The primary objectives of the trial are to assess erythroid response to darbepoetin alfa, as determined by changes in hemoglobin and/or red blood cell (RBC) transfusion-dependence and to describe the safety profile of darbepoetin alfa in patients with MDS. The secondary objective is to assess bone marrow progenitor BFU-E growth before and after treatment with darbepoetin alfa.

Inclusion Criteria:- Diagnosis:

• Bone marrow aspirate/biopsy-proven MDS for > 2 months prior to enrollment.

• MDS French-American-British (FAB) subtypes refractory anemia (RA), RA with ringed sideroblasts (RARS), RA with excess blasts (RAEB), and non-proliferative chronic myelomonocytic leukemia (CMML) [WBC < 12,000/ml].

• Patients must have an untransfused hemoglobin < 10.0 g/dL and/or patients must be red cell transfusion-dependent for a period of at least 2 months prior to study entry.

  - Laboratory:

• Bilirubin < or = to 2 mg/dL

• ALT/SGPT < or = to 2.5 x the upper limit of normal (ULN)

• Normal renal function (Stanford: serum creatinine < 1.2 mg/dL [male], < 1.0 mg/dL [female]; Vanderbilt: < 1.5 mg/dL).

  • Age: > or = to 18
  • Other:

• ECOG performance status 0-2.

• Patients may receive standard supportive care, including transfusions and antibiotics as required.

• Patients must be r-HuEPO naive or must not have received prior treatment with r-HuEPO > or = to 40,000 U/week for more than 4 weeks. Exclusion Criteria:- Patients with secondary MDS or prior allogeneic bone marrow transplant.