Pharmacokinetics, safety, activity, and biomarker analysis of palbociclib plus letrozole as first-line treatment for ER+/HER2– advanced breast cancer in Chinese women

PurposeThis phase 1, open-label, single-arm clinical trial evaluated pharmacokinetics, safety, and biomarker activity of palbociclib-letrozole as first-line treatment for estrogen receptor–positive/human epidermal growth factor receptor 2–negative advanced breast cancer (ABC) in postmenopausal Chinese women to support palbociclib approval in China.MethodsPatients received palbociclib 125 mg once daily (3/1 schedule) plus letrozole 2.5 mg once …