Inclusion Criteria:

          -  Previously untreated, infiltrating primary breast cancer with locally advanced,
             inflammatory, or early stage tumor (either greater than 2 cm in diameter or node
             positive) with no evidence of metastatic disease.

          -  HER2 positivity (either immunohistochemistry 3+ or fluorescent in situ hybridization
             amplification).

          -  Age 18 or older.

          -  Eastern Cooperative Oncology Group performance status of 0 to 1.

          -  Availability of tumor tissue for biologic and molecular examination before starting
             primary treatment.

          -  Left ventricular ejection fraction within the institutional range of normal.

          -  Normal organ and marrow function.

          -  Adequate contraception methods for women of childbearing potential.

          -  Prior diagnosis of cancer is allowed as long as patient is free of disease and has
             been off treatment for the prior malignancy for a minimal interval of 3 years.

          -  Written informed consent.

        Exclusion Criteria:

          -  Either stage I or IV breast cancer.

          -  Prior trastuzumab or pertuzumab.

          -  Any prior chemotherapy.

          -  Treatment with any other investigational agent, or participation in another clinical
             trial within 28 days prior to enrolment.

          -  Undergone major surgery (e.g., intrathoracic, intra-abdominal or intra-pelvic) 4 weeks
             prior to starting study drug or who have not recovered from side effects of such
             surgery.

          -  Breast radiotherapy prior to starting study.

          -  Known hypersensitivity to the investigational drugs or any of their excipients.

          -  Evidence of any disease, neurological or metabolic dysfunction, physical examination
             finding or laboratory finding giving reasonable suspicion of a disease or condition
             that contraindicates the use of an GOIRC-01-2016 ImmunHER Protocol Version 1.0, 11
             April 2016 Page 6 of 140 investigational drug, or puts the patient at high risk for
             treatment-related complications.

          -  Moderate/severe hepatic impairment (Child- Pugh B/C).

          -  Uncontrolled inter-current illness including, but not limited to, ongoing or active
             infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
             arrhythmia, or psychiatric illness/social situations that would limit compliance with
             study requirements.

          -  Concurrent malignancy or malignancy within 3 years prior to study enrollment, with the
             exception of adequately treated basal cell carcinoma, squamous cell carcinoma or other
             non-melanomatous skin cancer, or insitu carcinoma of the uterine cervix.

          -  Pregnancy or breastfeeding (breast feeding should be discontinued to be enrolled in
             the study).

          -  Women of childbearing potential that refusal to adopt adequate contraceptive measures.

          -  Unwilling or unable to comply with the protocol. -