ABSTRACT
Human epidermal growth factor receptor 2 （HER2）-positive breast cancer is aggressive and prone to metastasis，and the applications of HER2 agents have improved the prognosis of patients with HER2-positive breast cancer. Among the marketed HER2 agents，macromolecular monoclonal antibodies that target the extracellular domain Ⅳ of HER2 were the cornerstone drugs of HER2-positive breast cancer，including trastuzumab，inetetamab，and margetuximab. Trastuzumab is available for the full-line treatment of breast cancer with sufficient proof of evidence-based medicine，sufficient practical experience and controllable safety. Inetetamab and trastuzumab have similar efficacy and controllable safety in HER2-positive metastatic breast cancer and neoadjuvant/ adjuvant therapy. Margetuximab focuses on patients carrying the CD16A-158F allele，and is an option of posterior line treatment for advanced breast cancer. It is necessary to select the most suitable drugs clinically according to the specific condition of the patient.