 Daiichi Sankyo Co Ltd OTC: DSKYF and AstraZeneca plc NASDAQ: AZN have dosed the first patient in DESTINY-Gastric04, Phase 3 trial of Enhertu trastuzumab deruxtecan for gastric or gastroesophageal junction GEJ adenocarcinoma. The trial will evaluate the safety and efficacy of Enhertu compared to ramucirumabpaclitaxel combination therapy in patients with HER2 positive metastatic or unresectable gastric or GEJ adenocarcinoma with disease progression on or after a trastuzumab-containing regimen. 