Clinical Study to Investigate the Efficacy of Orally Administered SA001 in Patients With Primary Sjögren's Syndrome

Inclusion Criteria: * Age 19 through 80 years * Patient who diagnosed with Primary Sjögren's Syndrome(has a score of ≥ 4 when the weights from 5 criteria items are summed) ① Labial salivary gland with focal lymphocytic sialadenitis and focus score of ≥ 1 foci/4 mm2 (weight: 3) ② Anti-SSA/Ro-positive (weight: 3) ③ Ocular Staining Score ≥ 5 (or van Bijsterveld score ≥ 4) in at least one eye (weight: 1) ④ Schirmer's test ≤ 5 mm/5 min in at least one eye (weight: 1) ⑤ Unstimulated whole saliva flow rate ≤ 0.1 mL/min (weight: 1) * Standard Patient Evaluation of Eye Dryness(SPEED) score ≥ 5 Exclusion Criteria: * Secondary Sjögren's Syndrome patient * Severe blepharitis caused by Meibomian gland dysfunction * Administration of eye drops that may affect efficacy assessment in the past 2 weeks prior to baseline (Steroid, glaucoma, allergy, antibiotic, eye drop gel, Cyclosporine, Diquafosol tetrasodium, etc) * New administration or changing the dosage of systemic steroid drugs or immunosuppressant that may affect immune function in the past 4 weeks prior to baseline * Administration of oral medication of Tetracycline, Isotretinoin in the past 4 weeks prior to baseline * New administration or changing the dosage of Hydroxychloroquine medication in the past 12 weeks prior to baseline * Planning to undergo eye surgery(including eyesight correction surgery) during the study period * Wearing contact lenses during the study period * History of ophthalmic surgery and trauma in the past 6 months prior to signing the ICF * Participation in an investigational drug or device trial within 3 months prior to signing the ICF * Hypersensitivity to the ingredients of this drug * Genetic problems such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption * A woman who has a positive Serum hCG test at the screening visit (Visit 1), or who does not agree to use at least one effective contraceptive method that is medically acceptable * Take oral contraceptives during the study period * Pregnant or lactating women * A history of drug or alcohol abuse * Any condition that, in the opinion of the investigator, would inappropriate to participate in the clinical trial