.Attributes Medication, Posted online: 13 September 2024 doi:10.1038/ s41591-024-03261-7In the non-randomized phase 3b/4 DESTINY-Breast12 study, trastuzumab deruxtecan (T-DXd) treatment of people with HER2+ sophisticated breast cancer as well as active or even stable brain metastases showed steady intracranial activity and systemic efficacy of T-DXd.