Inclusion Criteria:

- Patients with primary refractory AML (that is no prior remission). Patients who have
greater than 10% AML blasts in the bone marrow or blood upon recovery from two cycles
of standard cytarabine- and anthracycline-based induction chemotherapy are eligible.
Patients who have received etoposide and/or 6-thioguanine during remission induction
will be eligible.

- Patients with relapsed AML. Patients must have had a documented remission lasting >
30 days at some point during their prior therapy. Their current relapse must be
untreated. Relapse is defined as the presence of greater than 10% AML blasts in the
bone marrow or blood after having had a documented remission.

- Patients who have received a high-dose cytarabine containing regimen (>2 g/m2/dose)
within 3 months prior to registration on this protocol are not eligible.

- No active CNS involvement. A lumbar puncture prior to treatment is not required and
should not be performed in the absence of significant CNS symptoms or signs.

- Non-pregnant and non-nursing. Treatment under this protocol would expose an unborn
child to significant risks. Women and men of reproductive potential should agree to
use an effective means of birth control.

Exclusion Criteria:

Although NOT considered formal Exclusion Criteria, study physicians are strongly
encouraged as part of this decision-making process to recognize that the following may
increase the risks to a subject entering this protocol:

- Other serious illnesses which would limit survival to <2 years, or a psychiatric
condition which would prevent compliance with treatment or informed consent.

- Performance Status > 2.

- Uncontrolled or severe cardiovascular disease, diabetes, pulmonary disease, or
infection, which in the opinion of the treating physician, would make this protocol
treatment unreasonably hazardous for the patient.

- Patients with a "currently active" second malignancy other than non-melanoma skin
cancers. Patients are not considered to have a "currently active" malignancy if they
have completed therapy and considered by their physician to be at less than 30% risk
of relapse within one year.

- Patients who have received any investigational agent within the prior 4 weeks.