Kidney Compass: Phase 3 Data on Telitacicept in IgA Nephropathy at ASN Kidney Week 2025

New phase 3 data released by Vor Bio underscore the potential of telitacicept, a dual BLyS/APRIL inhibitor, as a disease-modifying therapy for IgA nephropathy (IgAN), particularly for patients at high risk of progression.¹

In this special edition episode of Kidney Compass: Navigating Clinical Trials, hosts Brendon Neuen, MBBS, PhD, and Shikha Wadhwani, MD, MS sit down with study investigators Jicheng Lv, MD, PhD, and Hong Zhang, MD, PhD, professors of internal medicine at Peking University First Hospital, following their presentation at the American Society of Nephrology (ASN) Kidney Week 2025.

Telitacicept is a recombinant fusion protein designed to neutralize BLyS and APRIL, upstream drivers of B-cell survival and immunoglobulin class switching, including production of galactose-deficient IgA1, the pathogenic hallmark of IgAN. The 39-week multicenter, randomized, double-blind trial evaluated the agent’s impact on proteinuria, B-cell activity, immunoglobulin levels, and kidney function.²

In stage A, adults were randomly assigned 1:1 to telitacicept 240 mg subcutaneous weekly or placebo, in addition to background supportive care. The primary endpoint, which was defined as change in 24-hour urine protein-to-creatinine ratio (UPCR), was met with a −58.9% reduction in the telitacicept arm compared with −8.8% with placebo (P < .0001). Week-39 data were consistent, with the treatment group showing a 55% 24-hour UPCR reduction.¹

Clinically meaningful thresholds associated with improved long-term renal outcomes were achieved at substantially higher rates with telitacicept:

• 24h-UPCR <0.8 g/g: 61% vs 19.5% (placebo)
• <0.5 g/g: 42.1% vs 7.5%
• <0.3 g/g: 24.5% vs 0.6%

Investigators highlighted kidney function remained stable across secondary endpoints. Mean eGFR change at week 39 was essentially unchanged with telitacicept (−0.010 mL/min/1.73 m²) compared with a modest decline in the placebo group (−0.77 mL/min/1.73 m²). Investigators also observed a lower risk of ≥30% eGFR decline (27%) with telitacicept versus placebo.¹

Editor's Note: LV reports relevant disclosures with Chinook Therapeutics, KBP Bioscience, and others. Zhang reports no relevant disclosures.

References:

1. Lv, J, Liu LJ, Wang W, et al. Efficacy and Safety of Telitacicept in Patients with IgAN: Results from Stage A of a Phase 3 Clinical Study. Journal of the American Society of Nephrology.

2. Telitacicept Achieved Primary Endpoint in Phase 3 Clinical Study for IgA Nephropathy | Vor Bio. Vor Bio. Published 2025. https://ir.vorbio.com/news-releases/news-release-details/telitacicept-achieved-primary-endpoint-phase-3-clinical-study-0