Inclusion Criteria:

Each patient must meet the following criteria to be enrolled in this study:

1. Male or female patients age 18 years and older.
2. Patients must sign an institutional review board (IRB)-approved informed consent form, and understand the investigational nature of this study and its potential hazards prior to initiation of any study-specific procedures or treatment.
3. Must have Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
4. Adequate renal and hepatic function (creatinine < 2 times upper limit of normal, total bilirubin of < 2 times upper limit of normal, and AST and ALT ≤ 2 times upper limit of normal) unless proven to be related to disease infiltration.
5. Female patients need a negative serum or urine pregnancy test within 7 days prior to study drug administration (applies only if patient is of childbearing potential. Non-childbearing is defined as ≥ 1 year postmenopausal or surgically sterilized).
6. Women of childbearing potential and men must use contraception. Men and women must continue birth control for the duration of the study.
7. Patients with Low or Intermediate-1 Risk MDS by the International Prognostic Scoring System (IPSS) classification.

Exclusion Criteria:

Patients who meet any of the following criteria will be excluded from the study:

1. Women who are pregnant or nursing.
2. Those who have received prior therapy with decitabine.
3. Prior therapy with azacitidine (Vidaza®).
4. Those who received growth factor support or lenalidomide in the 30 days prior to the first dose of decitabine.
5. Those who have received an investigational agent 30 days prior to the first dose of decitabine.
6. Patients with active, uncontrolled, systemic infection considered opportunistic, life threatening or clinically significant; or any severe, concurrent disease, which, in the judgment of the Investigator and after discussion with the Sponsor and Primary Investigator, would make the patient inappropriate for study entry.