Used in the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer. It functions as a selective cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor, helping to block the progression of cancer cells from the G1 phase to the S phase of the cell cycle. Typically administered in combination with aromatase inhibitors or fulvestrant, it helps slow tumor growth and prolong progression-free survival. Its application is primarily in postmenopausal women and adult patients, with ongoing studies exploring use in earlier disease stages and other cancer types.