ONO-4915 in Patients With Primary Sjogren's Disease

Inclusion Criteria: * Age (at the time of informed consent): \>=18 and \<75 years * Patients who meet the criteria for primary Sjogren's disease defined by the 2016 ACR/EULAR Classification Criteria for Primary Sjogren's Syndrome * Patients with positive anti-SS-A/Ro antibody in the screening period * Patients with ESSPRI score of \>=5 and dry symptom score of \>=5 in the screening period * Patients with stimulated salivary secretion rate of \>=0.1 mL/min by the Saxon test in the screening period. * Patients diagnosed with primary Sjogren's disease within 10 years Exclusion Criteria: * Patients with other concurrent autoimmune diseases * Patients who may overlap with the clinical symptoms of primary Sjogren's disease or interfere with the evaluation of the clinical symptoms * Patients with any disease that may interfere with the evaluation of dry symptoms of primary Sjogren's disease * Patients with any disease that may interfere with the evaluation of pain of primary Sjogren's disease * Patients with severe, progressive, or uncontrolled renal, hepatic, hematologic, gastrointestinal, pulmonary, psychiatric, cardiac, endocrine, neurologic, or cerebral disease unrelated to the primary disease * Patients with current malignancy or history of malignancy within 5 years before the start of screening * Patients with active infection