Genentech, Inc. / PHASE II, OPEN-LABEL, PROSPECTIVE SINGLE ARM, MULTI-CENTER CLINICAL TRIAL TO EVALUATE IF ADDING VENETOCLAX TO PATIENTS ON COVALENT BTKI FOR 1L CLL CAN ACHIEVE DEEP DURABLE REMISSIONS (BY uMRD 10-4) TO ALLOW OFF TREATMENT PERIOD

Inclusion Criteria: 1. Diagnosed with CLL and currently receiving a stable dose of cBTKi (i.e., ibrutinib, acalabrutinib, or zanubrutinib) for at least 6 months for 1L treatment with a response of at least a PR per iwCLL criteria 2. Eastern Cooperative Oncology Group (ECOG) performance score of less than or equal to (\
Exclusion Criteria: 1. Prior B-cell lymphoma (Bcl-2) inhibitor therapy 2. Anti-cluster of differentiation 20 (CD20) therapy within the month prior to screening 3. Progressive or stable disease on cBTKi 4. Transformation of CLL to aggressive non-Hodgkin lymphoma (NHL) (Richter's transformation or pro-lymphocytic leukemia) 5. History of cardiomyopathy 6. Hypersensitivity to venetoclax or to any of the excipients (e.g., trehalose) 7. Clinically significant cardiovascular disease 8. Active bleeding or history of bleeding diathesis 9. Pregnant women and nursing mothers 10. Uncontrolled autoimmune hemolytic anemia or immune thrombocytopenia