The FDA has approved fam-trastuzumab deruxtecan-nxki (Enhertu®, Daiichi Sankyo, Inc.) for treatment of patients with unresectable or metastatic human epidermal growth factor receptor 2 (HER2)–positive breast cancer. The approval is specific to individuals who have had prior treatment with an anti–HER2-based regimen in the metastatic, neoadjuvant, or adjuvant setting and have developed disease recurrence within six months of completing therapy. "Although HER2-targeted therapies have improved dise...