Inclusion Criteria:

- Completed single-agent trastuzumab emtansine or combination trastuzumab emtansine
treatment in the parent study or who continue to receive single-agent trastuzumab
emtansine or combination trastuzumab emtansine treatment at the time of the parent
study closure and received the last study drug dose within the 6 weeks (42 days)
prior to the first scheduled dose of study therapy on the extension study or Continue
to receive treatment in the control arm of Study TDM4450g at the time of the parent
study closure if the patient received the last dose of control arm study drug within
the 6 weeks (42 days) prior to the first scheduled dose of control arm study therapy
in the extension study

- Patients in the control arm from Study TDM4450g whose disease progression has
occurred during the transition interval between the parent study and this extension
study may initiate trastuzumab emtansine treatment at the time of enrollment into
Study TDM4529g

- Expectation by the investigator that the patient may continue to benefit from
additional single-agent trastuzumab emtansine or combination trastuzumab emtansine
treatment or Expectation of the investigator that the patient may continue to benefit
from control arm treatment as given in Study TDM4450g and at the time of disease
progression may benefit from single-agent trastuzumab emtansine treatment

- Patients from parent study BO25499 must be on a stable dose of trastuzumab emtansine
for at least two cycles

- Women of childbearing potential and men with partners of childbearing potential, must
be willing to use a highly effective form of non-hormonal contraception or two
effective forms of non-hormonal contraception by the patient and/or partner, and to
continue the use of contraception for the duration of study treatment and for at
least 6 months after the last dose of study treatment

- Male patients whose partners are pregnant should use condoms for the duration of the
pregnancy

Exclusion Criteria:

- Adverse event(s)leading to single-agent trastuzumab emtansine or combination
trastuzumab emtansine treatment discontinuation in the parent study

- Ongoing serious adverse event(s) from the parent study

- Progressive disease on single-agent trastuzumab emtansine or a trastuzumab
emtansine-containing regimen during the parent study or before starting the extension
study, with the exception of patients from Study TDM4688g with early PD who went on
to receive pertuzumab + trastuzumab emtansine treatment and have not experienced
further disease progression on the combination regimen

- Peripheral neuropathy of Grade >/= 3 per the National Cancer Institute Common
Terminology Criteria for Adverse Events (NCI CTCAE), Version 3.0

- History of symptomatic congestive heart failure ([CHF]; New York Heart Association
[NYHA] Classes II-IV), ventricular arrhythmia requiring treatment, current unstable
angina, or history of myocardial infarction within 6 months prior to study entry

- Severe dyspnea at rest due to complications of advanced malignancy or current
requirement for continuous oxygen therapy

- Current severe, uncontrolled systemic disease (e.g. clinically significant
cardiovascular, pulmonary, or metabolic disease)

- Major surgical procedure or significant traumatic injury within 28 days prior to
study entry or anticipation of the need for major surgery during the course of study
treatment Current pregnancy or lactation

- History of receiving any investigational treatment or other systemic therapy directed
at controlling cancer (e.g., chemotherapy, trastuzumab, etc.) since the patient's
last study drug dose in the parent study

- History of hypersensitivity with previous trastuzumab emtansine or any agent used
with trastuzumab emtansine in the parent study, precluding further dosing

- Assessed by the investigator to be unable or unwilling to comply with the
requirements of the protocol