A Study of ET-743 (Trabectedin) in Patients With Advanced Breast Cancer

The purpose of this study is to test the safety and effectiveness of an investigational chemotherapy agent in patients with advanced breast cancer.

Patients will be enrolled in the study after all study specific-entry criteria are met and informed consent is obtained. Patients will be required to attend regular clinic visits to receive study medication and have their status monitored. Patients will also be required to have radiologic tumor assessments performed at multiple times throughout the study. A detailed explanation can be provided by the study physician (Investigator) conducting this study. Trabectedin 580 mcg/m2 once weekly for 3 consecutive weeks (Treatment A) or 1,300 mcg/m2 once every 21 days (Treatment B) will be given to patients as a 3-hour intravenous (i.v). infusion via a central venous catheter which is a tube placed into a large vein that is used to administer medications. All patients will be given dexamethasone 10 mg i.v. 30 minutes before each trabectedin infusion. Patients may receive multiple cycles of trabectedin in the absence of disease progression.

Trabectedin, Yondelis, ET743, Advanced breast cancer, Breast, Cancer, Antineoplastic Agents, Alkylating Agents, Molecular Mechanisms of Pharmacological Action

ET743 580 mcg/m2 3-hour i.v. infusion on Days 1 8 and 15 every 28 days for up to approximately 52 weeks in the absence of disease progression. Dexamethasone 10 mg i.v will be administered 30 minutes prior to each trabectedin infusion.

ET743 1 300 mcg/m2 3 hour i.v. infusion once every 21 days for up to approximately 52 weeks in the absence of disease progression. Dexamethasone 10 mg i.v will be administered 30 minutes prior to each trabectedin infusion.

580 mcg/m2, 3-hour i.v. infusion, on Days 1, 8, and 15 every 28 days for up to approximately 52 weeks in the absence of disease progression. Dexamethasone, 10 mg i.v, will be administered 30 minutes prior to each trabectedin infusion.

1,300 mcg/m2, 3 hour i.v. infusion once every 21 days for up to approximately 52 weeks in the absence of disease progression. Dexamethasone, 10 mg i.v, will be administered 30 minutes prior to each trabectedin infusion.

Inclusion Criteria: Diagnosis of advanced breast cancer Prior therapy with anthracycline and taxane (2 types of chemotherapy drugs) At least one measureable tumor lesion Adequate bone marrow, hepatic and renal function Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1 Exclusion Criteria: Known hypersensitivity to any components of the i.v. formulation of ET-743 or dexamethasone Pregnant or lactating women Known metastases (spread) of cancer to the central nervous system History of another neoplastic disease unless in remission for five years or more.

Goldstein LJ, Gurtler J, Del Prete SA, Tjulandin S, Semiglazov VF, Bayever E, Michiels B. Trabectedin as a single-agent treatment of advanced breast cancer after anthracycline and taxane treatment: a multicenter, randomized, phase II study comparing 2 administration regimens. Clin Breast Cancer. 2014 Dec;14(6):396-404. doi: 10.1016/j.clbc.2014.06.006. Epub 2014 Aug 15.