Efficacy Evaluation And Candidate Biomarkers Screening For Anti-PD-1 Therapy In Advanced Lung Cancer

Background:In the treatment of advanced non-small cell lung cancer(NSCLC),immune checkpoint inhibitor(ICI)has the advantages of long-term survival benefit and low side effects in some populations,but objective response rate is only 10%-30%.Therefore,screening of biomarkers related to ICSs efficacy is of great significance to the precise target population.Methods:Eighty patients with NSCLC were enrolled in phase III(Nivolumab,Nivo)clinical trials(CA209-078 and CA209-870)in our hospital between 2016 and 2018.Peripheral blood samples of patients before the first treatment(C0)and two weeks after the first treatment(C1)were collected and tested.The immune characteristics of peripheral CD4~+T cells were detected by multicolor flow cytometry.The efficacy was analyzed by?~2or Fisher exact test,rank sum test and logistic regression,and the survival was analyzed by Log-rank test,Kaplan-Meier and Cox regression.Moreover,in order to evaluate the efficacy of ICI in vitro,a three-dimensional(3D)culture model of lung cancer cell line was established to compare the growth and the functional protein expression in 2D and 3D cultured tumor cells.Results:Among the 80 patients with NSCLC,3 withdrew,and 16 were enrolled in CA209-078 and 61 in CA209-870 trial.Finally,50 patients were collected with peripheral blood samples at C0 and C1.The median progression-free survival(PFS)was 78 days(95%CI:12-756)and the median overall survival(OS)was 228 days(95%CI:21-1058).Survival analysis showed that C1 neutrophil/lymphocyte count(NLR),eosinophil percentage(EOS%)and adverse events(AEs)grading were independent risk factors for OS.According to the risk factors,0 point was considered as low risk,and 1 and 2 points were considered medium and high risk,respectively.OS for patients with high meidian,and low risk were 48.5±14.5days(95%CI:20.08-76.92),231.37±24.07days(95%CI:184.2-278.54)and 907.57±49.71 days(95%CI:810.13-1005.01),respectively.There was significant difference among the three groups(P=0.00).When patients were classified as responder group(R)and non-responder group(NR)according to their first efficacy evaluation point to ICIs treatments,it was found for the first time that the proportion of IFN-?~+CD4~+Tn cells at C0 in R group was significantly higher than that in NR group.The patients with higher cell proportion(?2.86)had longer median PFS(179±41.91 days vs55±1.13 days,P=0.01)than those with lower cell proportion(<2.86).In addition,after3D culture of lung cancer cell line A549 in vitro,the gene expression and protein secretion of MMP-2,MMP-9,VEGF and IL-8 in A549 cells were higher than those in 2D culture,indicating that 3D culture was more beneficial to A549 culture in vitro.Conclusions:This study demenstrated that Nivo treatment in Chinese patients with advanced NSCLC has long-term survival benefits.The combined risk scores of NLR,EOS%and AE in the early stage of treatment help to distinguish those target population with superior OS.Peripheral high proportion of IFN-?~+CD4~+Tn is a potential predictor of Nivo treatment.The establishment of 3D culture system in vitro will provide an important platform simulating the tumor environment for further studying the roles of IFN-?+CD4~+Tn cells in Nivo treatment and its efficacy.