Chimeric antigen receptor (CAR) T cells are a promising therapy for hematologic malignancies. B-cell maturation antigen (BCMA) is a rational target in multiple myeloma (MM).
We conducted a phase I ...study of autologous T cells lentivirally-transduced with a fully-human, BCMA-specific CAR containing CD3ζ and 4-1BB signaling domains (CART-BCMA), in subjects with relapsed/refractory MM. Twenty-five subjects were treated in 3 cohorts: 1) 1-5 x 108 CART-BCMA cells alone; 2) Cyclophosphamide (Cy) 1.5 g/m2 + 1-5 x 107 CART-BCMA cells; and 3) Cy 1.5 g/m2 + 1-5 x 108 CART-BCMA cells. No pre-specified BCMA expression level was required.
CART-BCMA cells were manufactured and expanded in all subjects. Toxicities included cytokine release syndrome and neurotoxicity, which were grade 3-4 in 8 (32%) and 3 (12%) subjects, respectively, and reversible. One subject died at day 24 from candidemia and progressive myeloma, following treatment for severe CRS and encephalopathy. Responses (based on treated subjects) were seen in 4/9 (44%) in cohort 1, 1/5 (20%) in cohort 2, and 7/11 (64%) in cohort 3, including 5 partial, 5 very good partial, and 2 complete responses, 3 of which were ongoing at 11, 14, and 32 months. Decreased BCMA expression on residual MM cells was noted in responders; expression increased at progression in most. Responses and CART-BCMA expansion were associated with CD4:CD8 T cell ratio and frequency of CD45RO-CD27+CD8+ T cells in the pre-manufacturing leukapheresis product.
CART-BCMA infusions with or without lymphodepleting chemotherapy are clinically active in heavily-pretreated MM patients.
NCT02546167.
University of Pennsylvania-Novartis Alliance and NIH.
Fibrosis is observed in nearly every form of myocardial disease
. Upon injury, cardiac fibroblasts in the heart begin to remodel the myocardium by depositing excess extracellular matrix, resulting in ...increased stiffness and reduced compliance of the tissue. Excessive cardiac fibrosis is an important factor in the progression of various forms of cardiac disease and heart failure
. However, clinical interventions and therapies that target fibrosis remain limited
. Here we demonstrate the efficacy of redirected T cell immunotherapy to specifically target pathological cardiac fibrosis in mice. We find that cardiac fibroblasts that express a xenogeneic antigen can be effectively targeted and ablated by adoptive transfer of antigen-specific CD8
T cells. Through expression analysis of the gene signatures of cardiac fibroblasts obtained from healthy and diseased human hearts, we identify an endogenous target of cardiac fibroblasts-fibroblast activation protein. Adoptive transfer of T cells that express a chimeric antigen receptor against fibroblast activation protein results in a significant reduction in cardiac fibrosis and restoration of function after injury in mice. These results provide proof-of-principle for the development of immunotherapeutic drugs for the treatment of cardiac disease.
The adoptive transfer of T lymphocytes reprogrammed to target tumour cells has demonstrated potential for treatment of various cancers
. However, little is known about the long-term potential and ...clonal stability of the infused cells. Here we studied long-lasting CD19-redirected chimeric antigen receptor (CAR) T cells in two patients with chronic lymphocytic leukaemia
who achieved a complete remission in 2010. CAR T cells remained detectable more than ten years after infusion, with sustained remission in both patients. Notably, a highly activated CD4
population emerged in both patients, dominating the CAR T cell population at the later time points. This transition was reflected in the stabilization of the clonal make-up of CAR T cells with a repertoire dominated by a small number of clones. Single-cell profiling demonstrated that these long-persisting CD4
CAR T cells exhibited cytotoxic characteristics along with ongoing functional activation and proliferation. In addition, longitudinal profiling revealed a population of gamma delta CAR T cells that prominently expanded in one patient concomitant with CD8
CAR T cells during the initial response phase. Our identification and characterization of these unexpected CAR T cell populations provide novel insight into the CAR T cell characteristics associated with anti-cancer response and long-term remission in leukaemia.
Immunotherapy approaches seek to boost immune responses against cancer. A single antibody engineered to recognize three targets shows promise, when tested in animals, in improving the ability of T ...cells to target cancer.
Chimeric antigen receptors (CARs) redirect T cell cytotoxicity against cancer cells, providing a promising approach to cancer immunotherapy. Despite extensive clinical use, the attributes of CAR ...co-stimulatory domains that impact persistence and resistance to exhaustion of CAR-T cells remain largely undefined. Here, we report the influence of signaling domains of coreceptors CD28 and 4-1BB on the metabolic characteristics of human CAR T cells. Inclusion of 4-1BB in the CAR architecture promoted the outgrowth of CD8+ central memory T cells that had significantly enhanced respiratory capacity, increased fatty acid oxidation and enhanced mitochondrial biogenesis. In contrast, CAR T cells with CD28 domains yielded effector memory cells with a genetic signature consistent with enhanced glycolysis. These results provide, at least in part, a mechanistic insight into the differential persistence of CAR-T cells expressing 4-1BB or CD28 signaling domains in clinical trials and inform the design of future CAR T cell therapies.
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•CAR T cells containing 4-1BB signaling domains have enhanced in vitro persistence•Increased central memory differentiation of CD8+ CAR T cells expressing 4-1BB•CD28-enforced metabolic reprograming enhances glycolytic metabolism•Mitochondrial biogenesis is selectively induced in 4-1BB CAR T cells
Despite the successes of chimeric antigen receptor (CAR) T cells in treating hematologic malignancies, the impact of various CAR signaling domains remains unclear. Kawalekar et al. show that the choice of signaling domain can metabolically reprogram T cells to alter its mitochondrial biogenesis and persistence.
Wu and colleagues devised a clever strategy to simultaneously boost T-cell activation and enhance the targeting of cancer cells in relation to multiple myeloma, which is a cancer of plasma cells in ...the blood. The addition of a co-stimulatory signal such as CD28 is notable because this signal has also been incorporated into another type of immunotherapy called chimaeric-antigen receptor T cell (CAR-T) therapy5, in which a receptor is engineered to both recognize a cancer-cell antigen and include T-cell activation domains such as CD3 and CD28. The presence of the CD28-targeting domain on the antibody boosted the ability of T cells to kill different myeloma cell lines in vitro and in the humanized mouse model, even at the lowest antibody dose tested. ...in terms of possible negative effects of the antibody on healthy non-cancerous cells, it is reassuring that only transient decreases in the number of normal white blood cells that express CD38, such as lymphocytes and myeloid cells, were observed in monkeys treated with the antibody.
CD19-directed immunotherapies are clinically effective for treating B cell malignancies but also cause a high incidence of neurotoxicity. A subset of patients treated with chimeric antigen receptor ...(CAR) T cells or bispecific T cell engager (BiTE) antibodies display severe neurotoxicity, including fatal cerebral edema associated with T cell infiltration into the brain. Here, we report that mural cells, which surround the endothelium and are critical for blood-brain-barrier integrity, express CD19. We identify CD19 expression in brain mural cells using single-cell RNA sequencing data and confirm perivascular staining at the protein level. CD19 expression in the brain begins early in development alongside the emergence of mural cell lineages and persists throughout adulthood across brain regions. Mouse mural cells demonstrate lower levels of Cd19 expression, suggesting limitations in preclinical animal models of neurotoxicity. These data suggest an on-target mechanism for neurotoxicity in CD19-directed therapies and highlight the utility of human single-cell atlases for designing immunotherapies.
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•Single-cell RNA-seq reveals CD19 expression in human brain mural cells•Mural cells line blood vessels and maintain blood-brain barrier integrity•Brain mural cell CD19 expression is present across brain regions and human age•Targeting CD19+ mural cells may contribute to neurotoxicity of CAR-T therapy
Single-cell RNA sequencing analysis shows that CD19, primarily considered as a B cell-specific surface antigen, is expressed in human brain mural cells that are critical for blood-brain-barrier integrity, suggesting that this cell population may contribute to the neurotoxicity of CD19-directed immunotherapy including CAR-T.
Chimeric antigen receptor (CAR) T cell therapy has achieved remarkable success in hematological malignancies but remains ineffective in solid tumors, due in part to CAR T cell exhaustion in the solid ...tumor microenvironment. To study dysfunction of mesothelin-redirected CAR T cells in pancreatic cancer, we establish a robust model of continuous antigen exposure that recapitulates hallmark features of T cell exhaustion and discover, both in vitro and in CAR T cell patients, that CAR dysregulation is associated with a CD8+ T-to-NK-like T cell transition. Furthermore, we identify a gene signature defining CAR and TCR dysregulation and transcription factors, including SOX4 and ID3 as key regulators of CAR T cell exhaustion. Our findings shed light on the plasticity of human CAR T cells and demonstrate that genetic downmodulation of ID3 and SOX4 expression can improve the efficacy of CAR T cell therapy in solid tumors by preventing or delaying CAR T cell dysfunction.
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•CAR T cells under chronic antigen stimulation show hallmarks of T cell exhaustion•CAR dysregulation is associated with a CD8+ T-to-NK-like T cell transition•CAR T cells with NK-like transition were identified in patients after treatment•Unlike WT CAR T cells, ID3 and SOX4 knockout CAR T cells retain anti-tumor immunity
Continuous antigen exposure drives CAR T cell exhaustion and promotes CD8+ T-to-NK-like T cell transition. Transcription factors ID3 and SOX4 are upregulated during CAR dysfunction and regulate genes associated with exhaustion, including NK receptors. Knocking out ID3 and SOX4 in CAR T cells slows dysfunction and improves anti-tumor immunity.
We conducted a first-in-human study of intravenous delivery of a single dose of autologous T cells redirected to the epidermal growth factor receptor variant III (EGFRvIII) mutation by a chimeric ...antigen receptor (CAR). We report our findings on the first 10 recurrent glioblastoma (GBM) patients treated. We found that manufacturing and infusion of CAR-modified T cell (CART)-EGFRvIII cells are feasible and safe, without evidence of off-tumor toxicity or cytokine release syndrome. One patient has had residual stable disease for over 18 months of follow-up. All patients demonstrated detectable transient expansion of CART-EGFRvIII cells in peripheral blood. Seven patients had post-CART-EGFRvIII surgical intervention, which allowed for tissue-specific analysis of CART-EGFRvIII trafficking to the tumor, phenotyping of tumor-infiltrating T cells and the tumor microenvironment in situ, and analysis of post-therapy EGFRvIII target antigen expression. Imaging findings after CART immunotherapy were complex to interpret, further reinforcing the need for pathologic sampling in infused patients. We found trafficking of CART-EGFRvIII cells to regions of active GBM, with antigen decrease in five of these seven patients. In situ evaluation of the tumor environment demonstrated increased and robust expression of inhibitory molecules and infiltration by regulatory T cells after CART-EGFRvIII infusion, compared to pre-CART-EGFRvIII infusion tumor specimens. Our initial experience with CAR T cells in recurrent GBM suggests that although intravenous infusion results in on-target activity in the brain, overcoming the adaptive changes in the local tumor microenvironment and addressing the antigen heterogeneity may improve the efficacy of EGFRvIII-directed strategies in GBM.
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