A Study to Evaluate the Safety and Efficacy of Zanubrutinib in Participants With Primary Membranous Nephropathy

The primary objectives of this study are: In Part 1 to evaluate the efficacy of zanubrutinib as measured by proteinuria reduction, and in Part 2 to evaluate the efficacy of zanubrutinib compared with tacrolimus as measured by complete remission rate, in participants with primary membranous nephropathy who are on optimal supportive care.

Inclusion Criteria:Participants with a secondary cause of membranous nephropathyBiopsy-confirmed primary membranous nephropathyUPCR (based on 24-hour urine collection) > 3.5 at initial screening and confirmation assessmentTreatment with a maximally tolerated or allowed dose of an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB) for ≥ 24 weeks before randomization (12 weeks before initiation of study drug for Part 1) and with adequate blood pressure controlAnti-PLA2R antibody > 50 RU/mL at confirmation assessment (Part 1 only)Exclusion Criteria:Type 1 or 2 diabetes mellitus with hemoglobin A1c (HbA1c) ≥ 7% at screeningThe eGFR < 40 mL/min/1.73 m2, or initiation of dialysisA known history of a primary immunodeficiency or an underlying condition such as human immunodeficiency virus (HIV) infection or splenectomy that predisposes the participant to infectionsPositive tuberculosis at screeningKnown infection with serologic status reflecting active or chronic hepatitis B virus infection, or presence of hepatitis C virus antibodySevere hepatic insufficiency (Child-Pugh C)Clinically significant cardio-cerebrovascular diseasesNote: Additional criteria may apply.