Inclusion Criteria:

- Confirmed diagnosis of CD20-positive B-CLL

- Rai Stage III/IV or Binet Stage C disease

- Rai Stage I/II or Binet Stage B disease that requires treatment

- Adequate baseline bone marrow function, unless there is clear evidence of extensive
bone marrow involvement with tumor infiltration, myelodysplasia, or hypocellularity

- No previous treatment for CLL by chemotherapy, radiotherapy, or immunotherapy

- ECOG performance status of 0, 1, or 2

- Life expectancy of > 6 months

Exclusion Criteria:

- Treatment with any other investigational agent or participation in another clinical
trial within 28 days prior to the start of Cycle 1

- Transformation of CLL to aggressive B-cell malignancy

- Creatinine clearance =< 60 mL/min, calculated according to the formula of Cockroft
and Gault

- Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 2.5 times the
upper limit of normal (ULN)

- Total bilirubin >= 3 x ULN

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

- History of sensitivity to mannitol (if bendamustine is to be administered)

- History of other malignancy that could affect compliance with the protocol or
interpretation of results

- Evidence of significant, uncontrolled concomitant diseases that could affect
compliance with the protocol or interpretation of results, including significant
cardiovascular disease or pulmonary disease

- Known active bacterial, viral, fungal, mycobacterial, or other infection (excluding
fungal infections of nail beds) or any major episode of infection requiring treatment
with IV antibiotics or hospitalization (related to the completion of the course of
antibiotics) within 4 weeks before the start of Cycle 1

- Recent major surgery (within 4 weeks prior to the start of Cycle 1), other than for
diagnosis

- Known infection with human immunodeficiency virus (HIV) seropositive status

- Presence of positive test results for hepatitis B (hepatitis B virus [HBV] surface
antigen [HBsAg] and/or total hepatitis B core antibody [anti-HBc]) or hepatitis C
(hepatitis C virus [HCV] antibody serology testing). Patients with chronic HBV
infection, occult HBV infection, or past HBV infection will be excluded. Patients who
have received IVIG within 3 months of enrollment and who are anti-HBc positive but
HBV DNA negative will be considered for inclusion on the study by the Medical Monitor
on a case-by-case basis. Patients positive for HCV antibody are eligible only if PCR
is negative for HCV RNA.

- Women who are pregnant or lactating

- Fertile men or women of childbearing potential unless 1) surgically sterile or 2)
using an adequate measure of contraception such as oral contraceptives, intrauterine
device, or barrier method of contraception in conjunction with spermicidal jelly

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