Sunitinib in Certain Subtypes of Soft Tissue Sarcomas

Inclusion Criteria: * Histopathologically-proven diagnosis of angiosarcoma, epithelioid sarcoma-like hemangioendothelioma or Kaposi's sarcoma. Both HIV-Related and HIV-Unrelated Kaposi's patients will be included in the trial. Patients with HIV-Related Kaposi's will be required to have a CD4 count \>50 cells/µL and Viral Load \< 50 copies/ml. They will also need to be willing to take HAART. They can either have stable Kaposi's on HAART for at least 3 months or have progression of their Kaposi's after having been on HAART for at least 10 weeks. * Not amenable to surgery, radiation, or combined modality treatment with curative intent. * Evidence of unidimensionally measurable disease by conventional radiographic techniques. In patients with Kaposi's sarcoma, skin lesions at least 10 mm will be considered measurable disease. Bone lesions, ascites, or lymphangitis of skin or lung are not considered measurable. * No more than 2 prior chemotherapy regimens for metastatic or unresectable disease. Patients may have received prior bevacizumab or other Tyrosine Kinase Inhibitors, excluding sunitinib. Treatment with bevacizumab or other Tyrosine Kinase Inhibitors will not be counted as prior chemotherapy regimens. * Four weeks since prior chemotherapy, surgery or radiation therapy and resolution of all toxic effects of any prior therapy, surgical procedure or radiation. * ECOG performance status 0-2. * Age 18 or greater. Exclusion Criteria: * Patients with a "currently active" second malignancy other than non-melanoma skin cancer or carcinoma in situ of the cervix are not to be registered. Patients who are not considered to have a "currently active" malignancy if they have completed therapy and are considered by their physician to be at less than 30% risk of relapse. * No areas of measurable disease by CT or MRI. * Any of the following within the 6 months prior to study drug administration: myocardial infarction, severe/unstable angina, coronary/peripheral artery bypass graft, symptomatic congestive heart failure, or cerebrovascular accident. or transient ischemic attack, or pulmonary embolism. * Ongoing cardiac dysrhythmias, atrial fibrillation or prolongation of the QTc interval to \>450 msec for males of \> 470 msec for females. Medications that may prolong the QT intervals should be discontinued or switched to another medication prior to starting Sutent unless determined by the investigator to be absolutely necessary. * Pregnancy or breastfeeding. * Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with the study participation or study drug administration. * Major surgery or radiation therapy within 4 weeks of starting the study treatment.