Gene expression analysis of treatment-naïve hormone receptor-positive metastistic breast cancer

A large-panel gene expression analysis was conducted to identify biomarkers associated with the effectiveness of adding palbociclib to letrozole Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have demonstrated significant activity in estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced breast cancer. Further biomarkers to refine the population beyond ER+/HER2- that benefits remain to be identified. We performed a comprehensive biomarker analysis using patient tissues from PALOMA-2, a randomized phase 3 study of palbociclib-letrozole versus placebo-letrozole, to determine markers of sensitivity and resistance to the combination. Baseline tumor tissue from PALOMA-2 trial were profiled using EdgeSeq Oncology BM Panel, with 455 tumor samples evaluable for analysis