Non-corticosteroid immunosuppressive medications for steroid-sensitive nephrotic syndrome in children

BACKGROUND: About 80% of children with steroid-sensitive nephrotic syndrome (SSNS) have relapses. Of these children, half will relapse frequently, and are at risk of adverse effects from corticosteroids. While non-corticosteroid immunosuppressive medications prolong periods of remission, they have significant potential adverse effects. Currently, there is no consensus about the most appropriate second-line agent in children with frequently relapsing SSNS. In addition, these medications could be used with corticosteroids in the initial episode of SSNS to prolong the period of remission. This is the fifth update of a review first published in 2001 and updated in 2005, 2008, 2013 and 2020. OBJECTIVES: To evaluate the benefits and harms of non-corticosteroid immunosuppressive medications in SSNS in children with a relapsing course of SSNS and in children with their first episode of nephrotic syndrome. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to October 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-RCTs were included if they involved children with SSNS and compared non-corticosteroid immunosuppressive medications with placebo, corticosteroids or no treatment; different non-corticosteroid immunosuppressive medications, or different doses, durations or routes of administration of the same non-corticosteroid immunosuppressive medication. DATA COLLECTION AND ANALYSIS: Two authors independently assessed study eligibility, risk of bias and extracted data from the included studies. Statistical analyses were performed using a random-effects model and results expressed as risk ratio (RR) for dichotomous outcomes or mean difference (MD) for continuous outcomes with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. MAIN RESULTS: We identified 58 studies (122 reports) randomising 3720 children. Half were multicentre studies, and most studies were undertaken in South and East Asia (28 studies) and Europe (20 studies). The numbers of children randomised ranged from 14 to 211. Risk of bias assessment indicated that 32 and 33 studies were at low risk of bias for sequence generation and allocation concealment, respectively. Eleven studies were at low risk of performance bias and 13 were at low risk of detection bias. Forty-eight and 36 studies were at low risk of incomplete and selective reporting, respectively. Rituximab with or without prednisone compared with placebo with or without prednisone probably reduces the number of children experiencing relapse at six months (5 studies, 182 children: RR 0.22, 95% CI 0.11 to 0.43) and 12 months (3 studies, 108 children: RR 0.38, 95% CI 0.13 to 1.09) (moderate certainty), may increase the number with severe infusion reactions (4 studies, 162 children: RR 5.21, 95% CI 1.19 to 22.89; low certainty), but not severe infection or arthropathy (low certainty). Rituximab compared with tacrolimus probably reduces the risk of relapse at 12 months (4 studies, 238 children: RR 0.64, 95% CI 0.42 to 0.96) and may reduce the risk of relapse when compared with low dose mycophenolate mofetil (MMF) (1 study, 30 children: RR 0.17, 95% CI 0.04 to 0.62). Rituximab followed by MMF for 500 days reduces the risk of relapse compared with rituximab followed by placebo for 500 days (1 study, 78 children: RR 0.29, 95% CI 0.13 to 0.63; high certainty). Rituximab probably does not differ from ofatumumab in the riisk of relapse and 12 months (1 study, 140 children: RR 1.03, 95% CI 0.75 to 1.41; moderate certainty) or in adverse events. MMF and levamisole (1 study, 149 children: RR 0.90, 95% CI 0.70 to 1.16) may have similar effects on the number of children who relapse at 12 months (low certainty). Cyclosporin compared with MMF may reduce the risk of relapse at 12 months (3 studies, 114 children: RR 1.57, 95% CI 1.08 to 2.30) (low certainty). Levamisole compared with steroids or placebo may reduce the number of children with relapse during treatment (8 studies, 474 children: RR 0.52, 95% CI 0.33 to 0.82) (low certainty). Preliminary data from single studies indicate that levamisole and prednisone compared with prednisone alone may delay the onset of relapse after the initial episode of SSNS and that levamisole compared with increasing prednisone administration from alternate day to daily at the onset of infection may reduce the risk of relapse with infection (low certainty). Cyclosporin compared with prednisone may reduce the number of children who relapse (1 study, 104 children: RR 0.33, 95% CI 0.13 to 0.83) (low certainty). Alkylating agents compared with cyclosporin may make little or no difference to the risk of relapse during cyclosporin treatment (2 studies, 95 children: RR 0.91, 95% CI 0.55 to 1.48) (low certainty evidence) but may reduce the risk of relapse at 12 to 24 months (2 studies, 95 children: RR 0.51, 95% CI 0.35 to 0.74) (low certainty). Alkylating agents (cyclophosphamide and chlorambucil) compared with prednisone probably reduce the number of children who experience relapse at six to 12 months (6 studies, 202 children: RR 0.44, 95% CI 0.32 to 0.60) and at 12 to 24 months (4 studies, 59 children: RR 0.20, 95% CI 0.09 to 0.46) (moderate certainty). AUTHORS' CONCLUSIONS: New studies incorporated in this review update indicate that rituximab compared with prednisone, tacrolimus, or MMF is a valuable additional agent for managing children with relapsing SSNS. Comparative studies of CNIs, MMF, and levamisole suggest that CNIs may be more effective than MMF and that levamisole may be similar in efficacy to MMF. Important new studies suggest that MMF prolongs remission following rituximab, that levamisole may prevent infection-related relapse more effectively than changing from alternate-day to daily prednisone and that levamisole and prednisone compared with prednisone alone may prolong the time to first relapse. There are currently 23 ongoing studies which should improve our understanding of how to treat children with frequently relapsing SSNS.