Inclusion Criteria:

- Patients with metastatic or locally advanced or unresectable GIST who have
intolerance of or disease progression following prior treatment with imatinib and/or
sunitinib

- ECOG (Eastern Cooperative Oncology Group) performance status ≤2

- Must have measurable disease per RECIST (Response Evaluation Criteria in Solid
Tumors)

- Recovery from toxicity from prior therapy to Common Terminology Criteria for Adverse
Events (CTCAE) v3.0 Grade ≤1 or to subject's baseline status

- Adequate organ and marrow function

- Sexually active subjects (male and female) must agree to use accepted methods of
contraception during the course of the study and for 3 months following
discontinuation of study drugs.

- Female subjects of childbearing potential must have a negative pregnancy test at
enrollment.

Exclusion Criteria:

- Therapy with imatinib or sunitinib within 14 days before the first dose of study drug

- Chemotherapy, immunotherapy, targeted therapy, chemoembolization, or any
investigational drug for the treatment of GIST after the last dose of imatinib or
sunitinib

- Anticoagulation with warfarin or coumarin-related compounds

- Radiation to ≥25% of bone marrow within 28 days of study entry

- Treatment with other investigational agents within 28 days of the first dose of XL820

- Known central nervous systems metastases

- Uncontrolled or intercurrent illness

- Pregnancy or breast-feeding

- Active bacterial or viral infection requiring systemic treatment