An Efficacy Study of Trabectedin in the Treatment of Participants With Specific Subtypes of Metastatic Breast Cancer

Dexamethasone 4 mg orally 24 hrs and 12 hrs before study drug infusion on Day -1, followed by dexamethasone 20 mg intravenously 30 minutes before study drug infusion on Day 1, followed by dexamethasone 4 mg orally 24, 36, 48, 60 and 72 hrs after the start of study drug infusion on Day 1 to 3.

Trabectedin 1.3 mg/m\^2 intravenous infusion over 3-hrs every 3 weeks, on Day 1 of each cycle. Each cycle length will be 3 weeks.