A Study to Investigate Safety and Effectiveness of BGB-16673 in Combination With Other Agents in Participants With Relapsed or Refractory B-Cell Malignancies

Inclusion Criteria

• Must sign the informed consent form (ICF) and be capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the ICF
• Confirmed diagnosis of a R/R B-cell malignancy
• Protocol-defined measurable disease
• Stable Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 2
• Adequate organ function
• Female participants of childbearing potential must be willing to use a highly effective method of birth control and refrain from egg donation for the duration of the study and for 30 days after the last dose of BGB-16673 or zanubrutinib, 60 days after the last dose of glofitamab, or 90 days after the last dose of sonrotoclax or mosunetuzumab. A negative urine or serum pregnancy test result must be provided 10-14 days before the first dose of study treatment
• Nonsterile male participants must be willing to use a highly effective method of birth control and refrain from sperm donation for the duration of the study and for 30 days after the last dose of BGB-16673 or zanubrutinib, 60 days after the last dose of glofitamab, or 90 days after the last dose of sonrotoclax or mosunetuzumab
• Substudies 1, 3, and 4 Inclusion Criterion:
• Adequate renal function as indicated by estimated glomerular filtration rate (eGFR) of ≥ 50 mL/min
• Substudy 2 Inclusion Criteria:
• Bruton tyrosine kinase (BTK) inhibitor-naive, or previously received treatment with a covalent BTK inhibitor and discontinued for reasons other than clinical progression
• Adequate renal function as indicated by eGFR of ≥ 30 mL/min Key

Exclusion Criteria

• Treatment-naive B-cell malignancies
• Unable to comply with the requirements of the protocol
• Active leptomeningeal disease or uncontrolled, untreated brain metastasis
• Any malignancy ≤ 2 years before first dose of study treatment except for the specific cancer under investigation in this study or any locally recurring cancer that has been treated curatively
• Autologous stem cell transplant ≤ 3 months prior to screening or chimeric antigen T-cell therapy ≤ 3 months prior to screening
• Substudies 1 and 2: Prior allogeneic stem cell transplant with active graft-versus-host disease (GVHD), or requiring immunosuppressive drugs for treatment of GVHD, or who have taken calcineurin inhibitors within 4 weeks prior to consent
• Participants who have a history of severe allergic reactions or hypersensitivity to the active ingredient and excipients of BGB-16673, sonrotoclax, zanubrutinib, mosunetuzumab, or glofitamab
• Substudy 1 Exclusion Criterion:
• Prior treatment with a B-cell lymphoma-2 (Bcl-2) inhibitor (with exception for participants who relapsed ≥ 24 months after completion of a full course of a prior Bcl-2 inhibitor containing regimen)
• Substudy 2 Exclusion Criterion:
• Participants who discontinued prior zanubrutinib treatment due to intolerance
• Substudies 3 and 4 Exclusion Criteria:
• Prior exposure to a CD20 x CD3 T-cell engager antibody treatment
• All participants with a prior allogeneic stem cell transplant Note: Other protocol defined Inclusion/Exclusion criteria may apply.