Used in the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer. It is typically combined with aromatase inhibitors or fulvestrant as a first- or second-line therapy. As a CDK4/6 inhibitor, it works by blocking proteins that promote cancer cell division, thereby slowing tumor growth and extending progression-free survival. Approved for use in postmenopausal women and in male patients, it plays a key role in targeted therapy for advanced breast cancer.