Identification and Monitoring of Resistance to First-line Treatment with CDK 4/6 Inhibitors in Combination with Aromatase Inhibitors in Patients with Metastatic Luminal Breast Cancer Through Non-invasive Biomarkers
This is a multi-center biomarkers study aiming to prospectively collect biological samples from patients with ER+ and HER2-negative metastatic breast cancer, who are candidate to first-line treatment with an aromatase inhibitor and a CDK4/6 inhibitor as per standard clinical practice. Blood and tissue samples will be collected for biomarker analysis, including thymidine kinase1 activity, gene expression signatures and circulating tumor DNA.
• Women aged 18 years or older, with a diagnosis of metastatic breast cancer
• ER-positive and HER2-negative disease as assessed locally either on primary tumor tissue or on a biopsy of a metastasis
• The patient has not received any prior systemic therapy for metastatic breast cancer (may have received prior hormonal therapy or chemotherapy in the neo/adjuvant setting)
• The patient is candidate to receive first-line therapy with an aromatase inhibitor (AI) and a CDK4/6 inhibitor per local clinical practice
• The patient must have evaluable disease according to RECIST 1.1 (either measurable or non-measurable).
• Note: Patients with bone-only disease will be allowed in a specific sub-cohort, which will comprise 10% of the total sample size.
• Hystologic material from one formalin-fixed, paraffin-embedded (FFPE) tumor block from a diagnostic core or excisional biopsy of a metastatic lesion, taken before study entry must be provided (patients with bone-only disease will be accepted into the trial without a biopsy of the metastatic site). Hystologic material from an additional biopsy (core or excisional) taken at time of disease progression on the study treatment must also be provided, if clinically feasible. When available, hystologic material from an FFPE tumor block from the primary breast cancer must also be submitted.
• The patient agrees to provide blood samples. at the trial specified time points