At the present time, two phase 2 trials in HER2-positive gastric cancer patients who progressed on prior trastuzumab are evaluating T-DXd as a monotherapy (DESTINY-Gastric02, NCT04014075) or in combination with chemotherapy and trastuzumab (DESTINY-Gastric03, NCT04379596) (Table 2). This evidence concerns the gene ERBB2 and gastric cancer.