Inclusion Criteria:

- Diagnosis Patients must have a clinical diagnosis of acute promyelocytic leukemia
(APL) morphology or FAB M3 variant confirmed by RT-PCR assay for PML-RARα or
chromosome analysis/FISH showing t(15:17) translocation. A patient may be entered
prior to confirmatory studies, but a patient who is subsequently found to be PML-RARα
negative will be removed from protocol treatment.

- Prior Treatment The patient must not have received any systemic definitive treatment
for APL, including cytotoxic chemotherapy, retinoids or arsenic trioxide. Prior
therapy with corticosteroids, hydroxyurea or leukapheresis will not exclude the
patient.

- Age: Patients must be of age eighteen (18) or above.

- Other Criteria

- Patients must have the following laboratory values:

- Bilirubin equal or less than 1.5 times the upper limit of normal.

- Creatinine equal or less than 1.5 times the upper limit of normal

- Pregnancy / Nursing Status

- Patients entered into this study should be non-pregnant and non-nursing and
should not plan on becoming pregnant while on treatment. Treatment under this
protocol would expose an unborn child to significant risks. treatment. Women and
men of reproductive potential should agree to use an effective means of birth
control. There is an extremely high risk of fetal malformation if pregnancy
occurs while on treatment in any amount with retinoid drugs even for short
periods.

Exclusion Criteria:

- Non-APL, AML patients should be excluded from the study.

- Other serious illnesses which would limit survival to 1 year.

- Psychiatric conditions which would prevent compliance with treatment or informed
consent.

- Uncontrolled or severe cardiovascular disease. This would include history of a recent
acute myocardial infarction, uncontrolled congestive heart failure, or active angina.

- AIDS or HIV positive patients, although HIV test is not required for accrual.