A Real-World Study of Pyrrolitinib Maleate Tablets for HER-2-Positive Early or Locally Advanced Breast Cancer After Adjuvant Trastuzumab Therapy

Purpose of the Study: Primary Study Objective: To evaluate the efficacy of pyrrolitinib maleate tablets in the treatment of HER-2-positive early or locally advanced breast cancer after adjuvant therapy with trastuzumab Secondary Research Objectives: To evaluate the safety of pyrrolitinib maleate tablets in the treatment of HER-2 positive early or locally advanced breast cancer after trastuzumab adjuvant therapy Study Endpoints Primary Study Endpoint: Invasive disease free survival (iDFS) Secondary Study Endpoints: 1. overall survival (OS); 2. disease-free survival (DFS); 3. distant metastasis free survival (DDFS); 4. safety Study Population: Patients with early or locally advanced HER-2 positive breast cancer with clinical stage 0-III who have received prior neoadjuvant or adjuvant therapy. where the neoadjuvant and/or adjuvant treatment phase has been completed at least ≥24 weeks (8 dosing cycles) of trastuzumab therapy and the time interval between the end of the last course of trastuzumab therapy and entry into the study must be ≤1 year Study Design: Single-arm, multicenter, interventional study Administration Pyrrolitinib: The recommended dose of this product is 400 mg orally once daily within 30 minutes after breakfast for 52 weeks (approximately one year). Dose adjustments may be made in accordance with this protocol, taking into account adverse reactions in subjects. Each consecutive suspension of piretinib during the course of the study should not exceed 14 days, prophylactic use of medications for the treatment of diarrhea is permitted during the course of treatment, multiple suspensions of study medication due to adverse events are permitted, and doses of piretinib that are missed for any reason will not be made up.