Inclusion Criteria

Inclusion Criteria

- Age ≥ 18 years;

- Disease progression per Response Evaluation Criteria in Solid Tumors (RECIST) during
previous treatment with imatinib mesylate at least 600 mg daily for at least 8 weeks,
as per two independently assessed prestudy computerized tomography (CT) scans;

- Presence of at least one measurable (per RECIST)

- Progressing tumor lesion not previously treated with radiotherapy or embolization and
evaluable by CT scan or magnetic resonance imaging (MRI);

- Karnofsky performance status ≥ 60;

- imatinib treatment terminated at least 7 days before study day 1;

- Adequate hepatic, renal, and cardiac function.

Exclusion criteria:

- Prior malignancy (other than GIST, in situ cervical cancer, or basal cell cancer of
the skin) unless treated with curative intent and without evidence of disease for ≥ 3
years; cardiac disease including myocardial infarction, unstable angina, and
congestive heart failure (New York Heart Association class > II),

- uncontrolled hypertension (systolic > 145 mmHg or diastolic > 85 mmHg),

- History of arterial thrombosis or deep vein thrombosis (including pulmonary embolus)
within 1 year of study day 1;

- Absolute neutrophil count < 1.5x109/L, platelet count < 100x109/L, hemoglobin < 9.0
g/dL;

- Prior treatment with motesanib diphosphate or other KIT (except imatinib) or VEGF
inhibitors.

- The study was approved by the institutional review board of each participating
institution, and all patients provided written informed consent before any
study-related procedures were performed.