Study of Telitacicept in Patients With Refractory IgA Nephropathy

Inclusion Criteria:

1. Voluntarily sign the informed consent form.
2. IgA nephropathy was confirmed by pathological biopsy.
3. Age range: ≥ 18 years old, ≤ 70 years old, male or female.
4. During the screening period, the 24-hour urine protein of Visit 1 and Visit 2 shouldmeet at least one ≥0.75g/24h, and the 24-hour urine protein ≥ 0.75g/24h at Visit 3.
5. Measured glomerular filtration rate or estimated GFR (using the CKD-EPI formula) > 35mL/min/1.73 m2.
6. Participants had received a basic regimen including ACE inhibitors/ARBs for 12 weeksprior to randomization, and the dose of ACE inhibitors/ARBs (within the maximumtolerated range) was stable for 4 weeks prior to randomization.

Exclusion Criteria:

1. Abnormal laboratory indicators of participants need to be excluded.
2. Secondary IgA nephropathy need to be excluded.
3. Specific pathologic or clinical renal disease types, and IgA nephropathy that mayrequire hormone therapy.
4. Patients who have experienced any of the following cardiovascular and cerebrovascularevents within the 12 weeks prior to screening.
5. Use of systemic corticosteroids within 3 months prior to randomization (except local,nasal inhalation, etc.)
6. Immunosuppressants were used within 3 months prior to randomization.
7. Patients requiring hospitalization for active infection or intravenous anti-infectivetherapy within 3 months prior to randomization.
8. Previously or currently diagnosed active tuberculosis Untreated latent tuberculosis.
9. Herpes zoster HIV antibody positive or HCV antibody positive during the screeningperiod.
10. Those who currently have active hepatitis or have severe liver disease and medicalhistory.
11. Patients with malignant tumors.
12. Pregnant and lactating women, and men or women with planned children during the trialperiod.
13. Those who could not avoid the use of nephrotoxic drugs during the trial.
14. Allergic to human biological products.
15. Patients who have been given any of the clinical trial drugs 4 weeks prior torandomization or within 5 times the half-life of the experimental drug (whichever islonger).
16. Patients deemed ineligible for the trial by the investigator.