8-Chloro-Adenosine in Chronic Lymphocytic Leukemia

8-Chloro-adenosine is a new drug similar to other drugs already approved by the FDA for the
treatment of CLL and other types of cancer. 8-Chloro-adenosine belongs to a class of
chemotherapy drugs called purine analogues that work to treat cancer by their ability to
interfere with cancer cell metabolism, causing cell death.

If you are eligible, you will receive 8-chloro-adenosine as an infusion into a vein once a
day for five days in a row. Each infusion will take about 1 hour. This 5-day treatment will
be repeated every 4 weeks (± 3 days) (1 course).

This is a dose escalation study. Patients treated on this study will be treated in groups of
3. The first group will receive the lowest dose of the drug. If the type, number, and
severity of any side effects experienced are acceptable, the next group of 3 patients will
receive the next higher dose of drug. The dose of drug will be increased for each new group
until the highest safe dose is found.

For your first course only, you will have blood tests (about 1 tablespoon) on Day 3 and Day
5 of treatment to monitor for safety. After that, you will have weekly (± 3 days)
evaluations and routine blood tests (about 1 tablespoon) in the clinic at UTMDACC. During
these evaluations, you will also have a physical exam and be asked about any side effects
you may have experienced. You will be evaluated for improvement in your CLL. If your disease
is stable or responding to treatment, you may continue with treatment. If your disease
improves to the point that your doctor feels that you are in complete remission, he or she
will request you to have a bone marrow biopsy to confirm complete remission.

If your disease is worsening and it appears that the treatment is not helping you, then you
will stop treatment with 8-chloro-adenosine and may begin other treatment at the direction
of your treating doctor. If you have unacceptable side effects, you may be taken off
treatment.

If you stop treatment, you will be evaluated in the clinic and have routine blood tests
(about 1 tablespoon) once a week for the first month, twice a month for the next 2 months,
then once a month from then on. During these evaluations, you will have a physical exam and
be asked about any side effects you may have experienced. If you begin other treatment, your
scheduled follow-up will end.

This is an investigational study. 8-Chloro-adenosine is not approved by the FDA and is not
commercially available. A total of up to 28 patients will take part in this study. All will
be enrolled and treated at MD Anderson.

Inclusion Criteria:

1. Patients must have a diagnosis of chronic lymphocytic leukemia and must be previously
treated with at least one prior treatment regimen, including a purine-analogue based
treatment.

2. Patients must be Rai Stage III or IV OR Rai Stage 0-II and have one or more criteria
for active disease as defined by the NCI-Working Group as: a) weight loss of more
than 10% in the last 6 months; b) fatigue; c) fever or night sweats without evidence
of infection; d) progressive anemia or thrombocytopenia; e) progressive lymphocytosis
with a lymphocyte doubling time paraproteinemia.

3. All patients must have a Zubrod performance status of
4. All patients must be age >/= 18 years.

5. Patients may not receive concurrent treatment for their CLL and must have been off
treatment (chemotherapy, immunotherapy, or radiotherapy) for 4 weeks prior to
treatment on this study and recovered from toxic effects of that therapy.

6. All patients must have adequate renal function indicated by serum creatinine upper limits of normal (ULN) and adequate liver function indicated by ALT or AST 2.5x ULN AND total bilirubin
7. All patients must have a pre-treatment platelet count of >/= 50,000 /µl and not
require transfusion to maintain this platelet count unless thrombocytopenia is due to
marrow infiltrated with disease.

8. All patients or appropriate surrogate must provide informed consent.

Exclusion Criteria:

1. Patients with active uncontrolled autoimmune hemolytic anemia or immune
thrombocytopenia purpura.

2. Patients with active uncontrolled fungal, bacterial, or viral infection.

3. Patients who are pregnant or breast-feeding.