Depsipeptide (Romidepsin) in Treating Patients With Metastatic or Unresectable Soft Tissue Sarcoma

Inclusion Criteria: * Histologically or cytologically confirmed soft tissue sarcoma (STS), including, but not limited to, the following histologies: * Gastrointestinal stromal tumors (GIST) * Refractory to imatinib mesylate * Desmoplastic small round cell tumors * Clear cell sarcoma * Extraskeletal osteosarcoma\* * Extraskeletal Ewing's sarcoma\* * Extraskeletal (myxoid) chondrosarcoma\* * Secondary STS (e.g., radiation-induced STS or neurofibrosarcoma due to neurofibromatosis) allowed * Metastatic or unresectable disease * No standard curative therapy exists * Patients with GIST must have received and progressed on imatinib mesylate * Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan * No known brain metastases * Performance status - Eastern Cooperative Oncology Group (ECOG) 0-2 * Performance status - Karnofsky 50-100% * More than 3 months * White blood cells (WBC) ⥠3,000/mm\^3 * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ⤠2.5 times upper limit of normal (ULN) * Bilirubin normal * Creatinine \< 1.5 times ULN * Creatinine clearance ≥ 60 mL/min * QTc ≤ 480 msec Exclusion Criteria: * No cardiac abnormalities (e.g., congenital long QT syndrome) * No myocardial infarction within the past year * No history of coronary artery disease (e.g., angina Canadian Class II-IV or posit…