Replication of the NefIgArd Trial of TRF-budesonide in Primary IgAN

Inclusion Criteria: 1. Male or female patients aged ≥18 years; 2. Primary IgA nephropathy confirmed by renal biopsy; 3. Stable use of RAS blockers; 4. 24-hour urine albumin quantitation ≥1g/day, or urine protein/creatinine ratio ≥0.8g/g (≥90 mg/mmol); 5. eGFR ≥30 mL/min/1.73m². Exclusion Criteria: 1. Systemic diseases that may cause interstitial IgA deposition, including but not limited to anaphylactoid purpura, systemic lupus erythematosus, herpetic dermatitis, and ankylosing spondylitis; 2. Patients who have received kidney transplants; 3. Those with other glomerular diseases (such as C3 glomerular disease or diabetic nephropathy) and nephrotic syndrome; 4. Patients with acute, chronic, or latent infectious diseases, including hepatitis, tuberculosis (TB), human immunodeficiency virus (HIV), and chronic urinary tract infections; 5. Patients with cirrhosis or severe liver function impairment, as assessed by the investigator; 6. Patients diagnosed with poorly controlled type 1 or type 2 diabetes; 7. Patients with a history of unstable angina, grade III or IV congestive heart failure, and/or arrhythmia as assessed by the investigator; 8. Patients with poorly controlled blood pressure with systolic or diastolic blood pressure ≥140mmHg or 90mmHg. At least one blood pressure measurement should be in the above range (based on up to three measurements, 1 minute apart, taken after resting in the supine position for at least 5 minutes); 9. Patients diagnosed with malignancy within the last 5 years, with the exception of treated basal cell carcinoma of the skin, curably resected squamous cell carcinoma of the skin, polyps of the colon, or carcinoma in situ of the cervix; 10. Patients with osteoporosis who are known to be at moderate or high risk. Chinese patients are defined according to the Asian Osteoporosis Self-Assessment Tool (OSTA) Index; 11. Patients with known glaucoma, known history of cataract and/or cataract surgery that may interfere with study drug action or release (such as peptic ulcer disease, inflammatory bowel disease, and chronic diarrhea); 12. Patients who are allergic to budesonide or any component of the investigational drug formulation; 13. Patients who have previously had a severe adverse reaction to steroids; 14. Patients with psychotic symptoms; 15. Have received any systemic glucocorticoid therapy within 3 months prior to medication; 16. Received immunosuppressants or biologics within 3 months prior to medication; 17. Patients taking potent inhibitors of the cytochrome P450 3A4 enzyme (CYP3A4); 18. Current or former (within the last 2 years) alcohol or drug abuse; 19. Patients who are unwilling or unable to meet program requirements; 20. Life expectancy \<5 years; 21. Women who are pregnant, nursing, or unwilling to use contraception during treatment.