A Study of Telitacicept in Lupus Nephritis

Main Inclusion Criteria:

1. Males or females aged 18-75 years of age, inclusive.

2. Diagnosis of systemic lupus erythematosus according to American College ofRheumatology criteria (1997).

3. Active, biopsy-proven proliferative lupus nephritis Class III or IV with/without thepresence of Class V, or pure Class V according to the 2003 ISN/RPS classification.The renal biopsy must be performed within 1 year prior to the screening visit orduring screening period. The biopsy report will be used to confirm subjecteligibility.

4. Positive serum antibody results, defined as positive anti-nuclear antibody (ANA)and/or a positive anti-dsDNA serum antibody based on the study's centrallaboratory results.

5. Active renal disease at screening requiring induction therapy with high dosecorticosteroids (HDCS) with mycophenolate mofetil (MMF) or other oral forms ofmycophenolate.

6. Induction therapy for active renal disease: HDCS with mycophenolate mofetil (MMF) orother oral forms of mycophenolate should be initiated within 60 days prior to or onDay 1 (baseline). Initiation of induction is when both HDCS and MMF have beenstarted.

7. Able to understand the requirements of the study and provide written informedconsent.

Main Exclusion Criteria:

1. Known hypersensitivity or contraindication to any drug products they plan to receive (e.g., MMF, corticosteroids).

2. History of allergy to parenteral administration of contrast agents, human or murineproteins or monoclonal antibodies.

3. Received any of the following therapies:

4. Treatment with any B cell targeted therapy (e.g., rituximab), unless it can beshown that B cells have returned to baseline level or normal;

5. Received tumor necrosis factor inhibitors, interleukin receptor blockers, orother small molecules or biologics (including Belimumab) during the 12 weeksprior to screening or the 5 half-lives of the drug, whichever is longer;

6. Received any experimental drugs during the 12 weeks prior to screening or the 5half-lives of the drug, whichever is longer;

7. Received plasma separation or plasma exchange during the 6 weeks prior toscreening;

8. Subjects who required dialysis within 1 year prior to screening.

9. Received a live vaccine or live-attenuated vaccine within 4 weeks prior toscreening or expected to vaccinate during the study.

10. Received BCG Vaccine within 1 year prior to screening.

11. History of severe active central nervous system (CNS) lupus (including seizures,psychosis, organic brain syndrome, cerebrovascular accident, cerebritis, or CNSvasculitis) requiring intervention within 60 days of baseline (Day 1).

12. History of a major organ transplant (e.g., heart, lung, kidney, liver) orhematopoietic stem cell/marrow transplant or are due to receive transplantation.

13. Significant, unstable or uncontrolled acute or chronic diseases not due to SLE (i.e., cardiovascular, pulmonary, hematologic, gastrointestinal, hepatic, renal,neurological, malignancy, or infectious diseases) which, in the opinion of theprincipal investigator, could confound the results of the study or put the subjectat undue risk.

14. Plan to undergo surgery or have any medical disease, laboratory abnormality, orcondition that, in the opinion of the principal investigator, makes the subjectunsuitable for the study.

15. History of drug or alcohol abuse or dependence within 364 days prior to baseline (Day 1).

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

17. History of malignant tumors within the last 5 years, excluding adequately treatedskin cancer (basal or squamous cell) or carcinoma in situ of cervix.

18. Have acute or chronic infection requiring treatment.

19. HIV positive.

20. Hepatitis B: Patients positive for HBsAg are excluded; Patients negative for HBsAgbut positive for Anti-HBc, regardless of Anti-HBs antibody status, will require testfor HBV DNA: if HBV DNA positive, patients will be excluded; if HBV DNA negative,patients will be eligible to enroll.

21. Hepatitis C antibody positive.

22. History of COVID-19 within 4 weeks prior to screening or history of hospitalizationdue to severe Covid-19 within 12 months prior to screening.

23. eGFR<30 mL/min/1.73 m2 using CKD-EPI.

24. Renal biopsy showed 50% glomerulosclerosis.

25. Have a Grade 3 or greater laboratory abnormality based on the Adverse Event SeverityGrading Tables.

26. Subjects who in the opinion of the investigator are not suitable to participate.