A Study to Evaluate the Efficacy and Safety of HR19042 Capsules in the Treatment of Primary IgA Nephropathy.

Inclusion Criteria: 1. Female or male patients ≥18 years old； 2. Biopsy-confirmed primary IgA nephropathy； 3. Urine protein≥0.75 g/24hr or urine protein creatinine ratio (UPCR)≥0.5 g/g； 4. Estimated GFR (using the CKD-EPI2009 formula) ≥30mL/min/1.73 m2； 5. Willing and able to take adequate contraception during the trial; 6. Willing and able to give informed consent and follow the protocols during the trial. Exclusion Criteria: 1. Systemic diseases which could lead to secondary IgA nephropathy； 2. Patients with severe chronic infection or active infection under systemic antibiotic therapy in previous 14 days； 3. Patients with severe cardiovascular diseases； 4. Patients diagnosed with malignancy within the past 5 years； 5. Patients with liver cirrhosis； 6. Patients received organ transplantation； 7. Patients with uncontrolled Type 1 or 2 diabetes； 8. Positive results in HIV-Ab/TP-Ab/ HBsAg/HCV-Ab tests； 9. Patients treated with any systemic immunosuppressive drugs (excluding corticosteroids) within the past 12 months before screening； 10. Patients treated with any systemic corticosteroids within the past 3 months before screening.