此第三期、随机、双盲、安慰剂对照、多中心研究将评估 giredestrant 联合 palbociclib 对比 letrozole 联合 palbociclib 在雌激素受体（ER）阳性、人类表皮生长因子受体-2（HER2）阴性局部晚期（复发或恶化）或转移性乳腺癌患者中的疗效与安全性。

适应症：Estrogen Receptor-Positive, HER2-Negative Locally Advanced or Metastatic Breast Cancer

入组条件

For women who are premenopausal or perimenopausal and for men: treatment with approved LHRH agonist therapy for the duration of study treatment
Locally advanced (recurrent or progressed) or metastatic adenocarcinoma of the breast, not amenable to treatment with curative intent
Documented ER-positive tumor and HER2-negative tumor, assessed locally
Patients who have bilateral breast cancers which are both ER-positive and HER2-negative can be included in the study because the metastases are suitably targeted by the study treatments. If patients have bilateral tumors which are of different biomarker status, then proof of the ER and HER2 status of the metastases is required for study entry
No history of systemic anti-cancer therapy for locally advanced (recurrent or progressed) or metastatic disease
Disease recurrence from early-stage breast cancer after standard adjuvant endocrine therapy meeting the protocol-defined criteria of having received at least 24 months of treatment without disease progression during treatment and a disease-free interval since the completion of treatment that was greater than 12 months
Measurable disease as defined per RECIST v.1.1 or bone only disease which must have at least one predominantly lytic bone lesion confirmed by CT or MRI which can be followed
Eastern Cooperative Oncology Group Performance Status 0-1
Adequate organ function

Disease recurrence during or within 12 months of completing prior neoadjuvant or adjuvant treatment with any CDK4/6 inhibitor
Prior treatment with a selective estrogen receptor degrader (SERD)
Treatment with any investigational therapy within 28 days prior to study treatment
Treatment with strong CYP3A inhibitors or inducers within 14 days or 5 drug elimination half-lives (whichever is longer) prior to randomization
Advanced, symptomatic, visceral spread that is at risk of life-threatening complications in the short term
Known active uncontrolled or symptomatic CNS metastases, carcinomatous meningitis, or leptomeningeal disease
Active cardiac disease or history of cardiac dysfunction, as defined in the protocol
Pregnant or breastfeeding

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。

评估 Giredestrant 联合 Palbociclib 对比 Letrozole 联合 Palbociclib 在雌激素受体阳性、HER2 阴性局部晚期或转移性乳腺癌患者中的疗效与安全性研究（persevERA 乳腺癌研究）