CoupledCAR technology for treating thyroid cancer.

e14507 Background: Chimeric antigen receptor modified T-cells (CAR-T) have demonstrated remarkable clinical efficacy in the treatment of B-cell malignancies. Significant challenges restrict their application across solid tumors due to multiple obstacles, including the lack of robust in vivo CAR-T cell expansion and persistence in the immunosuppressive tumor microenvironment. Methods: To address these difficulties, we generated CAR-T cells using a novel CoupledCAR technology. Specifically, we engineered CoupledCAR-T cells with lentiviral vectors encoding an anti-thyroid stimulating hormone receptor (TSHR) CAR molecule. In vitro co-culture experiments showed that TSHR CAR-T cells specifically recognized and subsequently killed TSHR-positive tumor cells. Animal model experiments showed that TSHR CAR-T cells inhibited the proliferation of TSHR-positive tumor cells. Results: Patient 1: Male, 64Y, Papillary Thyroid Carcinoma. In May 2017, his Thyroid cancer was diagnosed, bilateral total thyroidectomy, and right cervical lymph node functional dissection were performed in Jun 2018, followed by iodine 131 isotope therapy. In December 2018, bilateral multiple cervical lymph nodes were enlarged, especially on the right side. In February 2019, right neck lymphadenectomy was performed. One month after infusion (M1) of the anti-TSHR CoupledCAR-T cells, the patient was evaluated as PR. Three months after infusion (M3), the patient was evaluated as CR, and the patient's CR lasted from M3 to M12 after infusion of the CoupledCAR-T cells. We are still following the patient for long-term clinical effects. Patient 2: Female, 60Y, Thyroid Carcinoma: In Aug 2013, a "double lobectomy of the thyroid gland” was performed. From Oct 2013 to Jan 2014, she received iodine 131 isotope therapy. In Sep 2014, she was diagnosed with iodine-resistant thyroid cancer. From Sep to Jan 2016, 5 cycles of chemotherapy were performed. In Jun 2016, she enrolled in the Anlotinib experimental group. In Mar 2019, multiple metastases in both lungs and multiple enlarged lymph nodes in the mediastinum were observed. At month 1 (M1) post cell infusion, the patient was evaluated as PR (Partial Response): the tumor volume in the right lower lobe of the lung was reduced by approximately 67.51% (decreased from 65*55mm to 42*39mm). Three months after infusion (M3), the tumor volume was reduced by approximately 73.54% and SUV max value decreased from 14.9 to 2.8. Therefore, the patient was evaluated as nCR (near complete remission). Conclusions: In summary, we showed that TSHR is an attractive and specific target for treating thyroid cancer and our anti-TSHR CoupledCAR-T cells are safe and effective for treating thyroid cancer. Recruitment is ongoing to evaluate the safety and efficacy of our CoupledCAR-T cells. Further, since our CoupledCAR technology is a platform technology, we are developing additional CoulpledCAR-T cells to treat other solid tumors using different target tumor markers.

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400 CoupledCARTM technology for treating thyroid cancer

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0400 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A425-A425

Author(s):

Xingchen Liu ◽

Keshu Zhou ◽

Yong Huang ◽

Chengfei Pu ◽

Zhiyuan Cao ◽

...

Keyword(s):

T Cells ◽

Thyroid Cancer ◽

Lymph Node ◽

Tumor Cells ◽

Tumor Volume ◽

Safety And Efficacy ◽

Car T Cells ◽

Car T ◽

Iodine 131 ◽

The Right

BackgroundChimeric antigen receptor modified T cells (CAR T) have demonstrated remarkable clinical efficacy in the treatment of B cell malignancies and multiple myeloma. Significant challenges restrict their application across solid tumors due to multiple obstacles, including the lack of robust in vivo CAR-T cell expansion and persistence, the immunosuppressive tumor microenvironment, and tumor escape due to heterogeneous tumor cell composition with a potential loss of the targeted tumor antigen.To address these difficulties, we generated CAR T cells using a novel CoupledCAR® technology. Specifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-thyroid stimulating hormone receptor (TSHR) CAR molecule. Immunohistochemistry (IHC) results showed that TSHR was highly expressed in thyroid cancer cells making it an ideal tumor-specific target antigen. In vitro co-culture experiments showed that TSHR CAR T cells specifically recognized and subsequently killed TSHR-positive tumor cells. Animal model experiments showed that TSHR CAR T cells inhibited the proliferation of TSHR-positive tumor cells.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.ResultsTo evaluate the clinical safety and efficacy of anti-TSHR CoupledCAR T cells on refractory or relapsed thyroid cancer, we treated refractory/relapsed post-thyroidectomy thyroid cancer patients according to an IRB approved protocol. We treated two patients using anti-TSHR CoupledCAR T cells and observed the rapid expansion of CAR T cells and enhanced the killing of tumor cells. One patient‘s best response was complete remission, and the other was near complete remission.Patient Profile:Patient 1 Male, 64Y, Papillary Thyroid Carcinoma. In May 2017, Thyroid cancer was diagnosed, bilateral total thyroidectomy, and right cervical lymph node functional dissection were performed in Jun 2018, followed by iodine 131 isotope therapy. In December 2018, bilateral multiple cervical lymph nodes were enlarged, especially on the right side. In February 2019, right neck lymphadenectomy was performed.Patient 2 Female, 60Y, Thyroid Carcinoma. In Aug 2013, a ‘double lobectomy of the thyroid gland’ was performed. From Oct 2013 to Jan 2014, she received iodine 131 isotope therapy. In Sep 2014, she was diagnosed with iodine - resistant thyroid cancer. From Sep to Jan 2016, 5 cycles of chemotherapy were performed. In Jun 2016, she enrolled in the Anlotinib experimental group. In Mar 2019, multiple metastases in both lungs and multiple enlarged lymph nodes in the mediastinum were observed.Observations and Results:Patient 1: One month after infusion (M1), the patient was evaluated as PR: lymph node metastasis became undetectable and the size of the thoracic paratracheal tumor nodules decreased significantly. Three months after infusion (M3), the patient was evaluated as CR, and the tumor tissue was substantially smaller than M1.Patient 2: M1, the patient was evaluated as PR (Partial Response): the tumor volume in the right lower lobe of the lung was reduced by approximately 67.51% (decreased from 65*55 mm to 42*39 mm). Three months after infusion (M3), compared with that before, the tumor volume was reduced by approximately 73.54% and SUV max value decreased from 14.9 to 2.8, therefore, the patient was evaluated as nCR (near complete remission).ConclusionsWe show that TSHR is a good target for treating thyroid cancer, and our anti-TSHR CoupledCAR T cells are safe and effective for treating thyroid cancer. Recruitment is ongoing to evaluate the safety and efficacy of our CoupledCAR T cells. Further, since our CoupledCAR® technology is a platform technology, we are developing it to treat other solid tumors using different target tumor markers.

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CoupledCAR technology for treating thyroid cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2020.38.15_suppl.e15027 ◽

2020 ◽

Vol 38 (15_suppl) ◽

pp. e15027-e15027

Author(s):

Lei Xiao ◽

Xingchen Liu ◽

Keshu Zhou ◽

Yu Liu ◽

Yong Huang ◽

...

Keyword(s):

T Cells ◽

Thyroid Cancer ◽

Lymph Node ◽

Partial Response ◽

Thyroid Carcinoma ◽

Lymph Nodes ◽

Tumor Volume ◽

Car T Cells ◽

Car T ◽

Iodine 131

e15027 Background: Significant challenges restrict CAR-T cell therapy to treat solid tumors. Methods: Here, we generated CAR-T cells using a novel CoupledCAR technology. Specifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-thyroid stimulating hormone receptor (TSHR) CAR molecule, and anti-TSHR CAR-T cells showed anti-tumor activities in vitro and in vivo experiments. Further, we treated refractory/relapsed post-thyroidectomy thyroid cancer patients using anti-TSHR CoupledCAR T cells, and observed the rapid expansion of CAR-T cells and the enhanced killing of tumor cells. Results: Both patients achieved PR (Partial Response). Patient Profile: Patient 1 Male, 64Y, Papillary Thyroid Carcinoma. In May 2017, thyroid cancer was diagnosed, bilateral total thyroidectomy, and right cervical lymph node functional dissection were performed in June, followed by iodine 131 isotope therapy. In December 2018, bilateral multiple cervical lymph nodes were enlarged. In February 2019, right neck lymphadenectomy was performed. Patient 2 Female, 60Y, Thyroid Carcinoma. In Aug 2013, a "double lobectomy of the thyroid gland” was performed. From Oct 2013 to Jan 2014, she received iodine 131 isotope therapy. In Sep 2014, she was diagnosed with iodine-resistant thyroid cancer. In 2016, 5 cycles of chemotherapy were performed. In Mar 2019, multiple metastases in both lungs and multiple enlarged lymph nodes were observed. Observations and Results: Patient 1: One month after infusion (M1), the patient was evaluated as PR: lymph node metastasis became undetectable and the size of the thoracic paratracheal tumor nodules decreased significantly. Three months after infusion (M3), the patient was evaluated as having a durable response, and the tumor tissue was substantially smaller than M1. Patient 2: M1, the patient was evaluated as PR (Partial Response): the tumor volume in the right lower lobe of the lung was reduced by approximately 67.51% (decreased from 65*55mm to 42*39mm). Three months after infusion (M3), compared with that before, the tumor volume was reduced by approximately 73.54% and SUV max value decreased from 14.9 to 2.8, therefore, the patient was evaluated as nCR (near complete remission). Conclusions: We show that TSHR is a good target for treating thyroid cancer, and our anti-TSHR CoupledCAR T cells are safe and effective for treating thyroid cancer. Recruitment is ongoing to evaluate the safety and efficacy of our 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.

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CoupledCARTM Technology for Treating Thyroid Cancer

Blood ◽

10.1182/blood-2020-138668 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 46-46

Author(s):

Xingchen Liu ◽

Lei Xiao ◽

Keshu Zhou ◽

Yu Liu ◽

Yong Huang ◽

...

Keyword(s):

T Cells ◽

Thyroid Cancer ◽

Complete Remission ◽

Tumor Cells ◽

Tumor Volume ◽

Safety And Efficacy ◽

Car T Cells ◽

Car T ◽

Iodine 131 ◽

The Right

CoupledCAR TM Technology for Treating Thyroid Cancer Chimeric antigen receptor modified T cells (CAR T) have demonstrated remarkable clinical efficacy in the treatment of B cell malignancies and multiple myeloma. Significant challenges restrict their application across solid tumors due to multiple obstacles, including the lack of robust in vivo CAR-T cell expansion and persistence, the immunosuppressive tumor microenvironment, and tumor escape due to heterogeneous tumor cell composition with a potential loss of the targeted tumor antigen. To address these difficulties, we generated CAR T cells using a novel CoupledCARTM technology. Specifically, we engineered CoupledCAR T cells with lentiviral vectors encoding an anti-thyroid stimulating hormone receptor (TSHR) CAR molecule. Immunohistochemistry (IHC) results showed that TSHR was highly expressed in thyroid cancer cells making it an ideal tumor-specific target antigen. In vitro co-culture experiments showed that TSHR CAR T cells specifically recognized and consequently killed TSHR-positive tumor cells. Animal experiments showed that TSHR CAR T cells inhibited the proliferation of TSHR-positive tumor cells. To evaluate the clinical safety and efficacy of anti-TSHR CoupledCAR T cells on refractory or relapsed thyroid cancer, we treated refractory/relapsed post-thyroidectomy thyroid cancer patients according to an IRB approved protocol. We treated two patients using anti-TSHR CoupledCAR T cells and observed the rapid expansion of CAR T cells and enhanced the killing of tumor cells. One patient's best response was complete remission, and the other was near complete remission. Patient Profile: Patient 1 Male, 64Y, Papillary Thyroid Carcinoma. In May 2017, Thyroid cancer was diagnosed, bilateral total thyroidectomy, and right cervical lymph node functional dissection were performed in June, followed by iodine 131 isotope therapy. In December 2018, bilateral multiple cervical lymph nodes were enlarged, especially on the right side. In February 2019, right neck lymphadenectomy was performed. Patient 2 Female, 60Y, Thyroid Carcinoma. In Aug 2013, a "double lobectomy of the thyroid gland" was performed. From Oct 2013 to Jan 2014, she received iodine 131 isotope therapy. In Sep 2014, she was diagnosed with iodine - resistant thyroid cancer. From Sep to Jan 2016, 5 cycles of chemotherapy were performed. In Jun 2016, she enrolled in the Anlotinib experimental group. In Mar 2019, multiple metastases in both lungs and multiple enlarged lymph nodes in the mediastinum were observed. Observations and Results: Patient 1: One month after infusion (M1), the patient was evaluated as PR: lymph node metastasis became undetectable and the size of the thoracic paratracheal tumor nodules decreased significantly. Three months after infusion (M3), the patient was evaluated as CR, and the tumor tissue was substantially smaller than M1. Patient 2: M1, the patient was evaluated as PR (Partial Response): the tumor volume in the right lower lobe of the lung was reduced by approximately 67.51% (decreased from 65*55mm to 42*39mm). Three months after infusion (M3), compared with that before, the tumor volume was reduced by approximately 73.54% and SUV max value decreased from 14.9 to 2.8, therefore, the patient was evaluated as nCR (near complete remission). We show that TSHR is a good target for treating thyroid cancer, and our anti-TSHR CoupledCAR T cells are safe and effective for treating thyroid cancer. Recruitment is ongoing to evaluate the safety and efficacy of our CoupledCAR T cells. Further, since our CoupledCARTM technology is a platform technology, we are developing it to treat other solid tumors using different target markers. Disclosures Xiao: Innovative Cellular Therapeutics: Other: stockholder.

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New Generation Chimeric Antigen Receptor T-Cell Therapy (CoupledCAR) Induces High Rate Remissions in Solid Tumor

Blood ◽

10.1182/blood-2019-130703 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4631-4631

Author(s):

Lei Xiao

Keyword(s):

Clinical Trials ◽

T Cells ◽

Thyroid Cancer ◽

T Cell ◽

Cell Therapy ◽

Solid Tumors ◽

Tumor Cells ◽

T Cell Therapy ◽

Car T Cells ◽

Car T

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.

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121 ICAM-1-specific affinity tuned CAR T cells expressing SSTR2 for real-time imaging

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.121 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A130-A130

Author(s):

Jingmei Hsu ◽

Eric von Hofe ◽

Michael Hsu ◽

Koen Van Besien ◽

Thomas Fahey ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Phase I ◽

Tumor Cells ◽

Somatostatin Receptor ◽

Laboratory Animals ◽

Therapeutic Window ◽

Car T Cells ◽

Car T

BackgroundThe use of CAR T cells for solid tumors has a number of challenges, such as lack of tumor-specific targets, CAR T cell exhaustion, and the immunosuppressive tumor microenvironment. To address these challenges, AffyImmune has developed technologies to affinity tune and track CAR T cells in patients. The targeting moiety is affinity tuned to preferentially bind to tumor cells overexpressing the target while leaving normal cells with low basal levels untouched, thereby increasing the therapeutic window and allowing for more physiological T cell killing. The CAR T cells are designed to express SSTR2 (somatostatin receptor 2), which allows for the tracking of CAR T cells in vivo via PET/CT scan using FDA-approved DOTATATE.MethodsAIC100 was generated by affinity tuning the I-domain of LFA-1, the physiological ligand to ICAM-1. Various mutants with 106-fold difference in affinity were evaluated for affinity. This allowed structure activity relationships to be conducted using CAR T cells expressing the various affinity mutants against targets with varying antigen densities. The variant with micromolar affinity was clearly the most effective in non-clinical animal models. AIC100 is currently being evaluated to assess safety, CAR T expansion, tumor localization, and preliminary activity in patients with advanced thyroid cancer in a phase I study (NCT04420754). Our study uses a modified toxicity probability interval design with three dosage groups of 10 x 106, 100 x 106, and 500 x 106 cells.ResultsPreclinical studies demonstrated greater in vivo anti-tumor activity and safety with lower affinity CAR T cells. A single dose of AIC100 resulted in tumor elimination and significantly improved survival of animals. AIC100 activity was confirmed in other high ICAM-1 tumor models including breast, gastric, and multiple myeloma. In a Phase I patient given 10-million CAR T cells, near synchronous imaging of FDG and DOTATATE revealed preliminary evidence of transient CAR T expansion and tumor reduction at multiple tumor lesions, with the peak of CAR T density coinciding with the spike in CAR T numbers in blood.ConclusionsWe have developed affinity tuned CAR T cells designed to selectively target ICAM-1 overexpressing tumor cells and to spatiotemporally image CAR T cells. Near-synchronous FDG and DOTATATE scans will enhance patient safety by early detection of off-tumor CAR T activity and validation of tumor response. We anticipate that our ‘tune and track’ technology will be widely applicable to developing potent yet safe CAR T cells against hard-to-treat solid cancers.Trial RegistrationNCT04420754Ethics ApprovalIRB number19-12021154IACUC (animal welfare): All animal experiments were performed in accordance with the National Institute of Health’s Guide for the Care and Use of Laboratory Animals. Animal handling protocols were approved by the Institutional Laboratory Animal Use and Care Committee of Weill Cornell Medicine (Permit Number: 2012–0063).

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Abstract 6591: Antibody-based redirection of meditope-CAR T cells selectively kill antigen bearing tumor cells

10.1158/1538-7445.am2020-6591 ◽

2020 ◽

Author(s):

Yi-Chiu Kuo ◽

Jeremy D. King ◽

Cheng-Fu Kuo ◽

Victor Kenyon ◽

Miso Park ◽

...

Keyword(s):

T Cells ◽

Tumor Cells ◽

Car T Cells ◽

Car T

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Abstract 2329: Clinical manufacturing of CAR T cells targeting ICAM-1 for a phase I study against advanced thyroid cancer therapy

10.1158/1538-7445.sabcs18-2329 ◽

2019 ◽

Author(s):

Yogindra Vedvyas ◽

Jaclyn E. McCloskey ◽

Yanping Yang ◽

Irene M. Min ◽

Thomas J. Fahey ◽

...

Keyword(s):

T Cells ◽

Thyroid Cancer ◽

Cancer Therapy ◽

Phase I ◽

Phase I Study ◽

Car T Cells ◽

Car T ◽

Advanced Thyroid Cancer

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CHIMERIC ANTIGEN RECEPTOR FOR CHRONIC LYMPHOCYTIC LEUKEMIA - A REVIEW

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2019.v12i1.29642 ◽

2019 ◽

Vol 12 (1) ◽

pp. 62

Author(s):

Kiruthiga Raghunathan ◽

Brindha Devi P

Keyword(s):

Bone Marrow ◽

T Cells ◽

Radiation Therapy ◽

Chronic Lymphocytic Leukemia ◽

Tumor Cells ◽

Chimeric Antigen Receptor ◽

Lymphocytic Leukemia ◽

Normal Cells ◽

Car T Cells ◽

Car T

Chronic lymphocytic leukemia cancer is a deadly one which affects the bone marrow from making it to produce more amounts of white blood cells in the humans. This disease can be treated either by radiation therapy, bone marrow transplantation, chemotherapy, or immunotherapy. In radiation therapy, the ionizing radiation is used toward the tumor cells, but the main drawback is the radiation may affect the normal cells as well. To overcome this drawback, immunotherapy chimeric antigen receptor (CAR) is used. These CAR cells will target only the antigen of the tumor cells and not damage the normal cells in the body. In this therapy, the T-cells are taken either from the patients or a healthy donor and are engineered to express the CARs which are called as CAR-T-cells. When these CAR-T-cells come in contact with the antigen present on the surface of the tumor cells, they will get activated and become toxic to the tumor cells. This new class of therapy is having a great prospect in cancer immunotherapy.

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CD19-Targeted Donor T Cells Exert Potent Graft Versus Lymphoma Activity and Attenuated Gvhd

Blood ◽

10.1182/blood.v120.21.451.451 ◽

2012 ◽

Vol 120 (21) ◽

pp. 451-451 ◽

Cited By ~ 2

Author(s):

Arnab Ghosh ◽

Marco L. Davila ◽

Lauren F. Young ◽

Christopher Kloss ◽

Gertrude Gunset ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Tumor Cells ◽

Acute Gvhd ◽

Tcr Signaling ◽

Car T Cells ◽

Donor T Cells ◽

Car T

Abstract Abstract 451 Chimeric antigen receptors (CAR) represent a potent strategy to target T cells against selected tumor antigens. Ongoing clinical trials indicate that autologous T cells expressing CARs targeting CD19, a B cell-associated antigen, can induce complete remission and B cell aplasia in patients with B cell malignancies. Donor CD19-CAR+ T cells could potentially be used to treat recipients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the risk of alloreactivity mediated by endogenous T cell receptors (TCR) triggering an acute GVHD is not known. This is partly due to the absence of in vivo models to study the relative effects of CAR and endogenous TCR signaling. For the first time, we have evaluated the relative effects of CD19-targeted donor T cells on the elimination of CD19+ B cells and endogenous TCR-mediated alloreactivity in mouse models of allo-HSCT. We generated a panel of retroviral vectors encoding mouse CD19-specific CARs: as a control, CD19-delta, a tail-less CAR lacking the CD3ζ signaling domain; CD19z1, which signals through its CD3ζ endodomain; and CD19-28z, which signals through CD28 and CD3ζ (Figure 1A). CD19z1+ and CD19-28z+ T cells mediated specific lysis of CD19-expressing tumors in vitro, while CD19-delta+ T cells did not. In order to assess the anti-tumor capacity of CD19-CAR+ T cells in vivo, we transferred the transduced B6 donor T cells into lethally irradiated BALB/c recipients that were administered T cell-depleted allografts and CD19+ lymphoma A20-TGL (B6–> BALB/c+A20-TGL). CD19-CAR+ T cells (CD19z1 and CD19-28z) mediated clearance of A20 tumor cells visualized by in vivo imaging of luciferase-expressing tumor cells (Figure 1B and data not shown) and significantly improved tumor free survival. CD19-CAR+ B6 T cells could sustain prolonged B cell hypoplasia when adoptively transferred into lethally irradiated haploidentical CBF1 recipients of T cell-depleted allografts (B6–> CBF1, Figure 1C). These data indicate that under alloreactive conditions, donor CD19-CAR+ T cell signaled through the CAR leading to specific elimination of CD19+ tumors and B lineage cells. In order to determine the risk of GVHD, we transferred the donor CD19-CAR+ T cells into haploidentical HSCT recipients. Interestingly, CD19-CAR+ T cells mediated significantly less acute GVHD, resulting in improved survival and lower GVHD scores (Figure 1D). Donor CD19-delta+ T cells however mediated lethal GVHD, indicating that the endogenous TCR mediated strong alloreactivity in the absence of CAR signaling. Similar results were obtained from experiments using MHC-mismatched (B6–> BALB/c) models. It is known that signaling through endogenous TCR is accompanied by down-regulation of surface TCR expression. We found significant decreases in surface CD3ϵ, TCRβ and CD90 expressions in donor CD19-delta+ T cells under alloreactive conditions. In contrast, donor CD1928z+ T cells failed to down-regulate surface TCR expression under similar conditions, suggesting that endogenous TCR function was altered in CAR-activated T cells. In the context of allo-HSCT, preferential CAR signaling at the expense of alloreactive endogenous TCR signaling may thus lead to reduced alloreactivity and attenuation of GVHD. These results provide the first pre-clinical evidence suggesting that CAR-modified, unselected donor T cells may be safely applied in an allogeneic context. Disclosures: No relevant conflicts of interest to declare.

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Targeting An Ancient Retrovirus In Tumor Using Engineered T Cells

Blood ◽

10.1182/blood.v122.21.4206.4206 ◽

2013 ◽

Vol 122 (21) ◽

pp. 4206-4206

Author(s):

Janani Krishnamurthy ◽

Brian Rabinovich ◽

Simon Olivares ◽

Mi Teijuan ◽

Kirsten Switzer ◽

...

Keyword(s):

Clinical Trials ◽

T Cells ◽

Tumor Cells ◽

Treatment Strategy ◽

Conflicts Of Interest ◽

Sleeping Beauty ◽

Normal Organ ◽

Car T Cells ◽

Car T ◽

Env Protein

Abstract Human endogenous retroviruses (HERVs) are ancient viruses forming 8% of human genome. One subset of HERVs, the HERV-K has recently been found to be expressed on tumor cells including melanoma, breast cancer and lymphoma but not on normal body cells. Thus, targeting HERV-K protein as a tumor associated antigen (TAA) may be a potential treatment strategy for tumors that are resistant to conventional therapies. One approach to improve therapeutic outcome is by infusing T cells rendered specific for such TAAs preferentially expressed on tumor cells. Recognition of cell-surface TAAs independent of major histocompatibility complex can be achieved by introducing a chimeric antigen receptor (CAR) on T cells using gene therapy. This approach is currently being used in our clinical trials adoptively transferring CD19-specific CAR+ T cells into patients with B-lineage malignancies. Preliminary analysis of HERV-K env protein expression in 268 melanoma samples and 139 normal organ donor tissues using immunohistochemistry demonstrated antigen expression in tumor cells and absence of expression in normal organ tissues. The scFv region from a mouse monoclonal antibody to target HERV-K env was used to generate a CAR and cloned into Sleeping Beauty (SB) plasmid for stable expression in T cells. HERV-K-specific CAR+T cells were selectively propagated ex vivo on artificial antigen presenting cells (aAPC) using an approach already in our clinical trials. Indeed, after genetic modification of T cells and selection on HERV-K+ aAPC, over 95% of propagated T cells stably expressed the introduced HERV-K-specific CAR and exhibited redirected specificity for HERV-K+ melanoma (Figure 1). Further, the adoptive transfer of HERV-K-specific CAR+T cells killed metastatic melanoma in a mouse xenograph model. While we have chosen melanoma as our tumor model, this study has the potential to be applied to other malignancies, including lymphoma and myeloma due to restricted expression of HERV-K envelope (env) protein on these tumor cells. These data demonstrate that it is feasible to generate T cells expressing a HERV-K-specific CAR using a clinically-appealing approach as a treatment strategy for HERV-K env+ tumors. Disclosures: No relevant conflicts of interest to declare.

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