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 non-life-threatening relapses.