A Phase Ⅲ Clinical Study of MIL62 in Primary Membranous Nephropathy

Inclusion Criteria: 1. Age 18-80; 2. Diagnosis of primary membranous nephropathy (pMN) according to renal biopsy prior to or during screening; 3. Screening 24-hour urinary protein \>= 5 g after best supportive care for \>= 3 months prior to screening or screening Screening 24-hour urinary protein \> 3.5 g after best supportive care for \>= 6 months prior to screening, or Screening 24-hour urinary protein \> 3.5 g with at least one high-risk factor defined by the protocol; 4. Estimated glomerular filtration rate (eGFR ) by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula ≥40 mL/min/1.73 m\^2; 5. If taking ACEI(Angiotensin converting enzyme inhibitors), ARB(Angiotensin receptor blocker), a stable dose within 4 weeks before screening is required; 6. Sufficient organ function; 7. Able and willing to provide written informed consent and to comply with the study protocol. Exclusion Criteria: 1. Participants with a secondary cause of MN; 2. Cyclosporine resistance; 3. Received treatment drugs for membranous nephropathy; 4. Concomitant with other serious diseases； 5. Received live vaccination, major surgery (excluding diagnostic procedures), and participated in other clinical trials within 28 days prior to receiving the first study drug; 6. Patients who are positive for hepatitis B surface antigen (HBsAg) and/or hepatitis B core antibody (HBcAb), with HBV DNA levels above the normal range (HBsAg and/or HBcAb-positive patients require regular HBV DNA testing); patients positive for hepatitis C virus (HCV) antibodies; or patients with a positive human immunodeficiency virus (HIV) serology. 7. Participants with CD4+ T lymphocyte count \< 200 cells/μL; 8. Those who have a clear history of tuberculosis or have received anti- tuberculosis treatment; 9. Participants with known history of severe allergic reactions to humanized monoclonal antibodies, MIL62, or Cyclosporine 10. Breastfeeding or pregnant women; 11. Childbearing potential and unwillingness or impossibility to comply with a scientifically acceptable birth-control method 12. Other conditions unsuitable for participation in this study determined by the Investigator.