Efficacy of Obinutuzumab for Frequently Relapsing or Steroid-Dependent Nephrotic Syndrome

The first-generation anti-CD20 monoclonal antibody, rituximab, has effectively reduced relapse rates in patients with frequently relapsing or steroid-dependent nephrotic syndrome (FRNS or SDNS). However, its effects are often transient, and some patients are nonresponsive. Obinutuzumab, a next-generation humanized type II anti-CD20 monoclonal antibody, demonstrates stronger and more sustained B-cell depletion than rituximab. However, clinical evidence regarding its efficacy in FRNS or SDNS remains limited.

This retrospective single-center cohort study included 161 patients with FRNS or SDNS who received ≥ 1 dose of obinutuzumab and had > 3 months of follow-up at our institution. We evaluated the efficacy and safety of obinutuzumab in FRNS or SDNS by analyzing the remission, relapse, and adverse events in all enrolled patients.

During the follow-up period, 91.9% of patients (148/161) achieved remission following obinutuzumab infusion with a median time of 2.3 months (interquartile range [IQR]: 0.8-5.8). The median relapse-free survival (RFS) was 26.9 months (95% confidence intervals [CI]: 23.2-30.6). Significant improvements were observed in nephrotic syndrome parameters: the urine protein-to-creatinine ratio (UPCR) markedly decreased (median decreased from 5.7000 g/g to 0.1024 g/g, P < 0.001), and the median serum albumin level significantly increased (median increased from 28.4 g/l to 44.5 g/l, P < 0.001), whereas the estimated glomerular filtration rate (eGFR) showed no significant change (92 vs. 96 ml/min per 1.73 m², P = 0.25). One patient experienced a severe pulmonary infection, and no other serious adverse events were reported.

Obinutuzumab may offer a new treatment option for patients with FRNS or SDNS, providing rapid disease control, high remission rates, and durable benefits with a tolerable safety profile.