• Voluntary informed consent provided;

• Male or female aged ≥ 18 years old;

• IgA nephropathy confirmed by pathological biopsy;

• During the screening period, UPCR ≥ 0.8 g/g or 24-hour urine protein ≥ 1.0 g/day based on 24-hour urine collection at Visit 1 and/or Visit 2 and at Visit 3;

• eGFR ≥ 30 mL/min per 1.73 m\^2 (using the CKD-EPI);

• Have been on a treatment regimen including ACEI/ARB for 12 weeks and on a stable use of ACEI/ARB medication at the maximum tolerated dose/maximum allowable dose within 4 weeks prior to randomization. Subjects who use both ACEIs and ARBs will be excluded.