這是一項第三期、隨機、開放標籤多中心研究，將評估 giredestrant 對比 fulvestrant（兩者均聯合研究者選擇的 CDK4/6 抑制劑：palbociclib、ribociclib 或 abemaciclib）用於對輔助荷爾蒙治療產生耐藥的雌激素受體陽性（ER+）、人類表皮生長因子受體2陰性（HER2-）晚期乳癌患者的療效與安全性。
適應症：Estrogen Receptor-Positive, HER2-Negative Advanced Breast Cancer
收案條件
納入條件
- 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
排除條件
- 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
收案條件維持 ClinicalTrials.gov 原始英文登錄資料，實際收案資格以研究團隊的正式評估與受試者同意書為準。資料來源：ClinicalTrials.gov，每兩週自動更新，最後同步：2026年10月8日。