Utilizing de-identified data derived from the Flatiron Health Analytic Database, the retrospective observational study is to describe patient characteristics, treatment patterns and effectiveness of Palbociclib + AI as first-line therapy in HR+/HER2-MBC in the US real-world clinical practice setting. Patients will be evaluated retrospectively from index therapy date to death, or last visit in the database, whichever comes first. Descriptive and multivariate statistical analyses will be performed.
