.Attribute Medicine, Published online: 13 September 2024 doi:10.1038/ s41591-024-03261-7In the non-randomized phase 3b/4 DESTINY-Breast12 research, trastuzumab deruxtecan (T-DXd) treatment of patients along with HER2+ innovative breast cancer cells and also energetic or stable human brain metastases showed steady intracranial activity and also systemic efficacy of T-DXd.