Neratinib is an orally available, small, irreversible, pan-HER kinase inhibitor. HER-2-positive breast cancer is a breast cancer subtype with an increasing body of knowledge regarding potential targeted drug combinations that are significantly improving outcomes through a biologically tailored therapy approach; neratinib emerges as a promising tool in this context. This article reviews the molecular and clinical development of neratinib, an example of a covalent drug, from preclinical models to Phase III clinical trials, focusing on breast cancer treatment. The potential combinations of neratinib with chemotherapy in the metastatic, adjuvant and even neoadjuvant settings are appraised. These results and future perspectives will be discussed.