A Phase 2 Study to Investigate Efficacy and Safety of HZN-1116 in Participants With Sjogren's Syndrome

Key Inclusion Criteria: * Diagnosed with SS by meeting the 2016 American College of Rheumatology (ACR)/EULAR Classification Criteria. * Have an ESSDAI score of \>= 5 at screening (only for Population 1). * Have an ESSPRI score of \>= 5 at screening (only for Population 2). * Have an ESSDAI score of \< 5 at screening (only for Population 2). * Positive for anti-Ro autoantibodies, rheumatoid factor (RF) at screening, or both at screening. Key Exclusion Criteria: * Concomitant system sclerosis. * Active malignancy or history of malignancy within the last 5 years with exception of in situ carcinoma of the cervix treated with apparent success with curative therapy \> 12 months prior to screening; OR cutaneous basal cell carcinoma following presumed curative therapy. * Individuals who are pregnant or lactating or planning to become pregnant during the study. * Individuals who have a positive test for, or have been treated for, hepatitis B, hepatitis C, or HIV infection. * Individuals with history of more than one episode of herpes zoster and/or opportunistic infections in the last 12 months, with the exception of non-invasive herpes simplex at any site, oral candidiasis, vaginal candidiasis, or cutaneous fungal infections, which are permitted within the prior 12 months unless of unusual severity. Individuals with a prior history of ophthalmic herpes zoster will be excluded. * Active infections requiring systemic treatment at the time of screening or through randomization, or history of more than 2 infections requiring intravenous (IV) antibiotics within 12 months prior to screening. * Last administration of experimental biologic or oral agents \< 6 months or 5 half-lives, whichever is longer, before screening. * Individuals who have had previous treatment with any biologic B cell-depleting therapy (eg, rituximab, ocrelizumab, inebilizumab, or ofatumumab) within 12 months or other B cell targeting therapy (eg, belimumab) or anti-type I IFN pathway therapy (eg, anifrolumab) \< 6 months before randomization.