Daiichi Sankyo Company, Limited and AstraZeneca announced that the first patient was dosed in DESTINY- Gastric06, a phase 2 trial in China evaluating the safety and efficacy of ENHERTU® (trastuzumab deruxtecan) in patients with HER2 positive locally advanced or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma previously treated with at least two prior regimens including a fluoropyrimidine and a platinum agent. Approximately half of all worldwide cases of gastric cancer occur in China, 1,2 with about 80% of patients presenting with advanced disease at the time of diagnosis. 3 For patients with HER2 positive metastatic gastric cancer in China, there are limited HER2 directed therapies available following disease progression with a trastuzumab-containing regimen, and more options are needed to address this continued unmet need. 4 DESTINY-Gastric06 is an open-label, single-arm phase 2 trial in China evaluating the safety and efficacy of ENHERTU (6.4 mg/kg) in patients with HER2 positive locally advanced or metastatic gastric or GEJ adenocarcinoma previously treated with at least two prior regimens including a fluoropyrimidine and a platinum agent. The primary endpoint of DESTINY-Gastric06 is confirmed objective response rate (ORR). Secondary endpoints include investigator assessed ORR, progression-free survival, duration of response, disease control rate, overall survival, pharmacokinetics, immunogenicity and safety. Gastric (stomach) cancer is the fifth most common cancer worldwide and the fourth highest leading cause of cancer mortality. 5 There were approximately one million new cases of gastric cancer and 768,000 deaths reported worldwide in 2020.5 Gastric cancer is typically diagnosed in the advanced stage but even when diagnosed in earlier stages of the disease the survival rate remains modest, 6,7,8 with a five-year survival rate of 5% to 10% for advanced or metastatic disease. Incidence rates for gastric cancer are markedly higher in eastern Asia, particularly in China, where approximately half of all worldwide cases occur.2,5 Gastric cancer is the third most common cancer in China with about 478,000 new cases and is the third leading cause of cancer-related death with approximately 374,000 deaths in 2020. Approximately 80% of patients present with advanced disease at the time of diagnosis in China. Approximately one in five gastric cancers are considered HER2 positive. 10,11 HER2 is a tyrosine kinase receptor growth-promoting protein expressed on the surface of many types of tumors including breast, gastri, lung and colorectal cancers.11 HER2 overexpression may be associated with a specific HER2 gene alteration known as HER2 amplification.