A Study of Trastuzumab Emtansine (Trastuzumab-MCC-DM1) Administered Intravenously to Patients With Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Metastatic Breast Cancer

A Phase II, Single-arm, Open-label Study of Trastuzumab-MCC-DM1 Administered Intravenously to Patients With HER2-Positive Metastatic Breast Cancer Who Have Progressed While Receiving HER2-Directed Therapy

This was a multi-institutional, open-label, single-arm, Phase II study of trastuzumab emtansine (T-DM1) administered by intravenous (IV) infusion to patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC).

Inclusion Criteria:

• Signed informed consent form.
• Human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC); tissue (slides or blocks) available for HER2 confirmation.
• History of progression on HER2-directed therapy for the treatment of HER2-positive breast cancer.
• At least 1, and no more than 3, chemotherapy regimens for MBC.
• Granulocyte count ≥ 1500/μL, platelet count ≥ 100,000/μL, and hemoglobin ≥ 9 g/dL.
• Serum bilirubin ≤ 1.5 mg/dL, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase ≤ 2.5x the upper limit of normal (ULN).
• Serum creatinine ≤ 1.5 mg/dL or creatinine clearance ≥ 60 mL/min.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2.

Exclusion Criteria:

• Any chemotherapy, hormonal therapy, radiotherapy, immunotherapy, or biological therapy for the treatment of breast cancer within 2 weeks of the first study treatment.
• Prior cumulative doxorubicin dose > 360 mg/m^2 or the equivalent.
• History of significant cardiac disease, unstable angina, congestive heart failure (CHF), myocardial infarction, or ventricular arrythmia requiring medication.