In adult phase I and phase II studies, trabectedin has been well-tolerated up to dose levels of 1.9mg/m(2)/dose with the most common toxicities being fatigue, neutropenia, and reversible transaminase elevations. Objective responses were seen at doses equal to or greater than 1.5mg/m(2)/dose. Trabectedin 1.5mg/m(2) administered as a 24-hour continuous intravenous infusion is the recommended dose and schedule in adults.