Vor Bio Begins Dosing In Global Phase 3 UPSTREAM SjD Trial, Testing Telitacicept For Primary Sjögren’s Disease With No Approved Disease-Modifying Therapy

Vor Bio announced that it has begun dosing the first patient in UPSTREAM SjD, a global Phase 3 clinical trial evaluating telitacicept in adults with active primary Sjögren’s disease (SjD), previously known as Sjögren’s syndrome. This randomized, double-blind, placebo-controlled study marks an important step forward in developing a potential new therapy for a condition that currently lacks approved disease-modifying treatment options.

Jean-Paul Kress, M.D., Chief Executive Officer and Chairman of Vor Bio, noted that dosing the first patient is a major milestone for both telitacicept and the SjD community. He highlighted that telitacicept is the only BAFF/APRIL inhibitor currently being tested in a Phase 3 trial for this disease. Kress also referenced results shared in late 2025 by RemeGen from a Phase 3 trial conducted in China, where telitacicept showed promising outcomes. 

The therapy demonstrated statistically significant and clinically meaningful improvements in ESSDAI and ESSPRI—two validated EULAR measures widely used to assess patient disease activity and symptoms. According to Kress, these data support the therapeutic potential of dual BAFF/APRIL inhibition and reinforce confidence in telitacicept’s ability to address both systemic inflammation and the symptoms that most affect patients’ quality of life.

The UPSTREAM SjD study will enroll approximately 250 adult patients with active primary Sjögren’s disease. Participants must meet the 2016 ACR/EULAR classification criteria and have an ESSDAI score of 5 or higher to qualify. The trial will compare telitacicept, administered subcutaneously via a pre-filled syringe, with placebo to evaluate its safety and effectiveness. The primary endpoint of the study is the change in ESSDAI score from baseline to Week 48, measuring improvements in systemic disease activity.

In addition to the primary outcome, key secondary endpoints will assess telitacicept’s impact at Week 48 on glandular function, patient-reported symptoms, and broader systemic disease measures. These findings are intended to provide a comprehensive understanding of how the therapy may help patients manage both the clinical severity and daily challenges of Sjögren’s disease.