Immune-based changes in gene expression determine clinical efficacy of CDK4/6i in metastatic breast cancer

By using standardized tissue-based transcriptomic analysis in pre-treatment tumor samples, we identified and characterized immunological and molecular pathways associated with different treatment outcomes, identifying putative tissue-based biomarkers that might be used in clinical settings. Importantly, we show that high intratumorally expression of Treg and IFNgamma signatures is significantly associated with poor clinical response and shorter progression-free survival. 63 tumor samples, stratified in good/bad efficacy based on criteria from pivotal clinica trials that led to CDK4/6 inhibitor approval