Efficacy and safety of Telitacicept in IgA nephropathy and its impact on urinary Gd-IgA1: insights from a real-world study

Objective In this study, we evaluated the efficacy and safety of Telitacicept for treating patients with primary IgA nephropathy (IgAN) in our single hospital. We also explored the effect of Telitacicept on urinary Gd-IgA1 levels among patients with IgAN. Methods A retrospective study was conducted. Patients were grouped according to 24-hour proteinuria (≥ 2.0 vs. < 2.0 g/day), eGFR (≥ 35 vs. < 35 mL/min/1.73 m 2 ), gender (man vs. woman), age (≥ 35 vs. < 35 years) and therapy options (Telitacicept vs. Telitacicept plus glucocorticoid/immunosuppressor) to evaluate the therapeutic effect of Telitacicept on IgAN. We conducted a propensity score-matched comparison of the primary outcome between 20 IgAN patients with Telitacicept plus supportive treatment and 20 patients with supportive care alone. The urinary Gd-IgA1 levels were determined using ELISA. Results A total of 68 IgAN patients who received Telitacicept were included in this study. At baseline, the median baseline proteinuria was 1753.5 mg/day, and eGFR was 71.5 ml/min/1.73m². Significant reductions in proteinuria were observed at 1 month and sustained through 6 months of follow-up. The eGFR remained stable throughout the follow-up period. Subgroup analyses stratified by baseline proteinuria, eGFR, gender, age, and therapy options showed no significant differences in proteinuria reduction rates. Both patients initially starting Telitacicept and those who had previously failed other therapy before starting it showed significant reductions in proteinuria and stable eGFR. Importantly, we observed an improvement in the eGFR slope within the Prior Treatment plus Telitacicept Group, with the annual rate of decline slowing from 6.35 ml/min/1.73m²/year pre-treatment to 3.68 ml/min/1.73m²/year after Telitacicept therapy. Furthermore, the responsive group to Telitacicept exhibited significantly higher IgA levels compared to the non-responsive group. Compared with patients receiving supportive care alone, those who initially added Telitacicept showed a greater reduction in proteinuria by the last follow-up. Additionally, Telitacicept therapy led to a decrease in urinary Gd-IgA1/Cr levels. Telitacicept treatment was well-tolerated. Conclusions In IgAN, Telitacicept demonstrated promising efficacy, significantly reducing proteinuria and stabilizing eGFR, with a favorable safety profile.