Daiichi Sankyo Company, Limited and AstraZeneca announced that the first patient was dosed in DESTINY-Gastric04, a global phase 3 trial evaluating the safety and efficacy of ENHERTU® (trastuzumab deruxtecan) compared to ramucirumab/paclitaxel combination therapy in patients with HER2 positive metastatic and/or unresectable gastric or gastroesophageal junction (GEJ) adenocarcinoma with disease progression on or after a trastuzumab-containing regimen. Gastric cancer is associated with a poor prognosis, particularly in the advanced stages of the disease, with only 5% to 10% of patients surviving 5 years. One in five gastric cancers are considered HER2 positive, however loss of HER2 expression has been observed in 29% to 69% of patients with gastric cancer following treatment with trastuzumab, suggesting a decrease in HER2 expression can result in progression on trastuzumab and may be associated with poor outcomes. After progression on first-line HER2 targeted systemic treatment, second-line treatment options are limited, driving a need for new HER2 targeted therapies for these patients.