Mycophenolate Mofetil Versus Prednisone for Induction Therapy in Steroid-Sensitive Idiopathic Nephrotic Syndrome in Children: An Observational Study

Rationale & Objective: High-dose steroids are recommended for the induction of idiopathic nephrotic syndrome. The aim of this study was to compare standard induction therapy with Mycophenolate Mofetil (MMF). We hypothesized that MMF could be noninferior to steroids in maintaining steroid-induced remission. The second aim was to reduce steroid-induced side effects. Study Design: This was an observational study. Setting & Population: Patients 2-11 years with first episode of nephrotic syndrome who entered remission within 2 weeks of standard steroid treatment were eligible for enrollment. Patients in the experimental group completed 12-week induction with MMF, whereas the control group continued a standard 12-week steroid protocol. Exposures: MMF and prednisolone were used in the study. Outcomes: The primary study outcomes were relapse rate and relapse-free interval during a 52-week follow-up. Analytical Approach: Descriptive statistics were used for analysis. Results: Ten of 41 eligible patients consented to participate in the MMF group and 8 completed the study. The control group included 31 patients, with 23 patients who completed 52 weeks follow-up. During the induction phase, 3 out of 10 patients (30%) in the MMF group and 1 out of 31 (3%) in the control group (P = 0.04) developed relapse. During the 52 weeks follow-up period, 7 out of 10 patients (70%) in the MMF group and 19 out of 31 (61%) in the control group developed relapse (P = 0.72). The median relapse-free interval was 11 and 19 weeks in MMF and control groups, respectively (P = 0.60). No serious side effects were recorded in either group. Limitations: The limitations of the study were low patient numbers receiving MMF and single-center design. Conclusions: Our small cohort of patients treated with MMF reported a higher relapse rate during the induction phase. However, by 12 months of follow-up the relapse rate and relapse-free intervals were similar between both groups. All patients tolerated MMF without significant side effects, and those who relapsed remained steroid-sensitive. Plain-Language Summary: Despite their known side effects steroids remain a standard induction therapy for new onset nephrotic syndrome in children. The aim of this study was to assess whether mycophenolate mofetil (MMF) can be as successful as steroids in maintaining steroid-induced remission. Patients who achieved remission within 2 weeks of steroid treatment had either continued steroids for an additional 10 weeks or switched to MMF. The results of the study showed a higher relapse and infection rate in the MMF group. By 12 months there were no differences in the relapse rate and relapse-free interval between the groups. Larger multicenter studies are underway to demonstrate noninferiority of MMF to steroids in steroid-sensitive nephrotic syndrome.