Background and objectives Mycophenolate mofetil (MMF) has emerged as a new agent for treatment of a variety of glomerular diseases. This study examines the safety and efficacy of MMF in treating pediatric patients with steroid-dependent (SD) and/or frequently relapsing (FR) nephrotic syndrome (NS).

Methods We retrospectively reviewed the medical records of 18 patients with SDNS and/or FRNS treated with MMF for at least 3 months. MMF was used in 11 patients with SDNS (n = 10) and FRNS (n = 1), including 7 males and 4 females.

Results Mean age at time of diagnosis of NS was 3.3 years (range 1.1–8.5 years), and at the start of MMF 5.9 years (range 2.9–10 years). Seven patients had a renal biopsy prior to starting MMF; all had mesangial proliferative glomerulonephritis. Mean follow-up after starting MMF was 12.2 months (range 4–24 months). Mean MMF dose was 948 mg/m²/day (range 500–1087 mg/m²/day). MMF resulted in improvement in 9 of 11 patients, with 8 patients weaned off steroids completely, with a reduction in the mean relapse rate from 4.7 relapses/patient/year (range 2.4–6) before MMF to 1.05 relapses/patient/year (range 0–4.5) after MMF therapy (p = 0.0001). The relative risk for relapse before MMF was 4.7 (p = 0.0002). None of the patients had significant adverse events or intolerance to MMF therapy.

Conclusion We conclude that MMF is a safe and effective option for treatment of children with SDNS and/or FRNS.