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

Abstract Introduction The first-generation anti-CD20 monoclonal antibody, rituximab, has effectively reduced relapse rates in patients with frequently relapsing or steroid-dependent nephrotic syndrome (FRNS/SDNS). However, its effects are often transient, and some patients are non-responsive. Obinutuzumab, a next-generation humanized type II anti-CD20 monoclonal antibody, demonstrates stronger and more sustained B-cell depletion compared to rituximab. However, clinical evidence regarding its efficacy in FRNS/SDNS remains limited. Methods This retrospective single-center cohort study included 161 patients with FRNS/SDNS who received at least one dose of Obinutuzumab and had over 3 months of follow-up at our institution. We evaluated the efficacy and safety of Obinutuzumab in FRNS/SDNS by analyzing the remission, relapse, and adverse events in all enrolled patients. Results During the follow-up period, 91.9% (148/161) of patients achieved remission following Obinutuzumab infusion with a median time of 2.3 months (IQR 0.8, 5.8). The median relapse-free survival was 26.9 months (95% CI: 23.2–30.6). Significant improvements were observed in nephrotic syndrome parameters: the urine protein-to-creatinine ratio markedly decreased (median level decreased from 5.7000 g/g to 0.1024 g/g, P < 0.001), the median serum albumin level significantly increased (median level increased from 28.4 g/L to 44.5 g/L, P < 0.001), although the estimated glomerular filtration rate showed no significant change (92 vs. 96 mL/min/1.73m², P = 0.25). One patient experienced severe pulmonary infection, and no other serious adverse events were reported. Conclusion Obinutuzumab may offer a new treatment option for patients with FRNS/SDNS, delivering rapid disease control, high remission rates, and durable benefit with a tolerable safety profile.