Near infrared photoimmunotherapy (NIR-PIT) is a highly selective molecularly targeted phototherapy for cancer which is based on injecting a conjugate of IRDye700DX,a water-soluble near-infrared silicon-phthalocyanine dye,and a monoclonal antibody that targets an antigen on the cancer cell surface. Subsequent local irradiation of NIR light causes the rapid and specific tumor cell death. Due to the good clinical translation prospects of NIR-PIT,this paper summarizes the influencing factors,antitumor mechanism,main challenges and recent strategies,which may benefit for its research and clinical application.

Photoimmunotherapy (PIT) is an emerging tumor-targeted phototherapy that combines the tumor specificity of monoclonal antibodies with the phototoxicity of light absorbers to rapidly and selectively induce the immunogenic death of target tumor cells. PIT has minimal side effects due to its high specificity. The immunogenic cell death induced by PIT results in rapid maturation of immature dendritic cells proximal to dying tumor cells. Subsequently, the mature dendritic cells present the tumor antigens to CD8+ T cells and induce their activation and proliferation, thus enhancing the antitumor immune response of the host. PIT can also improve the anticancer efficacy by enhancing the penetration of nanomedicines into tumor tissues. In view of the excellent application prospects of PIT, this review summarizes the advances in the immune activation mechanism of PIT, the superenhanced permeability and retention effect, and the new strategies for combinatory therapy, providing references for future research and clinical translation.
Antibodies, Monoclonal/therapeutic use* ; Humans ; Immunotherapy ; Neoplasms/therapy* ; Photosensitizing Agents ; Phototherapy