Inclusion Criteria:

- CD20-positive B-cell chronic lymphocytic leukemia (per IWCLL guidelines)

- Rai Stage III/IV or Binet Stage C disease, or Rai Stage I/II or Binet Stage B disease
that requires treatment according to IWCLL guidelines

- No previous treatment for CLL chemotherapy, radiotherapy or immunotherapy; no
previous rituximab treatment for autoimmune hemolytic anemia (AIHA) or ITP; prior use
of steroids for AIHA or ITP is allowed

- Eastern Cooperative Oncology Group performance status of 0, 1 or 2

Exclusion Criteria:

- Transformation of CLL to aggressive B-cell malignancy

- History of severe allergic or anaphylactic reactions to monoclonal antibody therapy

- Evidence of severe, uncontrolled concomitant disease

- Known active infection or any major episode of infection requiring treatment with IV
antibiotics or hospitalization within 4 weeks before the start of Cycle 1

- Seropositive for human immunodeficiency virus (HIV)

- Positive for chronic hepatitis B infection (defined as positive HBsAg serology)

- Positive for hepatitis C (hepatitis C virus [HCV] antibody serology testing)

- Pregnant or lactating women

- Concurrent (or within 7 days prior to fist dose of study treatment) systemic
corticosteroid use, except for low-dose corticosteroid therapy used to treat illness
other than lymphoma