The FDA has approved palbociclib with trastuzumab, with or without pertuzumab, plus endocrine therapy for adults with HR-positive, HER2-positive advanced breast cancer following results from the PATINA trial led by the Alliance Foundation. The approval gives clinicians a new combination option in a setting where sequencing and regimen selection materially affects outcomes. The decision broadens the role of CDK4/6 inhibition alongside HER2-targeted antibody therapy in an advanced disease population, potentially reshaping treatment pathways for patients and providers navigating overlapping biomarker-driven regimens.