Belimumab versus telitacicept in sequential treatment after rituximab for refractory lupus nephritis: a real-world multicentre study.

Objective: Both belimumab and telitacicept are recognised blockers for B lymphocyte activation, both of which have been approved as add-on therapies for SLE in China. The aim of this study is to compare the efficacy of rituximab (RTX) followed by belimumab or telitacicept in a real-world cohort.

Methods: A total of 49 refractory lupus nephritis patients were enrolled from four independent centres, subsequently categorised into two treatment groups: belimumab group (n=35) and telitacicept group (n=14) based on their treatment following RTX. The outcomes of renal response rates were evaluated.

Results: In this study cohort, 63.3% presented with anti-dsDNA antibody positivity and 79.6% exhibited hypocomplementemia, with a mean Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) Score of 13±6, estimated glomerular filtration rate (eGFR) of 76.2 (30.2, 113.7) mL/min and urinary protein creatinine ratio (uPCR) of 2.45 (0.77, 5.19) g/g. There was no significant differences between groups. After a follow-up duration of 26±12 months, renal objective remission rate was 80.0% (28 patients) in belimumab group and 85.7% (12 patients) in telitacicept group (difference, 5.7 percentage points, 95% CI, -25.8 to 26.8, p=1.000). Renal complete response was 54.3% (19 patients) in belimumab group and 78.6% (11 patients) in telitacicept group (difference, 24.3 percentage points, 95% CI, 9.7 to 47.8, p=0.194). The anti-dsDNA antibody, complement, eGFR, uPCR and SLEDAI-2K Score were improved in both groups with a significant reduction in prednisone dose. Major adverse effects included immunoglobulin deficiency, respiratory tract infection and urinary tract infection. No death occurred.

Conclusions: The sequential treatment of belimumab or telitacicept following RTX may represent a promising therapeutic approach in the management of refractory lupus nephritis. Further investigation is necessary to establish optimal protocols and long-term benefits.