Inclusion Criteria:

          -  primary diagnosis of infiltrating breast cancer

          -  HR positivity (ER ≥ 10% and/or PgR ≥10%) and HER2 positivity (IHC 3+ or FISH/CISH
             amplification), as assessed by local laboratory.

          -  Stage II-IIIA

          -  age >18 yrs

          -  ECOG Performance Status 0-1

          -  Postmenopausal status, defined by at least one of the following:

             60 years of age; < 60 years of age and amenorrheic for >/=12 months prior to day 1 <
             60 years of age, without a uterus, and luteinizing hormone (LH) and follicle
             stimulating hormone (FSH) values within postmenopausal range Prior bilateral
             oophorectomy Prior radiation castration with amenorrhea for at least 6 months

          -  Cardiac ejection fraction within the institutional range of normal (as measured by
             echocardiogram or MUGA scan).

          -  Normal organ and marrow function as defined below:

        (leukocytes >=3000/mcL; absolute neutrophil count >=1,500/mcL; platelets >=100,000/mcL;
        total bilirubin within 1.25 x normal institutional limits (with the exception of Gilbert's
        syndrome); AST (SGOT)/ALT(SGPT) within 1.25 x institutional upper limit of normal
        creatinine within normal institutional limits

          -  Availability of tumor tissue suitable for biological and molecular examination before
             starting primary treatment

          -  Ability to understand and the willingness to sign a written informed consent document

        Exclusion Criteria:

          -  Stage IIIB, IIIC, and inflammatory breast cancer

          -  Stage IV breast cancer

          -  Prior treatment with chemotherapy, endocrine therapy or radiotherapy. Prior treatment
             with HER2 targeting therapies

          -  LVEF below the ULN

          -  Uncontrolled hypertension (systolic >150 mm Hg and/or diastolic >100 mm Hg) or
             clinically significant (i.e. active) cardiovascular disease: cerebrovascular accident
             (CVA)/stroke or myocardial infarction within 6 months prior to first study medication,
             unstable angina, congestive heart failure (CHF) of New York Heart Association (NYHA)
             grade II or higher, or serious cardiac arrhythmia requiring medication.

          -  Received any investigational treatment within 4 weeks of study start.

          -  Subjects with known infection with HIV, HBV, HCV

          -  Known hypersensitivity to any of the study drugs or excipients.

          -  Dyspnoea at rest or other disease requiring continuous oxygen therapy.

          -  Psychiatric illness/social situations that would limit compliance with study
             requirements

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