A Study Evaluating the Efficacy and Safety of Obinutuzumab in Participants With Primary Membranous Nephropathy

This study will evaluate the efficacy, safety, pharmacodynamics, and pharmacokinetics (PK) of obinutuzumab compared with tacrolimus in participants with primary membranous nephropathy (pMN).

Inclusion Criteria: * 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 Exclusion Criteria: * 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