- Adult Asian women with locoregionally recurrent or metastatic disease not amenable to
curative therapy
- Confirmed diagnosis of ER positive breast cancer
- No prior systemic anti-cancer therapy for advanced ER+ disease
- Postmenopausal women
- Measurable disease as per Response Evaluation Criterion in Solid Tumors [RECIST] or
bone-only disease
- Eastern Cooperative Oncology Group [ECOG] 0-1
- Adequate organ and marrow function
- Patient must agree to provide tumor tissue
- Confirmed diagnosis of HER2 positive disease
- Patients with advanced, symptomatic, visceral spread that are at risk of life
threatening complication in the short term
- Known uncontrolled or symptomatic CNS metastases
- Prior neoadjuvant or adjuvant treatment with a non steroidal aromatase inhibitor (ie,
anastrozole or letrozole) with disease recurrence while on or within 12 months of
completing treatment
- Prior treatment with any CDK 4/6 inhibitor