First-line treatment with trastuzumab deruxtecan (T-DXd) significantly improved progression-free survival compared with pembrolizumab plus platinum-based chemotherapy in patients with advanced or metastatic HER2-mutant non-small cell lung cancer (NSCLC), according to primary results from the Phase 3 DESTINY-Lung04 trial presented at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer (WCLC).