Inclusion Criteria

DISEASE CHARACTERISTICS: Cytologically confirmed myelodysplastic syndrome (MDS)
Intermediate 1, 2, or high risk disease OR Low risk disease with one of the following:
Symptomatic anemia requiring transfusion for at least 3 months prior to study Symptomatic
thrombocytopenia requiring platelet transfusion Platelet count less than 50,000/mm3
Absolute neutrophil count less than 1,000/mm3 with an infection Stable disease for 1 month
with no progression to acute myeloid leukemia Declined or not eligible for allogeneic bone
marrow transplant (alloBMT) No prior treatment of MDS with chemotherapy or alloBMT No
prior leukemia or more than 30% myeloblasts in the bone marrow

PATIENT CHARACTERISTICS: Age: Over 18 Performance status: 0-2 Life expectancy: Greater
than 4 months Hematopoietic: See Disease Characteristics Hepatic: Bilirubin less than 1.5
times normal (unless due to hemolysis or ineffective erythropoiesis) AST and ALT less than
2 times normal Renal: Creatinine less than 1.5 times normal Cardiovascular: No
uncontrolled or severe congestive heart failure Pulmonary: Serum CO2 greater than 18 mmHg
Other: No uncorrected folate or vitamin B12 deficiency HIV negative No other medical or
psychiatric illness that would preclude study At least 3 years since prior nonleukemic
malignancy Not pregnant or nursing Negative pregnancy test Fertile patients must use
effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: See Disease Characteristics At least 1 month
since prior interferon, interleukin-3, or interleukin-11 At least 1 month since prior
epoetin alfa, filgrastim (G-CSF), or sargramostim (GM-CSF) No concurrent hematologic
growth factors Chemotherapy: See Disease Characteristics Prior chemotherapy for
nonleukemic malignancy allowed No prior azacitidine Endocrine therapy: At least 1 month
since prior corticosteroids or danazol No concurrent steroids Radiotherapy: Prior
radiotherapy for nonleukemic malignancy allowed Surgery: Not specified Other: No prior
antithymocyte globulin or cyclosporine No prior amifostine