Combination of Bremachlorin PDT and immune checkpoint inhibitor anti-PD-1 shows response in murine immunological T-cell high and T-cell low PDAC models

Pancreatic ductal adenocarcinoma (PDAC) is one of the most induces direct tumor killing that increased survival in both “hot” challenging types of cancer with little or no response to immune T-cell–high and “cold” T-cell–low PDAC tumors and that it can checkpoint inhibitors (ICI). Photodynamic therapy (PDT) has make T-cell–high tumors more sensitive to ICIs blocking PD-1. been shown to ablate tumors and induce an immune response. In We found that T-cell–high tumor-bearing mice had an overall our study, we investigated the effect of PDT using the photo- greater response to therapy than did T-cell–low tumor-bearing sensitizer Bremachlorin, in its ability to reduce tumor burden and mice. One mouse with T-cell–high tumors exhibited complete immunologically sensitize T-cell–high and T-cell–low murine tumor regression in both the treated and nontreated distant tuPDAC tumors to the ICIs that blocks PD-1 immune checkpoint. mor 90 days after treatment. These results indicate that com-In addition, we monitored the effect on survival and investigated bining ICIs with Bremachlorin PDT could be a promising if there was a response in PDT-treated and non–PDT-treated therapeutic intervention for enhancing PDAC’s response to distant tumors. Our results showed that Bremachlorin PDT therapy.