A Clinical Study of B007 in the Treatment of Primary Membranous Nephropathy.

Inclusion Criteria: 1. Subjects with primary membranous nephropathy pathologically confirmed by renal biopsy; 2. Subjects with glomerular filtration rate（eGFR） ≥ 45 mL/min/1.73 m2. 3. If taking Angiotensin converting enzyme inhibitors/angiotensin II receptor antagonists/sodium-glucose cotransporter 2 inhibitors/endothelin inhibitors, a stable dose within 4 weeks before randomization; 4. Subjects with 24-hour elevated urinary protein in accordance with the prescribed conditions; 5. Subjects whose laboratory test results meet the prescribed standards during the screening period; 6. Subjects who have fully understood this study and voluntarily signed the informed consent form； 7. Subjects who are able to follow the study protocol as judged by the investigator. Exclusion Criteria: 1. Subjects with secondary membranous nephropathy or primary membranous nephropathy whose pathological reports suggest concomitant crescent bodies; 2. Subjects identified by the investigator as previously resistant to CD20 monoclonal antibody or cyclosporine; 3. Subjects who have received medication prescribed for membranous nephropathy; 4. Subjects with concomitant prescribed diseases; 5. Subjects with a known history of severe allergic reactions to humanized monoclonal antibodies, or known allergies to any component of cyclosporine or B007; 6. Subjects who received live vaccination, major surgery, or participated in other clinical trials within 28 days before receiving the study drug; 7. Subjects with positive hepatitis B surface antigen; those with positive hepatitis C virus antibody; those with a history of immunodeficiency or suffer from other acquired or congenital immunodeficiency diseases; 8. Subjects who have a clear history of tuberculosis or have received anti-tuberculosis treatment; 9. Subjects with CD4+ T lymphocyte count \< 400 cells/μL; 10. Pregnant or lactating women; women of childbearing potential who have not been sterilized do not agree to use appropriate contraceptive measures during treatment and for at least 12 months after the last dose of the study drug; 11. For male subjects who have not been sterilized: those who do not consent to the use of barrier contraception during the study period and for at least 12 months after the last administration of the study drug, and who do not consent to the use of other contraceptive methods by their spouses; 12. Other conditions unsuitable for participation in this study determined by the Investigator.