GENERATION OF MEMORY STEM T CELLS (TSCM) MODIFIED WITH A NOVEL OPTIMIZED CD30-SPECIFIC CHIMERIC ANTIGEN RECEPTOR (CAR) FOR THE TREATMENT OF CD30+ T-CELL MALIGNANCIES
(Abstract release date: 05/18/17)
EHA Library. Escribà L. 06/25/17; 182103; S816
Laura Escribà
Contributions
Contributions
Abstract
Abstract: S816
Type: Oral Presentation
Presentation during EHA22: On Sunday, June 25, 2017 from 08:30 - 08:45
Location: Room N111
Background
Peripheral T-cell lymphomas (PTCL) represent the most aggressive form among non-Hodgkin lymphomas with a very poor prognosis (5-year survival of 30%), demanding innovative novel treatment strategies. Adoptive immunotherapy with chimeric antigen receptor (CAR) engineered T cells has demonstrated its therapeutic potential in advanced hematological malignancies. However, its application to PTCL remains a formidable challenge mainly due to a lack of truly tumor-specific antigens that are not expressed on normal T cells. Anaplastic large T-cell lymphomas (ALCL) and several other subtypes of PTCL express CD30, which is expressed by activated normal T cells but no other healthy tissues. Indeed, brentuximab vedotin, an anti-CD30 antibody-drug conjugate, has shown some clinical efficacy in PTCL and ALCL patients although duration of responses is short in the majority of cases.
Here, we developed a refined CD30-CAR T-cell approach to target CD30+ PTCL as a potential novel therapeutic strategy. We selected a novel targeting domain that is unaffected by soluble CD30 protein to prevent blockade of the CD30-CAR in vivo. Moreover, we optimized the therapy by using memory stem T cells (TSCM) to promote engraftment and persistence of CD30-CAR Tc ells after transfer, and we have included an EGFRt depletion marker as a safety feature.
Aims
We evaluated the antitumor effect of memory stem T cells (TSCM) genetically-modified with a novel CD30-specific CAR that recognizes a membrane-proximal epitope in the CD30 molecule in a CD30+ T-cell lymphoma model.
Methods
A second generation CD30-41BBz-EGFRt CAR was generated using a scFv that recognizes a tumor-cell membrane-proximal epitope of CD30 protein (Nagata S et al. Clin Cancer Res, 2002). Naive T cells from healthy donors were activated with anti-CD3/CD28 beads in presence of IL-7, IL-15 and IL-21 during 10 days to obtain a TSCM-enriched population (Alvarez C et al. J Transl Med, 2016); on day 2 of culture, cells were transduced with a third-generation lentiviral vector encoding the CD30-CAR. The anaplastic large T-cell lymphoma cell line Karpas 299 was used as tumor model. Cytotoxicity assay was performed at 4 hours at 10:1, 5:1, 1:1 and 1:5 effector/target (E/T) ratios, and the tumor cell death was detected by flow citometry. Cytokines (IFN-γ and IL-2) were analysed at 24 hours in a 5:1 E/T ratio culture using Luminex technology.
Results
TSCM were the most prevalent T-cell subset at day 10 of culture, representing 84 ± 3.1% of total cells, and the CD30-CAR expression in these cells was 76.9 ± 1.0% in CD4+ TSCM and 77.3 ± 2.0% in CD8+ TSCM. Although CD30 protein was detected in a fraction of activated T cells in culture (CD4+ T cells: 32.4 ± 2.1%; CD8+ T cells: 59 ± 4.3%), lentiviral transduction of TSCM with our CD30-CAR did not compromise their ex vivo expansion (CD4+ CD30-CAR TSCM: 96.0 ± 3.2 fold expansion; CD8+ CD30-CAR TSCM: 109.0 ± 4.2 fold expansion). CD8+ CD30-CAR TSCM conferred specific cytolytic activity and lysed Karpas 299 cells in vitro (tumor cell death 1:1 ratio: 92.6 ± 2.4% vs. 0% with untransduced TSCM; p<0.001), while control CD30- target cells (Raji) were not recognized. In addition, CD30-CAR TSCM secreted IFN-γ and IL-2 after stimulation with Karpas 299 cells (IFN-γ: 126.6 ± 18.12 pg/ml vs. 5.03 ± 0.16 pg/ml with control targets, p=0.002; IL-2: 20.47 ± 2.3 pg/ml vs. 4.06 ± 0.24 pg/ml, p=0.002, respectively).
Conclusion
Collectively, our data demonstrate the potential to generate CD30-CAR T cells with enhanced functional attributes against CD30+ PTCL. TSCM cells can be efficiently transduced and ex vivo expanded with a novel CD30-CAR and confer potent antitumor efficacy against CD30+ PTCL in vitro. Our findings suggest the potential to improve outcome of patients with CD30+ PTCL through adoptive therapy with CD30-CAR modified T cells.
Session topic: 24. Gene therapy, cellular immunotherapy and vaccination
Keyword(s): Memory T cells, CD30, Adoptive immunotherapy, t cell lymphoma
Abstract: S816
Type: Oral Presentation
Presentation during EHA22: On Sunday, June 25, 2017 from 08:30 - 08:45
Location: Room N111
Background
Peripheral T-cell lymphomas (PTCL) represent the most aggressive form among non-Hodgkin lymphomas with a very poor prognosis (5-year survival of 30%), demanding innovative novel treatment strategies. Adoptive immunotherapy with chimeric antigen receptor (CAR) engineered T cells has demonstrated its therapeutic potential in advanced hematological malignancies. However, its application to PTCL remains a formidable challenge mainly due to a lack of truly tumor-specific antigens that are not expressed on normal T cells. Anaplastic large T-cell lymphomas (ALCL) and several other subtypes of PTCL express CD30, which is expressed by activated normal T cells but no other healthy tissues. Indeed, brentuximab vedotin, an anti-CD30 antibody-drug conjugate, has shown some clinical efficacy in PTCL and ALCL patients although duration of responses is short in the majority of cases.
Here, we developed a refined CD30-CAR T-cell approach to target CD30+ PTCL as a potential novel therapeutic strategy. We selected a novel targeting domain that is unaffected by soluble CD30 protein to prevent blockade of the CD30-CAR in vivo. Moreover, we optimized the therapy by using memory stem T cells (TSCM) to promote engraftment and persistence of CD30-CAR Tc ells after transfer, and we have included an EGFRt depletion marker as a safety feature.
Aims
We evaluated the antitumor effect of memory stem T cells (TSCM) genetically-modified with a novel CD30-specific CAR that recognizes a membrane-proximal epitope in the CD30 molecule in a CD30+ T-cell lymphoma model.
Methods
A second generation CD30-41BBz-EGFRt CAR was generated using a scFv that recognizes a tumor-cell membrane-proximal epitope of CD30 protein (Nagata S et al. Clin Cancer Res, 2002). Naive T cells from healthy donors were activated with anti-CD3/CD28 beads in presence of IL-7, IL-15 and IL-21 during 10 days to obtain a TSCM-enriched population (Alvarez C et al. J Transl Med, 2016); on day 2 of culture, cells were transduced with a third-generation lentiviral vector encoding the CD30-CAR. The anaplastic large T-cell lymphoma cell line Karpas 299 was used as tumor model. Cytotoxicity assay was performed at 4 hours at 10:1, 5:1, 1:1 and 1:5 effector/target (E/T) ratios, and the tumor cell death was detected by flow citometry. Cytokines (IFN-γ and IL-2) were analysed at 24 hours in a 5:1 E/T ratio culture using Luminex technology.
Results
TSCM were the most prevalent T-cell subset at day 10 of culture, representing 84 ± 3.1% of total cells, and the CD30-CAR expression in these cells was 76.9 ± 1.0% in CD4+ TSCM and 77.3 ± 2.0% in CD8+ TSCM. Although CD30 protein was detected in a fraction of activated T cells in culture (CD4+ T cells: 32.4 ± 2.1%; CD8+ T cells: 59 ± 4.3%), lentiviral transduction of TSCM with our CD30-CAR did not compromise their ex vivo expansion (CD4+ CD30-CAR TSCM: 96.0 ± 3.2 fold expansion; CD8+ CD30-CAR TSCM: 109.0 ± 4.2 fold expansion). CD8+ CD30-CAR TSCM conferred specific cytolytic activity and lysed Karpas 299 cells in vitro (tumor cell death 1:1 ratio: 92.6 ± 2.4% vs. 0% with untransduced TSCM; p<0.001), while control CD30- target cells (Raji) were not recognized. In addition, CD30-CAR TSCM secreted IFN-γ and IL-2 after stimulation with Karpas 299 cells (IFN-γ: 126.6 ± 18.12 pg/ml vs. 5.03 ± 0.16 pg/ml with control targets, p=0.002; IL-2: 20.47 ± 2.3 pg/ml vs. 4.06 ± 0.24 pg/ml, p=0.002, respectively).
Conclusion
Collectively, our data demonstrate the potential to generate CD30-CAR T cells with enhanced functional attributes against CD30+ PTCL. TSCM cells can be efficiently transduced and ex vivo expanded with a novel CD30-CAR and confer potent antitumor efficacy against CD30+ PTCL in vitro. Our findings suggest the potential to improve outcome of patients with CD30+ PTCL through adoptive therapy with CD30-CAR modified T cells.
Session topic: 24. Gene therapy, cellular immunotherapy and vaccination
Keyword(s): Memory T cells, CD30, Adoptive immunotherapy, t cell lymphoma
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