Inclusion Criteria:

- Diagnosis of CLL established by bone marrow aspiration and biopsy or flow cytometry
of peripheral blood.

- No previous therapy for CLL.

- Expected remaining life span greater than or equal to six months.

- 18 years or older.

- Willingness and ability to sign an informed consent.

Exclusion Criteria:

- Other active malignancy or history of treatment of any malignancy (excluding
non-melanoma skin cancer) within the previous three years.

- History of other malignancy which could affect the diagnosis or assessment of
OSI-461.

- Previous therapy for CLL.

- Use of an investigational medication or device within one month of initiating study
therapy.

- Concurrent immunotherapy.

- Use of steroids at the time of enrollment (patients who require steroids after
enrollment may remain on study).

- Any condition or any medication which may interfere with the conduct of the study.

- Serious uncontrolled intercurrent medical or psychiatric illness, including serious
infection.

- Evidence of CNS involvement.

- Pregnant or nursing women.