Inclusion Criteria:

- To be eligible for the study, patients must fulfill all of the following criteria:

1. Patients must have signed an IRB-approved informed consent.

2. Patients with low, intermediate-1, intermediate-2, and high-risk MDS (defined by
IPSS) with documented diagnosis of MDS (refractory anemia, refractory anemia
with excess blasts, refractory anemia with ringed sideroblasts, refractory
anemia with mixed lineage dysplasia, or chronic myelomonocytic leukemia).

3. Patients must have a documented history of all transfusions (pRBC and/or
platelets) received in the 60-day period prior to their initial Trisenox
treatment on this protocol.

4. Patients with ECOG Performance Status of 0 or 1 (see Appendix I).

5. Absolute QT interval below 460 msec in the presence of serum potassium and
magnesium values within the normal range.

6. Patients must be >/= 18 years of age.

7. Patients must either be not of child bearing potential or have a negative serum
pregnancy test within 24 hours prior to registration. Patients are considered
not of child bearing potential if they are surgically sterile (they have
undergone a hysterectomy, bilateral tubal ligation or bilateral oophorectomy) or
they are postmenopausal for at least 24 months.

8. For patients of childbearing potential, patient has agreed to use 2 reliable
forms of contraception simultaneously for at least 1 month before beginning
Thalomid therapy, during Thalomid therapy, and for 1 month following
discontinuation of Thalomid therapy.

9. Renal function: creatinine < 1.5 x institutional upper limit of normal (ULN),
CTCAE Grade 1.

10. Hepatic function: bilirubin CTCAE Grade 1.

11. Serum potassium >4.0mEq/dL and serum magnesium >1.8 mg/dL.

Exclusion Criteria:

- Any of the following criteria will make the patient ineligible to participate in this
study:

1. Patients who have received prior chemotherapy or prior therapy with either
Trisenox or Thalomid.

2. Patients who have a history of hypersensitivity to arsenic or thalidomide or any
of the components in these drugs.

3. Patients with a significant history of cardiac disease (i.e., uncontrolled
hypertension, unstable angina, congestive heart failure, or myocardial
infarction in the last 6 months).

4. Patients with a history of torsade de pointes.

5. Patients planning to receive any concurrent therapy to treat MDS during the
study treatment period.

6. Patients with a serious uncontrolled intercurrent medical or psychiatric
illness, including serious infection.

7. Patients with a history of other malignancy within the last 5 years, which could
affect the diagnosis or assessment of these study drugs for MDS.

8. Any patient who is pregnant or lactating.

9. Any patient who is unable to comply with requirements of study.

10. Patients with peripheral neuropathy >grade 1.