The treatment of breast cancer is generally determined according to breast cancer subtype: hormone receptor-positive (luminal), triple-negative (basal-like), and HER2-overexpressing breast cancer. Recent years have seen the development of exciting novel and potent therapeutics based on molecular pathways, immune modulation, and antibody conjugates. In this article, we cover new and emerging therapeutic areas and ongoing clinical trials that may result in further improvements in breast cancer outcomes.