This study is a randomized, double-blind, placebo-controlled single-center clinical trial. The aim of this study is to investigate the efficacy and safety of low-dose telitacicept for prevention of flares in SLE patients with low disease activity.

Background: There are still two major problems in the treatment of SLE: flare and long-term organ damage. BLISS-52 showed there was some reduction of flare (80% vs 71%) in belimumab , but the difference was not significant. Another study tested the efficacy and safety of atacicept for prevention of flares in patients with moderate-to-severe SLE in which analysis of atacicept 150 mg suggested benefit.

Telitacicept , a BAFF/APRIL dual-target-inhibitor, which has been proved to be effective in treatment of SLE. But there is no study to show its effectiveness for prevention of flares in SLE patients with low disease activity. In this study, we take telitacicept as maintain treatment in stable SLE patients to investigate the efficacy and safety of low-dose telitacicept for prevention of flares in SLE patients with low disease activity.

Inclusion Criteria:

1. Age 18-70 years;
2. SLE patients with low disease activity (SELENA-SLEDAI score< 8 at screening ); disease duration more than 3 months；no British Isles Lupus Assessment Group (BILAG) A and no more than one B;
3. A stable treatment regimen with fixed doses of prednisone (≤ 30mg/day), antimalarial, or immunosuppressive drugs (mycophenolate mofetil/azathioprine/ciclosporin /tacrolimus/methotrexate/leflunomide) for at least 3 months;
4. Sign the informed consent.

Exclusion Criteria:

1. Hepatic or renal dysfunction: alanine aminotransferase (ALT)/ aspartate aminotransferase (AST) > 2 times upper normal limits; GFR < 60ml/min;
2. Exposure to cyclophosphamide within past 6 months before screening;
3. Exposure to any B cell targeted therapy (Rituximab/Belimumab/Telitacicept) within past 6 months before screening;
4. Pregnant women, lactating women;
5. History of Malignancy within the last 5 years, excluding adequately treated skin tumors (basal cell or squamous cell carcinoma) or carcinoma in situ of cervix;
6. Active hepatitis or a history of severe liver disease;
7. Current infections (HIV/tuberculosis/COVID-19, etc.) at screening;
8. A significant decrease in immunoglobulin level, IgG<5g/L;
9. Not suitable for the study in the opinion of the investigator.