10532 Background: S is an oral multi-kinase inhibitor of VEGFR, PDGFR, Raf, Flt-3 and c-KIT. STS of vascular derivation (VS: angiosarcoma, hemangiopericytoma) express VEGFR and VEGF mRNA. Prognosis for high grade liposarcomas (LPS) and leiomyosarcomas (LMS) has been correlated with levels of serum VEGF. We therefore studied S in patients (pts) with advanced VS, LPS and LMS. Methods: Pts with advanced VS, LPS and LMS with 0–1 prior chemotherapies for advanced disease were treated with S 400 mg BID. Solitary fibrous tumors were included as VS because of morphologic similarity to hemangiopericytoma. Pts were required to have adequate blood parameters, PS of 0–1, and no uncontrolled hypertension or history of thromboembolic disease. Prohibited medications included therapeutic anticoagulation, combination anti-retroviral therapy, and prior VEGFR or MAPK inhibitors. 15 pts were accrued to each of three strata: VS, LPS, LMS. If ≥1 RECIST responses were seen in a stratum, an additional 10 pts were to be added to ...