Doxorubicin-Near infrared dye conjugate induces immunogenic cell death to enhance cancer immunotherapy

Cancer immunotherapy often fails to result in a favorable outcome owing to poor activation of immune response, the immunosuppressive tumor microenvironment, and systemic toxicity. In this study, indocyanine green (ICG) was conjugated with doxorubicin (DOX) using a hydrazone linker (DOX-ICG). Results of our in vitro and in vivo studies indicated that DOX-ICG could trigger powerful immunogenic cell death (ICD) of tumor cells. Moreover, its use in combination with immune checkpoint inhibitors could effectively inhibit both primary and abscopal tumors growth and suppress tumor metastasis. Therefore, this simple, safe, and efficient prodrug shows great potential for use in photo-activated chemo-immunotherapy.