Eligibility Criteria:
Inclusion Criteria:
1. An informed consent form must be completed before beginning any study procedure. In order to meet the proposed scientific endpoints, a tissue biopsy will be required at entry. The patient has the right to refuse participation in this study. The ease and ability of the biopsy will be an essential component of the selection process.
2. Continued from #1- Ease and ability of the biopsy will be determined by the enrolling physician and the physician performing the biopsy. The risks and potential complications of biopsy will be explained to each individual patient, with consideration of tumor location, potential damage to nearby organs, potential effect on the patients' quality of life, and the potential effect on the patients performance status.
3. Patients must be greater than or equal to 18 years of age.
4. Histologically documented diagnosis of primary, recurrent, locally advanced and/or metastatic GIST for which complete surgical resection (R0 or R1) is planned by a MDACC sarcoma surgeon.
5. Immunohistochemical documentation of c-kit expression by the tumor.
6. At least one measurable site of disease greater than 1 cm that can be accurately measured in one dimension by plain radiograph, CT, or MRI.
7. Performance status 0, 1, or 2 (ECOG)
8. Adequate end organ function, defined as the following: total bilirubin \< 1.5 x ULN (Does not apply to patients with isolated hyperbilirubinemia (e.g. Gilbert's disease) grade \<3), ALT and AST \< 2.5 x ULN, creatinine \< 1.5 x ULN, ANC \> 1.5 x 10\^9/L, platelets \> 100 x 10\^9/L, Serum amylase and lipase \</ = 1.5 x ULN, Alkaline Phosphatase \</= 2.5 x ULN
9. Patients must have the following laboratory values (WNL = within normal limits at the local institution lab) or corrected to within normal limits with supplements prior to the first dose of study medication: Potassium, Magnesium, Phosphorus, Calcium
10. Female patients of childbearing potential must have negative pregnancy test within 7 days before initiation of study drug dosing. Female patients who have been surgically sterilized(ie., tubal ligation) should be considered non- childbearing. Postmenopausal women must be amenorrheic for at least 12 months to be considered of non-childbearing potential. Male and female patients of reproductive potential must agree to employ an effective barrier method of birth control throughout the study and for up to 3 months following discontinuation of study drug.
11. Written, voluntary informed consent.
Exclusion Criteria:
1. Patient has received any other investigational agents within 28 days of first day of study drug dosing, unless the disease is rapidly progressing.
2. Patient is \< 5 years free of another primary malignancy except: if the other primary malignancy is not currently clinically significant nor requiring active intervention, or if other primary malignancy is a basal cell skin cancer or a cervical carcinoma in situ. Existence of any other clinically significant malignant disease which requires systemic treatment (chemotherapy or radiation) is not allowed.
3. Female patients who are pregnant or breast-feeding.
4. Patients with severe and/or uncontrolled concurrent medical disease that in the opinion of the investigator could cause unacceptable safety risks or compromise compliance with the protocol.
5. Patient has a rare hereditary problem of galactose intolerance, severe lactase deficiency or of glucose-galactose malabsorption.
6. Patient with electrolyte abnormality (e.g., hypokalemia, hypomagnesemia, hypophosphatemia, hyperkalemia, hypocalcemia, hyponatremia) unless the level can be corrected to normal levels prior to initiating study drug.
7. Patient has a known brain metastasis
8. Patients with metastasis outside of the peritoneal cavity
9. If patients have any signs or symptoms of metastasis, the appropriate workup should occur prior to enrollment (e.g., CT of the head for a patient with CNS symptoms).
10. Patient has known chronic liver disease (i.e., chronic active hepatitis, and cirrhosis), acute liver disease, acute or chronic pancreatic disease.
11. Patient has a known diagnosis of human immunodeficiency virus (HIV) infection.
12. Patient received chemotherapy within 4 weeks (6 weeks for nitrosourea or mitomycin-C) prior to study entry, unless the disease is rapidly progressing.
13. Patient with prior exposure to sunitinib, nilotinib or imatinib.
14. Patient previously received radiotherapy to greater than or equal to 25 % of the bone marrow.
15. Patient had a major surgery within 2 weeks prior to study entry.
16. Impaired cardiac function, including any one of the following: Inability to monitor the QT/QTc interval on ECG, Long QT syndrome or a known family history of long QT syndrome, Clinically significant resting bradycardia (\<50 beats per minute), QTc \> 450 msec on baseline ECG (using the QTcF formula). If QTcF \>450 msec and electrolytes are not within normal ranges, electrolytes should be corrected and then the patient re-screened for QTc, Myocardial infarction within 12 months prior to starting study
17. Continued from question #16 - Other clinically significant uncontrolled heart disease (e.g. unstable angina, congestive heart failure or uncontrolled hypertension defined as greater than 160/100 mmHg despite use of antihypertensive medication), History of or presence of clinically significant ventricular or atrial tachyarrhythmias, Complete left bundle branch block or bifascicular block (right bundle branch block plus left anterior hemiblock) or use of ventricular-paced pacemaker
18. Patients who are currently receiving treatment with any of the medications that have the potential to prolong the QT interval and the treatment cannot be either discontinued or switched to a different medication prior to starting study drug
19. Patient with any significant history of non-compliance to medical regimens or with inability to grant reliable informed consent.