A Study on the Efficacy and Safety of CDK4/6 Inhibitors Combined With Standard Adjuvant Endocrine Therapy in High-Risk, HR+/HER2+ Early Breast Cancer Patients Who Have Completed Adjuvant Anti-HER2 Targeted Therapy
This study is a prospective, open-label, multicenter, randomized controlled Phase III clinical trial. Building upon anti-HER2 targeted therapy combined with endocrine therapy, the addition of CDK4/6 inhibitors has demonstrated greater clinical benefits for advanced TPBC patients. This study aims to investigate the efficacy and safety of CDK4/6 inhibitor combination with standard adjuvant endocrine therapy in HR+/HER2+ early breast cancer patients.
• Females aged ≥18 and ≤70 years.
• ECOG systemic status grade 0 to 1.
• Histologically confirmed invasive HR+/HER2+ breast cancer (Specific definition: breast cancer patients whose estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) are all determined to be positive by pathologic testing. Specifically: ER positive: IHC\>10%, PR positive: IHC\>10%, HER2 positive: IHC+++ or IHC++ but amplified by FISH.
• Early-stage breast cancer after radical mastectomy with postoperative pathology consistent with TNM staging of ≥pN1 ; or postoperative pathology suggestive of non-pCR after neoadjuvant therapy; or postoperative pathology suggestive of pCR after neoadjuvant therapy but with clinical staging consistent with cT4 or N3 before neoadjuvant therapy
• Within 1 year of completion of adjuvant anti-HER2 targeted therapy: anti-HER2 targeted therapy includes trastuzumab-based therapy, and/or T-DM1 therapy, and/or TKI therapy.
• The function of major organs is basically normal, and the following conditions are met: ① The criteria for routine blood tests need to be met: HB ≥ 90g/L (no blood transfusion within 14 days); ANC ≥ 1.5 × 109/L; PLT ≥ 75 × 109/L; ② The biochemical tests need to be met as follows: TBIL ≤ 1.5 × ULN (the upper limit of normal value); ALT and AST ≤ 3 × ULN; serum Cr ≤ 1 × ULN, and endogenous creatinine clearance \> 50 ml/min (Cockcroft-Gault formula).
• Female subjects of childbearing potential are required to use a medically approved form of contraception during study treatment, and for at least 3 months after the last dose of study drug.
• Subjects voluntarily enrolled in the study, signed an informed consent form, were compliant, and cooperated with follow-up visits.