Overview

This study is a multicenter Phase Ib/II clinical trial aimed at evaluating the safety, tolerability and efficacy of SCTB35 in patients with systemic lupus erythematosus (SLE).

Eligibility

Inclusion Criteria:

1. Age 18-75 years；
2. Diagnosed with SLE for ≥12 weeks prior to screening (2019-ACR/EULAR criteria);
3. SLEDAI-2K ≥ 8 at screening, or ≥6 if there is hypocomplementemia or elevated anti-dsDNA antibody levels;
4. Positive for ANA (1:80) or positive for anti-dsDNA and/or anti-Sm antibodies within the last 12 months or at screening;
5. Currently receiving ≥1 stable dose of standard treatment: oral corticosteroids, antimalarials, or conventional immunosuppressive drugs
   1. Stable corticosteroid dose for ≥4 weeks prior to baseline;
   2. Stable dose of antimalarial drugs for ≥4 weeks prior to baseline;
   3. Stable dose of immunosuppressive agents for ≥4 weeks prior to baseline;
6. All male participants or females of reproductive potential must agree to use

   reliable contraception with their partner from signing the ICF through 6 months after the last dose of the study drug;

7. Understanding of the study procedures and voluntary signing of the informed consent form.

Exclusion Criteria:

1. Severe active or unstable lupus-related neuropsychiatric disorders;
2. Other autoimmune diseases that may interfere with efficacy evaluation;
3. Catastrophic antiphospholipid syndrome;
4. Received treatments that may affect the drug's effect:
5. Received live vaccines or attenuated vaccines within 28 days prior to baseline or screening;
6. Clinically significant bleeding risk;
7. Abnormal laboratory results:
   1. AST or ALT >2.5 x ULN;
   2. Total bilirubin >1.5 x ULN;
   3. ANC <1.5x10⁹/L;
   4. Platelets <75x10⁹/L;
   5. Hemoglobin <100g/L;
8. eGFR <30 mL/min/1.73 m²;
9. Positive serum HCG;
10. Received any investigational treatment within 30 days prior to baseline or within 5 half-lives of the investigational drug (whichever is longer);
11. Participants with recurrent, chronic, or other active infections as assessed by the investigator;
12. Severe or uncontrolled disease, which would prevent participation in the study;
13. Positive viral serology tests, including HIV, HCV, and HBV;
14. Tuberculosis screening: Known active tuberculosis or latent tuberculosis infection (LTBI);
15. Any type of active infection except nail bed fungal infections;
16. Severe infections;
17. History of progressive multifocal leukoencephalopathy (PML);
18. Diagnosed with type 1 or type 2 diabetes with poor control;
19. Uncontrolled hypertension (systolic >140 mmHg or diastolic >90 mmHg);
20. History of malignancy within 5 years prior to baseline;
21. Alcohol abuse or drug misuse within 12 months prior to screening;
22. Intolerance to the study drug or contraindications, including a history of severe allergic reactions to monoclonal antibodies or any component of SCTB35 injection;
23. Required hospitalization for major surgery within 4 weeks prior to screening or within 12 weeks post-study drug administration;
24. Participants with mental disorders or poor compliance;
25. Severe lupus nephritis;
26. History of solid organ or hematopoietic stem cell/bone marrow transplant, or expected to undergo transplant surgery during the study;
27. Pregnant or breastfeeding;
28. Any other condition that the investigator deems unsuitable for participation in the study.