Inoperable Locally Advanced HER2-Negative Breast Cancer

This study aims to evaluate the safety and effectiveness of JSKN016 in combination with different treatments for patients with HER2-negative breast cancer that cannot be removed by surgery or has spread to other parts of the body. The study includes four groups of patients based on treatment history and tumor characteristics. Each group will receive JSKN016 with chemotherapy or immunotherapy. The goal is to find out how well the treatment works and how safe it is.