Study of Neoadjuvant Carboplatin, Eribulin and Trastuzumab for Operable HER2 Positive Breast Cancer

During Phase I, the eribulin dose will be assigned upon study enrollment. The maximum
tolerated dose (MTD) determined in Phase I will be the dose used for Phase II. Eribulin will
be administered intravenously (IV) over 2 to 5 minutes on Days 1 and 8 of each cycle.
Carboplatin area under the curve (AUC) 6 will be administered IV over 15 to 30 minutes on
Day 1 of each cycle. Trastuzumab will be administered as an IV infusion on Day 1 of each
cycle. A loading dose of 8 mg/kg of trastuzumab will be administered over 90 minutes on
Cycle 1 Day 1. Then, a maintenance dose of 6 mg/kg of trastuzumab will be administered over
30 to 90 minutes on Day 1 of Cycles 2 - 6.

eribulin: During Phase I, the eribulin dose will be assigned upon study enrollment. The
maximum tolerated dose (MTD) determined in Phase I will be the dose used for Phase II.
Eribulin will be administered intravenously (IV) over 2 to 5 minutes on Days 1 and 8 of each
cycle.

carboplatin: Carboplatin area under the curve

Inclusion Criteria:

- Written informed consent

- Females; 18 years of age or greater

- Histologically proven invasive breast cancer

- American Joint Committee on Cancer (AJCC) clinical stage IIA - IIIB

- Tumor size greater than 10 millimeters

- HER2 positive

- Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

- Estrogen receptor (ER) positive or negative

- Ejection fraction greater than or equal to lower limit of normal for the institution
by echocardiogram (ECHO) or multiple gated acquisition scan (MUGA)

- Less than or equal to Grade 1 neuropathy according to Common Terminology Criteria for
Adverse Events (CTCAE) version 4.0

- Planned lumpectomy or mastectomy

- Eligible for radiation therapy

- No prior treatment for invasive breast cancer

- Adequate organ system function per protocol as determined within 7 days prior to
first dose of study treatment

- Women of childbearing potential must have a negative pregnancy test within 7 days
prior to the first dose of study treatment and must agree to use adequate
contraception methods during study treatment and for a minimum of 6 months following
trastuzumab discontinuation

- Female subjects who are lactating should discontinue nursing prior to the first dose
of study treatment and should refrain from nursing throughout the treatment period

Exclusion Criteria:

- Fine needle cytology only without other histologic evidence of invasive breast cancer

- Inflammatory breast cancer

- AJCC clinical stage T1a-b breast cancer (primary tumor less than or equal to 10
millimeters)

- Evidence of metastatic disease

- HER2 negative

- Ejection fraction less than lower limit of normal for the institution by ECHO or MUGA

- Corrected QT interval greater than 480 milliseconds

- Pre-existing cardiac dysfunction

- Prior history of invasive cancer within the past 3 years

- Synchronous bilateral breast cancer

- Pre-existing CTCAE v4.0 Grade 2 or greater neuropathy

- Hypersensitivity to halichondrin B or halichondrin B chemical derivative

- History of severe allergic reactions to cisplatin or other platinum containing
compounds, or mannitol

- Mild, moderate, or severe hepatic impairment

- Moderate or severe renal impairment

- Hypokalemia or hypomagnesemia if it cannot be corrected prior to the first dose of
study treatment

- Organ allografts requiring immunosuppression

- Known positive human immunodeficiency virus (HIV) status

- Prior major surgery within 28 days prior to the first dose of study treatment and/or
presence of any non-healing wound, fracture, or ulcer

- Minor surgery or radiation therapy within 14 days prior to the first dose of study
treatment

- Any serious and/or unstable pre-existing medical, psychiatric, or other condition
that could interfere with subject's safety, provision of informed consent, or
compliance to study procedures