PF-06873600 + letrozole

PF-06873600 + letrozole is an investigational oral combination therapy composed of PF-06873600, a small molecule inhibitor targeting cyclin-dependent kinases 2, 4, and 6 (CDK2/4/6), and letrozole, an aromatase inhibitor that suppresses estrogen biosynthesis. PF-06873600 is under development by Pfizer and has been studied in combination with letrozole in hormone receptor-positive, HER2-negative advanced or metastatic breast cancer, particularly in patients previously treated or resistant to standard hormonal therapy. The rationale combines cell cycle inhibition (by PF-06873600) with endocrine blockade (by letrozole) to provide a potentially synergistic antitumor effect in hormone-driven cancers[1][3][5].