The PFS is defined as the time from date of randomization to the date of first IRC-assessed PD or death due to any cause, whichever occurred first. PD (per International Workshop on Chronic Lymphocytic Leukemia [iwCLL] 2008 criteria): Lymphocytes >= 50% increase over baseline, or >= 50% increase in lymphadenopathy/hepatomegaly/splenomegaly, or >= 50% platelets or > 2 g/dL hemoglobin decreases from baseline secondary to chronic lymphocytic leukemia (CLL). The PFS is assessed using the Kaplan-Meier method.

ITT population included all participants randomized and were analyzed according to the arm to which they were randomly assigned.

Number of participants with treatment-emergent infections Grade >=3 are reported.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

Richter's transformation is defined as the occurrence of an aggressive lymphoma in participants with a previous or concomitant diagnosis of CLL. Richter's transformation was assessed by central pathology. Number of participants with treatment-emergent Richter's transformation are reported.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

Number of participants with treatment-emergent atrial fibrillation (including atrial flutter) are reported.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

The OS is defined as the time from date of randomization to date of death due to any cause. The OS is assessed using the Kaplan-Meier method.

ITT population included all participants randomized and were analyzed according to the arm to which they were randomly assigned.

An adverse event (AE) is any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. A serious adverse event (SAE) is an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. The TEAEs are defined as events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

Number of participants with treatment-emergent laboratory abnormalities are reported. Laboratory abnormality is defined as any abnormal finding during analysis of hematology and serum chemistry.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

Number of participants with abnormal vital signs reported as TEAEs are reported. Abnormal vital signs are defined as any abnormal finding in the vital sign parameters (body temperature, blood pressure, heart rate, and respiratory rate).

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

Percentage of participants with at least one occurrence of treatment-related lymphocytosis defined as an elevation in ALC of >= 50% compared with baseline and a postbaseline assessment of > 5000/μL in the peripheral blood are reported.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

Number of participants with ECG abnormality at baseline are reported.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated.

The ECOG performance status assessed participant's performance status on 5 point scale: 0=Fully active/able to carry on all pre-disease activities without restriction; 1=restricted in physically strenuous activity, ambulatory/able to carry out light or sedentary work; 2=ambulatory (>50% of waking hours), capable of all self-care, unable to carry out any work activities; 3=capable of only limited self care, confined to bed/chair >50% of waking hrs; 4=completely disabled, cannot carry on any self care, totally confined to bed/chair; 5=death. Number of participants with shift from baseline (Days -28 to -1) to worst Grade 3 and 4 in ECOG performance status are reported.

Safety population included all participants who received at least one dose of study drug and were analyzed as treated. Here, "number of participants analyzed" (N) signified those participants who had a baseline value and at least 1 postbaseline value of ECOG performance status score during the study.