Biomarkers of palbociclib response in hormone receptor-positive advanced breast cancer from the PARSIFAL trial.

Currently, there are no clinically actionable biomarkers to predict patient to cyclin-dependent kinases 4 and 6 inhibitors (CDK4/6i) plus endocrine therapy for hormone receptor (HR)[+]/ human epidermal growth factor receptor 2 (HER2)[-] advanced breast cancer (ABC). Herein, we report an exploratory...

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Bibliographic Details
Authors: Albanell J; Pozo AG; Arteaga CL; Bellet M; Rojo F; González A; Bellosillo B; Serra V; Gener P; Guerrero JA; Shimizu E; Mancino M; Rodríguez-Morató J; Mina L; Pérez-García JM; Cortés J; Llombart-Cussac A
Format: Article
Status:Published version
Publication date:2025
Country:España
Institution:Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana (FISABIO)
Repository:r-FISABIO. Repositorio Institucional de Producción Científica
OAI Identifier:oai:fisabio.fundanetsuite.com:p18999
Online Access:https://fisabio.portalinvestigacion.com/publicaciones/18999
Access Level:Open access
Description
Summary:Currently, there are no clinically actionable biomarkers to predict patient to cyclin-dependent kinases 4 and 6 inhibitors (CDK4/6i) plus endocrine therapy for hormone receptor (HR)[+]/ human epidermal growth factor receptor 2 (HER2)[-] advanced breast cancer (ABC). Herein, we report an exploratory biomarker substudy (transFAL) from a subset of patients included in PARSIFAL, a phase II randomized clinical trial that evaluated first-line palbociclib plus fulvestrant or letrozole for HR[+]/HER2[-] ABC. No definitive biomarkers were discovered, however, worse outcomes were found with CDK6 postivity (p = 0.008), ER negativity (p = 0.008), high Ki67 (p = 0.04), and TP53 mutation (p = 0.04). ctDNA density (p = 0.036) and number of mutations (p = 0.033) at baseline were significantly higher for resistant patients. Our study reveals future directions to explore in the goal to determine biomarkers of response to CDK4/6i.