Real-world Treatment Patterns and Outcomes in Hormone Receptor–positive, HER2-low Metastatic Breast Cancer, 2018–2023: a Retrospective, Observational, US Cohort Study

To investigate real-world demographics, clinical characteristics, treatment patterns, and outcomes in US patients with ≥ 1 line of therapy (LOT) for hormone receptor–positive (HR+) HER2-low metastatic breast cancer (mBC). This retrospective cohort study used a US-based electronic health record-derived de-identified database of patients with mBC diagnosed in 2018–2023. Patient demographics, clinical characteristics at date of mBC diagnosis, treatment patterns, and real-world overall survival (rwOS) and progression-free survival (rwPFS) were analyzed. Of 2662 patients, 49.4