Real-World Outcomes of Patients With Metastatic Breast Cancer After Treatment With First-Line ET+CDK4/6i

This analysis will assess real-world outcomes in HR+/HER2- mBC patients who initiated a subsequent line of therapy (LOT) (i.e., 2L) after progressing on 1L treatment with ET+CDK4/6i. This study will also characterize the treatment patterns, clinical characteristics, and outcomes in this patient population. No study drug was administered in this non-interventional study.