Objective: Monthly intravenous (IV) cyclophosphamide for 6 months has been the standard induction regimen for lupus nephritis, followed by a maintenance regimen of quarterly infusions for 2 years. We undertook this study to compare the efficacy and safety of the standard regimen versus a high-dose IV cyclophosphamide regimen.
Methods: We performed a prospective randomized trial comparing monthly IV cyclophosphamide at 750 mg/m(2) body surface area for 6 months followed by quarterly IV cyclophosphamide for 2 years (traditional treatment) against high-dose IV cyclophosphamide (50 mg/kg daily for 4 days) (high-dose treatment). Entry criteria included renal lupus, neurologic lupus, or other organ system involvement with moderate-to-severe activity.
Results: Fifty-one patients were randomized; 3 withdrew before treatment and 1 committed suicide after 2 months of high-dose treatment. Twenty-two had renal lupus, 14 had neurologic lupus, and 11 had other organ involvement. The outcome measure was the Responder Index for Lupus Erythematosus (complete response, partial response, no change, or worsening). At 6 months (the end of induction), 11 of 21 patients (52%) in the high-dose treatment group had a complete response compared with 9 of 26 patients (35%) in the traditional treatment group (P = 0.13). At the final visit (30 months), 10 of 21 patients (48%) in the high-dose treatment group had a complete response compared with 13 of 20 patients (65%) who continued with traditional treatment (P = 0.13). Six patients crossed over from traditional treatment to high-dose treatment because of lack of response, and 3 of those patients became complete responders.
Conclusion: There was not strong evidence that monthly IV cyclophosphamide and high-dose IV cyclophosphamide differed in complete or in any (complete or partial) response to induction or maintenance therapy. However, nonresponders to monthly IV cyclophosphamide can sometimes be rescued with high-dose IV cyclophosphamide.
Trial registration: ClinicalTrials.gov NCT00010400.