Given the growing significance of immunotherapy in addressing the limitations of conventional acute myeloid leukemia (AML) treatments, this study aimed to elucidate the hotspot evolution and frontiers of immunotherapy in AML using bibliometric analysis. With a strict retrieval strategy applied in the Web of Science Core Collection, 2411 publications were obtained and exported. The temporal and geographical distributions of these publications and the countries, institutions, journals, and authors who contributed to the field were investigated. An in-depth content analysis was performed. The United States had various research institutions dedicated to AML immunotherapy. Frontiers in Immunology had the highest number of publications, but Blood had the highest H-index. Marion Subklewe was the most productive author. The current research hotspots of AML immunotherapy included chimeric antigen receptor-T-cell therapy, antibody-based immunotherapies, immune checkpoint blockade, and combination therapy, highlighting the key aspects of immunotherapy for AML treatment and providing comprehensive insights into the research status and advances in this field. Novel immunotherapies combined with chemotherapy may become the primary focus of AML treatment.

Acute myeloid leukaemia (AML) was an incurable disease prior to allogeneic haematopoietic cell transplantation (allo-HCT), which was proven to be a potent cellular immunotherapy-approach. However, allo-HCT has major side effects, with disease relapse presenting as a frequent complication. Novel immunotherapies aim to reduce toxicity and increase the anti-leukaemia activity of allo-HCT. Technological advancements in genetic engineering approaches enable potent immunotherapeutic activity while limiting toxicities. A biology-driven application of small molecules that target AML vulnerabilities holds promise to enhance anti-leukaemia immunotherapy. Extensive preclinical testing of these approaches is essential to reduce toxicity and to find the ideal combination partners for future clinical testing.

Acute leukemia (AL), which includes acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL), is a hematological malignancy characterized by the uncontrolled proliferation of immature myeloid or lymphoid cells. Allogeneic stem cell transplantation (ASCT) remains a therapeutic option for patients with AL. Determination of transplantation indications is a key step in successful ASCT and in curing patients. Currently, the measurable residual disease (MRD) is used as a biomarker for response evaluation, relapse prediction, preemptive therapy, and post-remission treatment selection. In this review, we discuss the advantages and disadvantages of these techniques for MRD detection. We focused mainly on the residual disease-directed selection of transplant indications for patients with either AML or ALL and provided expert opinions in these settings. We also discuss the challenges associated with transplantation indications and propose expert opinions and future directions for the selection of indications for transplantation.

This review evaluates the long-term outcomes and adverse events associated with chimeric antigen receptor (CAR) T-cell therapy in patients with relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL).

We conducted the search in relevant databases up to June 2024. We included clinical trials on CAR T-cell therapy for patients with r/r B-ALL. Meta-analyses were conducted using Comprehensive Meta-Analysis V3 and Review Manager 5.4.

Out of 2659 identified studies, 10 were included in this review. The pooled analysis demonstrated a high minimal residual disease-negative complete remission, with an overall event rate (ER) of 70% (95% CI: 61%-78%, I2 =8 8.35%). Anti-CD19 CAR T-cell therapy showed the highest efficacy with an ER of 74.75% (95% CI: 61%-80%, I2 = 89.84%). Combination therapies targeting CD19 and CD22 had an ER of 69% (95% CI: 53%-83%, I2 = 82.56%). Significant adverse effects included cytokine release syndrome with a mean incidence of 81.8% (95% CI: 76.7%-86.9%), neurotoxicity at 33.2% (95% CI: 28.1%-38.3%), and hematologic toxicities at 71.9% (95% CI: 66.4%-77.4%).

CAR T-cell therapy is a groundbreaking advancement in treating r/r B-ALL, offering high rates of durable remissions.

This study aims to compare the efficacy and safety of chimeric antigen receptor T-cell (CAR-T) immunotherapy with standard treatment for B-cell lymphoma, providing evidence-based support for the more efficient use of CAR-T cell immunotherapy.

We conducted a comprehensive literature search of high-quality randomized controlled trials (RCTs) on CAR-T therapy for B-cell lymphoma in the following databases: Wanfang, Web of Science, CNKI, VIP database, and PubMed, up to February 2024. The outcome measures included objective remission rate (ORR), complete remission rate (CRR), and incidence of adverse reactions. Subgroup analysis was performed based on the differences in co-stimulatory domains. Meta-analysis was conducted using Review Manager 5.4 and Stata software.

A total of five RCTs involving 1670 patients were included in this meta-analysis. The results showed that the CAR-T treatment group had significantly higher ORR (RR: 1.47, 95% CI 1.23-1.76, I2 = 80%, p < 0.0001), CRR (RR: 2.19, 95% CI 2.16-3.79, I2 = 93%, p = 0.005), cytokine release syndrome (CRS) incidence (RR: 34.51, 95% CI 2.27-523.78, I2 = 98%, p = 0.01), neurotoxicity (NT) incidence (RR: 6.00, 95% CI 1.82-19.75, I2 = 80%, p = 0.003), neutropenia incidence (RR: 1.39, 95% CI 1.02-1.88, I2 = 93%, p = 0.03), leukopenia incidence (RR: 1.39, 95% CI 1.04-1.87, I2 = 61%, p = 0.03), and headache incidence (RR: 1.56, 95% CI 1.25-1.95, I2 = 34%, p < 0.0001) compared to the standard treatment group. Subgroup analysis based on co-stimulatory domains revealed that the 4-1BB subgroup had higher incidences of CRR, CRS, NT and leukopenia than the CD28 subgroup; however, the CD28 subgroup exhibited higher ORR and neutropenia than the 4-1BB subgroup.

CAR-T cell immunotherapy demonstrates superior efficacy compared to standard therapy in treating B-cell lymphoma. However, CAR-T treatment can lead to adverse reactions such as CRS and NT. Infusion of an appropriate dose of CAR-T cells (e.g., 100 × 106) may be a strategy to mitigate the risk of CRS and NT.

While Chimeric Antigen Receptor (CAR) T cell therapy may result in durable remissions in recurrent large B cell lymphoma, persistence is limited and the mechanisms underlying long-term response are not fully elucidated. Using longitudinal single-cell immunoprofiling, here we compare the immune landscape in durable remission versus early relapse patients following CD19 CAR T cell infusion in the NCT02348216 (ZUMA-1) trial. Four weeks post-infusion, both cohorts demonstrate low circulating CAR T cells. We observe that long-term remission is associated with elevated native cytotoxic and proinflammatory effector cells, and post-infusion clonotypic expansion of effector memory T cells. Conversely, early relapse is associated with impaired NK cell cytotoxicity and elevated immunoregulatory cells, potentially dampening native T cell activation. Thus, we suggest that durable remission to CAR T is associated with a distinct T cell signature and pattern of clonotypic expansion within the native T cell compartment post-therapy, consistent with their contribution to the maintenance of response.

Few studies have thoroughly evaluated the symptom burden and quality of life (QOL) among patients diagnosed with hematologic malignancies who underwent chimeric antigen receptor T-cell (CAR-T) therapy. In total, 97 eligible patients completed the Functional Assessment of Cancer Therapy generic scale (FACT-G) at week 4 after CAR-T cell infusion. We used the Common Terminology Criteria Adverse Events (CTCAE) to measure symptom burden of CAR-T patients during the same period. We studied factors associated with QOL using liner regression analysis. During the period of hospitalization after CAR-T treatment, the prevalence of self-reported symptoms among CAR-T patients was highest for fatigue (89.7%), followed by sleep disorders (79.4%) and decreased appetite (66.0%). And the mean score of FACT-G was 69.06 (SD = 13.88). Liner regression analysis showed that decreased appetite (β = -0.30, 95% CI = -7.48 to -1.83, P = 0.002), fatigue (β = -0.28, 95% CI = -7.23- -1.69, P = 0.002), nausea (β = -0.26, 95% CI = -10.50 to -2.16, P = 0.003) and a history of hematopoietic stem cell transplantation (HSCT) (β = -0.21, 95% CI = -13.38- -1.56, P = 0.014) were associated with poorer quality of life. The symptom burden experienced by patients undergoing CAR-T treatment is substantial during their hospitalization, and it is closely associated with a diminished quality of life. It is imperative for clinical medical staff to be attentive to the symptom burden of CAR-T patients and to enhance the effectiveness of symptom management interventions.

T-cell malignancies are highly aggressive hematological tumors with limited effective treatment options. CAR-NK cell therapy targeting CD7 has emerged as a promising approach for treating T-cell malignancies. However, conventional CAR-NK cell therapy faces the challenges of cell fratricide due to CD7 expression on both malignant cells and normal NK cells. Additionally, engineering CARs into human tissue-derived NK cells demonstrates heterogeneity, low transduction efficiency, and high manufacturing costs.

The human pluripotent stem cells (hPSCs) were genetically modified by knocking out the CD7 gene and introducing the CD7 CAR expression cassette to generate CD7 KO-CD7 CAR-hPSCs. These modified hPSCs were subsequently differentiated into CD7 KO-CD7 CAR-iNK cells using an efficient organoid induction method. The cytotoxicity of CD7 KO-CD7 CAR-iNK cells against CD7+ tumor cells was evaluated. Furthermore, we overexpressed the CXCR4 gene in CD7 KO-CD7 CAR-hPSCs and derived CXCR4-expressing CD7 KO-CD7 CAR-iNK (CRO-CD7 CAR-iNK) cells. The dynamics of CRO-CD7 CAR-iNK cells in vivo were tracked, and their therapeutic efficacy was assessed using human T-cell acute lymphoblastic leukemia (T-ALL) xenograft models.

The CD7 KO-CD7 CAR-iNK cells derived from CD7 KO-CD7 CAR-hPSCs effectively avoided fratricide, demonstrated normal expansion, and exhibited potent and specific anti-tumor activity against CD7+ T-cell tumor cell lines and primary T-ALL cells. CXCR4 overexpression in CRO-CD7 CAR-iNK cells improved their homing capacity and extended their persistence in vivo. The CRO-CD7 CAR-iNK cells significantly suppressed tumor growth and prolonged the survival of T-ALL tumor-bearing mice.

Our study provides a reliable strategy for the large-scale generation of fratricide-resistant CD7 CAR-iNK cells with robust anti-tumor effects from hPSCs, offering a promising cell product to treat T-cell malignancies.

Recent advancements in immunotherapy, particularly Chimeric antigen receptor (CAR)-T cell therapy and cancer vaccines, have significantly transformed the treatment landscape for leukemia. CAR-T cell therapy, initially promising in hematologic cancers, faces notable obstacles in solid tumors due to the complex and immunosuppressive tumor microenvironment. Challenges include the heterogeneous immune profiles of tumors, variability in antigen expression, difficulties in therapeutic delivery, T cell exhaustion, and reduced cytotoxic activity at the tumor site. Additionally, the physical barriers within tumors and the immunological camouflage used by cancer cells further complicate treatment efficacy. To overcome these hurdles, ongoing research explores the synergistic potential of combining CAR-T cell therapy with cancer vaccines and other therapeutic strategies such as checkpoint inhibitors and cytokine therapy. This review describes the various immunotherapeutic approaches targeting leukemia, emphasizing the roles and interplay of cancer vaccines and CAR-T cell therapy. In addition, by discussing how these therapies individually and collectively contribute to tumor regression, this article aims to highlight innovative treatment paradigms that could enhance clinical outcomes for leukemia patients. This integrative approach promises to pave the way for more effective and durable treatment strategies in the oncology field. These combined immunotherapeutic strategies hold great promise for achieving more complete and lasting remissions in leukemia patients. Future research should prioritize optimizing treatment sequencing, personalizing therapeutic combinations based on individual patient and tumor characteristics, and developing novel strategies to enhance T cell persistence and function within the tumor microenvironment. Ultimately, these efforts will advance the development of more effective and less toxic immunotherapeutic interventions, offering new hope for patients battling this challenging disease.

As a marker of minimal residual disease in B-cell acute lymphoblastic leukemia (B-ALL), CD58 has been reported in B-ALL at diagnosis and short-term follow-ups after standard chemotherapies. However, there are no data available in relapsed/refractory (r/r) patients who have received long-term and multiline therapies, especially chimeric antigen receptor (CAR) T cells; here, we focused on investigating CD58 status in these patients.

CD58 expression on lymphoblasts was detected by multiparameter flow cytometry. CD58 status was evaluated in patients with r/r B-ALL before CAR-T therapy, and the patients who failed or relapsed after CAR-T.

Among 274 pediatric and adult patients prior to exposure to CAR-T cells (22.3% of them underwent allogeneic hematopoietic cell transplantation, allo-HCT), 228 (83.2%) showed CD58 positivity. Furthermore, among 58 patients who were CD58 positive before CAR-T failed or relapsed after CAR-T (half also received CD22 CAR-T or allo-HCT as a consolidation treatment following CD19 CAR-T), the frequency of CD58 expression was 79.3% (46/58) in all patients and 86.2% (25/29) in patients exposed to CD19 CAR-T cells alone.

CD58 antigen was stably expressed in patients with r/r B-ALL after multiline therapies, including allo-HCT and CAR-T, indicating that it could still be a leukemic marker in heavily treated patients.

Gene therapies and adoptive cell therapy (ACT) are promising strategies for cancer immunotherapy. Referring to their different mechanisms, the combination of these two might result in a strategy with potential collaborative and compensatory effects. However, it is challenging to combine gene therapies and ACT that work in a proper logical order. Here, we developed a double-layered spherical scaffold (DLS) to codeliver mRNA and T cells and constructed an implantable hydrogel formulation, named the GD-920 scaffold. With a diameter of 7 mm, this scaffold loaded primary T cells in the inner layer and the Bim mRNA nanocomplex in the outer layer. While maintaining their bioactivities, GD-920 released gene and cell payloads in a controllable and sequential manner. The mRNA complex from the outer layer was first released and induced immunogenic tumor cell death. The produced antigens then migrated into the scaffold with dendritic cells, triggering a tumor-specific immune response. Finally, activated T cells released by the inner layer attacked the tumor tissue via massive infiltration. We showed that in situ implantation of the GD-920 scaffold is capable of effectively inhibiting tumor growth and is far more potent than that of control scaffolds containing a single payload. Our results demonstrated the outstanding potential of this DLS in combining gene and cell therapeutic approaches to cancer immunotherapy.

Off-the-shelf, allogeneic CD19 chimeric antigen receptor (CAR) T-cell products may improve access to treatment versus autologous ones. We report the phase I experience of the allogeneic CD19 CAR T-cell product cemacabtagene ansegedleucel (cema-cel) and its predecessor, ALLO-501, in CD19 CAR T-naïve patients with relapsed/refractory large B-cell lymphoma (R/R LBCL).

In the ALPHA2/ALPHA studies, the safety and efficacy of allogeneic CD19 CAR T cells were evaluated in CD19 CAR T treatment-naïve patients with R/R LBCL. Patients received healthy donor-derived, human leukocyte antigen-unmatched cema-cel/ALLO-501 following a 3-day lymphodepletion regimen of fludarabine (30 mg/m2 once daily), cyclophosphamide (300 or 500 mg/m2 once daily), and escalating doses of the anti-CD52 monoclonal antibody, ALLO-647.

As of September 26, 2024, 33 CD19 CAR T-naïve patients with LBCL (median age, 66 years; median number of previous therapies, 3) received allogeneic CAR T cells. CAR T-cell expansion was observed following infusion, with persistence observed up to 4 months. The overall and complete response (CR) rates were 58% and 42%, respectively; the median duration of response in patients with a CR was 23.1 months. The most common treatment-emergent adverse events were hematologic toxicities. No cases of graft-versus-host disease, immune effector cell-associated neurotoxicity syndrome, or grade ≥3 cytokine release syndrome were reported.

Allogeneic CD19 CAR T cells demonstrated promising overall and durable CR rates with a manageable safety profile in CD19 CAR T-naïve patients with R/R LBCL, supporting additional evaluation of cema-cel in patients with LBCL.

Since the inception of Molecular Therapy in 2000, the field of gene therapy has made remarkable progress, evolving from no approved clinical products to 23 clinical gene therapy products today. In this review, we aim to capture the transformative changes in the field by surveying the literature over this period, with a particular focus on advancements in gene delivery vector technology, disease and tissue targeting, and the revolutionary molecular tools that have become central to the field. We also discuss the current challenges facing gene therapy and the need for greater collaboration to ensure its accessibility worldwide.

The efficacy of adoptive T cell therapy (ACT) against solid tumors is significantly limited by the immunosuppressive tumor microenvironment (TME). Systemic administration of immunostimulants provides inadequate support to ACT cells and often elicits systemic toxicities. Here we present cell-surface-anchored nucleic acid therapeutics (NATs) to robustly enhance ACT through synergistic blockade of immunosuppressive adenosine and PD-1/PD-L1 pathways in tumors. Two distinct NATs-DNA aptamers targeting PD-L1 (aptPD-L1) and ATP (aptATP)-are engineered to form partially-hybridized duplexes (aptDual) that can efficiently anchor to cell surface before transfer. Backpacked aptDual spatial-temporally co-localize with ACT cells in vivo and jointly infiltrate the ATP-rich TME. Upon binding with ATP, aptDual dissociates to responsively release aptPD-L1. Concurrently, aptATP scavenges extracellular ATP and its metabolite adenosine to disrupt the inhibitory adenosinergic axis, thereby sensitizing ACT cells to immune checkpoint blockade by aptPD-L1. This dual inhibition elicited a remarkable 40-fold increase in functional tumor-infiltrating ACT cells, substantially boosting the efficacy of TCR-T and CAR-T cells in multiple solid tumor models, even in immunologically "cold" tumors. NAT backpacks provide a facile, versatile, and safe strategy to augment various ACTs against solid tumors.

Brexucabtagene autoleucel (brexu-cel) is an autologous anti-CD19 CAR T-cell therapy approved in the US to treat adults aged ≥18 years (≥26 years in the EU) with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Brexu-cel showed an overall complete remission (CR)/CR with incomplete hematologic recovery (CRi) rate of 73% (CR rate 60%) and median overall survival (OS) of 25.4 months in 78 patients with R/R B-ALL after 2 years in ZUMA-3. Here, we report updated outcomes after >3 years median follow-up. As of July 23, 2022, median follow-up in all patients (N = 78) was 41.6 months. Median OS (95% CI) was 25.6 months (1.2-47.0; N = 78) and was 38.9 months (25.4-not estimable) for responders (n = 58), with 9 patients in ongoing remission without subsequent therapies. Five deaths (none deemed brexu-cel-related) occurred since prior data cut. Benefits from brexu-cel were maintained regardless of age, prior therapies, and subsequent allogeneic stem cell transplantation (alloSCT). Subsequent alloSCT was not associated with survival benefit among responders versus responders without subsequent alloSCT. No secondary T-cell malignancies were reported in ZUMA-3 with long-term follow-up.

Chimeric antigen receptor T cells recognizing CD19 (19CAR-T) cell therapy has achieved robust clinical efficacy when treating some hematological malignancies, but which patient subgroups benefit mostly remains elusive. Here we summarized the data of 541 patients from 30 clinical trials who underwent 19 CAR-T therapy and analyzed the different clinical responses between young (<44 years), middle-aged (45-59 years) and elderly (>60 years) patients and found that the young patients showed a higher level of complete response (CR) rate. Therefore, we then summarize the advances of studies focusing on the effects of age on anti-tumor efficacy of CAR-T therapy and analyze the reasons for the low CR rate after CAR-T cell therapy in elderly patients with tumors, aiming to provide hints for oncologists to select the most suitable candidate for this cancer immunotherapy.

Oral squamous cell carcinoma (OSCC) represents the most common type of oral cancer, and its prognosis remains poor. In this study, we found that almost OSCC cases showed high Ephrin type-B receptor 4 (EPHB4) expression that was mainly localized on the membrane of tumor cells. Therefore, EPHB4 represents a potential target of chimeric antigen receptor (CAR) T cell therapy for OSCC treatment. Because the oral cavity can be directly accessed, local administration of CAR-T cells is feasible for treating OSCC. In this study, we investigated the efficacy of intratumoral injection of EPHB4-specific CAR-T cells in OSCC using xenograft models. To evaluate the anti-tumor effect, the SAS OSCC cell line or an OSCC patient-derived xenograft (PDX) tumor was subcutaneously implanted into NOD SCID gamma mice, and EPHB4-CAR-T cells were intratumorally injected twice. As expected, administration of CAR-T cells suppressed tumor growth of both SAS cells and PDX tumor. EPHB4 expression in tumor tissues was attenuated by CAR-T cell treatment, which was accompanied by a reduction in tumor area and accumulation of CAR-T cells. Our findings suggest that intratumoral injection of EPHB4-CAR-T cells represents a potential therapeutic strategy for OSCC.

The development of chimeric antigen receptor (CAR) T-cells, engineered from peripheral T-lymphocytes of a patient with lymphoma, in order to specifically target tumor cells, has been a revolution in adoptive cell therapy (ACT). As outlined in this review, ACT was initiated by hematopoietic cell transplantation (HSCT) and re-injection of interleukin-boosted tumor-infiltrating lymphocytes (TIL). The innovative venture of genetically modifying autologous peripheral T-cells to target them to cell-surface tumoral antigens through an antibody-derived structure (i.e. independent of major histocompatibility antigen presentation, physiologically necessary for T-cell activation), and intracytoplasmic T-cell costimulatory peptides, via a novel membrane CAR, has been an outstanding breakthrough. Here, focusing on B-cell hematological malignancies and mostly non-Hodgkin lymphoma, attention is brought to the importance of providing an optimal microenvironment for such therapeutic cells to proliferate and positively develop anti-tumoral cytotoxicity. This, perhaps paradoxically, implies a pre-infusion step of deep lymphopenia and deregulation of immunosuppressive mechanisms enhanced by tumoral cells. Fludarabine and cyclophosphamide appear to be the most efficient lymphodepletive drugs in this context, dosage being of importance, as will be illustrated by a thorough literature review.

The immune-related adverse events associated with chimeric antigen receptor (CAR)-T cell therapy result in substantial morbidity as well as considerable cost to the health-care system, and can limit the use of these treatments. Current therapeutic strategies to manage immune-related adverse events include interleukin-6 receptor (IL-6R) blockade and corticosteroids. However, because these interventions do not always address the side effects, nor prevent progression to higher grades of adverse events, new approaches are needed. A deeper understanding of the cell types involved, and their associated signalling pathways, cellular metabolism and differentiation states, should provide the basis for alternative strategies. To preserve treatment efficacy, cytokine-mediated toxicity needs to be uncoupled from CAR-T cell function, expansion, long-term persistence and memory formation. This may be achieved by targeting CAR or independent cytokine signalling axes transiently, and through novel T cell engineering strategies, such as low-affinity CAR-T cells, reversible on-off switches and versatile adaptor systems. We summarize the current management of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and review T cell- and myeloid cell-intrinsic druggable targets and cellular engineering strategies to develop safer CAR-T cells.

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by antiplatelet autoantibodies, with many patients refractory or relapsing on conventional treatments. GPIbα, an important autoantigen in ITP, is notably linked to refractoriness, highlighting the need for novel treatments. We assessed CD19 chimeric antigen receptor (CAR)-T cell therapy's potential in a modified murine model targeting GPIbα. CD19 CAR-T cell infusion accelerated platelet count recovery compared to the control group, effectively depleted CD19+ B cells and CD138+ plasma cells, and markedly reduced anti-GPIbα autoantibodies in vivo. In vitro CD19 CAR-T cells reduced both plasma cells and B cells in the spleens of mice and ITP patients. CD19 CAR-T cell therapy significantly altered T-cell subsets, increasing regulatory T cells, T helper 1 and T helper 17 populations, suggesting a role in modulating the immune response for sustained ITP remission. Monitoring of body/spleen weights and temperature showed no significant cytokine release syndrome, indicating a favourable safety profile. These promising results support the potential of CD19 CAR-T cell therapy as a novel treatment option for refractory ITP, particularly in GPIbα-positive autoantibody patients. Further clinical studies are warranted to assess the safety and efficacy of this approach in human patients.

Current challenges in Chimeric Antigen Receptor (CAR) -T cell therapy for hematological cancers include T cell exhaustion and limited persistence, which contribute to cancer relapse.

The effects of Axitinib, a VEGFR inhibitor, on the biological functions of CAR-T cells in vitro and in vivo were investigated by comparing CAR-T cells pre-treated ex vivo with Axitinib, as well as utilizing a B-ALL mouse model. Real-time quantitative PCR and Western blotting were employed to detect the expression of molecules related to differentiation, exhaustion, and the Wnt pathway in CAR-T cells. Flow cytometry was used to assess changes in CAR-T cell differentiation, exhaustion, activation, apoptosis, proliferation, and cytokine secretion. Western blotting and flow cytometry were used to assess changes in VEGFR expression. Bioluminescence imaging, flow cytometry, and immunohistochemistry (IHC) analysis were used to evaluate changes in tumor burden in mice receiving different treatments, while hematoxylin and eosin (H&E) staining were used to monitor histological changes in the liver and spleen of mice.

Axitinib treatment notably reduced CAR-T cell exhaustion and terminal differentiation both under tonic signaling and tumor antigen exposure scenarios. Furthermore, CAR-T cells pretreated with Axitinib demonstrated enhanced anti-tumor efficacy and prolonged survival in vivo. Mechanistically, Axitinib treatment upregulated the Wnt/β-catenin signaling pathway in CAR-T cells. Using agonists/inhibitors of the Wnt/β-catenin pathway could respectively mimic or counteract the effects of Axitinib on CAR-T cell exhaustion and differentiation. CAR-T cells treated with Axitinib can inhibit the VEGFR2 pathway. CAR-T cells treated with anti-VEGFR2 antibody can activate the Wnt/β-catenin pathway and prevent CAR-T cell exhaustion.

Axitinib confers resistance to exhaustion in CAR-T cells by modulating the Wnt/β-catenin signaling pathway.

The tumor microenvironment, characterized by low oxygen tension and scarce nutrients, impairs chimeric antigen receptor (CAR)-T cell metabolism, leading to T cell exhaustion and dysfunction. Notably, Foxp3 confers a metabolic advantage to regulatory T cells under such restrictive conditions. Exploiting this property, we generated CAR-TFoxp3 cells by co-expressing Foxp3 with a third-generation CAR construct. The CAR-TFoxp3 cells exhibited distinct metabolic reprogramming, marked by downregulated aerobic glycolysis and oxidative phosphorylation coupled with upregulated lipid metabolism. This metabolic shift was driven by Foxp3's interaction with dynamin-related protein 1. Crucially, CAR-TFoxp3 cells did not acquire regulatory T cell immunosuppressive functions but instead demonstrated enhanced antitumor potency and reduced expression of exhaustion markers via Foxp3-mediated adaptation. The potent antitumor effect and absence of immunosuppression were confirmed in a humanized immune system mouse model. Our findings establish a metabolic reprogramming-based strategy to enhance CAR-T cell adaptability within the hostile tumor microenvironment while preserving therapeutic efficacy.

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of B cell and plasma cell malignancies, and numerous promising targets against solid tumours are being explored. Despite their initial therapeutic success in hematological cancers, relapse occurs in a significant fraction of patients, highlighting the need for further innovations in advancing CAR T cell therapy. Tumour antigen heterogeneity and acquired tumour resistance leading to antigen escape (antigen loss/downregulation) have emerged as a crucial factor contributing to immune escape and CAR T cell resistance, particularly in the case of solid tumours with only limited success achieved to date. In this review, we discuss mechanisms of tumour relapse in CAR T cell therapy and the promising strategies that are under development to overcome multiple resistance mechanisms, thereby reducing outgrowth of antigen escape variants. Specifically, we emphasize the importance of designing clinical translational strategies to enhance CAR T cell crosstalk with host immune cells, eliciting endogenous antitumour immune responses through antigen/epitope spreading, which offers a genuine solution to the limitations of targeting tumour antigen heterogeneity in solid tumours with monospecific T cell therapies.

The landscape of acute lymphoblastic leukemia (ALL) treatment is rapidly evolving, with new therapies challenging traditional treatment paradigms. While allogeneic hematopoietic cell transplantation (allo-HCT) remains essential for many high-risk patients, advances in measurable residual disease (MRD) monitoring and the increasing use of immunotherapies in earlier treatment lines have reshaped transplant decision-making. Improvements in donor availability, conditioning strategies, and post-transplant care have expanded access and improved survival, yet relapse and toxicity remain major challenges. This review examines the evolving role of allo-HCT in ALL, highlighting key advancements and ongoing challenges.

Chimeric Antigen Receptor (CAR) T-cell therapy has emerged as a revolutionary approach to cancer treatment. Given the rapid expansion of new indications addressed by newly developed CAR T-cell products, it is essential to standardize analytical methods for the characterization/monitoring of apheresis materials, drug products, and post-infusion patient samples.

The T2Evolve Consortium, part of the European Union's Innovative Medicines Initiative (IMI), conducted an extensive anonymous online survey between February and June 2022. Comprising 36 questions, the survey targeted a wide range of stakeholders involved in engineered T-cell therapies, including researchers, manufacturers, and clinicians. Its goal was to address the current variability within the CAR T-cell field, focusing on analytical assays for quality control of apheresis materials, drug products, and post-infusion immunomonitoring. Another objective was to identify gaps and needs in the field.

A total of 53 respondents from 13 european countries completed the survey, providing insights into the most commonly used assays for apheresis material and drug product characterization, alongside safety and efficacy tests required by the Pharmacopeia. Notably, a minority of respondents conducted phenotypical characterization of T-cell subsets in the drug product and assessed activation/exhaustion T cell profiles.

The survey underscored the necessity to standardize CAR T-cell functional potency assays and identify predictive biomarkers for response, relapse, and toxicity. Additionally, responses indicated significant variability in CAR T-cell monitoring during short-term patient follow-up across clinical centers. This European survey represents the first initiative to report current approaches in different stages of CAR T-cell therapies via a survey, from drug product quality controls to post-infusion immunomonitoring. Based on these findings, and with input from T2EVOLVE experts, the next step will be to address harmonization in the identified areas. These efforts are anticipated to significantly enhance cancer patients' access to engineered T cell therapy safely and effectively throughout Europe.

The advent of chimeric antigen receptor (CAR) T cells has revolutionized the treatment landscape for hematologic malignancies, and emerging evidence suggests their potential in autoimmune diseases (AIDs). This article evaluates the early successes and future implications of B-cell-targeting CAR T-cell therapy in AIDs. Initial applications, particularly in refractory systemic lupus erythematosus, have demonstrated significant and durable clinical remissions, with accompanying evaluation of the immune system suggesting a so-called "reset" of innate inflammation and adaptive autoimmunity. This has generated widespread interest in expanding this therapeutic approach. CAR T cells offer unique advantages over other treatment modalities, including very deep B-cell depletion and unique therapeutic activity within inflamed tissues and associated lymphoid structures. However, the field must address key concerns, including long-term toxicity, particularly the risk of secondary malignancies, and future accessibility given the higher prevalence of AIDs compared with malignancies. Technological advances in cell therapy, such as next-generation CAR T cells, allogeneic off-the-shelf products, and alternative cell types, such as regulatory CAR T cells, are being explored in AIDs to improve efficacy and safety. In addition, bispecific antibodies are emerging as potential alternatives or complements to CAR T cells, potentially offering comparable efficacy without the need for complex logistics, lymphodepletion, and the risk of insertional mutagenesis. As the field evolves, cellular therapists will play a critical role in the multidisciplinary teams managing these complex cases. The transformative potential of CAR T cells in AIDs is undeniable, but careful consideration of safety, efficacy, and implementation is essential as this novel therapeutic approach moves forward.

CD19-directed chimeric antigen receptor-engineered (CAR) T-cell therapy elicits high response rates but fails to induce durable responses in most adults with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). In a previous clinical trial, we observed anti-CAR immune responses associated with impaired in vivo CAR T-cell expansion after second infusions. Because these CD8+ T-cell responses were predominantly directed at peptides derived from the murine single-chain variable fragment (scFv) in the CAR, we conducted a clinical trial investigating the safety and efficacy of CD19 CAR T-cells engineered with a CAR incorporating a fully human scFv (JCAR021) in adults with R/R B-ALL (NCT03103971). Twenty-three patients received lymphodepletion chemotherapy and JCAR021 infusion. Nineteen patients developed cytokine release syndrome (any grade, 83%; grade 2, 61%) and 12 developed neurotoxicity (52%; grade ≥3, 35%). The overall response and complete response (CR)/CR with incomplete hematologic recovery (CRi) rates were 82% and 64%, respectively. We observed measurable residual disease-negative bone marrow (BM) responses in 82% of those with BM disease and extramedullary responses by positron emission tomography-computed tomography in 79% (CR, 50%) of those with measurable fluorodeoxyglucose-avid disease. The median duration of remission (DOR) was 10 months with a 4-year DOR probability of 29%. Four patients underwent allogeneic hematopoietic cell transplantation while in CR/CRi after JCAR021. Durable remissions were observed in patients with low BM disease burden. In contrast, the DOR was limited in those with high BM burden. We observed similar outcomes in CAR-naïve adult patients with B-ALL receiving CD19 CAR T cells expressing a fully human or murine scFv-containing CAR. This trial was registered at www.ClinicalTrials.gov as #NCT03103971.

Chimeric antigen receptor (CAR)-modified NK (CAR-NK) cells are candidates for next-generation cancer immunotherapies. Here we generated CD19-specific CAR-NK cells with 4-1BB and CD3ζ signaling endo-domains (CD19-BBz CAR-NK) by transduction of cord blood-derived NK cells using baboon envelope pseudotyped lentiviral vectors and demonstrated their antitumor activity in preclinical B cell lymphoma models in female mice. We next conducted a phase 1 dose-escalation trial involving repetitive administration of CAR-NK cells in 8 patients with relapsed/refractory large B cell lymphoma (NCT05472558). Primary end points were safety, maximum tolerated dose, and overall response rate. Secondary end points included duration of response, overall survival, and progression-free survival. No dose-limiting toxicities occurred, and the maximum tolerated dose was not reached. No cases of cytokine release syndrome, neurotoxicity, or graft-versus-host disease were observed. Results showed an overall response rate of 62.5% at day 30, with 4 patients (50%) achieving complete response. The median progression-free survival was 9.5 months, and the median overall survival was not reached. A post hoc exploratory single-cell RNA sequencing analysis revealed molecular features of CAR-NK cells associated with therapeutic efficacy and efficacy-related immune cell interaction networks. This study met the pre-specified end points. In conclusion, CD19-BBz CAR-NK cells were feasible and therapeutically safe, capable of inducing durable response in patients with B cell lymphoma.

Cancer immunotherapy has been transformed by chimeric antigen receptor (CAR) T-cell treatment, which has shown groundbreaking results in hematological malignancies. However, its application in solid tumors remains a formidable challenge due to immune evasion, tumor heterogeneity, and safety concerns arising from off-target effects. A long-standing effort in this field has been the development of synthetic receptors to create new signaling pathways and rewire immune cells for the specific targeting of cancer cells, particularly in cell-based immunotherapy. This field has undergone a paradigm shift with the introduction of synthetic Notch (synNotch) receptors, which offer a highly versatile signaling platform modeled after natural receptor-ligand interactions. By functioning as molecular logic gates, synNotch receptors enable precise, multi-antigen regulation of T-cell activation, paving the way for enhanced specificity and control. This review explores the revolutionary integration of synNotch systems with CAR T-cell therapy, emphasizing cutting-edge strategies to overcome the inherent limitations of traditional approaches. We delve into the mechanisms of synNotch receptor design, focusing on their ability to discriminate between cancerous and normal cells through spatiotemporally controlled gene expression. Additionally, we highlight recent advancements to improve therapeutic efficacy, safety, and adaptability in treating solid tumors. This study highlights the potential of synNotch-based CAR-T cells to transform the field of targeted cancer therapy by resolving present challenges and shedding light on potential future paths.

Chimeric antigen receptor (CAR) T cells effectively treat B cell malignancies. However, CAR-T cells cause inflammatory toxicities such as cytokine release syndrome (CRS), which is in contrast to T cell receptor (TCR)-engineered T cells against various antigens that historically have rarely been associated with CRS. To study whether and how differences in receptor types affect the propensity for eliciting inflammatory responses in a model system wherein TCR and CAR target equalized sources of clinically relevant antigen, we discovered a CD22-specific TCR and compared it to CD22 CAR. Both CD22 TCR-T and CD22 CAR-T cells eradicated leukemia in xenografts, but only CD22 CAR-T cells induced dose-dependent systemic inflammation. Compared to TCR-T cells, CAR-T cells disproportionately upregulated inflammatory pathways without concordant augmentation in pathways involved in direct cytotoxicity upon antigen engagement. These differences in antileukemia responses comparing TCR-T and CAR-T cells highlight the potential opportunity to improve therapeutic safety by using TCRs.

Despite clinical benefit with the use of chimeric antigen receptor (CAR) T cells, the need to manufacture patient-specific products limits its clinical utility. To overcome this barrier, we developed an allogeneic "off-the-shelf" CAR T-cell product using Epstein-Barr virus (EBV)-specific T cells (EBV-VSTs) genetically modified with a CD19-specific CAR (19-28z). Patients with relapsed/refractory (R/R) B-cell malignancies were stratified into 3 treatment cohorts: cohort 1 (n = 8; disease recurrence after allogeneic or autologous hematopoietic cell transplantation [HCT]), cohort 2 (n = 6; consolidative therapy after autologous HCT), or cohort 3 (n = 2; consolidative therapy after allogeneic HCT). The primary objective of this trial was to determine the safety of multiple CAR EBV-VST infusions. Most patients (n = 12/16) received multiple doses (overall median, 2.5 [range, 1-3]) with 3 × 106 T cells per kg determined to be the optimal dose enabling multiple treatments per manufactured cell line. Severe cytokine release syndrome or neurotoxicity did not occur after infusion, and no dose-limiting toxicity was observed in the trial. Median follow-up was 48 months (range, 4-135) with 4 deaths due to disease progression. Overall survival of all patients was 81% at 12 months and 75% at 36 months. Postinfusion expansion and persistence were limited, and CAR EBV-VSTs demonstrated a unique T-cell phenotype compared with autologous 19-28z CAR T cells. Our study demonstrates the feasibility and safety of an allogeneic "off-the-shelf" CAR EBV-VST product with favorable outcomes for patients with CD19+ R/R B-cell malignancies. This trial was registered at www.ClinicalTrials.gov as #NCT01430390.