Sacituzumab Govitecan + Toripalimab as First - Line Therapy for Advanced Triple - Negative Breast Cancer and Biomarker Exploration

The goal of this study is to explore the efficacy and safety of sacituzumab govitecan in combination with toripalimab as first - line treatment in patients with advanced triple - negative breast cancer. The main questions it aims to answer are: 1. To investigate the efficacy and safety of sacituzumab govitecan in combination with toripalimab as first - line treatment for advanced triple - negative breast cancer. 2. To explore the biomarkers that can predict the efficacy of sacituzumab govitecan in combination with toripalimab as first - line treatment for advanced triple - negative breast cancer. Participants will: Have their progression - free survival (PFS) observed and evaluated. Have all adverse events and immune - related adverse events monitored to assess safety. Have their objective response rate measured as a secondary outcome. Have their survival period tracked as a secondary outcome. Have biomarkers associated with efficacy observed and explored as a secondary outcome.