Triple-negative breast cancers (TNBC) have poorer outcomes than hormone positive or human epidermal growth factor receptor 2 (HER2)-positive breast cancers, with chemotherapy being the usual standard of care. Veliparib, a poly ADP-ribose polymerase (PARP) inhibitor, has been studied in both breast cancer susceptibility genes 1 and 2 (BRCA)-mutation related and sporadic cancers as a single agent and in combination with chemotherapy. This evidence concerns the gene ERBB2 and breast cancer.