scholarly journals Base-edited CAR T cells for combinational therapy against T cell malignancies

Leukemia ◽  
2021 ◽  
Author(s):  
Christos Georgiadis ◽  
Jane Rasaiyaah ◽  
Soragia Athina Gkazi ◽  
Roland Preece ◽  
Aniekan Etuk ◽  
...  

AbstractTargeting T cell malignancies using chimeric antigen receptor (CAR) T cells is hindered by ‘T v T’ fratricide against shared antigens such as CD3 and CD7. Base editing offers the possibility of seamless disruption of gene expression of problematic antigens through creation of stop codons or elimination of splice sites. We describe the generation of fratricide-resistant T cells by orderly removal of TCR/CD3 and CD7 ahead of lentiviral-mediated expression of CARs specific for CD3 or CD7. Molecular interrogation of base-edited cells confirmed elimination of chromosomal translocations detected in conventional Cas9 treated cells. Interestingly, 3CAR/7CAR co-culture resulted in ‘self-enrichment’ yielding populations 99.6% TCR−/CD3−/CD7−. 3CAR or 7CAR cells were able to exert specific cytotoxicity against leukaemia lines with defined CD3 and/or CD7 expression as well as primary T-ALL cells. Co-cultured 3CAR/7CAR cells exhibited highest cytotoxicity against CD3 + CD7 + T-ALL targets in vitro and an in vivo human:murine chimeric model. While APOBEC editors can reportedly exhibit guide-independent deamination of both DNA and RNA, we found no problematic ‘off-target’ activity or promiscuous base conversion affecting CAR antigen-specific binding regions, which may otherwise redirect T cell specificity. Combinational infusion of fratricide-resistant anti-T CAR T cells may enable enhanced molecular remission ahead of allo-HSCT for T cell malignancies.

2020 ◽  
Author(s):  
Christos Georgiadis ◽  
Jane Rasaiyaah ◽  
Soragia Athina Gkazi ◽  
Roland Preece ◽  
Aniekan Etuk ◽  
...  

AbstractTargeting T cell malignancies using chimeric antigen receptor (CAR) T cells is hindered by ‘T v T’ fratricide against shared antigens such as CD3 and CD7. Genome-editing can overcome such hurdles through targeted disruption of problematic shared antigens. Base editing offers the possibility of seamless disruption of gene expression through the creation of stop codons or elimination of splice donor or acceptor sites. We describe the generation of fratricide resistant, T cells by orderly removal of shared antigens such as TCR/CD3 and CD7 ahead of lentiviral mediated expression of CARs specific for CD3 or CD7. Molecular interrogation of base edited cells confirmed virtual elimination of chromosomal translocation events detected in conventional Cas9 treated cells. Interestingly, co-culture of 3CAR and 7CAR cells resulted in ‘self-enrichment’ yielding populations that were 99.6% TCR-/CD3/-CD7-. 3CAR or 7CAR cells were able to exert specific cytotoxicity against their relevant target antigen in leukaemia lines with defined CD3 and/or CD7 expression as well as primary T-ALL cells. Co-cultured 3CAR/7CAR cells exhibited the highest level of cytotoxicity against T-ALL targets expressing both target in vitro and an in vivo human:murine chimeric model. While APOBEC editors can reportedly exhibit guide-independent deamination of both DNA and RNA, we found no evidence of promiscuous base conversion activity affecting CAR antigen specific binding regions which may otherwise redirect T cell specificity. Combinational infusion of fratricide resistant anti-T CAR T cells may enable enhanced molecular remission ahead of allogeneic haematopoietic stem cell transplantation for T cell malignancies.


Blood ◽  
2017 ◽  
Vol 130 (3) ◽  
pp. 285-296 ◽  
Author(s):  
Diogo Gomes-Silva ◽  
Madhuwanti Srinivasan ◽  
Sandhya Sharma ◽  
Ciaran M. Lee ◽  
Dimitrios L. Wagner ◽  
...  

Key Points Genomic disruption of CD7 prior to CAR transduction allows generation of CD7 CAR T cells without extensive self-antigen-driven fratricide. CD7 CAR T cells have robust activity against T-cell malignancies in vitro and in vivo.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A109-A109
Author(s):  
Jiangyue Liu ◽  
Xianhui Chen ◽  
Jason Karlen ◽  
Alfonso Brito ◽  
Tiffany Jheng ◽  
...  

BackgroundMesothelin (MSLN) is a glycosylphosphatidylinositol (GPI)-anchored membrane protein with high expression levels in an array of malignancies including mesothelioma, ovaria, non-small cell lung cancer, and pancreatic cancers and is an attractive target antigen for immune-based therapies. Early clinical evaluation of autologous MSLN-targeted chimeric antigen receptor (CAR)-T cell therapies for malignant pleural mesothelioma has shown promising acceptable safety1 and have recently evolved with incorporation of next-generation CAR co-stimulatory domains and armoring with intrinsic checkpoint inhibition via expression of a PD-1 dominant negative receptor (PD1DNR).2 Despite the promise that MSLN CAR-T therapies hold, manufacturing and commercial challenges using an autologous approach may prove difficult for widespread application. EBV T cells represent a unique, non-gene edited approach toward an off-the-shelf, allogeneic T cell platform. EBV-specific T cells are currently being evaluated in phase 3 trials [NCT03394365] and, to-date, have demonstrated a favorable safety profile including limited risks for GvHD and cytokine release syndrome.3 4 Clinical proof-of-principle studies for CAR transduced allogeneic EBV T cell therapies have also been associated with acceptable safety and durable response in association with CD19 targeting.5 Here we describe the first preclinical evaluation of ATA3271, a next-generation allogeneic CAR EBV T cell therapy targeting MSLN and incorporating PD1DNR, designed for the treatment of solid tumor indications.MethodsWe generated allogeneic MSLN CAR+ EBV T cells (ATA3271) using retroviral transduction of EBV T cells. ATA3271 includes a novel 1XX CAR signaling domain, previously associated with improved signaling and decreased CAR-mediated exhaustion. It is also armored with PD1DNR to provide intrinsic checkpoint blockade and is designed to retain functional persistence.ResultsIn this study, we characterized ATA3271 both in vitro and in vivo. ATA3271 show stable and proportional CAR and PD1DNR expression. Functional studies show potent antitumor activity of ATA3271 against MSLN-expressing cell lines, including PD-L1-high expressors. In an orthotopic mouse model of pleural mesothelioma, ATA3271 demonstrates potent antitumor activity and significant survival benefit (100% survival exceeding 50 days vs. 25 day median for control), without evident toxicities. ATA3271 maintains persistence and retains central memory phenotype in vivo through end-of-study. Additionally, ATA3271 retains endogenous EBV TCR function and reduced allotoxicity in the context of HLA mismatched targets. ConclusionsOverall, ATA3271 shows potent anti-tumor activity without evidence of allotoxicity, both in vitro and in vivo, suggesting that allogeneic MSLN-CAR-engineered EBV T cells are a promising approach for the treatment of MSLN-positive cancers and warrant further clinical investigation.ReferencesAdusumilli PS, Zauderer MG, Rusch VW, et al. Abstract CT036: A phase I clinical trial of malignant pleural disease treated with regionally delivered autologous mesothelin-targeted CAR T cells: Safety and efficacy. Cancer Research 2019;79:CT036-CT036.Kiesgen S, Linot C, Quach HT, et al. Abstract LB-378: Regional delivery of clinical-grade mesothelin-targeted CAR T cells with cell-intrinsic PD-1 checkpoint blockade: Translation to a phase I trial. Cancer Research 2020;80:LB-378-LB-378.Prockop S, Doubrovina E, Suser S, et al. Off-the-shelf EBV-specific T cell immunotherapy for rituximab-refractory EBV-associated lymphoma following transplantation. J Clin Invest 2020;130:733–747.Prockop S, Hiremath M, Ye W, et al. A Multicenter, Open Label, Phase 3 Study of Tabelecleucel for Solid Organ Transplant Subjects with Epstein-Barr Virus-Driven Post-Transplant Lymphoproliferative Disease (EBV+PTLD) after Failure of Rituximab or Rituximab and Chemotherapy. Blood 2019; 134: 5326–5326.Curran KJ, Sauter CS, Kernan NA, et al. Durable remission following ‘Off-the-Shelf’ chimeric antigen receptor (CAR) T-Cells in patients with relapse/refractory (R/R) B-Cell malignancies. Biology of Blood and Marrow Transplantation 2020;26:S89.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A121-A121
Author(s):  
Nina Chu ◽  
Michael Overstreet ◽  
Ryan Gilbreth ◽  
Lori Clarke ◽  
Christina Gesse ◽  
...  

BackgroundChimeric antigen receptors (CARs) are engineered synthetic receptors that reprogram T cell specificity and function against a given antigen. Autologous CAR-T cell therapy has demonstrated potent efficacy against various hematological malignancies, but has yielded limited success against solid cancers. MEDI7028 is a CAR that targets oncofetal antigen glypican-3 (GPC3), which is expressed in 70–90% of hepatocellular carcinoma (HCC), but not in normal liver tissue. Transforming growth factor β (TGFβ) secretion is increased in advanced HCC, which creates an immunosuppressive milieu and facilitates cancer progression and poor prognosis. We tested whether the anti-tumor efficacy of a GPC3 CAR-T can be enhanced with the co-expression of dominant-negative TGFβRII (TGFβRIIDN).MethodsPrimary human T cells were lentivirally transduced to express GPC3 CAR both with and without TGFβRIIDN. Western blot and flow cytometry were performed on purified CAR-T cells to assess modulation of pathways and immune phenotypes driven by TGFβ in vitro. A xenograft model of human HCC cell line overexpressing TGFβ in immunodeficient mice was used to investigate the in vivo efficacy of TGFβRIIDN armored and unarmored CAR-T. Tumor infiltrating lymphocyte populations were analyzed by flow cytometry while serum cytokine levels were quantified with ELISA.ResultsArmoring GPC3 CAR-T with TGFβRIIDN nearly abolished phospho-SMAD2/3 expression upon exposure to recombinant human TGFβ in vitro, indicating that the TGFβ signaling axis was successfully blocked by expression of the dominant-negative receptor. Additionally, expression of TGFβRIIDN suppressed TGFβ-driven CD103 upregulation, further demonstrating attenuation of the pathway by this armoring strategy. In vivo, the TGFβRIIDN armored CAR-T achieved superior tumor regression and delayed tumor regrowth compared to the unarmored CAR-T. The armored CAR-T cells infiltrated HCC tumors more abundantly than their unarmored counterparts, and were phenotypically less exhausted and less differentiated. In line with these observations, we detected significantly more interferon gamma (IFNγ) at peak response and decreased alpha-fetoprotein in the serum of mice treated with armored cells compared to mice receiving unarmored CAR-T, demonstrating in vivo functional superiority of TGFβRIIDN armored CAR-T therapy.ConclusionsArmoring GPC3 CAR-T with TGFβRIIDN abrogates the signaling of TGFβ in vitro and enhances the anti-tumor efficacy of GPC3 CAR-T against TGFβ-expressing HCC tumors in vivo, proving TGFβRIIDN to be an effective armoring strategy against TGFβ-expressing solid malignancies in preclinical models.Ethics ApprovalThe study was approved by AstraZeneca’s Ethics Board and Institutional Animal Care and Use Committee (IACUC).


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A133-A133
Author(s):  
Cheng-Fu Kuo ◽  
Yi-Chiu Kuo ◽  
Miso Park ◽  
Zhen Tong ◽  
Brenda Aguilar ◽  
...  

BackgroundMeditope is a small cyclic peptide that was identified to bind to cetuximab within the Fab region. The meditope binding site can be grafted onto any Fab framework, creating a platform to uniquely and specifically target monoclonal antibodies. Here we demonstrate that the meditope binding site can be grafted onto chimeric antigen receptors (CARs) and utilized to regulate and extend CAR T cell function. We demonstrate that the platform can be used to overcome key barriers to CAR T cell therapy, including T cell exhaustion and antigen escape.MethodsMeditope-enabled CARs (meCARs) were generated by amino acid substitutions to create binding sites for meditope peptide (meP) within the Fab tumor targeting domain of the CAR. meCAR expression was validated by anti-Fc FITC or meP-Alexa 647 probes. In vitro and in vivo assays were performed and compared to standard scFv CAR T cells. For meCAR T cell proliferation and dual-targeting assays, the meditope peptide (meP) was conjugated to recombinant human IL15 fused to the CD215 sushi domain (meP-IL15:sushi) and anti-CD20 monoclonal antibody rituximab (meP-rituximab).ResultsWe generated meCAR T cells targeting HER2, CD19 and HER1/3 and demonstrate the selective specific binding of the meditope peptide along with potent meCAR T cell effector function. We next demonstrated the utility of a meP-IL15:sushi for enhancing meCAR T cell proliferation in vitro and in vivo. Proliferation and persistence of meCAR T cells was dose dependent, establishing the ability to regulate CAR T cell expansion using the meditope platform. We also demonstrate the ability to redirect meCAR T cells tumor killing using meP-antibody adaptors. As proof-of-concept, meHER2-CAR T cells were redirected to target CD20+ Raji tumors, establishing the potential of the meditope platform to alter the CAR specificity and overcome tumor heterogeneity.ConclusionsOur studies show the utility of the meCAR platform for overcoming key challenges for CAR T cell therapy by specifically regulating CAR T cell functionality. Specifically, the meP-IL15:sushi enhanced meCAR T cell persistence and proliferation following adoptive transfer in vivo and protects against T cell exhaustion. Further, meP-ritiuximab can redirect meCAR T cells to target CD20-tumors, showing the versatility of this platform to address the tumor antigen escape variants. Future studies are focused on conferring additional ‘add-on’ functionalities to meCAR T cells to potentiate the therapeutic effectiveness of CAR T cell therapy.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaojuan Shi ◽  
Daiqun Zhang ◽  
Feng Li ◽  
Zhen Zhang ◽  
Shumin Wang ◽  
...  

AbstractAsparagine-linked (N-linked) glycosylation is ubiquitous and can stabilize immune inhibitory PD-1 protein. Reducing N-linked glycosylation of PD-1 may decrease PD-1 expression and relieve its inhibitory effects on CAR-T cells. Considering that the codon of Asparagine is aac or aat, we wondered if the adenine base editor (ABE), which induces a·t to g·c conversion at specific site, could be used to reduce PD-1 suppression by changing the glycosylated residue in CAR-T cells. Our results showed ABE editing altered the coding sequence of N74 residue of PDCD1 and downregulated PD-1 expression in CAR-T cells. Further analysis showed ABE-edited CAR-T cells had enhanced cytotoxic functions in vitro and in vivo. Our study suggested that the single base editors can be used to augment CAR-T cell therapy.


Blood ◽  
2019 ◽  
Vol 133 (21) ◽  
pp. 2291-2304 ◽  
Author(s):  
Diego Sánchez-Martínez ◽  
Matteo L. Baroni ◽  
Francisco Gutierrez-Agüera ◽  
Heleia Roca-Ho ◽  
Oscar Blanch-Lombarte ◽  
...  

Abstract Relapsed/refractory T-cell acute lymphoblastic leukemia (T-ALL) has a dismal outcome, and no effective targeted immunotherapies for T-ALL exist. The extension of chimeric antigen receptor (CAR) T cells (CARTs) to T-ALL remains challenging because the shared expression of target antigens between CARTs and T-ALL blasts leads to CART fratricide. CD1a is exclusively expressed in cortical T-ALL (coT-ALL), a major subset of T-ALL, and retained at relapse. This article reports that the expression of CD1a is mainly restricted to developing cortical thymocytes, and neither CD34+ progenitors nor T cells express CD1a during ontogeny, confining the risk of on-target/off-tumor toxicity. We thus developed and preclinically validated a CD1a-specific CAR with robust and specific cytotoxicity in vitro and antileukemic activity in vivo in xenograft models of coT-ALL, using both cell lines and coT-ALL patient–derived primary blasts. CD1a-CARTs are fratricide resistant, persist long term in vivo (retaining antileukemic activity in re-challenge experiments), and respond to viral antigens. Our data support the therapeutic and safe use of fratricide-resistant CD1a-CARTs for relapsed/refractory coT-ALL.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2776-2776
Author(s):  
Salvatore Fiorenza ◽  
George S. Laszlo ◽  
Tinh-Doan Phi ◽  
Margaret C. Lunn ◽  
Delaney R. Kirchmeier ◽  
...  

Abstract Background: There is increasing interest in targeting CD33 in malignant and non-malignant disorders, but available drugs are ineffective in many patients. As one limitation, therapeutic CD33 antibodies typically recognize the membrane-distal V-set domain. Likewise, currently tested CD33-directed chimeric antigen receptor (CAR) T cells likewise target the V-set domain and have thus far shown limited clinical activity. We have recently demonstrated that binding closer to the cell membrane enhances the effector functions of CD33 antibodies. We therefore raised antibodies against the membrane-proximal C2-set domain of CD33 and identified antibodies that bound CD33 regardless of the presence/absence of the V-set domain ("CD33 PAN antibodies"). Here, we tested their properties as targeting moiety in CD33 PAN CAR T cell constructs, using a clinically validated lentiviral backbone. Methods: To generate CAR T cells, negatively selected CD8 + T cells were transduced with an epHIV7 lentivirus encoding the scFv from a CD33 PAN antibody (clone 1H7 or 9G2) linked to either a short (IgG 4 hinge only), intermediate (hinge plus IgG 4 CH3 domain), or long (hinge plus IgG 4 CH3 domain plus IgG 4 CH2 domain) spacer, the CD28-transmembrane domain, CD3zeta and 4-1BB intracellular signaling domains, and non-functional truncated CD19 (tCD19) as transduction marker. Similar constructs using scFvs from 2 different V-set domain-targeting CD33 antibodies, including hP67.6 (My96; used in gemtuzumab ozogamicin), were generated for comparison. CAR-T cells were sorted, expanded in IL-7 and IL-15, and used in vitro or in vivo against human AML cell lines endogenously expressing CD33 and cell lines engineered to lack CD33 (via CRISPR/Cas9) with/or without forced expression of different CD33 variants. Results: CD33 V-set-directed CAR T cells exerted significantly more cytolytic activity against AML cells expressing an artificial CD33 variant lacking the C2-set domain (CD33 ΔE3-4) than cells expressing full-length CD33 at similar or higher levels, consistent with the notion that CD33 CAR T cell efficacy is enhanced when targeting an epitope that is located closer to the cell membrane. CD33 PAN CAR T cells were highly potent against human AML cells in a strictly CD33-dependent fashion, with constructs containing the short and intermediate-length spacer demonstrating robust cytokine secretion, cell proliferation, and in vitro cytolytic activity, as determined by 51Cr release cytotoxicity assays. When compared to optimized CD33 V-set CAR T cells, optimized CD33 PAN CAR T cells were significantly more potent in cytotoxicity, proliferation, and cytokine production without appreciably increased acquisition of exhaustion markers. In vivo, CD33 PAN CAR T cells extended survival in immunodeficient NOD.SCID. IL2rg -/- (NSG) mice bearing significant leukemic burdens from various cell line-derived xenografts (HL-60, KG1α and MOLM14) with efficient tumor clearance demonstrated in a dose-dependent fashion. Conclusion: Targeting the membrane proximal domain of CD33 enhances the anti-leukemic potency of CAR T cells. Our data provide the rationale for the further development of CD33 PAN CAR T cells toward clinical testing. Disclosures Fiorenza: Link Immunotherapeutics: Consultancy; Bristol Myers Squibb: Research Funding. Godwin: Pfizer: Research Funding; Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Turtle: Allogene: Consultancy; Amgen: Consultancy; Arsenal Bio: Consultancy; Asher bio: Consultancy; Astrazeneca: Consultancy, Research Funding; Caribou Biosciences: Consultancy, Current holder of individual stocks in a privately-held company; Century Therapeutics: Consultancy, Other; Eureka therapeutics: Current holder of individual stocks in a privately-held company, Other; Juno therapeutics/BMS: Patents & Royalties, Research Funding; Myeloid Therapeutics: Current holder of individual stocks in a privately-held company, Other; Nektar therapeutics: Consultancy, Research Funding; PACT Pharma: Consultancy; Precision Biosciences: Current holder of individual stocks in a privately-held company, Other; T-CURX: Other; TCR2 Therapeutics: Research Funding. Walter: Kite: Consultancy; Janssen: Consultancy; Genentech: Consultancy; BMS: Consultancy; Astellas: Consultancy; Agios: Consultancy; Amphivena: Consultancy, Other: ownership interests; Selvita: Research Funding; Pfizer: Consultancy, Research Funding; Jazz: Research Funding; Macrogenics: Consultancy, Research Funding; Immunogen: Research Funding; Celgene: Consultancy, Research Funding; Aptevo: Consultancy, Research Funding; Amgen: Research Funding.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 27-28
Author(s):  
A. Samer Al-Homsi ◽  
Sebastien Anguille ◽  
Jason Brayer ◽  
Dries Deeren ◽  
Nathalie Meuleman ◽  
...  

Background Autologous CAR T-cell therapy targeting the B-cell maturation antigen (BCMA) has shown impressive objective response rates in patients with advanced multiple myeloma (MM). Clinical grade manufacturing of autologous CAR T-cells has limitations including vein-to-vein delivery time delay and potentially sub-optimal immunological capability of T-cells isolated from patients with advanced disease. Allogeneic CAR T-cell products, whereby cells from healthy third-party donors are used to generate an "off-the-shelf" CAR T-cell product, have the potential to overcome some of these issues. To circumvent the primary potential risk of graft-versus-host disease (GvHD) associated with the use of allogeneic T-cells, abrogation of the T-cell receptor (TCR) expression in the CAR T-cells, via gene editing, is being actively pursued. To avoid the potential safety risks and manufacturing challenges associated with gene editing, the allogeneic CYAD-211 CAR T-cell product exploits short hairpin RNA (shRNA) interference technology to down-regulate TCR expression thus avoiding the risk of life-threatening GvHD. Aim The aim is to generate a BCMA-specific allogeneic CAR T-cell product using a non-gene editing approach and study its activity both in vitro and in vivo. CYAD-211 combines a BCMA-specific CAR with a single optimized shRNA targeting the TCR CD3ζ subunit. Downregulation of CD3ζ impairs the TCR expression on the surface of the donor T-cells, preventing their reactivity with the normal host tissue cells and potential GvHD induction. Maintaining all the elements required for the therapy within a single vector (all-in-one vector) provides some significant manufacturing advantages, as a solitary selection step will isolate cells expressing all the desired traits. Results CYAD-211 cells produce high amounts of interferon-gamma (IFN-γ) during in vitro co-cultures with various BCMA-expressing MM cell lines (i.e., RPMI-8226, OPM-2, U266, and KMS-11). Cytotoxicity experiments confirmed that CYAD-211 efficiently kills MM cell lines in a BCMA-specific manner. The anti-tumor efficacy of CYAD-211 was further confirmed in vivo, in xenograft MM models using the RPMI-8226 and KMS-11 cell lines. Preclinical data also showed no demonstrable evidence of GvHD when CYAD-211 was infused in NSG mice confirming efficient inhibition of TCR-induced activation. Following FDA acceptance of the IND application, IMMUNICY-1, a first-in-human, open-label dose-escalation phase I clinical study evaluating the safety and clinical activity of CYAD-211 for the treatment of relapsed or refractory MM patients to at least two prior MM treatment regimens, is scheduled to begin recruitment. IMMUNICY-1 will evaluate three dose-levels of CYAD-211 (3x107, 1x108 and 3x108 cells/infusion) administered as a single infusion after a non-myeloablative conditioning (cyclophosphamide 300 mg/m²/day and fludarabine 30 mg/m²/day, daily for 3 days) according to a classical Fibonacci 3+3 design. Description of the study design and preliminary safety and clinical data from the first cohort will be presented at ASH 2020. Conclusion CYAD-211 is the first generation of non-gene edited allogeneic CAR T-cell product based on shRNA technology. The IMMUNICY-1 clinical study seeks to provide proof of principle that single shRNA-mediated knockdown can generate fully functional allogeneic CAR T-cells in humans without GvHD-inducing potential. We anticipate that subsequent generations of this technology will incorporate multiple shRNA hairpins within a single vector system. This will enable the production of allogeneic CAR T-cells in which multiple genes of interest are modulated simultaneously thereby providing a platform approach that can underpin the future of this therapeutic modality. Figure 1 Disclosures Al-Homsi: Celyad: Membership on an entity's Board of Directors or advisory committees. Brayer:Janssen: Consultancy; Bristol-Myers Squibb, WindMIL Therapeutics: Research Funding; Bristol-Myers Squibb, Janssen, Amgen: Speakers Bureau. Nishihori:Novartis: Other: Research support to institution; Karyopharm: Other: Research support to institution. Sotiropoulou:Celyad Oncology: Current Employment. Twyffels:Celyad Oncology: Current Employment. Bolsee:Celyad Oncology: Current Employment. Braun:Celyad Oncology: Current Employment. Lonez:Celyad Oncology: Current Employment. Gilham:Celyad Oncology: Current Employment. Flament:Celyad Oncology: Current Employment. Lehmann:Celyad Oncology: Current Employment.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1934-1934 ◽  
Author(s):  
Eduardo Huarte ◽  
Roddy S O'Connor ◽  
Melissa Parker ◽  
Taisheng Huang ◽  
Michael C. Milone ◽  
...  

Background: T-cells engineered to express a chimeric antigen receptor (CAR-T-cells) are a promising cancer immunotherapy. Such targeted therapies have shown long-term relapse survival in patients with B cell leukemia and lymphoma. However, cytokine release syndrome (CRS) represents a serious, potentially life-threatening, side effect often associated with CAR-T cells therapy. The Janus kinase (JAK) tyrosine kinase family is pivotal for the downstream signaling of inflammatory cytokines, including interleukins (ILs), interferons (IFNs), and multiple growth factors. CRS manifests as a rapid (hyper)immune reaction driven by excessive inflammatory cytokine release, including IFN-g and IL-6. Itacitinib is a potent, selective JAK1 inhibitor which is being clinically evaluated in several inflammatory diseases. Aims: To evaluate in vitro and in vivo the potential of itacitinib to modulate CRS without impairing CAR-T cell anti-tumor activity. Materials and Methods: In vitro proliferation and cytotoxic activity of T cells and CAR-T cells was measured in the presence of increasing concentrations of itacitinib or tocilizumab (anti-IL-6R). To evaluate itacitinib effects in vivo, we conducted experiments involving adoptive transfer of human CD19-CAR-T-cells in immunodeficient animals (NSG) bearing CD19 expressing NAMALWA human lymphoma cells. The effect of itacitinib on cytokine production was studied on CD19-CAR-T-cells expanded in the presence of itacitinib or tocilizumab. Finally, to study whether itacitinib was able to reduce CRS symptoms in an in vivo setting, naïve mice were stimulated with Concanavalin-A (ConA), a potent T-cell mitogen capable of inducing broad inflammatory cytokine releases and proliferation. Results: In vitro, itacitinib at IC50 relevant concentrations did not significantly inhibit proliferation or anti-tumor killing capacity of human CAR-T-cells. Itacitinib and tocilizumab (anti-IL-6R) demonstrated a similar effect on CAR T-cell cytotoxic activity profile. In vivo, CD19-CAR-T-cells adoptively transferred into CD19+ tumor bearing immunodeficient animals were unaffected by oral itacitinib treatment. In an in vitro model, itacitinib was more effective than tocilizumab in reducing CRS-related cytokines produced by CD19-CAR-T-cells. Furthermore, in the in vivo immune hyperactivity (ConA) model, itacitinib reduced serum levels of CRS-related cytokines in a dose-dependent manner. Conclusion: Itacitinib at IC50 and clinically relevant concentrations did not adversely impair the in vitro or in vivo anti-tumor activity of CAR-T cells. Using CAR-T and T cell in vitro and in vivo systems, we demonstrate that itacitinib significantly reduces CRS-associated cytokines in a dose dependent manner. Together, the data suggest that itacitinib may have potential as a prophylactic agent for the prevention of CAR-T cell induced CRS. Disclosures Huarte: Incyte corporation: Employment, Equity Ownership. Parker:Incyte corporation: Employment, Equity Ownership. Huang:Incyte corporation: Employment, Equity Ownership. Milone:Novartis: Patents & Royalties: patents related to tisagenlecleucel (CTL019) and CART-BCMA; Novartis: Research Funding. Smith:Incyte corporation: Employment, Equity Ownership.


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