1517: The Chinese Experience with Telitacicept in Lupus Nephritis Management: 51-Patient Cohort Analysis on Therapeutic Outcomes and Safety Parameters

Background/Purpose: Lupus nephritis (LN), affects 30%-50% of systemic lupus erythematosus (SLE) patients, a major contributor to SLE-related mortality. Telitacicept, an innovative recombinant fusion protein, disrupts the interaction between BLyS/APRIL and their receptors, thereby effectively curbing B lymphocyte proliferation and maturation. While both Phase I and Phase II clinical trials have substantiated Telitacicept's efficacy in ameliorating SLE progression, its therapeutic potential in LN remains underexplored, with limited data on efficacy and safety. To evaluate the real-world efficacy and safety of Telitacicept in LN patients at a single center, we aim to furnish evidence for B-cell-targeted therapeutic strategies in LN management.

Methods: A total of 51 LN patients treated with Telitacicept combined therapy (Group A) and 51 matched controls receiving conventional therapy (Group B) in the Second Hospital of Hebei Medical University from March 2021 to January 2024 were enrolled in the retrospective study. Clinical data, including laboratory results, disease activity, renal response rates, and adverse events (AEs) were collected at 4, 12, 24, and 52 weeks. Further, LN patients confirmed by renal biopsy were divided into Group A1 (n=12) and Group B1 (n=13), and clinical data were compared and analyzed based on different pathological types. Additionally, Group A patients were stratified by telitacicept dosage (160mg and 80mg) and compared with Group B.

Results: 1. Compared to Group B, Group A showed substantial improvement in serum albumin from week 4 to week 24 and reduced 24-hour urine protein at week 24 (P< 0.05). The systemic lupus erythematosus responder index 4 and complete renal response (CRR) rate in Group A were 71.88% and 87.5%, respectively, significantly higher than those in Group B (P=0.030 and P=0.050). At weeks 12 and 24, complement 3 (C3), C4, and immunoglobulins (Ig) in Group A improved notably, with faster IgG reduction (P< 0.05). Anti-dsDNA antibodies decreased at week 52 (P< 0.05). From week 4 to week 52, glucocorticoid (GC) use was considerably lower in Group A (P< 0.05).

2. Compared to Group B1, type IV LN patients in Group A1 showed improved C3, C4 and reduced GC use at 24 week (P< 0.05). Type V LN patients had lower GC use and increased C3 at week 52 (P=0.037). CRR rates were 91.67% (A1) vs. 76.92% (B1) (P=0.315). The partial RR rates were 8.33% and 23.08%, where type IV accounted for 100% and 66.67%, respectively, with no statistical analysis due to small sample size.

3. 160 mg of Telitacicept reduced IgG more effectively than 80mg group at week 24 (P=0.025).

4. AE rates were 23.5% (Group A) and 19.6% (Group B) (P=0.350) respectively, with infections being the most common. No severe AEs were reported in Telitacicept group.

Conclusion: Compared to conventional therapy, Telitacicept combined therapy remarkably reduces proteinuria, improves immunological markers, enhances CRR, and effectively reduces GC use in LN patients. The 160mg dose is more effective in reducing IgG. Telitacicept is safe, with no severe AEs reported.