Criteria for Inclusion and Exclusion \<Inclusion Criteria\>
1. The age range is between 18 and 70 years old (including 18 and 70), with no gender restrictions.
2. Weight ≥ 45kg.
3. Adult subjects who meet the revised classification criteria of the American College of Rheumatology (ACR) 1997 and were diagnosed with systemic lupus erythematosus before screening.
4. During the screening period, the disease activity was confirmed as follows: SLEDAI-2K score ≥ 6 points. Accompanied by lupus nephritis (according to the 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification criteria, there is active, biopsy-confirmed type III or type IV proliferative lupus nephritis, with coexistence of type V allowed; the biopsy must be performed within 1 year before the screening visit or during the screening period, and the biopsy report is used to confirm patient eligibility.)
5. During the screening period, the patient's 24-hour urinary protein to creatinine ratio (UPCR) is greater than 1.0g/g, and the estimated glomerular filtration rate (eGFR) calculated using the MDRD formula is ≥60 mL/min/1.73 m\^2; and the 24-hour urinary protein is ≥1g.
6. The patient's baseline serum IFN-γ exceeded the upper limit of normal values.
7. The Th1/Th2 ratio in peripheral blood of the patient during the baseline period is ≥14.
8. Subjects who have not undergone induction therapy are allowed to be enrolled, but during the study and follow-up period, they must not receive any other treatment for systemic lupus erythematosus and lupus nephritis. Subjects are allowed to be enrolled while receiving any of the following standard treatment regimens: 1) Oral prednisone (or equivalent) monotherapy: a. Treatment duration: medication use ≥2 weeks before screening and maintaining a stable dose ≥2 weeks before enrollment; b. Dose requirements: maximum daily dose: 1mg/kg/day; 2) Immunosuppressants: a. Permissible drugs include: antimalarials, azathioprine, cyclophosphamide, mycophenolate mofetil/mycophenolic acid, methotrexate, cyclosporine A, tacrolimus; b. Treatment duration: medication use ≥12 weeks before screening and maintaining a stable dose ≥8 weeks before enrollment; c. Dose requirements: hydroxychloroquine ≤400mg/day, azathioprine ≤100mg/day, cyclophosphamide ≤800mg/4 weeks, mycophenolate mofetil/mycophenolic acid ≤2g/day, oral, subcutaneous (SC), or intramuscular methotrexate ≤15mg/week, Cyclosporine A ≤ 3 mg/kg/d, tacrolimus ≤ 3 mg/d; 3) Oral prednisone (or equivalent medication) monotherapy ± hydroxychloroquine sulfate ± an immunosuppressant: a. The treatment duration and dose stability requirements for Oral glucocorticoids (OCS) and immunosuppressants mentioned above must be met; b. The maximum daily/weekly dose of each drug in 1) and 2) must not be exceeded.
9. Female subjects must be in a non-pregnant and non-breastfeeding period during the trial.
10. The subjects have no plans to become pregnant within 6 months after the screening and the end of the trial, voluntarily adopt effective contraceptive measures, and have no plans to donate sperm or eggs;
11. The subjects voluntarily participate in the study, are able to sign the informed consent form, and comply with the requirements stated on the informed consent form.
\<Exclusion Criteria\>
1. Pregnant and lactating women.
2. Screening for participation in other clinical trials within the previous 3 months and/or currently (excluding those who have not used the trial medication).
3. Active severe lupus nephritis, with estimated glomerular filtration rate (eGFR) calculated using the MDRD formula \<60ml/min/1.73m\^2.
4. Severe neuropsychiatric SLE includes but is not limited to the following: seizures, new or worsening impaired level of consciousness, psychosis, delirium or confusion state, aseptic meningitis, ascending or transverse myelitis, chorea, cerebellar ataxia, multiple mononeuropathy, demyelinating syndrome, or situations that make the subject unable to fully understand the ICF.
5. History or current diagnosis of clinically significant non-SLE-related vasculitis syndrome or overlap with other connective tissue diseases.
6. Any active skin diseases that may interfere with the research evaluation of SLE, including but not limited to psoriasis, dermatomyositis, systemic sclerosis, non-SLE skin lupus manifestations (such as skin vascular disease, perifollicular telangiectasia, fingertip sclerosis, rheumatoid nodules, erythema multiforme, leg ulcers) or drug-induced lupus, except for SLE.
7. Those with a history of lymphoproliferative diseases, or those who have had or currently have malignant tumors within the past 5 years (except for squamous cell carcinoma in situ, basal cell carcinoma, and cervical carcinoma in situ, which have been thoroughly treated and show no evidence of recurrence).
8. Patients with uncontrolled antiphospholipid syndrome (APS).
9. History of significant organ transplantation (e.g., heart, lung, kidney, liver) or hematopoietic stem cell/bone marrow transplantation.
10. Major surgical procedures (craniotomy, thoracotomy, or abdominal surgery) or unhealed wounds, ulcers, or fractures within 4 weeks before screening.
11. Individuals who have received live/attenuated vaccine within the 8 weeks before screening or plan to receive live/attenuated vaccine during the trial period.
12. Allergic to the trial medication (including excipients) or suffering from severe allergic diseases or belonging to an allergic constitution (such as being allergic to two or more drugs, foods, or pollen), which, in the judgment of the researcher, may compromise the safety of the subject.
13. During screening, any of the following cardiac impairments is present: a. New York Heart Association (NYHA) functional class III to IV; b. Uncontrolled angina, congestive heart failure, or myocardial infarction within 6 months prior to the first dose of medication; c. Prolonged QTcF interval calculated using the Fridericia formula (male \> 450 msec; female \> 470 msec); d. Second-degree type II atrioventricular (AV) block, third-degree AV block, or PR interval \>250 msec; e. Various factors that may increase the risk of QTcF prolongation or arrhythmic events, such as heart failure, hypokalemia, congenital long QT syndrome, or a family history of sudden unexplained death of a first-degree relative before the age of 40; f. Left ventricular ejection fraction (LVEF) \< 50%;
14. Active or latent tuberculosis infection during screening.
15. There is a serious herpes virus infection during screening, such as herpes encephalitis, disseminated herpes, and ocular herpes.
16. Needs to take oral anti-infective drugs (including antiviral drugs) or intravenous antibiotics due to infection within 2 weeks before screening.
17. Hospitalization due to opportunistic infections within 3 months before screening.
18. Treatment with traditional Chinese patent medicines and simple preparations such as Tripterygium Wilfordii within 4 weeks before screening.
19. Hepatitis B test shows HBsAg positive (if HBsAg is negative but HBcAb is positive, then HBV-DNA quantitative test is required, and patients with HBV-DNA test results ≥ the upper limit of the reference value of each center or requiring antiviral treatment do not meet the conditions to participate in the study), hepatitis C antibody positive (HCV-RNA test can be added, if negative, the patient can be included), Treponema pallidum antibody positive (if Treponema pallidum antibody is positive, further Treponema pallidum serological tests will be conducted. Patients who have been judged by the investigator to have been infected with syphilis in the past but have been cured meet the inclusion criteria), HIV antibody test positive.
20. During screening, subjects with significant abnormalities in liver and kidney function tests and blood routine examination, including: alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) exceeding twice the upper limit of normal values, total serum bilirubin exceeding 1.5 times the upper limit of normal values; serum creatinine greater than 1.5 times the upper limit of normal values; hemoglobin \<90g/L; white blood cell count \<3.0×10\^9/L, platelet count (PLT) \<75×10\^9/L; neutrophil count \<1.0×10\^9/L; other laboratory test results that may affect the subject's ability to complete the trial or interfere with the trial results as judged by the investigator.
21. Those who have difficulty swallowing.
22. History of drug addiction or drug abuse;
23. Those who have acute diseases before using the clinical trial drugs;
24. Other conditions that the investigator deem unsuitable for enrollment.
