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

Inclusion Criteria:

   - Biopsy-confirmed primary membranous nephropathy within 5 years before the initial
   screening (ie, the day the informed consent is signed)

   - UPCR (based on 24-hour urine collection) > 3.5 at initial screening and confirmation
   assessment

   - Treatment 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 control

   - Anti-PLA2R antibody > 50 RU/mL at confirmation assessment (Part 1 only)

Exclusion Criteria:

   - Participants with a secondary cause of membranous nephropathy

   - Type 1 or 2 diabetes mellitus with hemoglobin A1c (HbA1c) ≥ 7% at screening

   - A known history of a primary immunodeficiency or an underlying condition such as human
   immunodeficiency virus (HIV) infection or splenectomy that predisposes the participant
   to infections

   - Patients at risk for tuberculosis at screening

   - Known infection with serologic status reflecting active or chronic hepatitis B virus
   infection, or presence of hepatitis C virus antibody

   - Severe hepatic insufficiency (Child-Pugh C)

   - Clinically significant cardio-cerebrovascular diseases

Note: Additional criteria may apply.