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