Study to Evaluate the Efficacy and Safety of MY008211A in Subjects with Primary Immunoglobulin a Nephropathy (IgAN)

Prior treatment

• Patients previously treated with immunosuppressive agents exposure within 90 days prior to start of study drug dosing.
• Patients previously treated with traditional Chinese medicine containing immunosuppressive ingredients within 90 days prior to start of study drug dosing.
• Patients who had been treated with any systemic corticosteroids within the 180 days before treatment ≥20 mg/d for primary IgAN indication.
• Patients who previously have received biologic agent or monoclonal antibodies prior to start of study drug dosing within 5 half-lives or 30 days (whichever is longer).
• Patients who have received live/attenuated vaccines within the 4 weeks prior to randomization, or plan to receive during the trial.

Other illness

• Presence of other chronic kidney diseases.
• Patients with a diagnosis of type 1 or type 2 diabetes mellitus.
• A history of invasive infections caused by encapsulated bacteria, e.g., meningococci or pneumococci.

Other

• Systolic blood pressure \>130 mm Hg or diastolic blood pressure \>80 mm Hg.
• Presence of any secondary IgAN.
• Presence of rapidly progressive glomerulonephritis.

• Males or females ≥ 18 and ≤ 75 years of age at Screening.
• Estimated GFR(eGFR) ≥30 mL/min/1.73m2.
• Subjects with a biopsy-confirmed diagnosis of IgAN.
• Urine protein ≥0.75 g/24h from a 24h urine collection.
• All patients must have been on stable supportive care including a maximally tolerated dose or approved maximal dose of ACEi or ARB therapy for at least 90 days prior to the first administration of study drug.
• Subjects who received SGLT2i must have been on a stable treatment with the maximum allowed or tolerated dose prior to the first administration of study drug.
• Vaccination against Neisseria meningitidis(MenACWY) is required within 3 years.
• Vaccination for the prevention of S. pneumoniae is required within 5 years.