Sorafenib in Treating Patients With Malignant Gastrointestinal Stromal Tumor That Progressed During or After Previous Treatment With Imatinib Mesylate and Sunitinib Malate

Inclusion Criteria: Histologically confirmed gastrointestinal stromal tumor Not amenable to curative surgery Kit-expressing tumor Disease progression (i.e., new lesion or 20% increase in unidimensional tumor size) on or after treatment with imatinib mesylate and sunitinib malate Measurable disease, defined as ≥ 1 unidimensionally measurable lesion > 20 mm by conventional techniques OR > 10 mm by spiral CT scan Only site of measurable disease must be outside of previously irradiated area No known brain metastases Performance status - ECOG 0-2 More than 3 months Absolute neutrophil count > 1,500/mm^3 Platelet count > 100,000/mm^3 Bilirubin normal AST and ALT < 2.5 times upper limit of normal Creatinine ≤ 1.5 mg/dL Creatinine clearance > 60 mL/min No symptomatic congestive heart failure No unstable angina pectoris No cardiac arrhythmia No uncontrolled hypertension Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix No history of allergic reaction attributed to compounds of similar chemical or biological composition to sorafenib No ongoing or active infection No psychiatric illness or social situation that would preclude study compliance No other uncontrolled illness No evidence of bowel perforation or obstruction No prior angiogenesis inhibitors No immunotherapy after the last dose of imatinib mesylate or sunitinib malate No chemotherapy or chemoembolization therapy after the last dose of imatinib mesylate or sunitinib malate See Disease Characteristics At least 4 weeks since prior radiotherapy and recovered At least 14 days since prior imatinib mesylate or sunitinib malate No prior sorafenib No prior inhibitors of MAPK-signaling intermediates No other investigational agent after the last dose of imatinib mesylate or sunitinib malate Concurrent anticoagulation therapy with warfarin allowed provided the following criteria are met: On a therapeutic stable warfarin dose INR ≤3 No active bleeding or pathologic condition that confers a high risk of bleeding No concurrent combination antiretroviral therapy for HIV-positive patients No concurrent administration of any of the following: Enzyme-inducing antiepileptic drugs (e.g., carbamazepine, phenytoin, or phenobarbital) Hypericum perforatum (St. John's wort) Rifampin No other concurrent anticancer agents or therapies