Chimeric Antigen Receptor-modified T-cell Research Articles

CAR-NK for tumor immunotherapy: Clinical transformation and future prospects.

Recently, the use of chimeric antigen receptor-modified T (CAR-T)-cells in the treatment of hematological tumors has been successful and has become a clinical hotspot in tumor immunotherapy. However, their wide application is limited by inherent risks such as graft-versus-host disease (GvHD) and the amount of time it takes to produce CAR-T cells. Natural killer (NK) cells can be xenografted and have the potential to become off-the-shelf products, making CAR-NK cell therapies universal products. These products may be safer than CAR-T cell therapy. Considering that the fundamental researche is still in its infancy, this review focuses on clinical achievements and new strategies for improving the safety and efficacy of CAR-NK cell therapy, as well as the corresponding challenges.

Invasive Mold Infections After Chimeric Antigen Receptor-Modified T-Cell Therapy: A Case Series, Review of the Literature, and Implications for Prophylaxis.

Data on invasive mold infections (IMIs) after chimeric antigen receptor-modified T-cell (CAR-T-cell) therapy are limited. We describe 2 patients with post-CAR-T-cell IMI (Fusarium, Mucorales) and review the published literature. We propose strategies to prevent IMIs in patients, based on the IMI rate and presence of neutropenia or steroid use.

Influence of CD27- CD28- T-Cells on the Therapeutic Outcome in Adult Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma after CART-Infusion

Background: Therapies involving adoptive transfer of chimeric antigen receptor-modified T-cells (CARTs) targeting CD19-expressing B-cells have shown remarkable efficacy in patients with relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL). We hypothesized, that a higher fraction of more differentiated, senescent and exhausted T-cells affects negatively ex vivo T-cell expansion in the manufacturing phase of CARTs and the in vivo function of CARTs after infusion. Of note, naïve CD4+ T-cells were shown to uniformly express the co-stimulatory receptors CD27 and CD28, while repeated cycles of activation led to their progressive loss (van Leewen et al, J. Immunol, 2004), accompanied by telomere erosion and replicative senescence (van Baarle et al., Immunol. Lett. 2005; Effros RB et al., Dev Comp Immunol 1997). CD28 expression on T-cells within the tumor environment was shown to be a decisive factor for the efficacy of anti-PD-1 therapy (Kamphorst RO et al, Science 2017). We have therefore analyzed the CD27 and CD28 expression status of CD3+ T-cells from the peripheral blood and apheresis products of adult r/r DLBCL patients at the day of leukapheresis. Methods: Peripheral blood and apheresis samples of 22 consecutive r/r DLBCL patients scheduled for CART therapy were analyzed by flow cytometry to assess their CD27 and CD28 expression status on CD3+ T-cells. Samples were stained with fluorochrome conjugated antibodies (anti-CD3 PerCP, anti-CD27 FITC, CD28 PE, anti-CD4 FITC, BioLegend) and analyzed using a FACScalibur flow cytometer supported by CELLQUEST software (Becton Dickinson, BD, Palo Alto, CA). Results: To rule out an apheresis-related bias within cell populations we analyzed peripheral blood and apheresis samples for each patient. No differences in the distribution of CD27-, CD28-, CD27-/CD28- or CD27+/CD28+ T-cells between peripheral blood and apheresis product were detected. Mean CD3+ cell count in blood samples before apheresis was 624±399/µl (range, 75-1853cells/µL) with only about 25% of the patients presenting with CD3+ cell counts within the normal range (690-3320/µL) and 70% of the patients showed an inverse CD4/CD8 ratio (<1.0). We observed a considerable heterogeneity within the T-memory cell compartment. In all samples high percentages of CD27- (39.7±18.1%), CD28- (40.2±19.0%) and CD27-/CD28- (30.7±19.8%) T-cells were seen when compared to healthy controls (CD27-: 15.2±9.9%; CD28-: 18.4±8.9%; CD27-/CD28-: 9.9±8.7%; p<0.05). Patients receiving CARTs were embedded within three different CART-trials (NCT02445248, NCT03630159, NCT03484702). A significantly lower frequency of CD27-/CD28-T-cells (20.8±18.8 vs 42.4±13.7%; p=0.045 Mann Whitney U) was found in responders (n=8) compared to non-responders (n=5; Figure 1a). We also noticed a higher frequency of CD27+/CD28+ T-cells (57.5±22.7% vs 44.3±11.7%; Figure 1b) and a trend towards a normal (>1.0) CD4/CD8 ratio (Figure 1c) in responding patients. Furthermore, we did not observe significant differences in CD27-and CD28- expression in samples derived from patients who died prior to receiving CART therapy (n=6) when compared to patients responding or progressing after CART therapy. Three patients have not been infused yet. Conclusion: We demonstrate in this small patient cohort that individuals with a lower percentage of more differentiated, senescent or exhausted T-cells are more likely to respond to CART therapy. Our observation underscores the importance of T-cells with normal replicative capacity in the apheresis material for consecutive CART production to achive therapeutic success. Further analysis is needed to determine the effect of cytotoxic pretreatment on the fraction of immunosenescent/exhausted T-cells. However, to confirm our findings additional investigations including the T-cell status of manufactured cells are warranted. Disclosures Worel: Sanofi Genzyme, Malinckrodt Therakos: Speakers Bureau; Sanofi Genzyme, Malinckrodt Therakos: Research Funding; Jazz, Sanofi, Celgene, Novartis, Malinckrodt Therakos: Honoraria. Jaeger:Novartis, Roche, Sandoz: Consultancy; AbbVie, Celgene, Gilead, Novartis, Roche, Takeda Millennium: Research Funding; Celgene, Roche, Janssen, Gilead, Novartis, MSD, AbbVie, Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen, AbbVie, Celgene, Eisai, Gilead, Janssen, Novartis, Roche, Takeda Millennium, MSD, BMS, Sanofi: Honoraria. Hopfinger:Celgene, Gilead, GlaxoSmithKline, Janssen, Novartis, Roche, Takeda,: Honoraria; Gilead: Research Funding.

CD70-Specific CAR T Cells Have Potent Activity Against Acute Myeloid Leukemia (AML) without HSC Toxicity

The outcome for the majority of patients with AML remains dismal. Adoptive transfer of chimeric antigen receptor (CAR) modified T-cells (CARTs) holds the promise to improve outcomes since they do not rely on the cytotoxic mechanism of conventional therapies. CD70 is a promising CAR T-cell therapy target for AML since it is expressed on AML bulk cells and leukemic stem cells (LSC) whereas expression is absent on normal hematopoietic stem cells (HSCs) in contrast to other antigens, like CD33 and CD123, which are currently being explored as immunotherapy targets for AML. The goal of this project was to construct a panel of CD70-CARs and determine their effector function in vitro and in preclinical AML xenograft models. We generated a panel of CD70-CARs using a CD70-specific single chain variable fragment (scFv) as the antigen recognition domain, different spacers (intermediate [IMS] or long flexible spacer [LFS]) and signaling domains that contained CD3z combined with one of three co-stimulatory domains (CD27, CD28, or 41BB). An additional CAR comprising the human ligand of CD70, CD27 (including its costimulatory endodomain) fused to the CD3z chain (CD27z) was also included in the comparison. CD70-CARs were efficiently expressed from retroviral vectors as detected by FACS analysis. T-cells expressing IMS-CARs had lower viability and a more differentiated phenotype than T-cells expressing the LFS- or the CD27z-CARs. In sequential co-culture assays with live tumor cells, T-cells expressing the LFS-CAR with a 41BB co-stimulatory domain (LFS-41BBz) or CD27z-CARs had greater proliferative potential and an increased ability to repeatedly eliminate tumor cells than NT- and other CD70-CAR T-cell populations. In addition, CD27z-CAR T-cells secreted the highest levels of type I cytokines (TNF-a and Interferon-g) after tumor cell stimulation and expressed lower levels of markers (LAG3, TIM-3 and PD-1) that are associated with T-cell exhaustion. In vivo, only LFS-28z- or CD27z-CAR T-cells had significant anti-tumor efficacy in the murine Molm-13 xenograft model in comparison to NTs and all other CD70 CARTs resulting in a significant (p<0.001) overall survival advantage. The potent anti-tumor activity of LFS-28z- and CD27z-CARTs was confirmed in a second murine AML (THP-1) xenograft model. While LFS-28z- and CD27z-CARTs had similar anti-AML activity, adoptive transfer of fire-fly luciferase-expressing CAR T-cells into AML-bearing mice revealed that CD27z-CARTs had the greatest proliferative potential in vivo. Crucially, LFS-28z- or CD27z-CARTs did not recognize normal CD34+ HSCs in colony forming unit (CFU) assays, confirming that HSCs do not express CD70 and suggesting that treatment with CD70 CAR T cells is safe. In conclusion, CD70 is a promising target antigen for CAR T-cell therapy of AML. We demonstrate here that hinge and costimulatory domain greatly influences CD70-CAR T-cell function. LFS-28z- and CD27z-CAR T-cells had potent anti-AML activity in xenograft models with a favorable safety profile, warranting future early phase clinical testing of CD70-CAR T-cells in patients with CD70-positive AML. Disclosures Gottschalk: TESSA Therapeutics: Other: Research Collaboration; NHLBI: Research Funding; ASSISI fundation of Memphis: Research Funding; ViraCyte: Consultancy; California Institute for Regenerative Medicine: Research Funding; Sanofi: Honoraria; Merck: Consultancy; EMD Serono: Honoraria; Inmatics: Membership on an entity's Board of Directors or advisory committees; Tidal: Membership on an entity's Board of Directors or advisory committees; Patents and patent applications in the fields of T-cell & Gene therapy for cancer: Patents & Royalties; MBIO: Other: St. Jude Children's Research Hospital has an existing exclusive license and ongoing partnership with Mustang Bio for the further clinical development and commercialization of this XSCID gene therapy; America Lebanese Syrian Associated Charities: Research Funding. Rooney:Marker Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Founding member; Viracyte: Other: Founding member; Tessa Therapeutics: Research Funding; Cell Genic: Membership on an entity's Board of Directors or advisory committees.

Chimeric Antigen Receptor T Cells in Chronic Lymphocytic Leukemia: Are We Any Closer to a Cure?

Recent advances in the treatment of chronic lymphocytic leukemia (CLL) have dramatically changed outcomes for patients. Despite these improvements, CLL is still considered incurable. Chimeric antigen receptor-modified T cells have demonstrated the ability to produce long-term remissions in subsets of heavily pretreated patients with B-cell malignancies, including CLL. Unfortunately, the majority of patients with CLL do not attain durable responses. Recent studies have focused on understanding the mechanisms and predictors of response in these patients. In this review, we will discuss the literature for chimeric antigen receptor-modified T-cell therapy in CLL and highlight mechanisms of response and resistance as currently understood.

Safety of allogeneic hematopoietic cell transplant in adults after CD19-targeted CAR T-cell therapy

AbstractAllogeneic hematopoietic cell transplantation (allo-HCT) is offered to selected patients after chimeric antigen receptor–modified T-cell (CAR-T) therapy. Lymphodepleting chemotherapy and CAR-T therapy have immunosuppressive and immunomodulatory effects that could alter the safety profile of subsequent allo-HCT. We reviewed our experience with 32 adults (acute lymphoblastic leukemia [ALL], n = 19; B-cell non-Hodgkin lymphoma [NHL]/chronic lymphocytic leukemia [CLL], n = 13) who received an allo-HCT after CAR-T therapy, with a focus on posttransplant toxicities. Myeloablative conditioning (MAC) was used in 74% of ALL patients and 39% of NHL/CLL patients. The median time from CAR-T therapy to allo-HCT was 72 days in ALL patients and 122 days in NHL/CLL patients. Cumulative incidences of grade 3-4 acute graft-versus-host disease (GVHD) and chronic GVHD were 25% and 10%, respectively. All patients had neutrophil recovery (median, 18.5 days) and all but 3 had platelet recovery (median, 12 days). Twenty-two percent had viral or systemic fungal infection within 100 days after allo-HCT. The 100-day and 1-year cumulative incidences of NRM were 16% and 21%, respectively, for ALL patients and 15% and 33%, respectively, for NHL/CLL patients. In ALL patients, later utilization of allo-HCT after CAR-T therapy was associated with higher mortality. In NHL/CLL patients, MAC was associated with higher mortality. Toxicities did not exceed the expected incidences in this high-risk population.

CD123: A Novel Biomarker for Diagnosis and Treatment of Leukemia.

Leukemia is a group of progressive hematologic malignancies derived from stem cells in bone marrow which causes a large number of cancer deaths. Even with treatment such as traditional chemotherapy, targeted therapy, and allogeneic stem cell transplantation (allo-HSCT), many patients suffer from relapse/refractory disease, and the overall survival is dismal. Leukemic stem cells (LSCs) are induced by gene mutations and undergo an aberrant and poorly regulated proliferation process which is involved in the evolution, relapse, and drug-resistance of leukemia. Emerging studies demonstrate that CD123, the interleukin 3 receptor alpha (IL-3Rα), is highly expressed in LSCs, while not normal hematopoietic stem cells (HSCs), and associates with treatment response, minimal residual disease (MRD) detection and prognosis. Furthermore, CD123 is an important marker for the identification and targeting of LSCs for refractory or relapsed leukemia. Anti-CD123 target-therapies in pre-clinical studies and clinical trials confirm the utility of anti-CD123 neutralizing antibody-drugs, CD3×CD123 bispecific antibodies, dual-affinity retargeting (DART), and anti-CD123 chimeric antigen receptor-modified T-cell (CAR-T) therapies in progress. This review summarizes the most recent progress on the study of CD123 biology and the development of novel CD123-targeted therapies.

Current targeted therapies in lymphomas.

This article summarizes current targeted therapies that have received regulatory approval for the treatment of B- and T-cell lymphomas. Over the last 20 years, new drug therapies for lymphomas of B cells and T cells have expanded considerably. Targeted therapies for B-cell lymphomas include: (1) monoclonal antibodies directed at the CD20 lymphocyte antigen, examples of which are rituximab, ofatumumab, and obinutuzumab; (2) gene transfer therapy, an example of which is chimeric antigen receptor-modified T-cell (CAR-T) therapy directed at the CD19 antigen expressed on the cell surface of both immature and mature B cells; and (3) small-molecule inhibitors (ibrutinib, acalabrutinib, copanlisib, duvelisib, and idelalisib) that target the B-cell receptor signaling pathway. Of note, brentuximab vedotin is an antibody-drug conjugate that targets CD30, another lymphocyte antigen expressed on the cell surface of both Hodgkin lymphoma (a variant of B-cell lymphoma) and some T-cell lymphomas. Although aberrant epigenetic signaling pathways are present in both B- and T-cell lymphomas, epigenetic inhibitors (examples include belinostat, vorinostat, and romidepsin) are currently approved by the Food and Drug Administration for T-cell lymphomas only. In addition, therapies that target the tumor microenvironment have been developed. Examples include mogamulizumab, bortezomib, lenalidomide, nivolumab, and pembrolizumab. In summary, the efficacy of these agents has led to the development of supportive care to mitigate adverse effects, due to the presence of on- or off-target toxicities. The therapeutic landscape of lymphomas has continued to evolve. In turn, the efficacy of these agents has led to the development of supportive care to mitigate adverse effects, due to the presence of on- or off-target toxicities. Further opportunities are warranted to identify patients who are most likely to achieve durable response and reduce the risk of disease progression. Ongoing trials with current and investigational agents may further elucidate their place in therapy and therapeutic benefits.

Super-resolution microscopy reveals ultra-low expression of CD19 on myeloma cells that triggers elimination by CAR-T cells

Especially since the transfer of chimeric antigen receptor (CAR) T cell therapy to the clinic, there has been controversy over the amount of target molecules necessary to activate T cells via a CAR. Here, we evaluate the use of CAR-modified T-cells targeting CD19 (CD19CART) in multiple myeloma. A highly recognized study (Garfall et al, NEJM 2015) reported complete remission in one patient that had received CD19CART, even though only 0.05% of myeloma cells expressed CD19 as judged by flow cytometry (FC).

CD123 as a Therapeutic Target in the Treatment of Hematological Malignancies.

The interleukin-3 receptor alpha chain (IL-3Rα), more commonly referred to as CD123, is widely overexpressed in various hematological malignancies, including acute myeloid leukemia (AML), B-cell acute lymphoblastic leukemia, hairy cell leukemia, Hodgkin lymphoma and particularly, blastic plasmacytoid dendritic neoplasm (BPDCN). Importantly, CD123 is expressed at both the level of leukemic stem cells (LSCs) and more differentiated leukemic blasts, which makes CD123 an attractive therapeutic target. Various agents have been developed as drugs able to target CD123 on malignant leukemic cells and on the normal counterpart. Tagraxofusp (SL401, Stemline Therapeutics), a recombinant protein composed of a truncated diphtheria toxin payload fused to IL-3, was approved for use in patients with BPDCN in December of 2018 and showed some clinical activity in AML. Different monoclonal antibodies directed against CD123 are under evaluation as antileukemic drugs, showing promising results either for the treatment of AML minimal residual disease or of relapsing/refractory AML or BPDCN. Finally, recent studies are exploring T cell expressing CD123 chimeric antigen receptor-modified T-cells (CAR T) as a new immunotherapy for the treatment of refractory/relapsing AML and BPDCN. In December of 2018, MB-102 CD123 CAR T developed by Mustang Bio Inc. received the Orphan Drug Designation for the treatment of BPDCN. In conclusion, these recent studies strongly support CD123 as an important therapeutic target for the treatment of BPDCN, while a possible in the treatment of AML and other hematological malignancies will have to be evaluated by in the ongoing clinical studies.

PD-1 silencing impairs the anti-tumor function of chimeric antigen receptor modified T cells by inhibiting proliferation activity

BackgroundBlocking programmed death-1 (PD-1) is considered to be a promising strategy to improve T cell function, and this is being explored in many ongoing clinical trials. In fact, our knowledge about PD-1 is primarily based on the results of short-term experiments or observations, but how long-lasting PD-1 blockade can affect T cell function remains unclear.MethodsWe planned to use shRNA-based gene knockdown technology to mimic long-lasting PD-1 blockade. We constructed PD-1 steadily blocked chimeric antigen receptor modified T (CAR-T) cells, and with these cells we can clearly study the effects of PD-1 knockdown on T cell function. The anti-tumor function, proliferation ability and differentiation status of PD-1 silenced CAR-T cells were studied by in vitro and animal experiments.ResultsAccording to short-term in vitro results, it was reconfirmed that the resistance to programmed death-ligand 1 (PD-L1)-mediated immunosuppression could be enhanced by PD-1 blockade. However, better anti-tumor function was not presented by PD-1 blocked CAR-T cells in vitro or in vivo experiments. It was found that PD-1 knockdownmight impair the anti-tumor potential of CAR-T cells because it inhibited T cells’ proliferation activity. In addition, we observed that PD-1 blockade would accelerate T cells’ early differentiation and prevent effector T cells from differentiating into effect memory T cells, and this might be the reason for the limited proliferation of PD-1 silenced CAR-T cells.ConclusionThese results suggest that PD-1 might play an important role in maintaining the proper proliferation and differentiation of T cells, and PD-1 silencing would impair T cells’ anti-tumor function by inhibiting their proliferation activity.

Anti-CD19 chimeric antigen receptor-modified T-cell therapy bridging to allogeneic hematopoietic stem cell transplantation for relapsed/refractory B-cell acute lymphoblastic leukemia: An open-label pragmatic clinical trial.

Chimeric antigen receptor-modified T-cell (CAR-T) therapy is effective and safe for patients with relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL), but its value has been limited in terms of long-term leukemia-free survival. New strategies that can help CAR-T therapy achieve lasting effect are urgently warranted. This non-randomized interventional pragmatic clinical trial had a particular aim. It explored whether consolidative allogeneic hematopoietic stem cell transplantation (allo-HSCT) could improve the long-term prognosis of the minimal residual disease-negative complete remission (MRD- CR) patients after CAR-T therapy. In the first stage, 58 r/r B-ALL patients received split doses of CAR-T cells after lymphodepleting chemotherapy, and 51 (87.9%) achieved CR. In the second stage, 21/47 MRD- CR patients without previous allo-HSCT and contraindications or other restrictions, on their own accord, received consolidative allo-HSCT within three months after CAR-T therapy. There was no difference in overall survival (OS) between the MRD- CR patients who received allo-HSCT and those who did not. However, event-free survival (EFS) and relapse-free survival (RFS) were significantly prolonged by allo-HSCT in the subgroups. This was with either high (≥5%) pre-infusion bone marrow MRD assessed by flow cytometry (BM-FCM-MRD) or poor prognostic markers (P < .05). However, no difference was found in EFS and RFS for patients with pre-infusion BM-FCM-MRD <5% and without poor prognostic markers (P > .05). To conclude, CAR-T therapy bridging to allo-HSCT is a safe and effective therapeutic strategy for r/r B-ALL patients, and may prolong their EFS and RFS, especially when they have high pre-infusion BM-FCM-MRD or poor prognostic markers.

An IL-4/21 Inverted Cytokine Receptor Improving CAR-T Cell Potency in Immunosuppressive Solid-Tumor Microenvironment

Incorporation of inverted cytokine receptor (ICR) such as interleukin (IL)-4 vs. IL-7 (4/7) ICR is one strategy to improve the antitumor activities of chimeric antigen receptor (CAR) modified T (CAR-T) cells facing immunosuppressive cytokines. Here we report a novel interleukin (IL)-4 vs. IL-21 ICR (4/21 ICR) that enhanced CAR-T cell potency in IL-4+ tumor milieu via a different working-mechanism from 4/7 ICR. Upon IL-4 stimulation, 4/21 ICR activated the STAT3 pathway and promoted Th17-like polarization and tumor-targeted cytotoxicity in CAR-T cells in vitro. Furthermore, 4/21 ICR-CAR T cells persisted and eradicated established IL-4+ tumors in vivo. Thus, 4/21 ICR is a promising clinical CAR-T cell therapeutics for solid tumors rich in IL-4.

Chimeric Antigen Receptor T-Cell Therapy Clinical Results in Pediatric and Young Adult B-ALL.

Chimeric antigen receptor (CAR)-modified T-cell therapy has revolutionized the care of patients with relapsed and refractory B-cell acute lymphoblastic leukemia (B-ALL). Results from clinical trials across multiple institutions report remarkable remission rates with CD19-directed CAR-modified T-cell therapy. These remissions are also proving to be durable in many patients with a relapse-free survival (RFS) of approximately 50% to 60% at 1 year across several trials and institutions in this population that has been historically very difficult to treat. In addition, new products are being developed to enhance upon the original CAR T-cell products, which include a humanized CAR, allogeneic CARs, and both CD22 and biallelic CD19 and CD22 constructs. Toxicity after CAR-modified T-cell therapy is characterized by cytokine release syndrome (CRS) and neurotoxicity in the acute post-infusion period and B-cell aplasia as a long-term consequence of treatment. This review will summarize the published data thus far on the use of CAR-modified T-cell therapy in pediatric B-ALL and outline the various CAR products now being developed for this population. Delivery of this therapy and the decision to pursue hematopoietic stem cell transplant (HSCT) after treatment will be discussed.

Armored Inducible Expression of IL-12 Enhances Antitumor Activity of Glypican-3-Targeted Chimeric Antigen Receptor-Engineered T Cells in Hepatocellular Carcinoma.

Adoptive immunotherapy based on chimeric antigen receptor-modified T (CAR-T) cells has been demonstrated as one of the most promising therapeutic strategies in the treatment of malignancies. However, CAR-T cell therapy has shown limited efficacy for the treatment of solid tumors. This is, in part, because of tumor heterogeneity and a hostile tumor microenvironment, which could suppress adoptively transferred T cell activity. In this study, we, respectively, engineered human- or murine-derived-armored glypican-3 (GPC3)-specific CAR-T cells capable of inducibly expressing IL-12 (GPC3-28Z-NFAT-IL-12) T cells. The results showed that GPC3-28Z-NFAT-IL-12 T cells could lyse GPC3+ tumor cells specifically and increase cytokine secretion compared with GPC3-28Z T cells in vitro. In vivo, GPC3-28Z-NFAT-IL-12 T cells augmented the antitumor effect when encountering GPC3+ large tumor burdens, which could be attributed to IL-12 increasing IFN-γ production, favoring T cells infiltration and persistence. Furthermore, in immunocompetent hosts, low doses of GPC3-m28Z-mNFAT-mIL-12 T cells exerted superior antitumor efficacy without prior conditioning in comparison with GPC3-m28Z T cells. Also, mIL-12 secretion decreased regulatory T cell infiltration in established tumors. In conclusion, these findings demonstrated that the inducible expression of IL-12 could boost CAR-T function with less potential side effects, both in immunodeficient and immunocompetent hosts. The inducibly expressed IL-12-armored GPC3-CAR-T cells could broaden the application of CAR-T-based immunotherapy to patients intolerant of lymphodepletion chemotherapy and might provide an alternative therapeutic strategy for patients with GPC3+ cancers.

Derivation of mimetic γδ T cells endowed with cancer recognition receptors from reprogrammed γδ T cell.

Using induced pluripotent stem cells (iPSCs) to derive chimeric antigen receptor-modified T (CAR-T) cells has great industrial potential. A previous study used αβ T cell-derived CAR-modified iPSCs to produce CAR-T cells. However, these αβ T cells are restricted to autologous use and only recognize single cancer antigen. To make CAR-T alternative for allogeneic use, we reprogrammed γδ T cell into iPSCs (γδ T-iPSCs) to circumvent the risk of graft-versus-host disease. To target multiple cancer-associated antigens, we used an “NK cell-promoting” protocol to differentiate γδ T-iPSCs and to induce expression of natural killer receptors (NKRs). Through such two-step strategy, mimetic γδ T cells endowed with an array of NKRs and thus designated as “γδ natural killer T (γδ NKT) cells” were derived. With no/low-level expression of inhibitory killer cell immunoglobulin-like receptors (KIRs) and immune checkpoint receptors, γδ NKT cells may provide a potent “off-the-shelf” cytotoxic cell source to recognize multiple ubiquitous antigens in a broad spectrum of cancers.

Tisagenlecleucel for the Treatment of Relapsed or Refractory B-cell Acute Lymphoblastic Leukaemia in People Aged up to 25Years: An Evidence Review Group Perspective of a NICE Single Technology Appraisal.

As part of the National Institute for Health and Care Excellence's (NICE's) Single Technology Appraisal (STA) process, Novartis submitted evidence on the clinical effectiveness and cost-effectiveness of tisagenlecleucel for treating paediatric and young adult patients (under the age of 25years) with relapsed or refractory (r/r) B-cell acute lymphoblastic leukaemia (ALL). This article presents a summary of the Evidence Review Group's (ERG's) independent review of the evidence submission, the committee's deliberations, and the subsequent development of NICE guidance for the use of tisagenlecleucel on the National Health Service (NHS) in England. Tisagenlecleucel is a chimeric antigen receptor-modified T-cell (CAR-T) product, the first of this emerging therapeutic class to be considered by NICE in this indication. The company's evidence submission was based upon three single-arm, phase II studies: ELIANA, ENSIGN, and B2101J. These trials demonstrated a beneficial effect of tisagenlecleucel, with significant extensions in event-free survival (EFS) and overall survival (OS) compared to historical control datasets on blinatumomab and salvage chemotherapy. Adverse events were common; 77% of patients suffered from cytokine release syndrome (CRS), 56% of whom required intensive care unit-level care. The ERG did not consider clofarabine monotherapy an appropriate proxy for salvage chemotherapy. The company presented a hybrid cost-effectiveness model, combining a decision tree and three-state partitioned survival model structure. The majority of quality-adjusted life-years (QALYs) gained were generated through additional life-years in the extrapolated 'long-term survival' phase of the model, where patients were assumed to be 'cured'. The ERG considered the results to be subject to substantial uncertainty, due in part to immature trial data, unresolved long-term treatment effects, and a lack of appropriate comparator data. The ERG implemented a number of changes to the company's model in an alternative base case, producing deterministic incremental cost-effectiveness ratios (ICERs) of £45,397 per QALY gained versus salvage chemotherapy, and £27,732 versus blinatumomab. The probabilistic model produced ICERs of £48,265 per QALY gained versus salvage chemotherapy, and £29,501 versus blinatumomab. The committee considered the ERG's analysis to be most closely aligned with their preferred assumptions, and did not consider tisagenlecleucel to meet both of the end-of-life (EoL) criteria. In recognition of the innovative nature of tisagenlecleucel, and the present immaturity of ongoing clinical trials, the committee considered further data collection would be valuable in resolving uncertainties around OS, the technology's novel mechanism of action, and the management of CRS and B-cell aplasia. The committee therefore recommended tisagenlecleucel for use in the Cancer Drugs Fund (CDF) until the conclusion of the ELIANA study (June 2023). This appraisal highlighted the difficulty of interpreting EoL criteria in the context of curative therapies and the valuation of cure versus extension of life. Further clarification of NICE's position in these situations may be necessary to ensure consistency and equity in their decision-making.

Efficacy and Toxicity of CD19-Specific Chimeric Antigen Receptor T Cells Alone or in Combination with Ibrutinib for Relapsed and/or Refractory CLL

Background In relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) patients (pts) who had previously failed ibrutinib, we observed durable responses after CD19 chimeric antigen receptor-modified T-cell immunotherapy (Turtle CJ et al, JCO, 2017; NCT01865617). The combination of CD19 CAR-T cells with ibrutinib might improve response and decrease toxicity. Objectives To evaluate the efficacy and toxicity of CD19 CAR-T cell immunotherapy alone or in combination with ibrutinib for R/R CLL. Methods Our phase 1/2 study of CD19 CAR-T cell immunotherapy established a preferred regimen for R/R CLL pts of cyclophosphamide and fludarabine (Cy/Flu) lymphodepletion followed by 2 × 106 CD19 CAR-T cells/kg (Turtle, JCO, 2017). We then compared outcomes of these pts (No-ibr cohort) with a subsequent cohort receiving Cy/Flu with 2 × 106/kg JCAR014 CAR-T cells with concurrent ibrutinib (420 mg/d) from at least 2 weeks prior to leukapheresis until at least 3 months after JCAR014 infusion (Ibr cohort). Results We treated 19 and 17 pts in the No-Ibr and Ibr cohorts, respectively. Pt characteristics were comparable (Table 1). Median follow-up in responders was 764 and 98 days in the No-ibr and Ibr cohorts, respectively. Administration of ibrutinib with Cy/Flu and CD19 CAR-T cells was well tolerated in most pts; ibrutinib was reduced or discontinued in 6 pts (35%) at a median of 21 days after JCAR014 infusion. In the Ibr cohort 1 pt with grade 2 CRS (Lee, Blood, 2014) developed fatal presumed cardiac arrhythmia and 1 pt developed a subdural hematoma in the setting of trauma and thrombocytopenia. Although the proportions of pts with grade ≥1 CRS were similar between cohorts (76% vs 89%, P = 0.39), the severity of CRS (grade ≥3 CRS: Ibr, 0%; No-Ibr, 26%; P = 0.05) and serum peak IL-8 (P = 0.04), IL-15 (P = 0.003) and MCP-1 (P = 0.004) concentrations were lower in the Ibr cohort. However, we found higher peak CD4+ CAR-T cell counts (P = 0.06) and comparable peak CD8+ CAR-T cell counts (P = 0.29) in blood in the Ibr compared to the No-Ibr cohort. Sixteen pts (94%) and 18 pts (95%) in the Ibr and No-ibr cohorts, respectively, were evaluable for response. We observed a higher proportion of responders (complete response and partial response) by 2008 IWCLL criteria in the Ibr compared to the No-ibr cohort (88% vs 56%, respectively, P = 0.06). In pts with no disease by BM flow cytometry after treatment (N = 23), a higher proportion of pts in the Ibr cohort had no malignant IgH sequences at 4 weeks (83% vs 60%, P = 0.35). Using multivariable logistic regression (Table 2), treatment in the Ibr cohort and a lower pre-treatment SUVmax were associated with a higher probability of response (Ibr cohort, OR = 14.02, P = 0.05; SUVmax, OR = 1.31 per SUV unit decrease, P Conclusion The combination of ibrutinib with CD19 CAR-T cell immunotherapy was well tolerated in most pts, and might decrease the incidence of severe CRS and improve responses in pts with R/R CLL.

Chimeric antigen receptor modified T cell therapy in B cell non-Hodgkin lymphomas.

Chimeric antigen receptor modified T (CAR-T) cell therapy against the CD19 antigen has revolutionized the therapeutic landscape for patients with relapsed, refractory B cell non-Hodgkin lymphoma (NHL). Currently, there are two FDA approved products (axicabtagene ciloleucel and tisagenlecleucel) for B cell NHL, with several other constructs under clinical investigation. This review will focus on the clinical outcomes, toxicity profile, and differences among candidate CD19 CAR-T cell products for major subtypes of B cell NHL including diffuse large B cell lymphoma, follicular lymphoma, and mantle cell lymphoma. Lastly, we will describe novel CAR-T constructs currently under exploration in B cell NHL.

Current Progress in CAR-T Cell Therapy for Solid Tumors.

Cancer immunotherapy by chimeric antigen receptor-modified T (CAR-T) cells has shown exhilarative clinical efficacy for hematological malignancies. Recently two CAR-T cell based therapeutics, Kymriah (Tisagenlecleucel) and Yescarta (Axicabtagene ciloleucel) approved by US FDA (US Food and Drug Administration) are now used for treatment of B cell acute lymphoblastic leukemia (B-ALL) and diffuse large B-cell lymphoma (DLBCL) respectively in the US. Despite the progresses made in treating hematological malignancies, challenges still remain for use of CAR-T cell therapy to treat solid tumors. In this landscape, most studies have primarily focused on improving CAR-T cells and overcoming the unfavorable effects of tumor microenvironment on solid tumors. To further understand the current status and trend for developing CAR-T cell based therapies for various solid tumors, this review emphasizes on CAR-T techniques, current obstacles, and strategies for application, as well as necessary companion diagnostics for treatment of solid tumors with CAR-T cells.