Breast Cancer Clinical Trials

• Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1

• Histologically or cytologically confirmed and documented adenocarcinoma of the breast with metastatic or locally advanced disease not amenable to curative resection

• Confirmation of HER2 biomarker eligibility based on valid results from central testing of tumor tissue documenting HER2-positivity

• Confirmation of PIK3CA-mutation biomarker eligibility based on valid results from central testing of tumor tissue documenting PIK3CA-mutated tumor status

• Disease-free interval from completion of adjuvant or neoadjuvant systemic non-hormonal treatment to recurrence of \>= 6 months

• LVEF (left ventricular ejection fraction) of at least 50% measured by echocardiogram (ECHO) or multiple-gated acquisition scan (MUGA)

• Adequate hematologic and organ function prior to initiation of study treatment