This clinical trial is focused on studying a type of breast cancer known as hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer. This type of cancer is characterized by the presence of hormone receptors and the absence of a protein called HER2. The study involves patients who have advanced or metastatic breast cancer, meaning the cancer has spread beyond the breast to other parts of the body, and who have already received treatment with hormone therapy.

The main treatment being studied is a medication called sacituzumab govitecan, which is also known by its code name IMMU-132. This medication is an antibody-drug conjugate, which means it combines an antibody with a drug to target cancer cells more precisely. The study will compare the effects of sacituzumab govitecan with other treatments chosen by the patient’s doctor, which may include medications like capecitabine, nab-paclitaxel, or paclitaxel. These are all types of chemotherapy drugs used to treat cancer.

The purpose of the study is to evaluate how well sacituzumab govitecan works compared to the other treatments in terms of delaying the progression of the disease. Patients participating in the study will receive either sacituzumab govitecan or one of the other treatments, and their health will be monitored over time to assess the effects of the treatment. The study will involve regular check-ups and assessments to track the progress of the cancer and any side effects of the treatments. The study aims to provide valuable information that could help improve treatment options for patients with this type of breast cancer in the future.