The main purpose of this local, multicenter study is to investigate genetic and gene expression alterations in tumor prior to and following progression on ribociclib, during core phase and then prior to and following progression on alpelisib and thus identify patterns of mutations, how they evolve, and their association with CDK4/6 inhibition and outcomes such as sustained response or early progression. The study also aims to evaluate pharmacogenomics and its association with adverse events (frequency and severity), drug-drug interactions and clinical outcomes.
Finally, the study will also generate additional long-term safety and efficacy data in this specific Italian population.