In May 2020 trastuzumab deruxtecan (T-DXd) received the U.S. Food and Drug Administration breakthrough therapy designation for HER2-mutant metastatic NSCLC, and was added as an option for HER2-mutant NSCLC to the NCCN guidelines V1.2021. This evidence concerns the gene ERBB2 and non-small cell lung carcinoma.