Immune Checkpoints and CAR-T Cells: The Pioneers in Future Cancer Therapies?

Although the ever-increasing number of cancer patients pose substantial challenges worldwide, finding a treatment with the highest response rate and the lowest number of side effects is still undergoing research. Compared to chemotherapy, the relatively low side effects of cancer immunotherapy have provided ample opportunity for immunotherapy to become a promising approach for patients with malignancy. However, the clinical translation of immune-based therapies requires robust anti-tumoral immune responses. Immune checkpoints have substantial roles in the induction of an immunosuppressive tumor microenvironment and tolerance against tumor antigens. Identifying and targeting these inhibitory axes, which can be established between tumor cells and tumor-infiltrating lymphocytes, can facilitate the development of anti-tumoral immune responses. Bispecific T-cell engagers, which can attract lymphocytes to the tumor microenvironment, have also paved the road for immunological-based tumor elimination. The development of CAR-T cells and their gene editing have brought ample opportunity to recognize tumor antigens, independent from immune checkpoints and the major histocompatibility complex (MHC). Indeed, there have been remarkable advances in developing various CAR-T cells to target tumoral cells. Knockout of immune checkpoints via gene editing in CAR-T cells might be designated for a breakthrough for patients with malignancy. In the midst of this fast progress in cancer immunotherapies, there is a need to provide up-to-date information regarding immune checkpoints, bispecific T-cell engagers, and CAR-T cells. Therefore, this review aims to provide recent findings of immune checkpoints, bispecific T-cell engagers, and CAR-T cells in cancer immunotherapy and discuss the pertained clinical trials.

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Evaluation of chimeric antigen receptor T cell therapy in non-human primates infected with SHIV or SIV

PLoS ONE ◽

10.1371/journal.pone.0248973 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0248973

Author(s):

Nami Iwamoto ◽

Bhavik Patel ◽

Kaimei Song ◽

Rosemarie Mason ◽

Sara Bolivar-Wagers ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

Chimeric Antigen Receptor ◽

Viral Suppression ◽

Antigen Receptor ◽

T Cell Therapy ◽

Car T Cells ◽

Car T

Achieving a functional cure is an important goal in the development of HIV therapy. Eliciting HIV-specific cellular immune responses has not been sufficient to achieve durable removal of HIV-infected cells due to the restriction on effective immune responses by mutation and establishment of latent reservoirs. Chimeric antigen receptor (CAR) T cells are an avenue to potentially develop more potent redirected cellular responses against infected T cells. We developed and tested a range of HIV- and SIV-specific chimeric antigen receptor (CAR) T cell reagents based on Env-binding proteins. In general, SHIV/SIV CAR T cells showed potent viral suppression in vitro, and adding additional CAR molecules in the same transduction resulted in more potent viral suppression than single CAR transduction. Importantly, the primary determinant of virus suppression potency by CAR was the accessibility to the Env epitope, and not the neutralization potency of the binding moiety. However, upon transduction of autologous T cells followed by infusion in vivo, none of these CAR T cells impacted either acquisition as a test of prevention, or viremia as a test of treatment. Our study illustrates limitations of the CAR T cells as possible antiviral therapeutics.

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Efficiency and side effects of anti-CD38 CAR T cells in an adult patient with relapsed B-ALL after failure of bi-specific CD19/CD22 CAR T cell treatment

Cellular and Molecular Immunology ◽

10.1038/s41423-019-0355-5 ◽

2020 ◽

Vol 17 (4) ◽

pp. 430-432 ◽

Cited By ~ 2

Author(s):

Yelei Guo ◽

Kaichao Feng ◽

Chuan Tong ◽

Hejin Jia ◽

Yang Liu ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Side Effects ◽

Adult Patient ◽

Car T Cells ◽

Car T Cell ◽

Car T

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Strengthening the CAR-T Cell Therapeutic Application using CRISPR/Cas9 Technology

10.22541/au.162058094.49226022/v1 ◽

2021 ◽

Author(s):

Muhammad Sadeqi Nezhad ◽

Mahboubeh Yazdanifar ◽

Meghdad Abdollahpour-Alitappeh ◽

Arash Sattari ◽

Alexander seifalian ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Side Effects ◽

Hematologic Malignancies ◽

Genetically Engineered ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Promising Tool ◽

Car T

Adoptive cell immunotherapy with chimeric antigen receptor (CAR) T cell has brought a revolutionary means of treatment for aggressive diseases such as hematologic malignancies and solid tumors. Over the last decade, FDA approved three types of CAR-T cells against CD19 hematologic malignancies, including Tisagenlecleucel (Kymriah), Axicabtagene ciloleucel (Yescarta), and Brexucabtagene autoleucel (Tecartus). Despite outstanding results gained from different clinical trials, CAR-T cell therapy is not free from side effects and toxicities, and needs careful investigations and improvements. Gene-editing technology, clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR-associated protein 9 (Cas9) system has emerged as a promising tool to address some of the CAR-T therapy hurdles. Using CRISPR/Cas9 technology, CAR expression as well as other cellular pathways can be modified in various ways to enhance CAR-T cell’s anti-tumor function and persistence in immunosuppressive tumor microenvironment. CRISPR/Cas9 technology can also be utilized to reduce CAR-T cells toxicity and side effects. Hereby, we discuss the practical challenges and hurdles related to the accuracy, efficiency, efficacy, safety and delivery of CRISPR/Cas9 technology to the genetically engineered-T cells. Combining of these two state-of-the-art technologies, CRISPR/Cas9 and CAR-T cells, the field of oncology has an extraordinary opportunity to enter a new era of immunotherapy, which offers novel therapeutic options for different types of tumors.

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Clinical Development of a Non-Gene-Edited Allogeneic Bcma-Targeting CAR T-Cell Product in Relapsed or Refractory Multiple Myeloma

Blood ◽

10.1182/blood-2020-139516 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 27-28

Author(s):

A. Samer Al-Homsi ◽

Sebastien Anguille ◽

Jason Brayer ◽

Dries Deeren ◽

Nathalie Meuleman ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Lines ◽

Gene Editing ◽

Cell Product ◽

Car T Cells ◽

Car T Cell ◽

Car T

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.

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Immunicy-1: Targeting BCMA with Cyad-211 to Establish Proof of Concept of an shRNA-Based Allogeneic CAR T Cell Therapy Platform

Blood ◽

10.1182/blood-2021-147738 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 2817-2817

Author(s):

Ahmad-Samer Al-Homsi ◽

Sebastien Anguille ◽

Dries Deeren ◽

Taiga Nishihori ◽

Nathalie Meuleman ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Research Funding ◽

Gene Editing ◽

Advisory Board ◽

Clinical Grade ◽

Proof Of Concept ◽

Car T Cells ◽

Car T ◽

Dose Levels

Abstract Off-the-shelf allogeneic CAR T cells derived from healthy donor cells have the potential to overcome many of the issues associated with the time-consuming manufacturing of autologous CAR T cells. However, adoptive transfer of allogeneic T cells carries the risk of graft-versus-host disease (GvHD). Most of the clinical experience with allogeneic CAR T cells is based on gene editing to eliminate T cell receptor (TCR) to mitigate the risk of GvHD. While clearly effective, the downsides of gene editing include multiple manufacturing steps requiring multiple clinical grade reagents, thus extending culture times, which can be associated with T cell exhaustion. As an alternative, we have explored short hairpin RNA (shRNA) as a means to knockdown TCR expression at the mRNA level. This shRNA is co-expressed along with the CAR in a single clinical grade vector, therefore requiring just one step of genetic modification. CYAD-211 is an allogeneic anti-BCMA CAR T that co-expresses a shRNA targeting CD3z which results in reduction of cell surface TCR expression. IMMUNICY-1 is an ongoing open-label Phase 1 trial (NCT04613557) designed to evaluate CYAD-211 in adult patients with refractory or relapsed multiple myeloma (MM) following at least two prior MM regimens. Patients receive non-myeloablative preconditioning (cyclophosphamide 300 mg/m²/day and fludarabine 30 mg/m²/day, for 3 days) followed by a single CYAD-211 infusion in a 3+3 dose escalation design evaluating three dose-levels (DL): 30x10 6, 100x10 6 and 300x10 6 cells/infusion. As of July 29, 2021, nine patients were enrolled across the 3 DLs. Patients had received a median of four prior lines of treatment. Seventy-eight percent of patients were previously exposed to all three major MM drug classes (proteasome inhibitors, immunomodulatory drugs, and anti-CD38 antibody therapy). Eight patients had prior autologous stem cell transplantation. CYAD-211 was well tolerated. One patient developed grade 1 cytokine release syndrome. Two patients had Grade ≥ 3 hematologic toxicities possibly related to the experimental treatment. Two patients experienced infectious adverse events (1 grade 1 rhinitis and 1 grade 2 upper respiratory infection). There was no neurologic toxicity and no GvHD. There was no dose-limiting toxicity. Eight patients were evaluated for activity per IMWG criteria. Two patients achieved partial response at dose-levels 1 and 2 while 5 patients had stable disease (SD). One patient with an ongoing SD (3 months +) showed evidence of reduction in size of plasmacytomas. Analysis of peripheral blood samples by molecular methods confirmed the engraftment of CYAD-211. All patients had detectable CAR T cells. However, the engraftment was short lasting (3-4 weeks). There was a correlation between the depth of lymphodepletion and engraftment. There was also a dose-response in terms of CYAD-211 kinetics with a level neighboring 8,000 copies of CAR T per microgram of input DNA in patients at DL3. These early data indicate that CYAD-211 is well tolerated with a good safety profile. While further study is required to fully understand the anti-BCMA potency of the CAR used in this trial, the lack of observed GvHD despite engraftment of CYAD-211 provides proof of concept of the safe administration of CAR T using a shRNA-allogeneic platform. The lack of sustained engraftment of CYAD-211 can be explained by rejection of the allogeneic cells by the recovering immune system of the recipient and calls for exploring the role of augmented lymphodepletion. Furthermore, given the ability to include multiple shRNA within the single CAR vector, future strategies will also examine knocking down other molecules that are important in driving immune rejection. Disclosures Al-Homsi: BMS: Other: Independent Medical Education Grant; Daichii Sankyo: Consultancy; Celyad Oncology: Other: Advisory Board. Deeren: Alexion: Consultancy; BMS: Consultancy; Incyte: Consultancy; Novartis: Consultancy; Sanofi: Consultancy, Research Funding; Sobi: Consultancy; Takeda: Consultancy. Nishihori: Karyopharm: Research Funding; Novartis: Research Funding. Meuleman: iTeos Therapeutics: Consultancy. Abdul-Hay: Amgen: Membership on an entity's Board of Directors or advisory committees; Takeda: Speakers Bureau; Abbvie: Consultancy; Jazz: Other: Advisory Board, Speakers Bureau; Servier: Other: Advisory Board, Speakers Bureau. Braun: Celyad Oncology: Current Employment. Lonez: Celyad Oncology: Current Employment. Dheur: Celyad Oncology: Current Employment. Alcantar-Orozco: Celyad Oncology: Current Employment. Gilham: Celyad Oncology: Current Employment. Flament: Celyad Oncology: Current Employment. Lehmann: Celyad Oncology: Current Employment.

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Paving the Way toward Successful Multiple Myeloma Treatment: Chimeric Antigen Receptor T-Cell Therapy

Cells ◽

10.3390/cells9040983 ◽

2020 ◽

Vol 9 (4) ◽

pp. 983 ◽

Cited By ~ 1

Author(s):

Ewelina Grywalska ◽

Barbara Sosnowska-Pasiarska ◽

Jolanta Smok-Kalwat ◽

Marcin Pasiarski ◽

Paulina Niedźwiedzka-Rystwej ◽

...

Keyword(s):

Multiple Myeloma ◽

T Cells ◽

T Cell ◽

Side Effects ◽

Cell Therapy ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T Cell Therapy ◽

Car T

Despite the significant progress of modern anticancer therapies, multiple myeloma (MM) is still incurable for the majority of patients. Following almost three decades of development, chimeric antigen receptor (CAR) T-cell therapy now has the opportunity to revolutionize the treatment landscape and meet the unmet clinical need. However, there are still several major hurdles to overcome. Here we discuss the recent advances of CAR T-cell therapy for MM with an emphasis on future directions and possible risks. Currently, CAR T-cell therapy for MM is at the first stage of clinical studies, and most studies have focused on CAR T cells targeting B cell maturation antigen (BCMA), but other antigens such as cluster of differentiation 138 (CD138, syndecan-1) are also being evaluated. Although this therapy is associated with side effects, such as cytokine release syndrome and neurotoxicity, and relapses have been observed, the benefit–risk balance and huge potential drive the ongoing clinical progress. To fulfill the promise of recent clinical trial success and maximize the potential of CAR T, future efforts should focus on the reduction of side effects, novel targeted antigens, combinatorial uses of different types of CAR T, and development of CAR T cells targeting more than one antigen.

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A Novel Small Animal Model to Test on-Target Off-Tumor Cytoxicity of Adoptive Immune Therapies

Blood ◽

10.1182/blood.v126.23.5432.5432 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5432-5432

Author(s):

Mauro Castellarin ◽

Joseph A. Fraietta ◽

Jihyun Lee ◽

John Scholler ◽

Yangbing Zhao ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Normal Tissue ◽

Tumor Antigens ◽

Small Animal ◽

Expression Levels ◽

Car T Cells ◽

Car T Cell ◽

Car T

Abstract Chimeric antigen receptor (CAR) engineered T cells have been used clinically to improve outcomes in patients with hematopoietic malignancies owing to the ability of CAR T cells to recognize tumor antigens and kill malignant cells. CAR T cells possess the antigen recognizing capability of an antibody through the single chain variable fragment (scFv) and their cytotoxicity is enhanced through signaling via the intracellular domains of T cell receptors and co-activating receptors such as CD3zeta and 4-1BB, respectively. Thus, CAR expressing T cells are able to detect cancer cells through tumor antigens and can become activated to unleash their cytotoxic potentials in a non-MHC restricted manner. Therapeutic side-effects can occur when T-cell receptor targeting is misdirected to the incorrect tissue causing potentially serious on-target off-tumor cytotoxicity. Factors that influence CAR targeting include expression levels of tumor-associated antigen in normal tissue and the binding affinities of scFvs. Our first step in developing an in vivo, on target, off-tumor, CAR T cell toxicity model was to generate mice with tunable expression of a human tumor antigen in normal tissue. NSG mice were IV injected with recombinant adeno-associated virus serotype 8 (rAAV8) to deliver a truncated human ErbB2 (Her2/neu or CD340) gene and a Katushka fluorescent reporter that were driven by the liver-specific promoter, thyroxine binding globulin (TBG). AAV8 genomic copies (GCs) were injected at varying dilutions of 1.5 x 1012 GC/mouse, 7.25 x 1011 GC/mouseand 1.5x1010 GC/mouse to induce a range of expression of ErbB2 in the liver. Katushka expression was visualized in vivo using the IVIS small animal imager. ErbB2 gene expression was detected using reverse transcription polymerase chain reaction (qRT-PCR) and the ErbB2 protein was detected using western blots and immunohistochemistry (IHC). Our data has shown that expression levels of ErbB2 and the Katushka reporter positively correlated with the number of AAV8 GCs that were injected. This enabled us to obtain ErbB2 expression levels in the liver comparable to the levels seen in either ErbB2High tumors (eg. SK-OV3) or ErbB2Low tumors (eg. PC3 and HEK293T). To determine if affinity tuning of scFvs will allow CAR T cells to discriminate between high and low ErbB2 expression in the liver, T cells were engineered to co-express the click beetle red (CBR) reporter and either a high-affinity scFv, anti-ErbB2 CAR (4D5) or a low-affinity scFv, anti-ErbB2 CAR (4D5-5). These T cells were then IV injected into NSG mice that had either high or low ErbB2-expressing livers. Although these experiments were ongoing at the time of abstract submission, we will show our results on T cell trafficking in the liver, which will be visualized by IHC and by in vivo imaging using the IVIS small animal imager. Liver toxicity will be assessed by histological examination and by measuring liver function via standard enzymatic testing of blood. Furthermore, we aim to show whether affinity tuning of scFvs will allow CAR T cells to selectively recognize and target ErbB2High tumors while sparing ErbB2Low normal tissue. This will be performed by inoculating ErbB2high SK-OV3 tumor cells into mice with ErbB2Low livers followed by IV injection with either 4D5 or 4D5-5 CAR T cells. We expect that the low-affinity anti-ErbB2 CAR (4D5-5) T cells will target the ErbB2High SK-OV3 tumor cells and cause tumor regression while preserving function in the ErbB2Low liver. If so, then we will have shown that our pre-clinical mouse model can be used to identify on-target off-tumor CAR T cell toxicity, which will aid in improving the safety profile and clinical outcomes of future CAR T cell therapies. Disclosures Scholler: Novartis: Patents & Royalties. Zhao:Novartis: Patents & Royalties, Research Funding. June:Novartis: Patents & Royalties, Research Funding.

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Latest in Clinical Application of CAR Cell Therapy for B-cell Malignancy and Transplantation

Blood ◽

10.1182/blood.v126.23.sci-24.sci-24 ◽

2015 ◽

Vol 126 (23) ◽

pp. SCI-24-SCI-24

Author(s):

Crystal L. Mackall

Keyword(s):

Clinical Trials ◽

T Cells ◽

T Cell ◽

Immune Responses ◽

B Cell ◽

Graft Failure ◽

Cytokine Release ◽

Cytokine Release Syndrome ◽

Car T Cells ◽

Car T

Unparalleled remission rates in patients with chemorefractory B-ALL treated with CD19-CAR T cells illustrate the potential for immunotherapy to eradicate chemoresistant cancer. CD19-CAR therapy is poised to fundamentally alter the clinical approach to relapsed B-ALL and ultimately may be incorporated into frontline therapy. Despite these successes, as clinical experience with this novel modality has increased, so has understanding of factors that limit success of CD19-CAR T cells for leukemia. These insights have implications for the future of cell based immunotherapy for leukemia and provide a glimpse of more global challenges likely to face the emerging field of cancer immunotherapy. Five challenges limiting the overall effectiveness of CD19-CAR therapy will be discussed: 1) T cell exhaustion is a differentiation pathway that occurs in T cells subjected to excessive T cell receptor signaling. A progressive functional decline occurs, manifest first by diminished proliferative potential and cytokine production, following by diminished cytolytic function and ultimately cell death. High leukemic burdens predispose CD19-CAR T cells to exhaustion as does the presence of a CD28 costimulatory signal, while a 4-1BB costimulatory signal diminishes the susceptibility to exhaustion. This biology is likely responsible for limited CD19-CAR persistence observed in clinical trials using a CD19-zeta-28 CAR compared to that observed using a CD19-zeta-BB CAR. 2) Leukemia resistance occurs in approximately 20% of patients treated with CD19-CAR and is associated with selection of B-ALL cells lacking CD19 targeted by the chimeric receptor. Emerging data demonstrates two distinct biologies associated with CD19-epitope loss. Isoform switch is characterized by an increase in CD19 isoforms specifically lacking exon 2, which binds the scFvs incorporated into CD19-CARs currently in clinical trials. Lineage switch is characterized by a global change in leukemia cell phenotype, and is associated with dedifferentiation toward a more stem-like, or myeloid leukemia in the setting of CD19-CAR for B-ALL. These insights raise the prospect that effectiveness of immunotherapy for leukemia may be significantly enhanced by targeting of more than one leukemia antigen. 3) CAR immunogenicity describes immune responses induced in the host that can lead to rejection of the CD19-CAR transduced T cells. Anti-CAR immune responses have been observed by several groups, and mapping is underway to identify the most immunogenic regions of the CAR, as a first step toward preventing this complication. 4) The most common toxicities associated with CD19-CAR therapy are cytokine release syndrome, neurotoxicity and B cell aplasia. Cytokine release syndrome is primarily observed in the setting of high disease burdens and efforts are underway to standardize grading and treatment algorithms to diminish morbidity. Increased information is needed to better understand the neurotoxicity observed in the context of this therapy. Although clinical data is limited, B cell aplasia appears to be adequately treated with IVIG replacement therapy. 5) Technical graft failure (e.g. inadequate expansion/transduction) is a challenge that has received limited attention, primarily since many trials have not reported the percentage of patients in whom adequate products could not be generated. We have observed that technical graft failure is often associated with a high frequency of contaminating myeloid populations in the lymphocyte product and selection approaches designed to eradicate myeloid populations have resulted in improved T cell expansion and transduction. These results suggest that optimization of lymphocyte selection may diminish the incidence of technical graft failure. Disclosures Mackall: Juno: Patents & Royalties: CD22-CAR. Off Label Use: cyclophosphamide.

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T Cells Expressing a Novel Fully-Human Anti-CD19 Chimeric Antigen Receptor Induce Remissions of Advanced Lymphoma in a First-in-Humans Clinical Trial

Blood ◽

10.1182/blood.v128.22.999.999 ◽

2016 ◽

Vol 128 (22) ◽

pp. 999-999 ◽

Cited By ~ 17

Author(s):

Jennifer N. Brudno ◽

Victoria Shi ◽

David Stroncek ◽

Stefania Pittaluga ◽

Jennifer A. Kanakry ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

Low Dose ◽

Cytokine Release ◽

Cytokine Release Syndrome ◽

Car T Cells ◽

Car T ◽

Low Dose Chemotherapy ◽

Cd19 Expression

Abstract Background: Chimeric antigen receptors (CARs) are fusion proteins that combine antigen-recognition domains and T-cell signaling domains. T cells genetically modified to express CARs directed against the B-cell antigen CD19 can cause remissions of B-cell malignancies. Most CARs in clinical use contain components derived from murine antibodies. Immune responses have been reported to eliminate CAR T cells in clinical trials, especially after second infusions of CAR T cells (C. Turtle et al., Journal of Clinical Investigation, 2016). These immune responses could be directed at the murine components of CARs. Such immune responses might limit the persistence of the CAR T cells, and anti-CAR immune responses might be an especially important problem if multiple infusions of CAR T cells are administered. Development of fully-human CARs could reduce recipient immune responses against CAR T cells. Methods: We designed the first fully-human anti-CD19 CAR (HuCAR-19). The CAR is encoded by a lentiviral vector. This CAR has a fully-human single-chain variable fragment, hinge and transmembrane regions from CD8-alpha, a CD28 costimulatory domain, and a CD3-zeta T-cell activation domain. We conducted a phase I dose-escalation trial with a primary objective of investigating the safety of HuCAR-19 T cells and a secondary objective of assessing anti-lymphoma efficacy. Low-dose chemotherapy was administered before HuCAR-19 T-cell infusions to enhance CAR T-cell activity. The low-dose chemotherapy consisted of cyclophosphamide 300 mg/m2 daily for 3 days and fludarabine 30 mg/m2 daily for 3 days on the same days as cyclophosphamide. HuCAR-19 T cells were infused 2 days after the end of the chemotherapy regimen. Patients with residual lymphoma after a first treatment were potentially eligible for repeat treatments if dose-limiting toxicities did not occur with the first treatment. Repeat infusions were given at the same dose level as the first infusion or 1 dose level higher than the first infusion. Findings: A total of 11 HuCAR-19 T-cell infusions have been administered to 9 patients; 2 patients received 2 infusions each. So far, there is an 86% overall response rate (Table). Grade 3 adverse events (AEs) included expected cytokine-release syndrome toxicities such as fever, tachycardia, and hypotension. Corticosteroids were used to treat toxicity in Patient 3. The interleukin-(IL)-6 receptor antagonist tocilizumab was used to treat toxicity in Patient 4, and both tocilizumab and corticosteroids were used to treat toxicity in Patient 8. Only 1 of 8 evaluable patients, Patient 3, has experienced significant neurological toxicity to date. This patient experienced encephalopathy that was associated with a cerebrospinal fluid (CSF) white blood cell count of 165/mm3. Almost all of the CSF white cells were CAR T cells, and the CSF IL-6 level was elevated. All toxicities have resolved fully in all patients. In Patient 1, tumor biopsies revealed a complete loss of CD19 expression by lymphoma cells after 2 HuCAR-19 T-cell infusions, which to our knowledge is the first documented complete loss of CD19 expression by lymphoma after anti-CD19 CAR T-cell therapy. This loss of CD19 expression was associated with lymphoma progression. After first CAR-19 T-cell infusions, HuCAR-19 cells were detectable in the blood of every patient. The median peak number of blood CAR+ cells was 26/microliter (range 3 to 1005 cells/microliter). Blood HuCAR-19 cells were detected after second infusions in the blood of both patients who received second infusions. Patient 1 obtained a partial response after a second infusion after only obtaining stable disease after a first infusion. We detected elevations of inflammatory cytokines including IL-6, interferon gamma, and IL-8 in the serum of patients experiencing clinical toxicities consistent with cytokine-release syndrome. Interpretation: T cells expressing HuCAR-19 have substantial activity against advanced lymphoma, and infusions of HuCAR-19 T cells caused reversible toxicities attributable to cytokine-release syndrome. Disclosures Kochenderfer: Kite Pharma: Patents & Royalties, Research Funding; bluebird bio: Patents & Royalties, Research Funding.

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CAR T cell therapy in B-cell acute lymphoblastic leukaemia: Insights from mathematical models

10.1101/2020.03.18.20038257 ◽

2020 ◽

Cited By ~ 1

Author(s):

Odelaisy León-Triana ◽

Soukaina Sabir ◽

Gabriel F. Calvo ◽

Juan Belmonte-Beitia ◽

Salvador Chulián ◽

...

Keyword(s):

Mathematical Model ◽

T Cells ◽

T Cell ◽

Side Effects ◽

B Cell ◽

Target Cells ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T

AbstractImmunotherapies use components of the patient immune system to selectively target cancer cells. The use of CAR T cells to treat B-cell malignancies – leukaemias and lymphomas– is one of the most successful examples, with many patients experiencing long-lasting complete responses to this therapy. This treatment works by extracting the patient’s T cells and adding them the CAR group, which enables them to recognize and target cells carrying the antigen CD19+, that is expressed in these haematological tumors.Here we put forward a mathematical model describing the time response of leukaemias to the injection of CAR T-cells. The model accounts for mature and progenitor B-cells, tumor cells, CAR T cells and side effects by incorporating the main biological processes involved. The model explains the early post-injection dynamics of the different compartments and the fact that the number of CAR T cells injected does not critically affect the treatment outcome. An explicit formula is found that provides the maximum CAR T cell expansion in-vivo and the severity of side effects. Our mathematical model captures other known features of the response to this immunotherapy. It also predicts that CD19+ tumor relapses could be the result of the competition between tumor and CAR T cells analogous to predator-prey dynamics. We discuss this fact on the light of available evidences and the possibility of controlling relapses by early re-challenging of the tumor with stored CAR T cells.

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