Inclusion Criteria:

- Patients with relapsed/refractory leukemia with a confirmed diagnosis of acute
myelogenous leukemia or acute lymphoblastic leukemia who have in vitro kinase
inhibitor sensitivity as determined by our functional kinase inhibitor screen

- Patients have relapsed and are refractory to at least 1 cycle of salvage therapy

- Patients have not received leukemia treatment within 2 weeks of starting study drug

- Eastern Cooperative Oncology Group (ECOG) performance status greater than 2

- Patients must have normal organ function as defined by protocol

- Normal corrected QT (QTc) interval on screening electrocardiogram (ECG) evaluation

- Discontinuation of any medications known to contribute significantly to the risk of
QT prolongation up to 48 hours prior to start of study drug

- Discontinuation of anti-coagulants and anti-platelet drugs up to 5 days prior to
start of study drug

- No uncontrolled infections as determined by the investigator

- No uncontrolled thyroid disease

- No active graft-versus-host disease (GVHD)

- Must be able to take oral medication

- Women of childbearing potential must have a negative serum or urine pregnancy test
within 72 hours prior to the start of study drug administration

- Persons of reproductive potential must agree to use an adequate method of
contraception throughout treatment and for at least 4 weeks after study drug is
stopped. Women of childbearing potential and men with a significant other of
childbearing potential must be advised of the importance of avoiding pregnancy during
trial participation and the potential risk factors for an unintentional pregnancy

- Ability to understand and the willingness to sign a written informed consent and
Health Insurance Portability and Accountability Act (HIPAA) document

Exclusion Criteria:

- Patients may not receive concurrent chemotherapy, radiotherapy or immunotherapy, nor
have received any other investigational agents within the last 14 days of start of
screening

- Patients may not have pleural or pericardial effusion of any grade

- Known pulmonary arterial hypertension (dasatinib subjects only)

- Uncontrolled angina, greater than New York Heart Association (NYHA) class III
congestive heart failure or myocardial infarction within 6 months prior to study
enrollment

- Diagnosed congenital long QT syndrome

- Any history of clinically significant ventricular arrhythmias

- Subjects with hypokalemia or hypomagnesemia that cannot be corrected prior to kinase
inhibitor administration

- History of significant bleeding disorder unrelated to cancer.

- Concomitant medications that are generally accepted to have a risk of causing
Torsades de Pointes.

- Drugs that affect the Cytochrome P450 3A4 (CYP3A4) system
(inducers/inhibitors/substrates) are allowed but should be used with caution
depending on specific kinase inhibitor used.

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements.

- Pregnant or lactating women are excluded from this study because of possible risk to
the fetus or infant

- Known Human immunodeficiency virus (HIV) positive patients are excluded from the
study because of possible risk of lethal infection when treated with marrow
suppressive therapy.