Study of Forodesine Hydrochloride in Patients With Advanced, Fludarabine-refractory Chronic Lymphocytic Leukemia (CLL)

Inclusion Criteria: * Ages 18 years and older * Diagnosis of CLL established by peripheral blood and bone marrow examination and using the standard criteria * Patients with Rai stage III or IV, or earlier stage with massive, symptomatic lymphadenopathy requiring therapy * Primary resistance to fludarabine-based therapy (no complete response \[CR\] or partial response \[PR\]) or progressive disease within 6 months of response to prior fludarabine containing regimen. * ECOG performance status of 0, 1, 2 or 3 * Willing to take adequate contraception (i.e. latex condom, cervical cap, diaphragm, abstinence, etc.) for the entire duration of the study and 3 months after * All investigational treatments should have been discontinued for at least 1 week prior to the initiation of the study drug. Exclusion Criteria: * Pregnant or nursing * Unable or unwilling to sign consent * Severe, ongoing co-morbid conditions, which would preclude safe delivery of the investigational therapy * Active serious infections that are not controlled by antibiotics * ECOG performance status 4 * Inadequate renal function: creatinine 2.0 or more unless related to the disease * Inadequate liver function: bilirubin 3.0 or more, transaminases 3 x upper limit of normal or more unless related to the disease * Known positive test for HIV * Patients with known hepatitis B and/or hepatitis C active infection