335 Novel coupledCARTM technology for treating colorectal cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A361-A361
Author(s):  
Song Li ◽  
Chengfei Pu ◽  
Zhiyuan Cao ◽  
Ning Li ◽  
Xinyi Yang ◽  
...  

BackgroundChimeric antigen receptor (CAR) T cell therapy has made significant progress in the treatment of blood cancers such as leukemia, lymphoma, and myeloma. However, the therapy faces many challenges in treating solid tumors. These challenges include physical barriers, tumor microenvironment immunosuppression, tumor heterogeneity, target specificity, and limited reactive cell expansion in vivo.Conventional CAR T cell therapy has thus far shown weak cell expansion in solid tumor patients and achieved little or no therapeutic responses. Here, we developed CAR T cells based on a novel CoupledCAR® technology to treat solid tumors. In contrast to conventional CAR T cells, CoupledCAR T cells significantly improved the expansion of the CAR T cells in vivo and enhanced the CAR T cells’ migration ability and resistance to immunosuppression by the tumor microenvironment. The enhanced migration ability and resistance allow the CAR T cells to infiltrate to tumor tissue sites and increase anti-tumor activities.MethodsWe designed a ‘CoupledCAR’ lentivirus vector containing a single-chain variable fragment (scFv) targeting human TSHR. The lentivirus was produced by transfecting HEK-293T cells with ‘CoupledCAR’ lentiviral vectors and viral packaging plasmids. Patient‘s CD3 T cells were cultured in X-VIVO medium containing 125U/mL 1interleukin-2 (IL-2), and transduced with ‘CoupledCAR’ lentivirus at certain MOI. Transduction efficiency and was evaluated at 7 to 9 days after ‘CoupledCAR’ lentivirus transduction, and quality controls for fungi, bacteria, mycoplasma, chlamydia, and endotoxin were performed. After infusion, serial peripheral blood samples were collected, and the expansion and the cytokine release of CART cells were detected by FACS and QPCR. The evaluation of response level for patients were performed at month 1,month 3,and month 6 by PET/CT.ResultsSpecifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-GCC (guanylate cyclase 2C) CAR molecule. Furthermore, anti-GCC CAR T cells showed anti-tumor activities in vitro and in vivo experiments.To verify the safety and efficacy of CoupledCAR T cells for treating solid tumors, we conducted several clinical trials for different solid tumors, including seven patients with colorectal cancer. These seven patients failed multiple rounds of chemotherapy and radiotherapy. In the clinical trial, the patients were infused with autologous anti-GCC CoupledCAR T cells range from 4.9×105/kg to 2.9×106/kg. All patients using anti-GCC CoupledCAR T cells showed rapid expansion of CoupledCAR T cells and killing of tumor cells. Specifically, we observed that CoupledCAR T cells expanded significantly in the patients and infiltrated tumor tissue sites, demonstrating enhanced anti-tumor activities. PET/CT showed significant tumor shrinkage and SUV max declined, and the ongoing responses were monitored. Patient 3 achieved complete response and the best overall response rate (ORR, include complete remission, complete metabolic response, partial response, and partial metabolic response.) was 71.4% (5/7), complete remission (CR) rate was 14.3% (1/7).ConclusionsThe clinical data demonstrated that CoupledCAR T cells effectively expanded, infiltrated tumor tissue sites, and kill tumor cells in patients with colorectal cancer. We used immunotherapy to achieve complete remission in patients with advanced colorectal cancer for the first time. We are recruiting more colorectal cancer patients to further test the safety and efficacy of anti-GCC CoupledCAR T cells. Since our CoupledCAR® technology is a platform technology, we are expanding it to treat other solid tumors using different target tumor markers.

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 54-54
Author(s):  
Lei Xiao ◽  
Song Li ◽  
Chengfei Pu ◽  
Zhiyuan Cao ◽  
Xinyi Yang ◽  
...  

Chimeric antigen receptor (CAR) T cell therapy has made significant progress in the treatment of blood cancers such as leukemia, lymphoma, and myeloma. However, the therapy faces many challenges in treating solid tumors. These challenges include physical barriers, tumor microenvironment immunosuppression, tumor heterogeneity, target specificity, and limited reactive cell expansion in vivo. Conventional CAR T cell therapy has thus far shown weak cell expansion in solid tumor patients and achieved little or no therapeutic responses. Here, we developed CAR T cells based on a novel CoupledCAR® technology to treat solid tumors. In contrast to conventional CAR T cells, CoupledCAR T cells significantly improved the expansion of the CAR T cells in vivo and enhanced the CAR T cells' migration ability and resistance to immunosuppression by the tumor microenvironment. The enhanced migration ability and resistance allow the CAR T cells to infiltrate to tumor tissue sites and increase anti-tumor activities. Specifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-GCC (guanylate cyclase 2C) CAR molecule. Furthermore, anti-GCC CAR T cells showed anti-tumor activities in vitro and in vivo experiments. To verify the safety and efficacy of CoupledCAR T cells for treating solid tumors, we conducted several clinical trials for different solid tumors, including seven patients with colorectal cancer. These seven patients failed multiple rounds of chemotherapy and radiotherapy. In the clinical trial, the patients were infused with autologous anti-GCC CoupledCAR T cells range from 4.9×10^5/kg to 2.9×10^6/kg. All patients using anti-GCC CoupledCAR T cells showed rapid expansion of CoupledCAR T cells and killing of tumor cells. Specifically, we observed that CoupledCAR T cells expanded significantly in the patients and infiltrated tumor tissue sites, demonstrating enhanced anti-tumor activities. PET/CT showed significant tumor shrinkage and SUV max declined, and the ongoing responses were monitored. Patient 3 achieved complete response and the best overall response rate (ORR, include complete remission, complete metabolic response, partial response, and partial metabolic response.) was 71.4% (5/7), complete remission (CR) rate was 14.3% (1/7). The clinical data demonstrated that CoupledCAR T cells effectively expanded, infiltrated tumor tissue sites, and kill tumor cells in patients with colorectal cancer. We used immunotherapy to achieve complete remission in patients with advanced colorectal cancer for the first time. We are recruiting more colorectal cancer patients to further test the safety and efficacy of anti-GCC CoupledCAR T cells. Since our CoupledCAR® technology is a platform technology, we are expanding it to treat other solid tumors using different target tumor markers . Disclosures Xiao: Innovative Cellular Therapeutics: Other: stockholder.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15035-e15035 ◽  
Author(s):  
Lei Xiao ◽  
Song Li ◽  
Chengfei Pu ◽  
Zhiyuan Cao ◽  
Cheng Lu ◽  
...  

e15035 Background: Conventional CAR-T cell therapy has thus far shown weak cell expansion in solid tumor patients and achieved little or no therapeutic responses. Methods: We developed CAR T cells based on a novel CoupledCAR technology to treat solid tumors. We engineered CoupledCAR-T cells with lentiviral vectors encoding an anti- colorectal cancer specific protein CAR molecule, and anti- colorectal cancer specific protein (CRCSP) CAR-T cells showed anti-tumor activities in vitro and in vivo experiments. Further, we conducted several clinical trials for various solid tumors, including two patients with colorectal cancer. After the infusion of CoupledCAR T cells, these two patients showed rapid expansion of CoupledCAR T cells and the killing of tumor cells. Specifically, we observed that CoupledCAR T cells expanded significantly in the patients and infiltrated tumor tissue sites. Results: Both patients achieved PR (Partial Response). Patient Profile: Patient 1: Male, 55Y, Colon Adenocarcinoma. In May 2016, 8 cycles of XELOX chemotherapy and 1 dose of radiotherapy were performed. In Step 2016, “radical rectal resection and terminal ileum double ileostomy” was performed. After surgery, gemcitabine chemotherapy was performed for 2 cycles. In January 2018, relapse and metastasis of prostate and left lung were observed. In April 2019, relapse and metastasis were observed. Patient 2: Female, 57Y, Colon Adenocarcinoma. In December 2014, DT46Gy/2Gy/23 radiotherapy was performed. In December 2014 and January 2015, the single drug chemotherapy of Xeloda was taken orally. In February 2015, laparoscopic radical resection of rectal cancer was performed. In April, May, June, and July 2015, mFOLFOX6 chemotherapy was performed. In June 2019, CT showed tumor metastasis. Observations and Results: Patient 1: One month after infusion (M1), the patient was evaluated as PR; most of the target lesions were significantly reduced by more than 50%, and the primary tumor volume was reduced by ~45%. Patient 2: M1, the patient was also evaluated as PR; the tumor in the left upper lobe tip posterior segment was reduced by approximately 75%. Conclusions: The clinical data demonstrated that CoupledCAR-T cells effectively expanded, infiltrated tumor tissue sites, and kill tumor cells in patients with colorectal cancer. We are recruiting more colorectal cancer patients to further test the safety and efficacy of anti-CRCSP CoupledCAR T cells. Further, since our CoupledCAR technology is a platform technology, we are developing it to treat other solid tumors using different target markers.


2021 ◽  
Vol 12 ◽  
Author(s):  
Weizhen Li ◽  
Yang Zhou ◽  
Zhongen Wu ◽  
Yaoping Shi ◽  
Enming Tian ◽  
...  

Colorectal cancer (CRC) patients are still lacking viable treatments. Chimeric antigen receptor (CAR) T cells have shown promise in hematologic malignancies, but their efficacy in solid tumors has been limited due to the immunosuppressive tumor microenvironment. We found that cancer antigen- EpCAM expression increased in the metastatic stage compared with the primary stage in cancers and the activation of Wnt and TGFβ pathways was positively correlated with EpCAM expression in multiple cancers, including colorectal cancer. We constructed CAR T cells targeting EpCAM that successfully showed selective cytotoxicity in highly EpCAM-expressing cancer cell lines. The combination of EpCAM CAR-T with the Wnt inhibitor-hsBCL9CT-24 displayed synergetic effect against EpCAM-positive colon cells in vitro and also in vivo. A mechanistic study showed that hsBCL9CT-24 treatment could modulate the tumor environment and improve infiltration of T cells, while possibly promoting the effector T cells at the early stages and postponing the exhaustion of CAR T cells at advanced stages. Overall, these results demonstrated that the combination of EpCAM CAR T-cell therapy with the Wnt inhibitor can overcome the limitations of CAR T cells in treating solid tumors.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2528-2528
Author(s):  
Lei Xiao ◽  
Song Li ◽  
Chengfei Pu ◽  
Zhiyuan Cao ◽  
Xinyi Yang ◽  
...  

2528 Background: Chimeric antigen receptor (CAR) T cell therapy has made significant progress in the treatment of blood cancers such as leukemia, lymphoma, and myeloma. However, the therapy faces many challenges in treating solid tumors. These challenges include physical barriers, tumor microenvironment immunosuppression, tumor heterogeneity, target specificity, and limited expansion in vivo. Methods: We designed a CAR lentivirus vector that consisted of a humanized CD19-specific single-chain variable fragment (scFv), a 4-1BB costimulatory domain, and a CD3ζ signaling domain.The lentivirus was produced by transfecting HEK-293T cells with CAR lentiviral vectors and viral packaging plasmids. Patient’s CD3 T cells was cultured in X-VIVO medium containing 125U/mL 1interleukin-2 (IL-2), and transduced with CAR lentivirus at certain MOI 24h after stimulated by anti-CD3/CD28 magnetic beads. Transduction efficiency was evaluated at 7 to 9 days after CAR lentivirus transduction, and quality controls for fungi, bacteria, mycoplasma, chlamydia, and endotoxin were performed. After infusion, serial peripheral blood samples were collected, and the expansion and the cytokine release of CART cells were detected by FACS and QPCR,respectively. The evaluation of response level for patients were performed at month 1,month 3,and month 6 by PET/CT. Results: We engineered CoupledCAR T cells with lentiviral vectors encoding an anti-GCC (guanylate cyclase 2C) CAR molecule. To verify the safety and efficacy of CoupledCAR-T cells for treating solid tumors, we conducted several clinical trials for different solid tumors, including seven patients with colorectal cancer. These seven patients failed multiple rounds of chemotherapy and radiotherapy. In the clinical trial, the metastatic colorectal cancer patients were infused with autologous anti-GCC CoupledCAR-T cells range from 4.9×105/kg to 2.9×106/kg. We observed that CoupledCAR-T cells expanded significantly in the patients and infiltrated tumor tissue sites, demonstrating enhanced anti-tumor activities. PET/CT showed significant tumor shrinkage and SUV max declined, and the ongoing responses were monitored. Patient 3 achieved complete response and the best overall response rate (ORR, include complete remission, complete metabolic response, and partial response.) was 57.1% (4/7), complete remission (CR) rate was 14.3% (1/7). Conclusions: In conclusion, the clinical data demonstrated that CoupledCAR-T cells effectively expanded, infiltrated tumor tissue sites, and kill tumor cells in patients with colorectal cancer. We used immunotherapy to achieve complete remission in patients with advanced colorectal cancer for the first time. We are recruiting more colorectal cancer patients to further test the safety and efficacy of anti-GCC CoupledCAR T cells. Since our CoupledCAR technology is a platform technology, we are expanding it to treat other solid tumors using different target tumor markers.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A234-A234
Author(s):  
Rebecca Larson ◽  
Michael Kann ◽  
Stefanie Bailey ◽  
Nicholas Haradhvala ◽  
Kai Stewart ◽  
...  

BackgroundChimeric Antigen Receptor (CAR) therapy has had a transformative impact on the treatment of hematologic malignancies1–6 but success in solid tumors remains elusive. We hypothesized solid tumors have cell-intrinsic resistance mechanisms to CAR T-cell cytotoxicity.MethodsTo systematically identify resistance pathways, we conducted a genome-wide CRISPR knockout screen in glioblastoma cells, a disease where CAR T-cells have had limited efficacy.7 8 We utilized the glioblastoma cell line U87 and targeted endogenously expressed EGFR with CAR T-cells generated from 6 normal donors for the screen. We validated findings in vitro and in vivo across a variety of human tumors and CAR T-cell antigens.ResultsLoss of genes in the interferon gamma receptor (IFNγR) signaling pathway (IFNγR1, JAK1, JAK2) rendered U87 cells resistant to CAR T-cell killing in vitro. IFNγR1 knockout tumors also showed resistance to CAR T cell treatment in vivo in a second glioblastoma line U251 in an orthotopic model. This phenomenon was irrespective of CAR target as we also observed resistance with IL13Ralpha2 CAR T-cells. In addition, resistance to CAR T-cell cytotoxicity through loss of IFNγR1 applied more broadly to solid tumors as pancreatic cell lines targeted with either Mesothelin or EGFR CAR T-cells also showed resistance. However, loss of IFNγR signaling did not impact sensitivity of liquid tumor lines (leukemia, lymphoma or multiple myeloma) to CAR T-cells in vitro or in an orthotopic model of leukemia treated with CD19 CAR. We isolated the effects of decreased cytotoxicity of IFNγR1 knockout glioblastoma tumors to be cancer-cell intrinsic because CAR T-cells had no observable differences in proliferation, activation (CD69 and LFA-1), or degranulation (CD107a) when exposed to wildtype versus knockout tumors. Using transcriptional profiling, we determined that glioblastoma cells lacking IFNγR1 had lower upregulation of cell adhesion pathways compared to wildtype glioblastoma cells after exposure to CAR T-cells. We found that loss of IFNγR1 reduced CAR T-cell binding avidity to glioblastoma.ConclusionsThe critical role of IFNγR signaling for susceptibility of solid tumors to CAR T-cells is surprising given that CAR T-cells do not require traditional antigen-presentation pathways. Instead, in glioblastoma tumors, IFNγR signaling was required for sufficient adhesion of CAR T-cells to mediate productive cytotoxicity. Our work demonstrates that liquid and solid tumors differ in their interactions with CAR T-cells and suggests that enhancing T-cell/tumor interactions may yield improved responses in solid tumors.AcknowledgementsRCL was supported by T32 GM007306, T32 AI007529, and the Richard N. Cross Fund. ML was supported by T32 2T32CA071345-21A1. SRB was supported by T32CA009216-38. NJH was supported by the Landry Cancer Biology Fellowship. JJ is supported by a NIH F31 fellowship (1F31-MH117886). GG was partially funded by the Paul C. Zamecnik Chair in Oncology at the Massachusetts General Hospital Cancer Center and NIH R01CA 252940. MVM and this work is supported by the Damon Runyon Cancer Research Foundation, Stand Up to Cancer, NIH R01CA 252940, R01CA238268, and R01CA249062.ReferencesMaude SL, et al. Tisagenlecleucel in children and young adults with B-cell lymphoblastic leukemia. N Engl J Med 2018;378:439–448.Neelapu SS, et al. Axicabtagene ciloleucel CAR T-cell therapy in refractory large B-cell lymphoma. N Engl J Med 2017;377:2531–2544.Locke FL, et al. Long-term safety and activity of axicabtagene ciloleucel in refractory large B-cell lymphoma (ZUMA-1): a single-arm, multicentre, phase 1–2 trial. The Lancet Oncology 2019;20:31–42.Schuster SJ, et al. Chimeric antigen receptor T cells in refractory B-cell lymphomas. N Engl J Med 2017;377:2545–2554.Wang M, et al. KTE-X19 CAR T-cell therapy in relapsed or refractory mantle-cell lymphoma. N Engl J Med 2020;382:1331–1342.Cohen AD, et al. B cell maturation antigen-specific CAR T cells are clinically active in multiple myeloma. J Clin Invest 2019;129:2210–2221.Bagley SJ, et al. CAR T-cell therapy for glioblastoma: recent clinical advances and future challenges. Neuro-oncology 2018;20:1429–1438.Choi BD, et al. Engineering chimeric antigen receptor T cells to treat glioblastoma. J Target Ther Cancer 2017;6:22–25.Ethics ApprovalAll human samples were obtained with informed consent and following institutional guidelines under protocols approved by the Institutional Review Boards (IRBs) at the Massachusetts General Hospital (2016P001219). Animal work was performed according to protocols approved by the Institutional Animal Care and Use Committee (IACUC) (2015N000218 and 2020N000114).


Author(s):  
Ya.Yu. Kiseleva ◽  
A.M. Shishkin ◽  
A.V. Ivanov ◽  
T.M. Kulinich ◽  
V.K. Bozhenko

Adoptive immunotherapy that makes use of genetically modified autologous T cells carrying a chimeric antigen receptor (CAR) with desired specificity is a promising approach to the treatment of advanced or relapsed solid tumors. However, there are a number of challenges facing the CAR T-cell therapy, including the ability of the tumor to silence the expression of target antigens in response to the selective pressure exerted by therapy and the dampening of the functional activity of CAR T cells by the immunosuppressive tumor microenvironment. This review discusses the existing gene-engineering approaches to the modification of CAR T-cell design for 1) creating universal “switchable” synthetic receptors capable of attacking a variety of target antigens; 2) enhancing the functional activity of CAR T cells in the immunosuppressive microenvironment of the tumor by silencing the expression of inhibiting receptors or by stimulating production of cytokines.


Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 125 ◽  
Author(s):  
Aleksei Titov ◽  
Aygul Valiullina ◽  
Ekaterina Zmievskaya ◽  
Ekaterina Zaikova ◽  
Alexey Petukhov ◽  
...  

Chimeric antigen receptor (CAR) immunotherapy is one of the most promising modern approaches for the treatment of cancer. To date only two CAR T-cell products, Kymriah® and Yescarta®, have been approved by the Food and Drug Administration (FDA) for the treatment of lymphoblastic leukemia and B-cell lymphoma. Administration of CAR T-cells to control solid tumors has long been envisaged as one of the most difficult therapeutic tasks. The first two clinical trials conducted in sarcoma and neuroblastoma patients showed clinical benefits of CAR T-cells, yet multiple obstacles still hold us back from having accessible and efficient therapy. Why did such an effective treatment for relapsed and refractory hematological malignancies demonstrate only relatively modest efficiency in the context of solid tumors? Is it due to the lucky selection of the “magic” CD19 antigen, which might be one of a kind? Or do lymphomas lack the immunosuppressive features of solid tumors? Here we review the existing knowledge in the field of CAR T-cell therapy and address the heterogeneity of solid tumors and their diverse strategies of immunoevasion. We also provide an insight into prospective developments of CAR T-cell technologies against solid tumors.


2020 ◽  
Author(s):  
Mostapha Benhenda

AbstractChimeric antigen receptor (CAR) T cells still have limited effects in cancer, and especially in solid tumors, due to T cell dysfunction and exhaustion. CAR T cells overexpressing c-Jun (JUN CAR T cells) have been introduced to solve this problem. In this paper, we analyze JUN CAR T cells scRNA-seq data in solid tumors, by applying a genome-wide signature of T cell dysfunction, TID. This signature comes from the bulk RNA-seq signature TIDE, introduced to predict immune checkpoint inhibitor response. Our analysis confirms that on average, JUN CAR T cells are less dysfunctional than non-JUN CAR T cells. However, it also shows heterogeneity within JUN CAR T cells, which brings uncertainty about possible tumor resistance. We conclude that genome-wide dysfunction signature TID helps de-risking CAR T cell therapy for solid tumors.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4631-4631
Author(s):  
Lei Xiao

New Generation Chimeric Antigen Receptor T-Cell Therapy ( CoupledCAR ) Induces High Rate Remissions in Solid Tumor Yu Liu1,Song Li2,Youli Luo3,Haixia Song4,Chengfei Pu5, Zhiyuan Cao 5, Cheng Lu5,Yang Hang5,Xi Huang5,Xiaogang Shen5 ,Xiaojun Hu3 , Renbin Liu1,Xiuwen Wang2,Junjie Mao3,Shihong Wei4 ,Zhao Wu5and Lei Xiao5* 1.The Third Affiliated Hospital, SUN YAT-SEN University 2.Qilu Hospital of Shandong University 3.The Fifth Affiliated Hospital, SUN YAT-SEN University 4.Gansu Procincial Cancer Hospital 5.Innovative Cellular Therapeutics *Corresponding to: Lei Xiao, [email protected] Chimeric antigen receptor (CAR) T cell therapy made significant progress for treating blood cancer such as leukemia, lymphoma, and myeloma. However, the therapy faces many challenges, such as physical barrier, tumor microenvironment immunosuppression, tumor heterogeneity, target specificity, and cell expansion in vivo for treatment of solid tumors Conventional CAR T cell therapy showed weak CAR T expansion in patients and thus achieved no or little response for treating solid tumors. Here, we generated "CoupledCAR" T cells including an anti-TSHR CAR molecule. Compared with conventional CART cells,these "CoupledCAR" T cells successfully improved the expansion of CART cells more than 100 times and enhanced CAR T cells' migration ability, allowing the CAR T cells to resist and infiltrate the tumor microenvironment and killed tumor cells. To verify the effect of "CoupledCAR" T cells on solid tumors, we have completed several clinical trials for different solid tumors, including two patients with thyroid cancer. Immunohistochemistry (IHC) results showed that thyroid stimulating hormone receptors (TSHR) were highly expressed in thyroid cancer cells. In vitro co-culture experiments showed that TSHR CAR T cells specifically recognized and killed TSHR-positive tumor cells. Animal experiments showed that TSHR CAR T cells inhibited the proliferation of TSHR-positive tumor cells. Therefore, we designed "CoupledCAR" T cells expressing a binding domain against TSHR. Further,we did clinical trials of two group patients that were successfully treated using conventional TSHR CAR T cells and the "CoupledCAR" T cells, respectively. In the first group using conventional TSHR CAR T cells, patients showed weak cell expansion and less migration ability. In the group using TSHR "CoupledCAR" T cells, patients showed rapid expansion of CAR T cells and killing of tumor cells. One month after infusion (M1), the patient was evaluated as PR(Partial Response): the lymph node metastasis disappeared, and thoracic paratracheal tumors decreased significantly. Three months after infusion (M3), the patient was evaluated as a durable response, and the tumor tissue was substantially smaller than M1. Further, two patients with colonrectal cancer were enrolled in this trial and infused "CoupledCAR" T cells. One patient achieved PR and the other one achieved SD (Stable Disease). Therefore, "CoupledCAR" T cells can effectively promote expansion, migration and killing ability of CAR T cells in patients with thyroid cancer. "CoupledCAR" T cell technology is a technological platform, which may be used to treat other cancer types. Next, we are recruiting more patients with solid tumors in clinical trials using "CoupledCAR" T cells. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4836-4836
Author(s):  
Hui SHI ◽  
Kai Hu ◽  
Xiaoyan Ke ◽  
Tong Wu

Abstract Background: The Chimeric antigen receptor (CAR) T-cell therapy has shown very promising future in relapsed/refractory diffused large B cell lymphoma (R/R DLBCL) patients resisted to second-line chemotherapy and failed to auto hematopoietic cell transplantation. Trials with murine CD19-CAR T-cell therapy have shown only 40%-54% complete remission (CR) rate in patients with R/R DLBCL. However, 30%-60% of patients with previous CR relapse within 1 year. It is critical to develop new strategies to improve survival of R/R DLBCL patients failed to murine CD19-CAR T cells therapy. Forty-two R/R DLBCL patients failed to murine CD19-CAR T cells therapy who accepted secondary humanized CAR T cells salvage therapy in our center were recruited to this study Aim: 1. Investigate the effect and safety of Secondary humanized CAR T cells salvage therapy in R/R DLBCL patients failed to murine CD19-CAR T cells therapy. 2. Analyze the influence factor of curative effect of secondary humanized CAR T cells, to predict the outcome of treatment. Method: We retrospectively analyzed 42 cases treated with secondary humanized CAR T cells salvage therapy after failing to murine CD19-CAR T cells therapy in our center, enrolled from 05/01/2018 to 05/01/2020. According to the new result of tumor immunohistochemical analysis, five patients still chose to target CD19, twenty-one targeted CD20, and sixteen targeted CD22. Pretreatment regimen before infusion of CAR T cells were chemotherapy comprising fludarabine (three doses of 30 mg/m2 daily) and cyclophosphamide (three doses of 300mg/m2 daily). The T-cells with specific CAR expression in peripheral blood were dynamically detected by flow cytometry. After CAR T-cells infusion, PET-CT were performed every 3 months to evaluate the state of disease. Patients were followed up till 06/15/2021 Results: The incidence of cytokine release syndrome (CRS) was 84%, of which 22% was severe CRS (≥grade 3), as the incidence of immune effector cells associated neurologic toxicity (ICANS) was 7.14%, of which 2.83% was severe ICANS. The incidence of target organ damage was 12%. The rate of treatment-related mortality was 7%. In 3 months, complete remission rate was 26.2%, partial remission rate (PR) was 33.3% and the overall response rate (ORR) was 59.5%. Ten patients (26.2%) remained in complete remission at the cutoff date. The median of progression-free survival (PFS) length was 4.42 months (95%CI: 1.87-6.02). The median of overall survival (OS) length was 9.24 months (95%CI: 4.44-~). The 1-year overall survival rate was 38.1%. We also found high level of LDH, heavy tumor burden, no less than 4 IPI score, and double expression of MYC and BCL2 were risk factors of OS, PFS and CR. The patients who had achieved CR or PR after murine CD19-CAR T cells therapy had a favorable OS and PFS. The longer the patients had PFS during murine CD19-CAR T cells therapy, the longer PFS and OS during humanized CAR T cells therapy. Conclusion: 1. Secondary humanized CAR T cells salvage therapy improves survival of R/R DLBCL patients failed to murine CD19-CAR T cells therapy. 2. The incidence of severe CRS and treatment-related causality were relatively low. 3. The patients who got better curative effect during murine CAR T cells therapy prone to a longer survival time. Keywords: Secondary humanized CAR T cells therapy, murine CAR T cells therapy, R/R DLBCL, CRS, ICANS. Disclosures No relevant conflicts of interest to declare.


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