Combination of Photodynamic Therapy and Immune Checkpoint Blockade

Photodynamic therapy (PDT) for cancer not only strongly reduces tumor mass but can also induce or enhance immune responses against the tumor by causing the release of tumor antigen and danger signals from dying tumor cells. This supports combinations of PDT and immunotherapy for the treatment of advanced tumors for which single therapies are insufficiently effective. Immune checkpoint blockade is a prominent type of cancer immunotherapy that aims to restore the effector function of immune cells, most often T cells, by administering antibodies that block inhibitory molecules. In this chapter, we describe the combination of PDT with immune checkpoint blockade in a mouse tumor model.