A Study of the Combination of Ibrutinib Plus Venetoclax Versus Chlorambucil Plus Obinutuzumab for the First-line Treatment of Participants With Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL)

The hypothesis is treatment with combination of I+VEN will result in longer PFS compared with
G-Clb in participants with previously untreated chronic lymphocytic leukemia (CLL)/ small
lymphocytic lymphoma (SLL) who meet International Workshop on CLL (iwCLL) treatment criteria.
The study includes screening (30 days), treatment (from randomization until treatment
discontinuation) and follow-up phase (from treatment discontinuation until death, lost to
follow up, consent withdrawal, or study end, whichever occurs first). Participants without
progression will continue disease evaluations until disease progression or death. Study
duration is approximately 6 years. Safety includes review of adverse events and laboratory
tests performed over time.

Inclusion Criteria:

- Adult participants who are: (a) greater than or equal to (>=) 65 years old or, (b) 18
to 64 years old and have at least 1 of the following:

1. Cumulative Illness Rating Scale (CIRS) score > 6

2. Creatinine clearance (CrCl) estimated less than (<) 70 milliliter per minute
(mL/min) using Cockcroft-Gault equation

- Diagnosis of chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL)
that meets International Workshop on Chronic Lymphocytic Leukemia (iwCLL) criteria

- Measurable nodal disease (by computed tomography [CT]), defined as at least one lymph
node > 1.5 centimeter (cm) in longest diameter

- Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) Grade less than or
equal to (<=) 2

- Active CLL/SLL requiring treatment per the iwCLL criteria

Exclusion Criteria:

- Prior anti-leukemic therapy for CLL or SLL

- Presence of deletion of the short arm of chromosome 17 (del17p) or known TP53 mutation
detected at a threshold of >10 percent (%) variable allele frequency (VAF)

- Major surgery within 4 weeks of first dose of study treatment

- Known bleeding disorders (example, von Willebrand's disease or hemophilia)

- Central nervous system (CNS) involvement or suspected Richter's syndrome