To estimate the percent of patients with myelodysplastic syndromes (MDS) who experience erythroid response and the interval to response with daily treatment of 25 mg of CC-5013 .

Ages Eligible for Study:  18 Years and above,  Genders Eligible for Study:  Both

Criteria

• Diagnosis of de novo myelodysplastic syndrome of at least 12 weeks duration.
• Baseline mean hemoglobin < 10.0 g/dL (untransfused) and/or be transfusion dependent defined by requiring at least 4 units of RBC in the 8 weeks prior to baseline.
• More than 30 days must have elapsed since any previous treatment for MDS, other than transfusion.
• Women must not be pregnant or lactating
• No use of another experimental study drug within 30 dy\ays of baseline
• Understand and sign written informed consent
• Able to adhere to study visit schedule, understand and comply with other protocol requirements.