A Study to Evaluate the Efficacy and Safety of Iguratimod Compared to Placebo in Patients With Active Primary Sjogren's Syndrome.

A Randomized, Double-blind, Placebo-controlled, Multicenter Phase II Clinical Study to Evaluate the Efficacy and Safety of Iguratimod in Patients With Active Primary Sjogren's Syndrome.

The purpose of this study is to evaluate the efficacy and safety of iguratimod compared to placebo in patients with active primary Sjogren's Syndrome.

Inclusion Criteria:

• meet the 2016 American College of Rheumatology (ACR) / European League Against Rheumatism Classification Criteria for Sjogren's Syndrome (EULAR SS)
• ESSDAI score ≥6
• IgG >16 g/L
• Positive anti-SS-A/Ro antibody at screening

Exclusion Criteria:

• Pregnancy or breast feeding

• Secondary Sjogren's syndrome

• severe renal or haematological failure, a history of cancer, hepatitis B or C, human immunodeficiency virus, severe diabetes or any other chronic disease or evidence of infection

• Prior administration of any of the following:

  1. Rituximab in the past 12 months prior to randomization;
  2. Cyclophosphamide, mycophenolate mofetil, methotrexate, leflunomide and iguratimod in the past 12 weeks prior to randomization;
  3. Azathioprine, cyclosporin, tacrolimus, sirolimus, sulfasalazine in the past 4 weeks prior to randomization;
  4. live vaccine in the past 12 weeks prior to randomization

• Corticosteroids: > 10 mg/day oral prednisone (or equivalent); Any change or initiation of new dose within 4 weeks prior to randomization; Intramuscular, subcutaneous, intravenous, or intra-articular corticosteroids within 4 weeks prior to randomization.