Study of JSKN016 Combination Therapy in Inoperable Locally Advanced or Metastatic HER2-Negative Breast Cancer

This trial is testing JSKN016, an antibody-drug conjugate (a drug that delivers chemotherapy directly into cancer cells), for patients with HER2-negative breast cancer that cannot be surgically removed or has spread. **You may be eligible if...** - You are aged 18–75 - You have confirmed HER2-negative breast cancer that is locally advanced or metastatic - If your cancer is hormone receptor-positive, it has progressed after standard hormone therapy - You have not had any prior systemic chemotherapy for advanced/metastatic breast cancer (prior hormone therapy is okay) - You have measurable disease outside the brain on scans - Your overall health and organ function meet the required thresholds **You may NOT be eligible if...** - You have active or unstable brain metastases - You have had prior chemotherapy for metastatic disease - You have severe heart problems (LVEF below 50%) - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.