.Attributes Medicine, Released 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) treatment of clients with HER2+ state-of-the-art breast cancer as well as active or stable human brain metastases showed regular intracranial activity as well as wide spread efficacy of T-DXd.