Trastuzumab deruxtecan in previously treated HER2-low advanced breast cancer

Among breast cancers without HER2 amplification, overexpression, or both, a large proportion express low levels of HER2 that may be targetable. Currently available HER2-directed therapies have been ineffective in patients with these HER2-low cancers. The multinational phase 3 DESTINY-Breast04 trial evaluated the antibody drug conjugate trastuzumab deruxtecan for previously treated HER2-low advanced breast cancer. Trastuzumab deruxtecan resulted in significantly longer progression-free survival and overall survival than physician’s choice of chemotherapy.