本研究旨在比较亚洲停经后ER(+)/HER2(-)晚期乳腺癌女性接受letrozole联合Palbociclib治疗与letrozole联合安慰剂治疗后的临床获益，该等患者未曾因晚期/转移性疾病接受过全身性抗癌治疗。
适应症：Breast Neoplasms
入组条件
纳入标准
- 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
排除标准
- 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
入组条件维持 ClinicalTrials.gov 原始英文登记资料，实际入组资格以研究团队的正式评估与受试者知情同意书为准。资料来源：ClinicalTrials.gov，每两周自动更新，最后同步：2026年10月8日。