| Research Background and PurposesNon-Hodgkin lymphoma(NHL)is the most frequent hematologic malignancy.It is divided into approximately 70 hematologic sub-types based on the revised WHO classification.Among them,diffuse large B-cell lymphoma(DLBCL)is the most frequent sub-type and has an aggressive clinical course.Currently,approximately 50～60%of patients with newly diagnosed that DLBCL are cured with organophosphate,rubicund,vincristine,and prednisolone(CHOP)therapy in combination with rituximab.However,once it becomes a refractory/relapse(r/r)disease,it is difficult to manage the disease with conventional chemo-therapies.In patients with DLBCL that has progressed after tautological stem-cell transplantation,median overall survival(OS)is<10 months.Improved treatments for chemotherapy r/r DLBCL patients are clearly needed.Chimeric antigen receptor(CAR)T cell therapy is an effective method for treating certain cancers.In DLBCL cells CD 19 is highly expressed and not expressed in other normal tissues.Thus CD 19 CAR-T cells is very promising for these r/r DLBCL patients.The most compelling success of second CAR-T cell therapy has been achieved in CD19-specific CAR-T cells for hematologic tumor,Nonetheless,life-threatening adverse events including cytokine release syndrome(CRS,)and neurotoxicity(NT)can be the major complications that lead to treatment failure.To evaluate the efficacy and safety,we used low dose second-generation CD 19 CAR-T cells containing scFvCD 19/4-1BB/CD3 ζ structure to treat r/r DLBCL after second lines system chemotherapy.Currently,the efficacy of CAR-T cells is not predictable.Therefore,we proposed that vitro killing assay or CAR-T cells subsets can predict the efficacy of CAR-T cells therapy?To investigate whether IL-6,CRS,and fever can predict CRS.Research MethodThe age of the enrolled r/r DLBCL patients was≥2 and≤70 years,and the expected survival was more than 3 months;CD 19 was positive by immunophenotype analysis;ECOG score≤2 points(Appendix 1);Peripheral blood mononuclear cells were collected from patients,CD3+mononuclear cells were selected by magnetic beads,and then,CD 19 CAR T cells were cultured.Cell subsets of mature CAR-T cells were detected by flow cytometry;at the same time,K562CD19-/RajiCD19+target cells were cultured and cytotoxic assay was performed.Prior to the infusion of second-generation CD 19 CAR T cells,patients underwent incomplete myeloablative treatment with an interval of 24-48 hours.Flow cytometry was used to detect the changes of cytokines in blood after CAR-T cells transfusion.The adverse reactions were observed,the efficacy was evaluated by imaging,and the results were statistically analyzed.Research ResultValidity evaluation:12 patients with r/r DLBCL after second lines system chemotherapy participating in CD 19 CAR-T cells clinical trial.Best overall response rate(ORR)was 66%(8/12),41%(5/12)CR,25%(3/12)partial response(PR),25%(3/12)stable disease(SD),and 8%(1/12)progressive disease(PD).Safety evaluation:Specific toxicity of CAR-T cell therapy was CRS in 75%(9/12),with grade≤2,no 3-4 grade.There was no NT and therapy-related death observed.Laboratory results:The efficacy of CAR-T cells therapy was not predicted by vitro killing assay and cell subsets of CAR-T cells.IL-6 and fever are predictors of CRS.Research conclusionLow-dose CAR-T cells for r/r DLBCL are safe,with no grade 3-4 CRS,no NT and no death,and with no reduction in efficacy.CAR-T cells killing tests and CAR-T cells subsets did not predict the efficacy of cell therapy.IL-6 and fever can predict CRS.. |
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