Toripalimab Plus FLOT in Locally Advanced Gastric Cancer

Neoadjuvant chemoimmunotherapy for locally advanced gastric and gastroesophageal junction (G/GEJ) cancer is currently under investigation. Most clinical studies have simply combined chemotherapy with anti-PD-1 therapy without considering the impact of chemotherapy drugs on activated immune cells. We designed this study to explore two different treatment regimens for neoadjuvant chemotherapy in patients with locally advanced G/GEJ cancer. One group received FLOT plus toripalimab on Day 1 of each cycle, every 2 weeks for 4 cycles, followed by surgery; the other group received FLOT plus toripalimab on Day 3 of each cycle, every 3 weeks for 3 cycles, followed by surgery. A total of 69 subjects were enrolled. Preliminary statistical analysis conducted one year after the last subject was enrolled revealed no statistically significant differences in pCR and MPR between the two regimens. The median DFS for both groups has not been reached, and there is no statistically significant difference in DFS between the two groups at present. Further subgroup analysis indicated that among subjects with PD-L1 CPS ≥1, the triweekly group achieved a rate of 42.1%, compared to 29.4% in the biweekly group, with no statistically significant difference between the two groups. However, the incidence of bone marrow suppression was lower in the triweekly group than in the biweekly group. Based on the preliminary findings, we plan to conduct an expanded study and transition to a multicenter clinical trial. This study aims to further validate the efficacy of the triweekly chemoimmunotherapy in patients with PD-L1 CPS ≥1 locally advanced G/GEJ cancer.