palbociclib + endocrine therapy (Pfizer)

Palbociclib is a selective, small molecule inhibitor of cyclin-dependent kinases (CDK) 4 and 6, developed by Pfizer. In the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer, it is administered in combination with endocrine therapy (ET), such as aromatase inhibitors (e.g., letrozole) or estrogen receptor antagonists (e.g., fulvestrant). The mechanism of action involves blocking the transition of the cell cycle from the G1 phase to the S phase by preventing the phosphorylation of the retinoblastoma (Rb) protein. This combination approach addresses endocrine resistance and has demonstrated significant improvements in progression-free survival in both first-line and subsequent treatment settings for advanced breast cancer.

Brand names

Ibrance

Other names

palbociclib plus endocrine therapypalbociclib plus ETpalbociclib + ET