Exceptional responses to Trastuzumab deruxtecan in HER2-positive breast cancer: two illustrative case reports

These case reports highlight the potential of T-DXd not only to induce deep and durable responses but also to maintain disease remission beyond drug exposure in selected patients. Such observations challenge the paradigm of incurability in metastatic HER2-positive breast cancer and warrant further investigation into the mechanisms and predictors of long-lasting responses.