A Study of Combination of Anti-PD1 Antibody-activated TILs and Chemotherapy in Colorectal Cancer

Postoperative colon cancer participants received 4 to 8 cycles of XELOX regimen adjuvant chemotherapy and received anti-PD1 antibody-activated TILs on the day 15 of the final cycle of chemotherapy. Fresh tumor tissues or sentinel lymph nodes were collected from participants with postoperative colon cancer, and the tumor tissues were digested with type IV collagenase at 37 °C for 2 to 4 hours. The cell pellet was washed, suspended in medium containing 10% AB serum, planted in a 24-well cell culture plate, and periodically changed according to the growth of the cells. After culturing for 2 to 3 weeks, TILs were co-stimulated with radioactively irradiated allogeneic peripheral blood mononuclear cells (PBMCs) and were expanded in 100 ml of Interleukin-2 (IL-2) medium in a cell culture flask. After rapid expansion for 15 days, the number of cells reached 0.1-1\*10\^10 cells. Before cell transfer, TILs were incubated with anti-PD-1 antibody, and a fraction of the TILs were collected to assess their number, phenotype, and viability of cells, and to test for possible contamination by bacteria, fungi, or endotoxins. Then, autologous TILs (0.1-1\*10\^10 cells) were transferred to participants via intravenous infusion.