Vor Bio Reports Positive Two-Year TELIGAN Results in IgA Nephropathy

Final two-year results from the Phase 3 TELIGAN trial showed that telitacicept was associated with substantially slower kidney function decline than placebo in adults with IgA nephropathy (IgAN). At Week 104, the annualised estimated glomerular filtration rate (eGFR) slope was −0.6 mL/min/1.73 m²/year with telitacicept versus −5.7 with placebo, a between-group difference of 5.1 mL/min/1.73 m²/year (p<0.001).

Announced by Vor Bio on October 22, 2026, the results were presented at the American Society of Nephrology (ASN) Kidney Week 2026. The study was conducted in China by Vor Bio’s collaborator, RemeGen.

Targeting the immune mechanisms of IgA nephropathy

IgAN is a progressive kidney disease characterised by IgA-containing immune complex deposition, inflammation and proteinuria. Overproduction of galactose-deficient IgA1 (Gd-IgA1) contributes to its underlying immunopathology. Despite supportive treatment, some patients continue to experience declining kidney function and remain at risk of kidney failure.

Telitacicept is a recombinant fusion protein that inhibits BLyS, also known as BAFF, and APRIL, two cytokines involved in B-cell and plasma-cell survival. By targeting these pathways, the drug aims to reduce pathogenic antibody production. China granted telitacicept conditional approval in June 2026 for reducing proteinuria in adults with primary IgAN at risk of progression.

TELIGAN trial design

TELIGAN (NCT05799287) enrolled 318 adults with biopsy-confirmed IgAN receiving stable background supportive therapy. Participants were randomised 1:1 to subcutaneous telitacicept 240 mg or placebo. Treatment was administered weekly through Week 39 (Stage A), followed by every-other-week dosing from Week 40 through Week 104 (Stage B).

Stage A evaluated changes in 24-hour urine protein-to-creatinine ratio (24h-UPCR) at Week 39. Those results were published in The New England Journal of Medicine in May 2026. The Stage B primary endpoint was annualised eGFR slope through Week 104.

Kidney function and disease progression

Telitacicept met the Stage B primary endpoint. Annualised eGFR slope was −0.6 mL/min/1.73 m²/year (95% CI, −1.7 to 0.4) with telitacicept and −5.7 (95% CI, −7.0 to −4.5) with placebo. The between-group difference was 5.1 mL/min/1.73 m²/year (95% CI, 3.5 to 6.7; p<0.001).

Telitacicept was also associated with an 89% lower risk of confirmed eGFR decline of at least 30% (hazard ratio [HR], 0.11) and an 81% lower risk of decline of at least 40% (HR, 0.19). No patients in the telitacicept group experienced an event in the prespecified kidney failure composite endpoint, compared with five in the placebo group, including two who required dialysis.

These findings extend the earlier proteinuria results to a kidney function measure relevant to long-term disease progression. However, the kidney failure comparison is based on few events and should be interpreted cautiously.

Sustained proteinuria reduction and safety

At Week 104, 24h-UPCR decreased 60.3% from baseline with telitacicept, compared with a 0.9% increase with placebo. Vor Bio reported a placebo-adjusted reduction of 60.7%. A UPCR below 0.5 g/g was achieved by 44.0% of telitacicept-treated patients versus 8.2% of placebo recipients. Serum Gd-IgA1 decreased 47.79% with telitacicept and increased 19.06% with placebo. Proteinuria reductions were maintained following the switch to every-other-week dosing.

Treatment-emergent adverse events occurred in 95.0% of patients receiving telitacicept and 89.3% receiving placebo. Serious adverse events occurred in 8.2% versus 18.2%, respectively. Overall infections occurred in 67.3% of both groups, while serious infections occurred in 1.9% versus 4.4%. Injection-site reactions were more frequent with telitacicept (56.0% versus 18.9%), mostly mild to moderate.

Although serious adverse events and serious infections were numerically less frequent with telitacicept, these findings do not establish a comparative safety advantage. The higher overall adverse-event rate and injection-site reactions remain relevant to long-term treatment.

Clinical interpretation and development outlook

The principal finding is the difference in eGFR slope over 104 weeks, supported by sustained proteinuria reduction and fewer observed confirmed kidney function decline events. Together, these results strengthen the evidence for a potential kidney-protective effect of dual BAFF/APRIL inhibition in IgAN. However, eGFR slope remains a measure of change over time, and the limited number of kidney failure events prevents firm conclusions about reductions in kidney failure.

The evidence also has important limitations. TELIGAN was conducted exclusively in China, and the two-year findings were announced by the companies before assessment of a peer-reviewed full report. Vor Bio stated that it had not independently verified the results. The study had no active comparator, and the findings do not establish how telitacicept compares with other IgAN treatments or whether benefits persist after treatment discontinuation.

RemeGen is responsible for development and commercialisation in Greater China, while Vor Bio holds rights outside that region. The two-year findings may inform further development, but their applicability to other populations and their acceptability to regulators outside China remain uncertain.

Reference

Telitacicept Demonstrates Durable Preservation of Kidney Function Through Two Years in Phase 3 TELIGAN Trial in IgA Nephropathy, Vor Bio, 22 October 2026

A Study of Telitacicept for IgA Nephropathy (TELIGAN), ClinicalTrials.gov ID NCT05799287