Inclusion Criteria:

          -  Previously untreated patients with a morphologic diagnosis of APL, confirmed by
             demonstration of t(15;17) using conventional cytogenetics OR florescence in situ
             hybridization (FISH), OR a positive RT-PCR assay for PML-RAR at the subject's local
             institution.

          -  Age ≥18 years. Karnofsky performance status of ≥ 60%.

          -  Adequate renal function as demonstrated by a serum creatinine ≤ 2.0 mg/dl or a
             creatinine clearance of > 60 ml/min.

          -  Adequate hepatic function as demonstrated by a bilirubin < 2.0 mg/dl (unless
             attributable to Gilbert's disease) and an alkaline phosphatase, AST, and ALT ≤ 2.5
             times the upper limit of normal.

          -  Normal cardiac function as demonstrated by a left ventricular ejection fraction ≥ 50%
             on echocardiogram or MUGA scan.

          -  QTc ≤ 500 msec on baseline ECG.

          -  Negative serum pregnancy test in women of childbearing potential.

          -  Ability to swallow oral medication.

          -  Men and women of child-bearing potential must be willing to practice an effective
             method of birth control during treatment and at least 4 months after treatment is
             finished.

          -  Patients with central nervous system involvement by APL are eligible and may receive
             concomitant treatment with radiation therapy and/or intrathecal chemotherapy in
             accordance with standard medical practice.

        Exclusion Criteria:

          -  Previous treatment for APL, except tretinoin, which may be given for up to 7 days
             prior to study entry.

          -  Active serious infections not controlled by antibiotics.

          -  Pregnant women or women who are breast-feeding.

          -  Concurrent active malignancy requiring immediate therapy.

          -  Clinically significant cardiac disease (NY Heart Association Class III or IV),
             including chronic arrhythmias, or pulmonary disease.

          -  Other serious or life-threatening conditions deemed unacceptable by the principal
             investigator.