Dose-Escalating and Safety Study of CP-461 in Patients With Chronic Lymphocytic Leukemia

Inclusion Criteria: 1. Relapsed or refractory chronic lymphocytic leukemia. 2. Patients must have either intermediate or high risk chronic lymphocytic leukemia according to the Rai Staging System. 3. Must have failed at least 1 prior chemotherapy regimen (at least 1 of which included fludarabine) for CLL. 4. No prior therapy within 4 weeks prior to entering the study. Patients must have fully recovered from the acute effects of prior therapy. 5. Platelet count = 75,000/mm3 , hemoglobin = 8 gm/dL. 6. Expected remaining life span \> or = three months. 7. ECOG performance status 0 - 2. 8. 18 years or of legal age. 9. Male patients or non-pregnant and non-lactating female patients, who are either using adequate birth control, are surgically sterile or post-menopausal. 10. Negative serum pregnancy test, if fertile female. 11. Willingness and ability to sign an informed consent document. Exclusion Criteria: 1. Evidence of CNS involvement. 2. Other active malignancy or history of treatment of any malignancy (excluding non-melanoma skin cancer) within the previous three years. 3. Previous therapy with Campath. 4. Patients with low-risk chronic lymphocytic leukemia according to the Rai Staging System. 5. Concurrent immunotherapy. 6. Concurrent use of steroids. 7. Use of an investigational medication or device within 1 month of initiating study therapy. 8. Patients who have had allogeneic bone marrow transplantation. 9. Total serum bilirubin above the upper limit of normal; serum creatinine above the upper limit of normal. 10. AST or ALT \> 2.5 times the upper limit of normal. 11. Any condition or any medication which may interfere with the conduct of the study.