PFS is defined as time from the date of randomization to the date of first disease progression or death, whichever occurs first, as determined by IRC using modified 2018 International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria for participants with chronic lymphocytic leukemia (CLL) and Lugano classification for participants with small lymphocytic lymphoma (SLL).

PFS is defined as time from the date of randomization to the date of first disease progression or death, whichever occurs first, as determined by IRC using modified 2018 International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria for participants with R/R CLL and the Lugano Classification for patients with R/R SLL.

PFS is defined as time from the date of randomization to the date of first disease progression or death, whichever occurs first, as determined by IRC using modified 2018 International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria for participants with chronic lymphocytic leukemia (CLL) and Lugano classification for participants with small lymphocytic lymphoma (SLL).

Number of participants with treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs), including findings from laboratory tests and electrocardiogram results.

Number of participants with AEs and SAEs as graded by the National Cancer Institute- Common Terminology Criteria for Adverse Events Version 5 (NCI CTCAE 5.0), including AEs that meet protocol-defined dose-limiting toxicity (DLT) criteria.

As determined by the sponsor based on the Safety Monitoring Committee's recommendation considering totality of the available clinical safety, clinical efficacy, pharmacokinetics, and pharmacodynamics data.

The highest dose evaluated as recommended by the Bayesian Optimal Interval Design with Informative Prior (iBOIN) design or the maximum assessed dose (MAD).

ORR is defined as the percentage of participants with partial response or better according to the Independent Review Committee (IRC) assessment and as determined by Lugano criteria.

ORR is defined as the percentage of participants with partial response or better as assessed by the IRC and determined by the International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria for CLL and by Lugano criteria for SLL

Number of participants with Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) including results from laboratory assessments, electrocardiograms (ECGs), and physical examinations, and that meet protocol-defined dose-limiting toxicities (DLTs); as graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) v5.0.

MTD is defined as the highest evaluated dose with an estimated toxicity rate closest to the target, while MAD is the highest dose given if MTD is not reached.

RDFE of BGB-16673 alone will be determined based upon the MTD or MAD.

Defined as the percentage of participants achieving a best overall response of partial response (PR) or better, assessed by the Independent Review Committee for participants with R/R CLL/SLL and R/R WM (in participants with WM, this is also referred to as major response rate) and by the investigator for other cohorts (R/R MCL, R/R MZL, R/R FL, R/R non-GCB DLBCL, R/R Richter's transformation to DLBCL), evaluated using the Lugano criteria for NHL and SLL, International Workshop of Chronic Lymphocytic Leukemia (iwCLL) criteria for CLL, and the 11th International Workshop on Waldenstrom's Macroglobulinemia (IWWM-11) criteria for WM.