A Study of Trastuzumab Emtansine in Patients With HER2-Positive Metastatic Breast Cancer and Normal or Reduced Hepatic Function

Inclusion Criteria: * Adult patients, \>/= 18 years of age * Histologically or cytologically documented invasive metastatic breast cancer * Human epidermal growth factor receptor 2 (HER2) -positive disease * Adequate bone marrow and organ function (other than hepatic dysfunction allowed by protocol) * Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2 * Left ventricular ejection fraction \>/=50% * Normal hepatic function, or mild to moderate hepatic impairment (Child-Pugh Class A or B) Exclusion Criteria: * History of Grade \>/=3 infusion reaction, hypersensitivity reaction, or pneumonitis in response to trastuzumab * Investigational therapy or any other anticancer therapy \</=28 days before first study treatment * Previous treatment with trastuzumab emtansine * Brain metastases that are untreated or symptomatic or require therapy to control symptoms or any radiation, surgery or other therapy to control symptoms from brain metastases within 1 month of the first study treatment * History of other malignancy within the last 5 years, except for appropriately treated carcinoma in situ of the cervix, non-melanoma skin carcinoma, Stage I uterine cancer, or other cancers with a similar outcome as those mentioned above * Current peripheral neuropathy of Grade \>/=2 * Child-Pugh Class C hepatic impairment * Encephalopathy \>/= Grade 2 * For patients with normal hepatic function: history of drug or alcohol addiction or history of hepatitis B and/or hepatitis C * Active hepatitis A, B and/or C * Current unstable ventricular arrhythmia requiring treatment * History of symptomatic CHF (NYHA Classes II-IV) * History of myocardial infarction or unstable angina within 6 months of enrollment * History of a decrease in LVEF to\<40% or symptomatic CHF with previous trastuzumab treatment * Pregnant or lactating women * Known HIV infection