Abstract: Objective: To evaluate the clinical efficacy and safety of Obinutuzumab (OBZ) in the treatment of patients with refractory and relapsing lupus nephritis (LN). Methodology: We retrospectively analyzed data from LN patients treated with OBZ at the National Clinical Research Center for Kidney Diseases from November 2023 to December 2024. Treatment regimen: 1.0g of OBZ was administered on days 1 and 15, whether to administer additional OBZ was based on remission status or B-cell reconstitution at month 6. The primary outcome was the cumulative renal response rate. Results: A total of 9 patients were included (7 relapsing LN, 2 refractory LN) with 8 females. The median follow-up was 12 months. All patients achieved renal response, and 4 patients achieved complete renal response (CRR). At month 6, the median proteinuria decreased from a baseline of 1.97(1.78~8.94)g/d to 0.79(0.46~1.09)g/d. Serum complement levels and Systemic Lupus Erythematosus Disease Activity Index (SLE-DAI) scores showed significant improvement, while renal function remained stable. All patients achieved complete peripheral B-cell depletion within 3 months, with only one patient showing reconstitution at month 6. The median prednisone dosage was tapered to 7.5mg/d by month 9. No serious adverse events occurred during the treatment period. Conclusion: OBZ therapy could effectively improve renal response in patients with refractory and relapsing LN, with alleviated immunological parameters and disease activity. The patients showed favorable tolerability and safety during the treatment. Large prospective studies are needed to confirm the efficacy of OBZ in these special patients.

Key words: font-family:Inter, -apple-system, BlinkMacSystemFont, ", font-size:16px, background-color:#FFFFFF, ">refractory lupus nephritis, Obinutuzumab, B-cell depletion, renal response