Decitabine and Clofarabine in Higher Risk Myelodysplastic Syndromes (MDS)

The Study Drugs:

Decitabine is designed to damage cells' DNA (genetic material), which may cause
myelodysplastic marrow cells to work more like normal marrow cells.

Clofarabine is designed to interfere with the growth and development of abnormal marrow
cells.

Study Groups:

If you are found to be eligible to take part in this study, you will be randomly assigned (as
in the flip of a coin) to 1 of 2 groups.

- If you are in Group 1, you will receive decitabine and clofarabine.

- If you are in Group 2, you will receive only decitabine.

Study Drug Administration:

Each cycle is 4-8 weeks depending on how you tolerate the drug and how the MDS responds to
it.

Group 1:

If you are in Group 1, you will receive the drugs in an alternating series of cycles. This
means that you will receive decitabine for the first 3 cycles, then clofarabine for the next
3 cycles, and then repeat. This pattern will continue for up to 24 cycles.

On Days 1-5 of Cycles 1-3, 7-9, 13-15, and 19-21, you will receive decitabine by vein over
1-2 hours.

On Days 1-5 of Cycles 4-6, 10-12, 16-18, and 22-24, you will receive clofarabine by vein over
1-2 hours.

Group 2:

If you are in Group 2, you will receive decitabine by vein over 1-2 hours on Days 1-5 of
every cycle.

Study Visits:

On Day 1 of every cycle, the following tests and procedures will be performed:

- You will have a physical exam, including measurement of your weight and vital signs.

- Your performance status will be recorded.

Once a week, blood (about 1-2 teaspoons) will be drawn for routine tests.

At the end of Cycle 3, you will have a bone marrow aspirate to check the status of the
disease.

If the disease has not gone into remission after Cycle 3, your next bone marrow aspirate will
depend on your group. If you are in Group 1, you may have another aspirate about 3 weeks
after you begin Cycle 4. After that, you may have an aspirate every 2 weeks (or more often if
your doctor feels it is needed) until the response (or lack thereof) is confirmed. If you are
in Group 2, you may not have another bone marrow aspirate until after the end of Cycle 6.

You will need to stay in Houston to receive the study drug(s). When you have study visits
where you are not receiving study drug(s), these tests can be performed by your local doctor.
If your MD Anderson leukemia doctor approves, your study drug can be administered outside MD
Anderson by your local doctor.

Length of Study:

You will be on study for up to 24 cycles. You will be taken off study early if the disease
gets worse or you experience any intolerable side effects.

Follow-up Visits:

After your last dose of study drug, you will have follow-up visits. You will only have these
visits if the disease has responded to the study drug.

- Once a month, blood (about 1 tablespoon) will be drawn routine tests. This can be done
at home through your local cancer doctor.

- Every 6 months, you will return to Houston for a physical exam and blood (about 1
tablespoon) will be drawn for routine tests.

This is an investigational study. Clofarabine is FDA approved and commercially available for
use in pediatric patients with a type of blood cancer (acute lymphocytic leukemia -- ALL).
Its use in patients with MDS is investigational.

Decitabine is FDA approved and commercially available for use in patients with MDS.

Up to 80 patients will take part in this study. All will be enrolled at MD Anderson.

Inclusion Criteria:

1. Patients with higher risk MDS (IPSS int-2 or high, or >/= 10% blasts as defined by WHO
or FAB). - No prior intensive chemotherapy or high-dose cytarabine (>/= 1 g/m2). -
Prior biologic therapies ( therapies, or single agent chemotherapy is allowed. - Off chemotherapy for 2 weeks
prior to entering this study with no toxic effects of that therapy, unless there is
evidence of rapidly progressive disease. - Hydroxyurea is permitted for control of
counts prior to treatment. - Hematopoietic growth factors are allowed. .

2. Age >/= 18 years.

3. Eastern Cooperative Oncology Group (ECOG) performance status
4. Have adequate renal function (serum creatinine
5. Serum bilirubin
6. Aspartate transaminase (AST) or alanine transaminase (ALT)
7. Alkaline phosphatase
8. Provide signed written informed consent.

9. Capable of understanding the investigational nature, potential risks and benefits of
the study, and able to provide valid informed consent.

10. Female patients of childbearing potential must have a negative pregnancy test within 2
weeks prior to enrollment.

11. Male and female patients must use an effective contraceptive method during the study
and for a minimum of 6 months after study treatment.

Exclusion Criteria:

1. Current concomitant chemotherapy, radiation therapy, or immunotherapy other than as
specified in the protocol.

2. Use of investigational agents within 30 days or any anticancer therapy within 2 weeks
before study entry with the exception of hydroxyurea. The patient must have recovered
from all acute toxicities from any previous therapy.

3. Have any other severe concurrent disease, or have a history of serious organ
dysfunction or disease involving the heart, kidney, liver, or other organ system that
may place the patient at undue risk to undergo treatment.

4. Patients with a systemic fungal, bacterial, viral, or other infection not controlled
(defined as exhibiting ongoing signs/symptoms related to the infection and without
improvement, despite appropriate antibiotics or other treatment)

5. Pregnant or lactating patients.

6. Any significant concurrent disease, illness, or psychiatric disorder that would
compromise patient safety or compliance, interfere with consent, study participation,
follow up, or interpretation of study results

7. Any concurrent malignancy (with the exception of exclusion # 8)

8. Exceptions to inclusion # 7: a) Patients with treated non-melanoma skin cancer, in
situ carcinoma, or cervical intraepithelial neoplasia, regardless of the disease-free
duration, are eligible for this study if definitive treatment for the condition has
been completed; b) Patients with organ-confined prostate cancer with no evidence of
recurrent or progressive disease based on prostate-specific antigen (PSA) values are
also eligible for this study if hormonal therapy has been initiated or a radical
prostatectomy has been performed.