This is a multicenter, randomized, double-blind, placebo-controlled Phase II study designed to evaluate the efficacy and safety of ESG206 in participants with primary Sjögren's syndrome.

Inclusion Criteria:

• Adults (≥18 years of age) with a confirmed diagnosis of primary Sjögren's syndrome according to the 2016 American College of Rheumatology (ACR) / European League Against Rheumatism (EULAR) classification criteria.
• Evidence of active disease at screening
• Willing and able to provide written informed consent

Exclusion Criteria:

• Secondary Sjögren's syndrome or other clinically significant autoimmune or inflammatory diseases
• Prior or recent use of prohibited immunomodulatory therapies
• Clinically significant infections, malignancies, or uncontrolled medical conditions
• Pregnancy or breastfeeding