Telitacicept Shows Promise in IgA Nephropathy Phase 3 Trial in China

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Vor Bio (Nasdaq: VOR) reported that telitacicept met the primary endpoint in Stage A of a Phase 3 IgA nephropathy study in China, showing a rapid, clinically meaningful proteinuria reduction at Week 39.

Key metrics: 24h-UPCR -58.9% vs -8.8% (p; eGFR stabilized (telitacicept -0.10 vs placebo -0.77); risk of ≥30% eGFR decline 6.3% vs 27.0%; remission rates 61% vs 19.5% for UPCR

Positive

24h-UPCR -58.9% vs -8.8% at Week 39 (p
eGFR stabilized in telitacicept group (-0.10 vs -0.77)
Risk of ≥30% eGFR decline reduced to 6.3% vs 27.0%
Higher remission rates: 61% vs 19.5% for UPCR
Fewer serious adverse events with telitacicept (2.5% vs 8.2%)

Negative

Treatment-emergent AEs were more frequent (89.3% vs 78.6%)
Results reported are from Stage A of the Phase 3 study, not full enrollment

Insights

Telitacicept met the Phase 3 Stage A primary endpoint in IgAN with strong proteinuria reduction and a BLA filed in China.

Telitacicept produced a large, statistically significant reduction in proteinuria at Week 39 (24h‑UPCR change: -58.9% vs -8.8%, p-0.10% vs -0.77%) and lower incidence of ≥30% eGFR decline (6.3% vs 27.0%). These are objective, regulator-recognized measures of disease activity and progression in IgA nephropathy.

The safety profile reported is largely favorable: more treatment‑emergent events occurred with treatment (89.3% vs 78.6%), but most were mild/moderate and serious adverse events were fewer with treatment (2.5% vs 8.2%). A submitted Biologics License Application to China’s CDE could materially accelerate local regulatory paths if accepted and reviewed.

Watch for formal regulatory timelines and full data disclosure from the late‑breaking presentation at ASN Kidney Week 2025; key near‑term monitors include the CDE review milestones and any published subgroup or long‑term safety/efficacy tables over the next 6–12 months.

11/08/2025 – 11:45 AM

Treatment with telitacicept for 39 weeks resulted in a rapid, clinically meaningful, and statistically significant reduction in proteinuria, with a favorable safety profile

Telitacicept demonstrated a 55% reduction in 24-hour urine protein-to-creatinine ratio (24h-UPCR) at 39 weeks compared with placebo; statistically significant benefits also achieved across all key secondary endpoints

Data presented as late-breaking oral presentation at American Society of Nephrology’s Kidney Week 2025

BOSTON, Nov. 08, 2025 — Vor Bio (Nasdaq: VOR), a clinical-stage biotechnology company transforming the treatment of autoimmune diseases, today announced positive topline results from its Phase 3 clinical study of telitacicept in adults with IgA nephropathy (IgAN) in China. The study, conducted by Vor Bio’s collaboration partner, RemeGen Co., Ltd, demonstrated that telitacicept met its primary endpoint, showing a statistically significant reduction in proteinuria after 39 weeks of treatment. Furthermore, the trial achieved statistically significant improvements across all key secondary endpoints.

“These Phase 3 results mark a significant milestone for Vor Bio and the IgAN community,” stated Jean-Paul Kress, M.D., Chief Executive Officer and Chairman of the Board. “The depth and durability of proteinuria reduction, coupled with stabilization of kidney function and a favorable safety profile, underscore telitacicept’s potential to become a transformative therapy for patients at risk of progressive kidney damage. The objective 24h-UPCR endpoint validates the therapeutic effect of dual BAFF/APRIL inhibition. These findings, alongside the strong pharmacodynamic evidence of telitacicept’s dual B-cell pathway inhibition, demonstrate its potential to deliver disease-modifying effects in IgAN.”

The Phase 3 study was a multicenter, randomized, double-blind, placebo-controlled trial conducted in China, enrolling 318 adult patients with IgAN, all at high risk of disease progression and receiving stable standard of care. Participants were randomized 1:1 to receive either 240 mg of telitacicept or placebo, administered subcutaneously on a weekly basis.

Efficacy Results: A Detailed Look
At Week 39, patients treated with telitacicept experienced a 58.9% reduction in 24-hour urine protein-to-creatinine ratio (24h-UPCR) compared to an 8.8% reduction in the placebo group (p

Secondary Endpoints Showcase Kidney Function Preservation
Beyond the primary endpoint, telitacicept demonstrated a significant impact on preserving kidney function. The estimated glomerular filtration rate (eGFR), a critical measure of kidney health, remained more stable in the telitacicept group (-0.10 change from baseline) compared to the placebo group (-0.77 change). Moreover, telitacicept reduced the risk of ≥30% decline in eGFR by 75%, observed in 6.3% of telitacicept patients versus 27.0% in placebo recipients. Notably, 61% of patients in the telitacicept arm achieved remission (defined as 24h-UPCR

Safety and Tolerability: A Favorable Profile
While treatment-emergent adverse events were more frequent in the telitacicept group (89.3%) compared to placebo (78.6%), the majority of events were mild or moderate in severity. Importantly, serious adverse events occurred less frequently in the telitacicept group (2.5%) than in the placebo group (8.2%), which may reflect the underlying disease activity better controlled with telitacicept, as well as a relatively safe profile of the drug. No unexpected safety findings were reported during the study.

Regulatory Pathway and Commercial Implications
With the data in hand, RemeGen has submitted a Biologics License Application (BLA) to the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) in China for telitacicept in IgAN. If approved, IgAN would be the fifth approved indication for telitacicept in China, representing a key expansion of therapeutic applications for the drug.

Market Opportunity and Competitive Landscape
IgA nephropathy is a significant market opportunity in China, where the prevalence of the disease is estimated to be higher than in Western countries. While current treatment options are limited to supportive care and immunosuppressants, recent approvals of targeted therapies like sparsentan (Filspari) and atrasentan (Kinpeygo) have demonstrated the market’s appetite for disease-modifying agents. The dual BAFF/APRIL inhibition mechanism of telitacicept, if approved, could position it as a competitive option in the evolving IgAN treatment landscape.

About Vor Bio

Vor Bio is a clinical-stage biotechnology company transforming the treatment of autoimmune diseases. The Company is focused on rapidly advancing telitacicept, a novel dual-target fusion protein, through Phase 3 clinical development and potential commercialization to address serious autoantibody-driven conditions worldwide. For more information visit www.vorbio.com.

About Telitacicept

Telitacicept is a novel, investigational recombinant fusion protein designed to treat autoimmune diseases by selectively inhibiting BLyS (BAFF) and APRIL – two cytokines essential to B cell and plasma cell survival. This dual-target mechanism reduces autoreactive B cells and autoantibody production, key drivers of autoimmune pathology.

Telitacicept is approved in China for systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and generalized myasthenia gravis (gMG). A global Phase 3 clinical trial in gMG is currently underway across the United States, Europe, South America, and Asia-Pacific to support potential approval in the United States, Europe, and Japan.

About IgAN Nephropathy

IgA nephropathy (IgAN) is one of the most common primary glomerular diseases worldwide and a leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD). It is characterized by IgA-containing immune complex deposition in the kidney, leading to inflammation, proteinuria, hypertension, and progressive loss of renal function. Up to 40% of patients progress to ESRD within 20 years of diagnosis, underscoring the significant unmet need for effective therapies. Current treatment approaches, including optimized blood pressure control, renin-angiotensin system blockade, and SGLT2 inhibitors, primarily slow disease progression but do not address the underlying immunopathology.

The prevailing scientific consensus is that overproduction of galactose-deficient IgA1 (Gd-IgA1) is a central driver of IgAN. BAFF and APRIL, two cytokines critical to B-cell survival and function, promote the production of Gd-IgA1 and its pathogenic antibodies.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. The words “aim,” “anticipate,” “can,” “continue,” “could,” “design,” “enable,” “expect,” “initiate,” “intend,” “may,” “on-track,” “ongoing,” “plan,” “potential,” “should,” “target,” “update,” “will,” “would,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Forward-looking statements in this press release include Vor Bio’s statements regarding the potential of telitacicept in various indications, including IgAN; telitacicept’s potential as a foundational therapy for B-cell mediated diseases worldwide; the timing of presentation of clinical data; Vor Bio’s development and commercialization plans for telitacicept; and other statements that are not historical fact.

Vor Bio may not actually achieve the plans, intentions, or expectations disclosed in these forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including the data for our product candidates may not be sufficient for obtaining regulatory approval to commercialize products; we may not be able to execute our business plans, including meeting our planned clinical and regulatory milestones and timelines, and possible limitations of financial and other resources. These and other risks are described in greater detail under the caption “Risk Factors” included in Vor Bio’s most recent annual or quarterly report and in other reports it has filed or may file with the Securities and Exchange Commission. The results of the clinical trial described in this press release is based on information reported by RemeGen; Vor Bio has not independently verified this data.

Any forward-looking statements contained in this press release speak only as of the date hereof, and Vor Bio expressly disclaims any obligation to update any forward-looking statements, whether because of new information, future events or otherwise, except as may be required by law.

Media & Investor Contacts:
Carl Mauch

Sarah Spencer

FAQ

What did Vor Bio (VOR) announce on November 8, 2025 about telitacicept in IgA nephropathy?

Vor Bio announced telitacicept met the primary endpoint in Stage A of a Phase 3 China study, showing 24h-UPCR -58.9% vs -8.8% (p at Week 39.

How did telitacicept affect kidney function in the VOR Phase 3 IgAN study?

Telitacicept stabilized eGFR (change -0.10) versus a decline in placebo (-0.77) and lowered risk of ≥30% eGFR decline (6.3% vs 27.0%).

What were the remission rates for telitacicept versus placebo in the VOR study?

Remission (24h-UPCR

What safety findings did Vor Bio report for telitacicept in the Phase 3 IgAN Stage A data?

Treatment-emergent AEs were higher with telitacicept (89.3% vs 78.6%), but serious AEs were lower (2.5% vs 8.2%) and no unexpected safety signals were noted.

Has telitacicept been submitted for regulatory approval in China for IgAN?

RemeGen announced a Biologics License Application (BLA) has been submitted to China’s CDE/NMPA for telitacicept in IgAN.

Vor Biopharma Inc.