RemeGen’s prior Phase 3 study in China of telitacicept in primary Sjögren’s disease reported statistically significant and clinically meaningful improvements on both ESSDAI and ESSPRI, the core EULAR measures of systemic activity and patient symptoms. Building on that signal, Vor Bio has dosed the first patient in UPSTREAM SjD, a global, randomized, double-blind, placebo-controlled Phase 3 trial testing telitacicept in approximately 250 adults with active primary Sjögren’s disease.
The study uses change from baseline in ESSDAI at Week 48 as the primary endpoint, with key secondaries spanning systemic disease activity, glandular function, and patient-reported symptoms at the same time point. Eligibility requires meeting the 2016 ACR/EULAR classification criteria and ESSDAI ≥5, positioning the trial squarely in an active, clinically relevant population. Telitacicept is administered subcutaneously via prefilled syringe, reflecting a practical route for potential broad autoimmune deployment if successful.
Strategically, Vor Bio is attempting to convert a strong regional efficacy signal and a growing safety database from China—where telitacicept is approved for SLE, RA, and gMG—into global validation for a high-unmet-need indication with no approved disease-modifying therapy. The choice of ESSDAI as the primary endpoint reflects a bid to establish regulatory precedent around systemic disease control in Sjögren’s, with symptom relief captured as key secondaries to address payer and clinician expectations. The dual BAFF/APRIL mechanism targets B-cell and plasma-cell survival more comprehensively than single-pathway inhibition, an approach that has struggled to translate consistently in Sjögren’s with prior BAFF- or CD20-focused programs. The tension is clear: regulators and clinicians want objective systemic control and meaningful symptom improvement, but symptom endpoints in Sjögren’s are variable and historically vulnerable to placebo effects.
For sites and CROs, UPSTREAM SjD raises operational demands that will be familiar to Sjögren’s veterans but unforgiving for newcomers. Accurate ESSDAI scoring requires rigorous rater training and, ideally, centralized oversight to limit inter-site variability. Objective glandular assessments and consistent execution of dryness tests must be standardized to avoid noise that can dilute treatment effects. ePRO capture of ESSPRI will need tight adherence support to mitigate missing data and placebo-responsive drift. The subcutaneous prefilled syringe reduces infusion chair time and can enable flexible visit models, but it shifts emphasis to pharmacovigilance, adherence monitoring, and infection surveillance typical of B-cell–directed therapies, including immunoglobulin tracking and vaccination management. Sponsors and vendors should also anticipate the need for robust global lab logistics, adjudication frameworks, and potentially stratified enrollment to balance extraglandular involvement that can confound readouts.
The forward look centers on endpoint alignment and durability. Watch for how closely FDA and EMA accept ESSDAI change at 48 weeks as a stand-alone primary, and whether success on key secondaries—particularly ESSPRI and objective glandular function—will be treated as supportive or essential for a differentiated label. Placebo management, rater consistency, and retention over a 48-week horizon will be critical execution risks. Competitive pressure from other B-cell–pathway agents in or approaching late-stage development means timing matters; the first program to demonstrate reproducible, dual-domain benefit with a manageable safety profile will likely frame the regulatory template for the disease. If UPSTREAM SjD confirms the Chinese signal across both systemic and symptom measures, attention will quickly shift to scalability of manufacturing for prefilled syringes, regional bridging plans, and whether Vor Bio can replicate this playbook across its broader autoimmune portfolio.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
