A Preliminary Clinical Study Of Multiple Tumor-associated Antigen-specific Cytotoxic T Lymphocytes In The Treatment Of Multiple Myeloma And Non-hodgkin Lymphoma

Objective: Both multiple myeloma(MM)and non-hodgkin lymphoma(NHL)are hematologic malignancies that mainly originated from B lymphocytes.Like other hematologic malignancies,chemotherapy is still the first choice in clinical treatment for these diseases.Although most of the patients can achieve some positive effect as stable disease or remission after completing the standard course of treatment,some of them are insensitive to medicine,or have a disease progression or relapse in a short time.Hematopoietic stem cell transplantation(HSCT),as a possibility to cure blood diseases,cannot be widely used in clinic because of its strict adaptability,difficulty in obtaining donors and high surgical cost.Therefore,the methods for treatment of malignant hematologic diseases such as myeloma and lymphoma need further exploration.Now,immune cell therapy represented by chimeric antigen receptor T cells(CAR-T)is the most promising method in the field of malignant tumor therapy.Car-T cells have achieved good results in the treatment of relapsed and refractory B cell-derived acute leukemia and lymphoma,as well as myeloma.But there are still severe side effects such as cytokine release syndrome,and some patients may experience relapse within a short time after remission.Clinical trials abroad and our clinical study have preliminarily demonstrated the safety and efficacy of tumor-associated antigen-specific T lymphocytes(TAA-CTL)in preventing the relapse,also in the treatment of patients with relapsed and refractory acute myeloid leukemia,lymphoma and several kinds of solid tumors.In this study,we will collect the peripheral blood from the patients,culture the specific T-lymphocytes ex vivo,and then infusing them back to the patients.We preliminarily investigate the safety and efficacy of tumor-associated antigen-specific cytotoxic T lymphocytes in the treatment for multiple myeloma and non-Hodgkin lymphoma(NHL)patients.Methods: A total of 9 patients were enrolled in this study,4 medium and high-risk MM and 5 NHL with relapsed/refractory disease or high-risk of relapse.The peripheral blood of these patients was collected for cell culture.Adherent cells were stimulated by a mixture of peptides containing a variety of tumor-associated antigens(NY-ESO-1,MAGE-A3,MAGE-A4,WT1,Survivin,PRAME for MM cells,NY-ESO-1,MAGE-A3,MAGE-A4,WT1,Survivin,PRAME,LMP1,LMP2 A for NHL cells).Dendritic cells(DC)were loaded with these tumor antigens.Under the stimulation of cytokines,the mature DC and non-adherent cells were mixed in a certain ratio to co-culture the tumor antigen-specific cytotoxic T lymphocytes.Cell products were collected and detected by flow cytometry for the phenotype and the proportion of each lymphocyte subset.The cell products which are tested to be pollution-free are infused back into the patients.The disease states of 7 patients who completed cell therapy were evaluated,and the peripheral blood was obtained weekly for ELISpot assay before and after infusions.By calculating the number of spot-forming cells(SFC),the levels of IFN-γ secreted by T cells were evaluated,and the proliferation and activity of T cells in peripheral blood were reflected.Results:(1)One of the nine patients withdrew from the study after blood collection,another one had his disease progression before the first cell infusion and then dropped out from the study,the remaining seven patients received 1-4 times of TAA-CTL infusions respectively,no significant adverse reactions were observed in all patients within 2weeks after infusion.Among three MM patients,one with partial remission achieved complete remission after the first infusion,and the other two patients in active stage were in stable disease state after treatment.Two of the four NHL patients were non-responsive,both of them died of infection in a short time as disease progress.One patient achieved complete remission for 19 months,her PET-CT result showed that the focus disappeared after the first infusion.Another NK/T patient in remission was treated with cell therapy to prevent relapse and relapsed 11 months later.(2)According to the phenotype test of the cell products from each patient,we found that82.98%(50%-99.71%)of T cells was CD3+.In these cells,the amount of CD4+T cells was the highest,which is 42.09%(7.21%-90.28%),followed by 25.32%(2.22%-71%)of CD8+T cells and a small amount of NK cells(CD3-CD56+,13.99%,0.95%-46.01%),the lowest proportion was B cells(CD19+),only 0.76%(0.07%-1.92%).Among these mature CTL,the majority are effector memory T cells expressing CD45RO+CD62L-CCR7-,accounting for 70%(38.74%-96.96%)of the total,the rests are 17.19% native T cells(0.47%-41%)and a small number of central memory T cells(2.58%).(3)ELISpot assay showed that in most patients who completed cell infusion,the level of SFC increased first and then decreased over time,the peak value of SFC basically appeared at 2 or 3 weeks after infusion,only one patient had no significant increase in the following test.Conclusions:(1)The immune cells loaded with tumor-associated antigens were successfully cultured ex vivo and infused back into patients.All patients were in good tolerance with infusion and had no related adverse reactions,suggesting the safety of the treatment.(2)The efficacy of TAA-CTL in the treatment of MM and NHL has been preliminarily proved,providing a new scheme for improving the prognosis of patients and prolonging their survival.(3)Since the number of enrolled cases in this study is small,whether it has sufficient clinical application value needs to be further discussed by a larger sample size of clinical trial.