The purpose of this study is to assess the safety and tolerability and to confirm the dose of nemtabrutinib in combination with venetoclax in participants with R/R CLL/SLL. The primary study hypotheses are that the combination of nemtabrutinib plus venetoclax is superior to VR with respect to progression-free survival (PFS) per 2018 International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria as assessed by blinded independent central review (BICR).
Confirmed diagnosis of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and active disease clearly documented to initiate therapy
Deletion (Del) (17p) status, tumor protein 53 (TP53) mutation status, and immunoglobulin heavy chain gene (IGHV) mutation status results required before randomization for Part 2 participants only
Relapsed or refractory to at least 1 prior available therapy
Have at least 1 marker of disease burden
Has an active hepatitis B virus/ hepatitis C virus (HBV/HCV) infection
Has gastrointestinal (GI) dysfunction that may affect drug absorption
Has a known additional malignancy that is progressing or has required active treatment within the past 2 years
Has diagnosis of Richter Transformation or active central nervous system (CNS) involvement by CLL/SLL