Phase II Study of Forodesine in Subjects With Chronic Lymphocytic Leukemia (CLL)

Inclusion Criteria:

1. Age 18 years and older

2. Diagnosis of CLL established by peripheral blood and/or bone marrow examination and
using the standard diagnostic criteria.

3. Subjects with Rai stage III or IV, or earlier stage requiring therapy as determined
by the 1996 National Cancer Institute -Working Group (NCI-WG) criterion

4. Primary resistant (no CR or PR) or progressive disease after response to at least one
prior treatment regimen OR treatment naïve subjects who meet at least one of the
following criteria.

1. age >65 years

2. Eastern Cooperative Oncology Group (ECOG) performance status of 2, 3, or 4

3. Inability to tolerate standard cytotoxic chemotherapy in the opinion of the
treating physician.

5. ECOG performance status of 0, 1, or 2 (for subjects with primary resistance or
progressive disease after response to at least one prior treatment regimen).

6. Willing to take adequate contraceptive measures (i.e., latex condom, cervical cap,
diaphragm, abstinence, etc.) for the entire duration of the study and 3 months after,
except for patients who are post menopausal or have prior hysterectomy.

7. All investigational treatments should have been discontinued for at least 3 weeks
prior to the initiation of the study drug.

Exclusion Criteria:

1. Pregnant or nursing.

2. Unable or unwilling to sign consent.

3. Severe, ongoing co-morbid conditions, which would preclude safe delivery of the
investigational therapy.

4. Active serious infections that are not controlled by antibiotics.

5. ECOG performance status >2 (except for treatment naïve subjects where ECOG
performance status 0, 1 or 5 is excluded).

6. Inadequate renal function: creatinine > or equal to 2.0 unless related to the
disease.

7. Inadequate liver function: bilirubin > or equal to 3.0; transaminases > or equal to
3.0 times the upper limit of normal unless related to the disease.

8. Known positive test for human immunodeficiency virus (HIV).

9. Subjects with known hepatitis B and/or hepatitis C active infection.