This study will evaluate the efficacy and safety of HS-10390 in subjects with primary IgA nephropathy, and explore the optimal dose for the treatment.

Inclusion Criteria:

• Male or female, between 18 and 65 years age.
• Biopsy-proven primary IgA nephropathy.
• Currently on stable dose of ACEI and/or ARB therapy, for at least 12 weeks prior to screening (the patient's maximum tolerated dose and is at least one-half of the maximum labeled dose).
• Average 24-hour urine total protein ≥ 0.75 g/24 h at screening.
• Estimated GFR (using the CKD-EPI 2009) ≥ 30 mL/min per 1.73 m^2 at screening.
• Systolic BP between 100 and 150 mmHg and diastolic BP between 60 and 100 mmHg.

Exclusion Criteria:

• IgA nephropathy secondary to another condition
• IgA nephropathy with rapid decline of renal function; Kidney pathology indicated that more than 50% of the glomerulus had large crescent body formation, which may affect the study results; Tubule atrophy - interstitial fibrosis of more than 50%;
• Chronic kidney disease (CKD) in addition to IgAN
• Patients treated with any systemic non-biologic immunosuppressive drugs (including systemic corticosteroids) within 12 weeks prior to randomizing；
• Require any prohibited medications prior to randomizing;
• Exposure to an investigational drug within 30 days or 5 half-lives (whichever is longer) prior to screening
• History of organ transplantation, with exception of corneal transplants
• Platelet< 100×109/L or hemoglobin value < 90 g/L) or Hematocrit value < 27% (0.27 V/V) at Screening
• Elevations of transaminases (ALT and/or AST) >2 times upper limit of normal or total bilirubin and/or direct bilirubin exceeding 1.5 times the upper limit of normal (ULN) at screening
• Potassium >5.5 mmol/L at Screening