letrozole + palbociclib (Pfizer)

Letrozole + palbociclib is a fixed combination regimen used primarily for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer in postmenopausal women. Letrozole is an aromatase inhibitor that reduces estrogen production, thereby limiting the growth stimulus for estrogen-dependent breast cancer cells. Palbociclib (PD 0332991) is an oral, selective small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), which blocks cell cycle progression from G1 to S phase by preventing phosphorylation of the retinoblastoma protein. The combination has demonstrated significant improvement in progression-free survival compared to letrozole alone in clinical trials[2][3][5][6]. Developed and manufactured by Pfizer, this regimen represents a targeted therapy approach combining endocrine therapy with cell cycle inhibition.

Brand names

IBRANCE

Other names

palbociclib + letrozolePD-0332991 + letrozole