In precision medicine, the study of the molecular profile of the disease and how it is modified by the different treatments is paramount. Thus, MedSIR trials are always designed with a translational objective in mind, implementing different molecular biology techniques and collaborating with prestigious research groups.
During the last edition of the San Antonio Breast Cancer Symposium (SABCS) held from December 10-14 2019 in San Antonio, Texas, MedSIR presented the first results of the transFAL study entitled “Baseline and pharmacodynamic changes of circulating exosomal microRNAs predict early versus late progression to palbociclib plus endocrine therapy in patients with metastatic breast cancer (MBC). A sub–analysis from the PARSIFAL trial”.
The transFAL study is a series of translational analyses derived from the PARSIFAL clinical trial. The PARSIFAL study is a randomized, multicentre, open-label, phase II trial to evaluate the efficacy and safety of palbociclib in combination with fulvestrant or letrozole in patients with HER2 negative, ER+ metastatic breast cancer.
No clinically validated markers of long–term benefit from palbociclib have been established and the clinically relevant resistance mechanisms to cyclin–dependent kinases 4 and 6 inhibitors remain undefined. miRNAs play a major role as modulators of gene expression and their dysregulation has been associated with carcinogenesis. Exosomes are extracellular vesicles that have been implicated in many cancer hallmark properties.
In this study, we have isolated miRNA from circulating exosomes from plasma samples obtained through liquid biopsies from the PARSIFAL trial and we have demonstrated that circulating exosomal miRNA profiling is feasible in liquid biopsies from MBC patients and that the differential expression of selected miRNAs at baseline or their treatment modulation may predict benefit from palbociclib combined with endocrine therapy in patients with HR+/HER2- MBC.
We would like to thank all participating patients and study teams involved in the PARSIFAL trial. Another special thanks are for Pfizer for their continuous support and contribution to improve treatment decisions for cancer patients.
Author: Lourdes Gómez y Leonardo Mina.