Galectin-9 and PD-L1 Antibody Blockade Combination Therapy Inhibits Tumour Progression in Pancreatic Cancer

Background: The study aimed to evaluate the effect of a galectin-9 and PD-L1 combined blockade in pancreatic ductal adenocarcinoma (PDAC). Methods: The expression of galectin-9 and PD-L1 was analyzed in PDAC. Furthermore, we explored the therapeutic effect of combined anti-galectin-9 and anti-PD-L1 therapy on pancreatic cancer in vivo. Results: Higher expression of galectin-9 and PD-L1 was observed in human PDAC compared with the normal pancreas. Furthermore, in a murine model of PDAC, combined anti-galectin-9 and anti-PD-L1 treatment was associated with a greater decrease in tumor growth compared with treatment with either antibody therapy alone. Conclusion: Anti-PD-L1 antibody treatment for PDAC patients may be enhanced by inhibiting galectin-9.Pancreatic cancer is considered to be a fatal disease with high mortality. Most pancreatic cancer patients are diagnosed at an advanced stage, with limited treatment options. Immunotherapy has become a new antitumor method by activating immunity and inhibiting tumor immune escape. Some clinical studies have shown that anti-PD-1/PD-L1 immunotherapy is a promising antitumor approach, but tumor resistance may develop. This study shows that both PD-L1 and galectin-9 are highly expressed in pancreatic cancer tissues, and the combined application of anti-PD-L1 and anti-galectin-9 antibodies can achieve a better tumor growth inhibition effect. These findings provide new strategies for the immunotherapy of pancreatic cancer.