Inclusion Criteria

INCLUSION CRITERIA:

- Men or women ≥18 years of age

- Histopathologically confirmed diagnosis of B-CLL expressing surface CD20 of any
detectable intensity

- Rai Stage III or IV. Rai Stages I and II with massive or progressive lymphadenopathy
or hepatosplenomegaly.

- Primary resistance to a fludarabine regimen (no PR or CR) or progressive disease
within 1 year of a prior response

- ECOG performance status 0, 1, or 2

- Written informed consent

EXCLUSION CRITERIA:

- Therapy for CLL within 4 weeks of Study Day 1 (including chemotherapy, radiation,
immunotherapy, cytokine or biologic [with the exception of hematopoietic growth
factors]). Patients must have recovered from the adverse effects of prior therapy.

- Known primary or secondary malignancy of the central nervous system

- Any malignancy within the 5 years immediately prior to the first dose of study
medication with the exception of basal cell or non-metastatic squamous cell carcinoma
of the skin, and carcinoma in-situ of the cervix

- Serum creatinine >2.0mg/dL (>176 micromol/L)

- AST or ALT ≥3 x the upper limit of normal (ULN)

- Total bilirubin ≥1.5 x ULN (unless secondary to Gilbert’s)

- Positive serology for hepatitis B (HBsAg) or hepatitis C (anti-HCV antibody)

- Known positivity for HIV

- Prior organ allograft

- Concurrent comorbid medical conditions that, in the opinion of the investigator,
preclude the safe delivery of the experimental treatment

- Pregnant or nursing women