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 administered in combination with endocrine therapy, such as fulvestrant, to improve progression-free survival. As a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, it works by blocking proteins that promote cancer cell proliferation, thereby slowing tumor growth. Dalpiciclib has shown efficacy in clinical trials involving patients who have progressed on prior endocrine therapy, offering an important option in the management of advanced breast cancer.