HR+/HER2- Advanced or Metastatic Breast Cancer Patients Treated With Sacituzumab Govitecan

This observational study is collecting real-world data on how sacituzumab govitecan (an antibody-drug that targets cancer cells) works in patients with advanced or metastatic hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer whose disease has progressed after CDK4/6 inhibitor therapy. **You may be eligible if...** - You are 18 or older (male or female) - You have been diagnosed with advanced or metastatic breast cancer that is HR-positive and HER2-negative - Your cancer has progressed during or after CDK4/6 inhibitor treatment - You are in reasonably good general health **You may NOT be eligible if...** - Your cancer is not classified as HR+/HER2- - Your disease has not progressed after CDK4/6 inhibitor therapy - You are not in adequate general health for treatment Talk to your doctor to see if this trial is right for you.