• Diagnosis of primary membranous nephropathy (pMN) according to renal biopsy prior to or during screening

• Screening urinary protein-to-creatinine ratio (UPCR) >= 5 g/g from 24-hour urine collection after best supportive care for >= 3 months prior to screening or screening UPCR >= 4 g/g after best supportive care for >= 6 months prior to screening

• eGFR >= 40 mL/min/1.73m^2 or qualified endogenous creatinine clearance >= 40 mL/min/1.73m^2 based on 24-hour urine collection during screening

• Other inclusion criteria may apply

• Participants with a secondary cause of MN

• Pregnancy or breastfeeding

• Evidence of >= 50% reduction in proteinuria during the previous 6 months prior to randomization

•Severe renal impairment, including the need for dialysis or renal replacement therapy

•Type 1 or 2 diabetes mellitus

• Receipt of an excluded therapy, including any anti-CD20 therapy less than 9 months prior to or during screening; or cyclophosphamide, tacrolimus, or cyclosporin less than 6 months prior to or during screening

• Significant or uncontrolled medical disease which, in the investigator's opinion, would preclude participant participation

• Known active infection of any kind or recent major episode of infection

• Major surgery requiring hospitalization within the 4 weeks prior to screening

• Current active alcohol or drug abuse or history of alcohol or drug abuse within 12 months prior to screening

• Intolerance or contraindication to study therapies

• Other exclusion criteria may apply

• Autoimmune Diseases

• Calcineurin Inhibitor

• Glomerulonephritis

• Glomerulonephritis, Membranous

• Immune System Diseases

• Immunologic Factors

• Immunosuppressive Agents

• Kidney Diseases

• Methylprednisolone

• Nephritis

• Obinutuzumab

• Tacrolimus

• WA41937

• Nephrology

• Hoffmann-La Roche