A Study of Nemtabrutinib vs Chemoimmunotherapy for Participants With Previously Untreated Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) Without TP53 Aberrations (MK-1026-008, BELLWAVE-008)

The main inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: * Confirmed diagnosis of chronic lymphocytic leukemia (CLL)/ small lymphocytic lymphoma (SLL) and active disease clearly documented to have a need to initiate therapy * Has previously untreated CLL/SLL participants without tumor protein 53 (TP53) aberrations and documented 11q status and immunoglobulin heavy chain gene (IGHV) mutational status * The ability to swallow and retain oral medication Exclusion Criteria: * Has active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection * Has gastrointestinal dysfunction that may affect drug absorption (eg, gastric bypass surgery, gastrectomy) * Has known additional malignancy that is progressing or has required active treatment within the past 3 years, except basal cell carcinoma of skin, squamous cell carcinoma of skin, or carcinoma in situ (eg, breast carcinoma, cervical cancer in situ) that have undergone potential curative therapy * Has history of severe bleeding disorders * Has not adequately recovered from major surgery or has ongoing surgical complications