Abstract GS01-02: Phase 3 study of neoadjuvant pembrolizumab or placebo plus chemotherapy, followed by adjuvant pembrolizumab or placebo plus endocrine therapy for early-stage high-risk ER+/HER2− breast cancer: KEYNOTE-756

作者：Fátima Cardoso, Joyce O’Shaughnessy, Heather L. McArthur, Peter Schmid, Javier Cortés, Nadia Harbeck, Melinda L. Telli, David W. Cescon, Peter A. Fasching, Zhimin Shao, Delphine Loirat, Yeon Hee Park, M. Fernández, Gábor Rubovszky, Seock‐Ah Im, Rina Hui, Toshimi Takano, Fabrice André, Hiroyuki Yasojima, Zhenzhen Liu, Yu Ding, Liyi Jia, Vassiliki Karantza, Konstantinos Tryfonidis, Aditya Bardia · 发表于：Cancer Research · 年份：2024 · DOI：10.1158/1538-7445.sabcs23-gs01-02 · 被引用次数：16 · 研究领域：Cancer Immunotherapy and Biomarkers、Advanced Breast Cancer Therapies、HER2/EGFR in Cancer Research

Abstract Background: KEYNOTE-756 (NCT03725059) is a global phase 3 study of neoadjuvant pembrolizumab or placebo + chemotherapy followed by adjuvant pembrolizumab or placebo + endocrine therapy (ET) in patients with early-stage high-risk ER+/HER2– breast cancer. Here, we report primary pCR results and residual cancer burden (RCB) outcomes. Methods: Eligible patients with T1c-2 (≥2 cm) cN1-2 or T3-4 cN0-2, centrally confirmed, grade 3, invasive ductal ER+/HER2− breast cancer were randomized 1:1 to receive neoadjuvant pembrolizumab 200 mg Q3W or placebo, both given with paclitaxel QW for 12 weeks, then 4 cycles of doxorubicin or epirubicin + cyclophosphamide (neoadjuvant treatment). After definitive surgery (± radiation therapy), patients received pembrolizumab or placebo for 9 cycles + standard ET. Stratification factors include region (Eastern Europe, China, or Other), tumor PD-L1 status (CPS ≥1 [positive] vs CPS < 1 [negative]), nodal involvement (positive vs negative), ER positivity (≥10% vs < 10%) and anthracycline schedule (Q3W vs Q2W). Dual primary endpoints are pCR (ypT0/Tis ypN0) and EFS. Secondary endpoints include OS, pCR defined as ypT0 ypN0 and ypT0/Tis and safety. RCB was an exploratory endpoint and was assessed by a local pathologist at the time of surgery. RCB-0, -1, -2, and -3 denote increasingly larger residual disease. Results: 1278 patients were randomized to pembrolizumab + chemotherapy (n=635) or placebo + chemotherapy (n=643). At the final p...