In a small phase II trial, response rates in metastatic gastroesophageal carcinoma improved by a relative 50% when patients received experimentally activated T cells in addition to standard therapy.[4] These are CAR-like T cells that enhance the tumor response in this type of cancer.[4] In related pivotal randomized controlled trials, satri-cel, a CAR-T therapy targeting Claudin18.2, significantly prolonged progression-free survival to 3.3 months versus 1.8 months with standard therapy.[1][3] Median overall survival was 7.9 months versus 5.5 months, although the difference was not statistically significant.[1][3] The objective response rate was 22% in the CAR-T group versus 4% in the control group, and the disease control rate was 63% versus 25%.[1][3] The study included 156 patients with advanced gastric or gastroesophageal junction cancer and was presented at ASCO 2025.[1][3] Side effects included grade 3 or worse events in 99% of patients in the CAR-T group, mainly decreases in lymphocytes (98%), leukocytes (77%), and neutrophils (66%), as well as cytokine release syndrome in 95%.[1][2]