A Study to Evaluate the Efficacy and Safety of Telitacicept in Subjects With Active Primary Sjogren's Syndrome

Main Inclusion Criteria:

1. Written informed consent provided.

2. Males and females, 18-70 years of age.

3. Fulfilled the classification criteria of pSS according to ACR/EULAR (2016).

4. Anti-SSA antibody tested positive at screening.

5. ESSDAI score ≥ 5 at screening.

Main Exclusion Criteria:

1. Secondary Sjogren's syndrome.

2. Severe organ involvement related to pSS in the opinion of the investigator,including but not limited to a) severe vasculitis (not cutaneous vasculitis)affecting the kidney, gastrointestinal system, cardiac, pulmonary or central nervoussystem (CNS); b) active CNS or peripheral nervous system involvement requiring highdose corticosteroids; c) severe kidney involvement, e.g. GFR < 60 ml/min, serumcreatinine > 2 mg/dL, or proteinuria > 3g/d; d) severe pulmonary involvement, e.g.shortness of breath at rest, FVC < 60% or DLCO < 40%; e) muscle diseases requiringhigh dose corticosteroids; f) lymphoma.

3. Received sodium hyaluronate eye drops, artificial tears or artificial saliva within 7 days prior to screening.

4. Received live vaccine within 28 days prior to randomization.

5. Active hepatitis or history of severe liver diseases.

6. HIV positive.

7. Patients with malignant tumors.

8. Received investigational pharmaceutical within 28 days or 5 half-lives prior torandomization, whichever is longer.

9. Nursing or pregnant female, or male or female who prepared for parenthood during thestudy.

10. Any condition that, in the opinion of the investigator, makes it unsuitable for thesubject to participate, e.g., poorly controlled high blood pressure, diabetes, heartfailure or mental illness.