.Nature Medicine, Published online: thirteen September 2024 doi:10.1038/ s41591-024-03261-7In the non-randomized period 3b/4 DESTINY-Breast12 study, trastuzumab deruxtecan (T-DXd) treatment of patients with HER2+ advanced breast cancer cells and energetic or secure brain metastases showed constant intracranial activity as well as wide spread effectiveness of T-DXd.