Comparison of the Treatments of Obinutuzumab + Venetoclax Versus Obinutuzumab + Chlorambucil in Patients With Chronic Lymphocytic Leukemia

Open to people ages 18 years and up

• Documented previously untreated CLL according to the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) criteria
• CLL requiring treatment according to IWCLL criteria
• Total Cumulative Illness Rating Scale (CIRS score) greater than (>) 6
• Adequate marrow function independent of growth factor or transfusion support within 2 weeks of screening as per protocol, unless cytopenia is due to marrow involvement of CLL
• Adequate liver function
• Life expectancy > 6 months
• Agreement to use highly effective contraceptive methods per protocol

• Transformation of CLL to aggressive Non-Hodgkin's lymphoma (Richter's transformation or pro-lymphocytic leukemia)
• Known central nervous system involvement
• Participants with a history of confirmed progressive multifocal leukoencephalopathy (PML)
• An individual organ/ system impairment score of 4 as assessed by the CIRS definition limiting the ability to receive the treatment regimen of this trial with the exception of eyes, ears, nose, throat organ system
• Participants with uncontrolled autoimmune hemolytic anemia or immune thrombocytopenia
• Inadequate renal function
• History of prior malignancy, except for conditions as listed in the protocol if participants have recovered from the acute side effects incurred as a result of previous therapy
• Use of investigational agents or concurrent anti-cancer treatment within the last 4 weeks of registration
• Participants with active bacterial, viral, or fungal infection requiring systemic treatment within the last two months prior to registration
• History of severe allergic or anaphylactic reactions to humanized or murine monoclonal antibodies or known sensitivity or allergy to murine products
• Hypersensitivity to chlorambucil, obinutuzumab, or venetoclax or to any of the excipients
• Pregnant women and nursing mothers
• Positive test results for chronic hepatitis B virus (HBV) infection (defined as positive hepatitis B surface antigen [HBsAg] serology) or positive test result for hepatitis C (hepatitis C virus [HCV] antibody serology testing)
• Participants with known infection with human immunodeficiency virus (HIV) or human T-cell leukemia virus-1 (HTLV-1)
• Requires the use of warfarin, marcumar, or phenprocoumon
• Received agents known to be strong and moderate Cytochrome P450 3A inhibitors or inducers within 7 days prior to the first dose of study drug