The Efficacy and Safety of BAT8001 Injection for the Treatment of HER2-positive Advanced Breast Cancer

This is a multicenter, randomized, open-label, positive-controlled, superiority phase III clinical study. The object is to evaluate the safety and efficacy of BAT8001 for the treatment of HER2-positive advanced breast cancer, using lapatinib in combination with capecitabine as the positive control drug. Eligible subjects will be randomized to the experimental or control group in a 1:1 ratio and stratified by the number of HER2-positive advanced/metastatic breast cancer treatment regimens (0, 1 VS \> 1) and lesion site (organ VS non-organ).