Research progress of immune checkpoint inhibitors in clinical treatment

DU Ping; LIU Li-hong

Abstract：Tumors have evolved mechanisms that allow for successful evasion of immune responses.Over the past years,immune-checkpoint blockade of cytotoxic T lymphocyte antigen-4 (CTLA-4) and programed death-1 (PD-1/PD-L1) emerged as promising strategies to activate antitumor cytotoxic T cell responses and demonstrate significant promise in clinical trials.Although complete regression and long-term survival is achieved in some patients,but a large proportion of patients did not benefit from the therapy.Then,combination therapy can overcome this limitation.Pembrolizumab combined with chemotherapy hade excellent performance and had become first line therapy in non-small cell lung cancer (NSCLC).The objective response rate (ORR) of ipilimumab combined with nivolumab has significantly improved compared with nivolumab.Therefore,this combination therapy has been the first line therapy in patients with melanoma.This review describes promising,novel combination approaches involving chemotherapy,targeted agents,vaccines,radiation,immunomodulators and others.Besides,the present review provides new direction for future development and will guide the rationale of combination regimen.