Vor Bio Initiates Global Phase 3 Trial of Telitacicept for Primary Sjögren's Disease
核心洞察
Vor Bio (搜索) has dosed the first patient in UPSTREAM SjD, a global Phase 3 registrational trial evaluating telitacicept in approximately 250 adult patients with active primary Sjögren's disease (搜索).
Telitacicept is the only BAFF (搜索)/APRIL (搜索) inhibitor currently in Phase 3 development for Sjögren's disease (搜索), targeting a condition that currently lacks approved disease-modifying therapies.
Previous Phase 3 results from China demonstrated statistically significant improvements in both ESSDAI and ESSPRI scores, providing clinical support for dual BAFF (搜索)/APRIL (搜索) inhibition in this autoimmune disease.
Vor Bio (搜索) has achieved a significant milestone in autoimmune disease research by dosing the first patient in UPSTREAM SjD, a global Phase 3 registrational trial evaluating telitacicept in adult patients with active primary Sjögren's disease (搜索). The randomized, double-blind, placebo-controlled trial represents a critical advancement for patients with this chronic autoimmune condition that currently lacks approved disease-modifying therapies.
Novel Dual-Target Mechanism Addresses Unmet Medical Need
Telitacicept stands as the only BAFF (搜索)/APRIL (搜索) inhibitor currently in Phase 3 development for Sjögren's disease (搜索). The investigational recombinant fusion protein is designed to treat autoimmune diseases by selectively inhibiting BLyS (搜索) (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.
"As the only BAFF (搜索)/APRIL (搜索) inhibitor currently in Phase 3 development for this condition, we believe telitacicept has the potential to address a serious autoimmune disease that currently lacks approved disease-modifying therapies," said Jean-Paul Kress, M.D., Chief Executive Officer and Chairman of Vor Bio (搜索).
Strong Clinical Foundation from Chinese Phase 3 Results
The global trial builds upon promising Phase 3 results from China, where RemeGen presented data demonstrating potential best-in-disease activity. The Chinese study showed statistically significant and clinically meaningful improvements in both ESSDAI (EULAR Sjögren's Syndrome Disease Activity Index) and ESSPRI (EULAR Sjögren's Syndrome Patient Reported Index), the two key, validated EULAR measurements used to assess patient disease burden.
"These prior results provide important clinical support for dual BAFF (搜索)/APRIL (搜索) inhibition as a therapeutic strategy in this disease and give us confidence in telitacicept's potential to address both systemic disease activity and the symptoms that matter most to patients," Kress noted.
Trial Design and Patient Population
UPSTREAM SjD will evaluate the efficacy and safety of telitacicept administered subcutaneously with a pre-filled syringe compared to placebo in approximately 250 adult patients with active primary Sjögren's disease (搜索). The trial will enroll patients who meet the 2016 ACR/EULAR classification criteria for primary SjD and have active disease as defined by an ESSDAI score ≥5.
The primary endpoint is the change from baseline in the ESSDAI score at Week 48. Key secondary endpoints will evaluate the effect of telitacicept at Week 48 across systemic disease activity, glandular function, and patient-reported symptoms.
Significant Disease Burden and Market Opportunity
Sjögren's disease (搜索) is a chronic autoimmune condition in which overactive B cells drive inflammation, damaging moisture-producing glands and, in many cases, other organs throughout the body. Hallmark symptoms include dry eyes and dry mouth, alongside fatigue, pain, and systemic complications affecting the skin, lungs, kidneys, and nervous system.
About one-third of patients develop significant extraglandular involvement, and the disease carries an elevated lymphoma risk, often leading to substantial impairment in daily life. One of the most common rheumatic autoimmune diseases, Sjögren's remains underdiagnosed, with roughly half of cases unrecognized and women comprising the vast majority of patients. Despite its prevalence and burden, no approved systemic disease-modifying therapies exist; current care focuses on symptom management with incomplete relief.
Broader Development Program and Financial Position
Telitacicept is already approved in China for systemic lupus erythematosus (搜索) (SLE), rheumatoid arthritis (搜索) (RA), and generalized myasthenia gravis (搜索) (gMG). Additional regulatory filings in China are underway, including biologics license applications for primary Sjögren's disease (搜索) and IgA nephropathy (搜索) (IgAN).
Vor Bio (搜索) is advancing global development programs across major autoimmune indications, including a global Phase 3 trial in gMG and SjD to support potential regulatory approvals in the United States, Europe, and Japan. The company recently strengthened its financial position with a $75 million private placement, bringing its pro-forma cash and investment balance to $530.2 million as of December 31, 2025, expected to provide runway into early 2029.
For the myasthenia gravis program, Vor Bio (搜索) anticipates topline data from the global UPSTREAM MG trial in the first half of 2027, which could serve as a significant catalyst for both the company and the MG treatment landscape.