Efficacy and Safety of Pyrotinib Maleate Combined With ARX788 Neoadjuvant Treatment in Breast Cancer Patients

The subjects who sign an informed consent will enter the treatment period after screening. Each eligible subject will receive pyrotinib, 320 mg once a day, with 21 days as a session, for 6 sessions in total before operation. Next-generation Site-specific human epidermal growth factor receptor 2 (HER2)-targeting Antibody-drug Conjugate (ARX788) will be intravenously injected at a dose of 1.5 mg/kg, once every 3 weeks, with 21 days as a session, for 6 sessions before surgery. Breast MRI and other imaging examinations will be reviewed every 2 sessions to evaluate the curative effect, and the patient's baseline will be defined based on the imaging report at the time of enrollment. If a definite effect (complete response/partial response) is achieved, surgical treatment will be performed within 4 weeks (\> 2 weeks) after completion of 6 sessions of neoadjuvant therapy.