这是一项第三期、随机、开放标签多中心研究，将评估 giredestrant 对比 fulvestrant（两者均联合研究者选择的 CDK4/6 抑制剂：palbociclib、ribociclib 或 abemaciclib）用于对辅助激素治疗产生耐药的雌激素受体阳性（ER+）、人类表皮生长因子受体2阴性（HER2-）晚期乳腺癌患者的疗效与安全性。
适应症：Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer
入组条件
纳入标准
- Locally advanced or metastatic adenocarcinoma of the breast, not amenable to treatment with curative intent
- Documented estrogen receptor-positive (ER+), HER2-negative (HER2-) tumor assessed locally on the most recent tumor biopsy (or an archived tumor sample if a recent tumor sample is not available for testing)
- Confirmed ESR1 mutation status (ESR1m versus ESR1nmd) in baseline circulating tumor DNA (ctDNA) through central laboratory testing
- Resistance to prior adjuvant endocrine therapy (ET), which is defined as having relapsed with prior standard adjuvant ET, on-treatment after \>/=12 months or off-treatment within 12 months of completion. Prior use of adjuvant CDK4/6i is allowed (if relapse occurred \>/=12 months since completion).
- No prior systemic anti-cancer therapy for advanced disease
- Measurable disease as defined per RECIST v.1.1 or non-measurable (including bone-only) disease
- Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1
- For pre/perimenopausal women and for men: willing to undergo and maintain treatment with approved LHRH agonist therapy (as per local guidelines) for the duration of study treatment
排除标准
- Prior systemic therapy (e.g., prior chemotherapy, immunotherapy, or biologic therapy) for locally advanced unresectable or metastatic breast cancer
- Prior treatment with another SERD (e.g., fulvestrant, oral SERDs) or novel ER-targeting agents
- Advanced, symptomatic, visceral spread that is at risk of life-threatening complications in the short term
- Active cardiac disease or history of cardiac dysfunction
- Clinically significant history of liver disease
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。