Immune Changes Following Trabectedin in Patients With Metastatic or Unresectable Sarcoma

Inclusion Criteria: * Subjects must have a diagnosis of advanced (unresectable or metastatic) sarcoma, for which trabectedin treatment is indicated * Subjects must have received prior anthracycline treatment; subjects who failed to tolerate it or for whom it is not clinically appropriate in the opinion of their treating physician may be included * All ongoing toxicities related to prior therapy must be resolved to grade 1 or better (except alopecia) * Total bilirubin level =\< upper limit of normal (ULN) mg/dL * Aspartate aminotransferase (AST) =\< 2.5 x ULN * Alanine aminotransferase (ALT) =\< 2.5 x ULN * Alkaline phosphatase \< 2.5 x ULN * Serum creatinine =\< 1.5 x ULN * Calculated creatinine clearance \>= 30 mL/min using the Cockcroft-Gault formula may be included * Creatine phosphokinase (CPK) =\< 2.5 x ULN * Absolute neutrophil count (ANC) \>= 1.5 x 10\^9/L * Platelet count \>= 100 x 10\^9/L * Hemoglobin \>= 9 g/dL * Baseline left ventricular ejection fraction (LVEF) 45% or greater (by echocardiogram or multigated acquisition scan \[MUGA\] study) and no evidence of New York Heart Association class ll to IV heart failure * Subjects with lesions safely accessible for biopsy, in the opinion of the treating physician and/or interventional radiology * Male or non-pregnant and non-breast feeding female: * Females of child-bearing potential must agree to use highly effective contraception without interruption from initiation of therapy and while on study medication and hav…