This is a multicenter expanded access study of zanubrutinib monotherapy for participants with B-cell malignancies who are ineligible to enroll into any available zanubrutinib clinical trials

Key Inclusion Criteria:

1. Histologically confirmed diagnosis of WM with R/R disease or treatment-naive and considered by their treating physician to be unsuitable for standard chemoimmunotherapy regimens
2. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2
3. Absolute neutrophil count (ANC) ≥ 0.75 x 109/L, independent of growth factor support; and Platelet count ≥ 50 x 109/L, independent of growth factor support or transfusion within 7 days of study entry
4. Creatinine clearance of ≥ 30 mL/min
5. Aspartate aminotransferase (AST)/serum glutamic-oxaloacetic transaminase (SGOT) and alanine aminotransferase (ALT)/serum glutamic pyruvic transaminase (SGPT) ≤ 3 x upper limit of normal (ULN)
6. Total bilirubin level ≤ 2 x ULN (unless documented Gilbert's syndrome)

Key Exclusion Criteria:

1. Prior exposure to a Bruton tyrosine kinase (BTK) inhibitor
2. Evidence of disease transformation at the time of study entry
3. Ongoing requirement for systemic corticosteroid other than systemic adrenal replacement therapy
4. Chemotherapy given with antineoplastic intent, targeted therapy, radiation therapy or antibody-based therapy within 4 weeks of the start of study drug
5. Ongoing toxicity of ≥ Grade 2 from prior anticancer therapy
6. Prior or concurrent active malignancy within the past 2 years
7. Clinically significant cardiovascular disease
8. Unable to swallow capsules or disease significantly affecting gastrointestinal function
9. Active fungal, bacterial and/or viral infection requiring systemic therapy
10. Known infection with HIV, or serologic status reflecting active viral hepatitis B (HBV) or viral hepatitis C (HCV) infection as follows
11. Pregnant or lactating women
12. History of stroke or intracranial hemorrhage within 180 days before first dose of study drug
13. History of severe bleeding disorder
14. Active central nervous system (CNS) involvement by WM and/or lymphoma

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.