Inclusion Criteria:

- Previously untreated subjects with intermediate-or high-risk CLL(modified Rai Stages
I-IV)

- Measurable disease as primarily established by the National Cancer
Institute-sponsored Working Group(NCI-WG) Guidelines for the diagnosis of CLL

- Requiring therapy for active disease, as primarily defined by the NCI-WG Guidelines

- Eastern Cooperative Oncology Group Performance Status < 2

- Adequate organ function determined , 14 days prior to the first dose of study
medication

Exclusion Criteria:

- Absolute Lymphocyte count > 100,000/uL

- Prior chemotherapy or other therapy for CLL, including allogeneic transplant

- Less than 3 weeks from any prior major surgery at the time of informed consent

- Failure to recover from any serious adverse effect of surgery

- History of autoimmune hemolytic anemia or autoimmune thrombocytopenia

- Active serious infection requiring systemic anti-infective therapy