Sacituzumab Govitecan is a treatment being tested for those with HER2-negative breast cancer that has spread to the brain. HER2-negative refers to a type of breast cancer that does not have high levels of the protein HER2. Brain metastases means the cancer has traveled to the brain. This study examines how well sacituzumab govitecan works in shrinking brain tumors or delaying their growth. Sacituzumab is a monoclonal antibody that targets cancer cells, delivering the chemotherapy drug govitecan directly to them. This trial lasts up to 2 years, with treatments every 21 days if the cancer doesn’t worsen or side effects aren't too severe. Participants will be monitored closely with follow-ups every few months for 2 years.

• The study lasts up to 2 years with treatments every 21 days.
• Participants must have brain metastases from HER2-negative breast cancer.
• Close monitoring and follow-ups are required.

Before joining, patients must meet specific health criteria and cannot be on certain medicines or have other health conditions that interfere with the treatment. If eligible, participants will help researchers understand if this therapy is effective and safe.