Dynamic Testing Of Biomarkers On Peripheral Blood Cells At Early Stages Of Immunotherapy Predicts Response In Advanced Cancer Patients

[Purpose]As the study on the role of immune checkpoints in the immune process of tumors continues,it has been found that interventions in the CTLA-4/B7 and PD-1/PD-L1 pathways have had outstanding clinical efficacy on the treatment of advanced tumors.especially agents targeting the programmed death 1(PD-1)pathway which have been approved by the US Food and Drug Administration(FDA)for the treatment of multiple cancers in recent years.While using PD-1 monoclonal antibody,the changes of other immune checkpoints on the surface of lymphocytes can reflect the changes of the tumor microenvironment to a certain extent.It is worth studying whether the effect of the treatment or the prognosis of the patient is related.In this study,we tried to establish a model to predict the relationship between the clinical benefit and the change of immune checkpoints of peripheral blood lymphocyte before and after the usage of PD-1 monoclonal antibody in the "real world".[Experimental design]All the patients enrolled were from patients with unresectable advanced cancer who received immunotherapy in our hospital from December 2016 to July 2017.It is a prospective study which includes patients receiving either nivolumab or Pembrolizumab alone or in combination with chemotherapy.Venous blood was collected before the patient received the first immunotherapy,after the first turn of immunotherapy,and after the second turn of immunotherapy.Peripheral blood lymphocytes including CD4 +T cells,CD8 + T cells and NK cells were analyzed by flow cytometry.The expression of 9 immune checkpoints are PD-1,CTLA-4,TIM-3,LAG-3,BTLA,CD160,Ki-67,OX40 and GITR.Patients’ clinical data were collected and the relationship between the expression of immune checkpoints and the efficacy was analyzed.Statistical analysis was performed using SPSS 22.0 and GraphPad Prism 7.0 software package,and P<0.05 was considered statistically significant.[Result]Twenty-five patients with advanced cancer were included in the study.The patients were divided into response group and non-response group according to the 2-week treatment efficacy evaluation.The response group included remission and stable disease,a total of 16 people.Non-response group was the patient with disease progression,a total of 6.Another 3 patients were excluded from the statistical analysis because they stopped immunotherapy after one cycle treatment.The 9 immune checkpoints were statistically analyzed on CD4+ T cells,CD8+ T cells,and NK cells,and no significant difference was found between the two groups at baseline(before the first cycle of immunotherapy).After the first cycle of immunotherapy,there was a statistically significant difference in the expression of PD-1 on CD4+ T cells and NK cells,and the expression of PD-1 was high in the response group.The expression of CD 160 in NK cells was higher in non-response group than that in the response group,and it was statistically significant.After the second turn of immunotherapy,the expression of GITR on three kinds of lymphocytes was different between the two groups,and the expression in the non-response group was significantly higher than that in the response group.Analyze the trends of three test results of nine immune checkpoints in two groups.And the expression of PD-1,CTLA-4,GITR and Ki-67 showed certain patterns.In the response group,the expression of PD-1,CTLA-4,and Ki-67 increased first and then decreased;the expression of three immune checqpoints in the non-response group did not change significantly.In contrast,GITR did not change significantly in the effective group,but it continued to rise in the non-response group.Analysis of all immune checkpoints generated a simple combinatorial model for predicting early stage of immunotherapy efficacy.[Conclusion]After patients with advanced cancer received PD-1 monoclonal antibody,the expression of p immune checkpoints on peripheral blood lymphocyte change and the changes were significant.Among them,PD-1,CTLA-4,GITR,OX40,and Ki-67 showed significant differences in two groups.Analyze the changes in immune checkpoints and comprehensive trend of immune checkpoints and simple trend charts can be used as one of the methods for predictuing early treatment effects of PD-1 monoclonal antibodies.