Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of 1 of the following hematologic malignancies:

- Acute myeloid leukemia

- Acute lymphoblastic leukemia

- Chronic myelogenous leukemia (CML)

- CML in blast crisis

- Chronic lymphocytic leukemia

- High-risk* myelodysplastic syndromes, including the following:

- Refractory anemia with excess blasts (RAEB)

- RAEB in transformation

- Chronic myelomonocytic leukemia NOTE: *High-risk myelodysplasia defined as
having an International Performance Scoring System score of at least 1.5,
based on adverse cytogenetics, greater than 10% blasts in marrow, and
cytopenias in at least 2 lineages

- Relapsed or refractory disease

- Ineligible for higher priority protocols

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2

Life expectancy

- More than 2 months

Hematopoietic

- See Disease Characteristics

Hepatic

- Bilirubin no greater than 2.0 mg/dL (unless considered due to malignancy)

- ALT or AST no greater than 3 times upper limit of normal

- Chronic hepatitis allowed

Renal

- Creatinine no greater than 2.0 mg/dL (unless considered due to malignancy)

Cardiovascular

- No myocardial infarction within the past 3 months

- No symptomatic coronary artery disease

- No arrhythmias (other than atrial fibrillation or flutter) requiring treatment

- No uncontrolled congestive heart failure

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Concurrent infections under active treatment with and controlled by antibiotics
allowed

- No other concurrent life-threatening illness

- No mental deficit or psychiatric history that would preclude giving informed consent
or complying with protocol

PRIOR CONCURRENT THERAPY:

Biologic therapy

- At least 1 week since prior growth factors, including the following:

- Epoetin alfa

- Filgrastim (G-CSF)

- Sargramostim (GM-CSF)

- Interleukin-3

- Interleukin-11

- No concurrent anticancer immunotherapy

Chemotherapy

- At least 72 hours since prior hydroxyurea

- Recovered from prior chemotherapy

- No other concurrent anticancer chemotherapy

Endocrine therapy

- Not specified

Radiotherapy

- At least 2 weeks since prior radiotherapy

- No concurrent anticancer radiotherapy

Surgery

- Not specified

Other

- At least 3 weeks since prior myelosuppressive cytotoxic agents (in the absence of
rapidly progressing disease)

- At least 1 week since prior nonmyelosuppressive therapy

- No other concurrent standard or investigational therapy for the malignancy