Mycophenolate mofetil versus cyclosporin a in children with frequently relapsing nephrotic syndrome

Abstract

The severe side effects of long-term corticosteroid or cyclosporin A (CsA) therapy complicate the treatment of children with frequently relapsing steroid-sensitive nephrotic syndrome (FR-SSNS). We conducted a randomized, multicenter, open-label, crossover study comparing the efficacy and safety of a 1-year treatmentwithmycophenolate mofetil (MMF; target plasmamycophenolic acid trough level of 1. 5-2. 5 μg/ml) orCsA (target trough level of 80-100 ng/ml) in 60 pediatric patientswith FR-SSNS. We assessed the frequency of relapse as the primary endpoint and evaluated pharmacokinetic profiles (area under the curve [AUC]) after 3 and 6 months of treatment. More relapses per patient per year occurred with MMF thanwith CsA during the first year (P=0. 03), but not during the second year (P=0. 14). No relapses occurred in 85% of patients during CsA therapy and in 64% of patients during MMF therapy (P=0. 06). However, the time without relapse was significantly longer with CsA than withMMF during the first year (P<0. 05), but not during the second year (P=0. 36). In post hoc analysis, patients with low mycophenolic acid exposure (AUC<50 μg·h/ml) experienced 1. 4 relapses per year compared with 0. 27 relapses per year in those with high exposure (AUC>50 μg·h/ml; P<0. 05). There were no significant differences between groups with respect to BP, growth, lipid levels, or adverse events. However, cystatin clearance, estimated GFR, and hemoglobin levels increased significantly with MMF compared with CsA. These results indicate thatMMF is inferior to CsA in preventing relapses in pediatric patients with FR-SSNS, but may be a less nephrotoxic treatment option. Copyright © 2013 by the American Society of Nephrology.