide. Eighty-nine percent of participants were proteinase 3-ANCA positive. At 6 months, 27 (66%) mycophenolate mofetil–treated participants versus 35 (81%) cyclophosphamide-treated participants were in remission ( P =0.11). Disease-free survival rates at 2 and 4 years were 61% and 39% for cyclophosphamide, respectively, and 43% and 32% for mycophenolate mofetil, respectively (at 4 years, log rank test, P =0.17). Conclusions We did not demonstrate mycophenolate mofetil to be similarly effective as cyclophosphamide in inducing remission of relapsed ANCA-associated vasculitis. However, mycophenolate mofetil might be an alternative to cyclophosphamide for the treatment of selected patients with nonlife-threatening relapses.