Efficacy and Safety of Treatment with Rituximab for Difficult Steroid-Resistant and -Dependent Nephrotic Syndrome: Multicentric Report

Background and objectives: The treatment of idiopathic nephrotic syndrome is often complicated by a refractory and relapsing course, with risk of drug toxicity and progressive renal failure. We report the efficacy and safety of rituximab in patients with steroid-resistant (SRNS) and steroid-dependent nephrotic syndrome (SDNS) refractory to standard therapy. Design, setting, participants, & measurements: This was a cohort study in academic, tertiary care centers in India and the United States. Patients with SRNS or SDNS, not responding to medications or showing calcineurin inhibitor toxicity, treated with two to four doses of intravenous rituximab, and followed >= 12 months were included. Remission was termed as complete, partial, or no response. Results: Thirty-three patients with SRNS (24 initial, 9 late resistance) and 24 with SDNS, with mean ages of 12.7 +/- 9.1 and 11.7 +/- 2.9 years, respectively, were included. Six months after rituximab therapy, 9 (27.2%) patients with SRNS showed complete remission, 7 (21.2%) had partial remission, and 17 (51.5%) had no response. At 21.5 +/- 11.5 months, remission was sustained in 15 (complete: 7, partial: 8) patients. Of 24 patients with SDNS, remission was sustained in 20 (83.3%) at 12 months and in 17 (71%) at follow-up of 16.8 +/- 5.9 months. The mean difference in relapses before and 12 months after treatment with rituximab was 3.9 episodes/patient per year. Conclusions: Therapy with rituximab was safe and effective in inducing and maintaining remission in a significant proportion of patients with difficult SRNS and SDNS. Clin J Am Soc Nephrol 5: 2207-2212, 2010. doi: 10.2215/CJN.03470410