A Study to Evaluate the Efficacy and Safety of VIB4920 in Participants With Sjögren's Syndrome

The study will enrol 2 SS populations: Population 1 will include participants with moderate to high systemic disease activity defined by European League Against Rheumatism (EULAR) Sjögren's Syndrome Disease Activity Index (ESSDAI) \>= 5; Population 2 will include participants with moderate to severe subjective symptoms defined by EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) score \>= 5 and residual stimulated salivary flow but with mild systemic disease activity defined by ESSDAI score \< 5. This study will include 3 periods: screening (4 weeks), treatment period (40 Weeks) and follow-up period (12 weeks). In the treatment period, participants from each of the populations will be randomized at 1:1 ratio to receive intravenous (IV) dose of VIB4920 or placebo (Stage I). After completion of Stage I, participants randomized to VIB4920 in Stage I will receive placebo and participants randomized to placebo in Stage I will receive VIB4920 (Stage II). Participants who had study drug discontinuation will not be eligible for treatment during Stage II. All participants will be followed for at least 12 weeks after their last dose of study drug administration. Study acquired from Horizon in 2024.