Trabectedin in Treating Young Patients With Recurrent or Refractory Soft Tissue Sarcoma or Ewing's Family of Tumors

Response (Complete Response [CR] and Partial Response [PR])

Any patient who is enrolled and receives at least one dose of trabectedin will be considered evaluable for response if the individual receives at least one dose of trabectedin and: (1) is removed from protocol therapy because of progressive disease where progressive disease is documented either by imaging studies or clinical progression; or (2) has at least one radiographic evaluation of disease status after the start of protocol therapy and is not electively removed from protocol therapy with stable disease or is not lost to follow-up with stable disease. Patients who achieve a complete response (CR) - disappearance of all target lesions or partial response (PR) - \>=30% decrease in the sum of the longest diameter of target lesions according to the RECIST criteria will be considered responders for the study design. All other patients who are evaluable for response will be considered non-responders for the study.

Time frame: Twenty-six (26) cycles of chemotherapy or termination of protocol therapy, whichever occurs first.

Number of Patients With Dose-Limiting Toxicity (DLT)

Any Grade 3 or Grade 4 non-hematologic toxicity attributable to the Investigational drug with the specific exclusion of: Grade 3 nausea and vomiting; Grade 3 transaminase (AST/ALT) elevation that return to less than or equal to Grade 1 or baseline prior to the time for the next treatment cycle; Grade 3 fever or infection; Alopecia; Grade 4 neutropenia of \> 7 days duration or Grade 4 thrombocytopenia of \> 7 days duration, which requires transfusion therapy on greater than 2 occasions in 7 days, or which causes a delay of more than 14 days beyond the planned interval between treatment cycles.

Time frame: 1 Cycle

Pharmacokinetics by a Miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method : Maximum Plasma Concentration (Cmax) of Trabectedin

The plasma concentrations at each time point were determined by miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method. The plasma concentration-versus-time data of trabectedin were estimated using non-compartmental methods. Individual time points were not available, so one estimated Cmax was derived for each patient.

Time frame: From baseline up to168 hours after trabectedin infusion in course 1

Pharmacokinetics by a Miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method : Apparent Volume at Steady State (Vss) of Trabectedin

The plasma concentrations at each time point were determined by miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method. The plasma concentration-versus-time data of trabectedin were estimated using non-compartmental methods. Individual time points were not available, so one estimated Vss was derived for each patient.

Time frame: From baseline up to168 hours after trabectedin infusion in course 1

Pharmacokinetics by a Miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method : Half-life of Trabectedin

The plasma concentrations at each time point were determined by miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method. The plasma concentration-versus-time data of trabectedin were estimated using non-compartmental methods. Individual time points were not available, so one estimated Half-life was derived for each patient.

Time frame: From baseline up to168 hours after trabectedin infusion in course 1

Pharmacokinetics by a Miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method : Area Under the Curve (AUC) of Trabectedin

The plasma concentrations at each time point were determined by miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method. The plasma concentration-versus-time data of trabectedin were estimated using non-compartmental methods. Individual time points were not available, so one estimated AUC was derived for each patient.

Time frame: From baseline up to168 hours after trabectedin infusion in course 1

Pharmacokinetics by a Miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method : Clearance of Trabectedin

The plasma concentrations at each time point were determined by miniaturized Liquid Chromatography/Tandem Mass Spectrometry Method. The plasma concentration-versus-time data of trabectedin were estimated using non-compartmental methods. Individual time points were not available, so one estimated Clearance was derived for each patient.

Time frame: From baseline up to168 hours after trabectedin infusion in course 1