Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of refractory myelodysplastic syndrome (MDS), acute myeloid leukemia (AML),
acute lymphocytic leukemia, or blastic phase chronic myelogenous leukemia MDS and AML
include:

- First salvage with primary refractory disease or first complete remission of no
more than 12 months

- Second or greater salvage

- After the maximum tolerated dose is determined, AML patients with an intermediate
prognosis (i.e., complete remission of more than 12 months, but less than 24 months)
are eligible

- No candidates for curative therapies such as allogeneic bone marrow transplantation

PATIENT CHARACTERISTICS:

- Age: 18 and over

- Performance status: Zubrod 0-2

- Bilirubin no greater than 1.5 mg/dL

- Creatinine no greater than 1.5 mg/dL OR creatinine clearance at least 60 mL/min

- No active congestive heart failure

- No uncontrolled angina

- No myocardial infarction within past 6 months

- No concurrent grade 4 infection

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No overt psychosis, mental disability, or other incompetency that would preclude
obtaining informed consent

- No life threatening nonmalignant illness

PRIOR CONCURRENT THERAPY:

- At least 2 weeks since prior biologic therapy and recovered

- No concurrent systemic anticancer biologic therapy

- At least 2 weeks since other prior chemotherapy and recovered

- Concurrent hydroxyurea allowed if needed to control blast counts

- No concurrent systemic anticancer chemotherapy

- At least 2 weeks since prior endocrine therapy and recovered

- Concurrent corticosteroids allowed if needed to control blast counts

- At least 2 weeks since prior radiotherapy and recovered

- No concurrent systemic radiotherapy

- No concurrent surgery

- At least 3 weeks since other prior investigational drugs (including analgesics or
antiemetics) and recovered

- No other concurrent investigational drugs