.Nature Medicine, Published online: 13 September 2024 doi:10.1038/ s41591-024-03261-7In the non-randomized phase 3b/4 DESTINY-Breast12 research study, trastuzumab deruxtecan (T-DXd) therapy of patients with HER2+ advanced bosom cancer cells as well as active or stable brain metastases presented consistent intracranial activity and wide spread efficacy of T-DXd.