A Study to Evaluate the Benefit of Venetoclax Plus Rituximab Compared With Bendamustine Plus Rituximab in Participants With Relapsed or Refractory Chronic Lymphocytic Leukemia (CLL)

Inclusion Criteria:

- Diagnosis of CLL per diagnostic criteria for relapsed or refractory CLL per the
international workshop on chronic lymphocytic leukemia (iwCLL) guidelines

- Previously treated with 1-3 lines of therapy (example: completed greater than or equal
to [>/=] 2 treatment cycles per therapy), including at least one standard
chemotherapy-containing regimen

- Participants previously treated with bendamustine only if their duration of response
was >/= 24 months

- Eastern Cooperative Oncology Group (ECOG) performance score of less than or equal to
(
- Adequate bone marrow function

- Adequate renal and hepatic function

- Participants must use effective birth control throughout study until at least 30 days
after study treatment or 1 year after rituximab treatment, whichever is later; female
participants must not be pregnant or breast-feeding

- For participants with the 17p deletion, previously treated with 1-3 lines of therapy,
including at least one prior standard chemotherapy-containing regimen or at least one
prior alemtuzumab-containing therapy

Exclusion Criteria:

- Transformation of CLL to aggressive non-Hodgkin lymphoma or central nervous system
(CNS) involvement by CLL

- Undergone an allogenic stem cell transplant

- A history of significant renal, neurologic, psychiatric, endocrine, metabolic,
immunologic, cardiovascular or hepatic disease

- Hepatitis B or C or known human immunodeficiency virus (HIV) positive

- Receiving warfarin treatment

- Received an anti-CLL monoclonal antibody within 8 weeks prior to the first dose of
study drug

- Received any anti-cancer or investigational therapy within 28 days prior to the first
dose of study drug or has not recovered to less than Grade 2 clinically significant
adverse effect(s)/toxicity(ies) of any previous therapy

- Received cytochrome P450 3A4 (CYP3A4) inhibitors (such as fluconazole, ketoconazole
and clarithromycin) or inducers (such as rifampin, carbamazapine, phenytoin, St.
John's Wort) within 7 days prior to the first dose of venetoclax

- History of prior venetoclax treatment

- Participants with another cancer, history of another cancer considered uncured on in
complete remission for <5 years, or currently under treatment for another suspected
cancer except non-melanoma skin cancer or carcinoma in situ of the cervix that has
been treated or excised and is considered resolved

- Malabsorption syndrome or other condition that precludes enteral route of
administration

- Other clinically significant uncontrolled condition(s) including, but not limited to,
systemic infection (viral, bacterial or fungal)

- Vaccination with a live vaccine within 28 days prior to randomization

- Consumed grapefruit or grapefruit products, seville oranges (including marmalade
containing seville oranges), or star fruit within 3 days prior to the first dose of
study treatment

- A cardiovascular disability status of New York Heart Association Class >/=3. Class 3
is defined as cardiac disease in which participants are comfortable at rest but have
marked limitation of physical activity due to fatigue, palpitations, dyspnea, or
anginal pain

- Major surgery within 30 days prior to the first dose of study treatment

- A participant who is pregnant or breastfeeding

- Known allergy to both xanthine oxidase inhibitors and rasburicase