Identification of Predictive Biomarkers for Cytokine Release Syndrome after Chimeric Antigen Receptor T-cell Therapy for Acute Lymphoblastic Leukemia

A review of immunotargeted therapy for Philadelphia chromosome positive acute lymphoblastic leukaemia: making progress in chemotherapy-free regimens

Philadelphia chromosome-positive acute lymphoblastic leukemia (PH + ALL) is the most common cytogenetic abnormality of B-ALL in adults and is associated with poor prognosis. Previously, the only curative treatment option in PH + ALL was allogeneic hematopoietic stem cell transplantation (Allo-HSCT). Since 2000, targeted therapy combined with chemotherapy, represented by the tyrosine kinase inhibitor Imatinib, has become the first-line treatment for PH + ALL. Currently, the remission rate and survival rate of Imatinib are superior to those of simple chemotherapy, and it can also improve the efficacy of transplantation. More recently, some innovative immune-targeted therapy greatly improved the prognosis of PH + ALL, such as Blinatumomab and Inotuzumab Ozogamicin. For patients with ABL1 mutations and those who have relapsed or are refractory to other treatments, targeted oral small molecule drugs, monoclonal antibodies, Bispecific T cell Engagers (BiTE), and chimeric antigen receptor (CAR) T cells immunotherapy are emerging as potential treatment options. These new therapeutic interventions are changing the treatment landscape for PH + ALL. In summary, this review discusses the current advancements in targeted therapeutic agents shift in the treatment strategy of PH + ALL towards using more tolerable chemotherapy-free induction and consolidation regimens confers better disease outcomes and might obviate the need for HSCT.

Breast cancer-on-chip for patient-specific efficacy and safety testing of CAR-T cells

Physiologically relevant human models that recapitulate the challenges of solid tumors and the tumor microenvironment (TME) are highly desired in the chimeric antigen receptor (CAR)-T cell field. We developed a breast cancer-on-chip model with an integrated endothelial barrier that enables the transmigration of perfused immune cells, their infiltration into the tumor, and concomitant monitoring of cytokine release during perfused culture over a period of up to 8 days. Here, we exemplified its use for investigating CAR-T cell efficacy and the ability to control the immune reaction with a pharmacological on/off switch. Additionally, we integrated primary breast cancer organoids to study patient-specific CAR-T cell efficacy. The modular architecture of our tumor-on-chip paves the way for studying the role of other cell types in the TME and thus provides the potential for broad application in bench-to-bedside translation as well as acceleration of the preclinical development of CAR-T cell products.

The CD33xCD123xCD70 Multispecific CD3-Engaging DARPin MP0533 Induces Selective T Cell-Mediated Killing of AML Leukemic Stem Cells

The prognosis of patients with acute myeloid leukemia (AML) is limited, especially for elderly or unfit patients not eligible for hematopoietic stem cell (HSC) transplantation. The disease is driven by leukemic stem cells (LSCs), which are characterized by clonal heterogeneity and resistance to conventional therapy. These cells are therefore believed to be a major cause of progression and relapse. We designed MP0533, a multispecific CD3-engaging designed ankyrin repeat protein (DARPin) that can simultaneously bind to three antigens on AML cells (CD33, CD123, and CD70), aiming to enable avidity-driven T cell-mediated killing of AML cells coexpressing at least two of the antigens. In vitro, MP0533 induced selective T cell-mediated killing of AML cell lines, as well as patient-derived AML blasts and LSCs, expressing two or more target antigens, while sparing healthy HSCs, blood, and endothelial cells. The higher selectivity also resulted in markedly lower levels of cytokine release in normal human blood compared to single antigen-targeting T-cell engagers. In xenograft AML mice models, MP0533 induced tumor-localized T-cell activation and cytokine release, leading to complete eradication of the tumors while having no systemic adverse effects. These studies show that the multispecific-targeting strategy used with MP0533 holds promise for improved selectivity toward LSCs and efficacy against clonal heterogeneity, potentially bringing a new therapeutic option to this group of patients with a high unmet need. MP0533 is currently being evaluated in a dose-escalation phase 1 study in patients with relapsed or refractory AML (NCT05673057).

Current understanding and management of CAR T cell-associated toxicities

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of several haematological malignancies and is being investigated in patients with various solid tumours. Characteristic CAR T cell-associated toxicities such as cytokine-release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are now well-recognized, and improved supportive care and management with immunosuppressive agents has made CAR T cell therapy safer and more feasible than it was when the first regulatory approvals of such treatments were granted in 2017. The increasing clinical experience with these therapies has also improved recognition of previously less well-defined toxicities, including movement disorders, immune effector cell-associated haematotoxicity (ICAHT) and immune effector cell-associated haemophagocytic lymphohistiocytosis-like syndrome (IEC-HS), as well as the substantial risk of infection in patients with persistent CAR T cell-induced B cell aplasia and hypogammaglobulinaemia. A more diverse selection of immunosuppressive and supportive-care pharmacotherapies is now being utilized for toxicity management, yet no universal algorithm for their application exists. As CAR T cell products targeting new antigens are developed, additional toxicities involving damage to non-malignant tissues expressing the target antigen are a potential hurdle. Continued prospective evaluation of toxicity management strategies and the design of less-toxic CAR T cell products are both crucial for ongoing success in this field. In this Review, we discuss the evolving understanding and clinical management of CAR T cell-associated toxicities.

Tethered IL15-IL15Rα augments antitumor activity of CD19 CAR-T cells but displays long-term toxicity in an immunocompetent lymphoma mouse model

BACKGROUND

Adoptive cell therapy using genetically modified T cells to express chimeric antigen receptors (CAR-T) has shown encouraging results, particularly in certain blood cancers. Nevertheless, over 40% of B cell malignancy patients experience a relapse after CAR-T therapy, likely due to inadequate persistence of the modified T cells in the body. IL15, known for its pro-survival and proliferative properties, has been suggested for incorporation into the fourth generation of CAR-T cells to enhance their persistence. However, the potential systemic toxicity associated with this cytokine warrants further evaluation.

METHODS

We analyzed the persistence, antitumor efficacy and potential toxicity of anti-mouse CD19 CAR-T cells which express a membrane-bound IL15-IL15Rα chimeric protein (CD19/mbIL15q CAR-T), in BALB/c mice challenged with A20 tumor cells as well as in NSG mice.

RESULTS

Conventional CD19 CAR-T cells showed low persistence and poor efficacy in BALB/c mice treated with mild lymphodepletion regimens (total body irradiation (TBI) of 1 Gy). CD19/mbIL15q CAR-T exhibits prolonged persistence and enhanced in vivo efficacy, effectively eliminating established A20 B cell lymphoma. However, this CD19/mbIL15q CAR-T displays important long-term toxicities, with marked splenomegaly, weight loss, transaminase elevations, and significant inflammatory findings in some tissues. Mice survival is highly compromised after CD19/mbIL15q CAR-T cell transfer, particularly if a high TBI regimen is applied before CAR-T cell transfer.

CONCLUSION

Tethered IL15-IL15Rα augments the antitumor activity of CD19 CAR-T cells but displays long-term toxicity in immunocompetent mice. Inducible systems to regulate IL15-IL15Rα expression could be considered to control this toxicity.

A meta-analysis to assess the risk of bleeding and thrombosis following chimeric antigen receptor T-cell therapy: Communication from the ISTH SSC Subcommittee on Hemostasis and Malignancy

BACKGROUND

Chimeric antigen receptor T-cell (CAR T-cell) therapy is increasingly utilized for treatment of hematologic malignancies. Hematologic toxicities including thrombosis and bleeding complications have been reported. Accurate estimates for thrombotic and bleeding outcomes are lacking.

OBJECTIVES

We performed a systematic review and meta-analysis in patients who received CAR T-cell therapy for an underlying hematologic malignancy with the objective to: a) assess the thrombosis and bleeding risk associated with CAR T-cell therapy, b) assess the impact of CRS and ICANS on the risks of thrombosis and bleeding, and c) assess the safety of anticoagulant or antiplatelet use in the period following treatment with CAR T-cell therapy.

METHODS

We searched MEDLINE, EMBASE, and Cochrane CENTRAL up to February 2022 for studies reporting thrombotic or bleeding outcomes in patients receiving CAR T-cell therapy. Pooled event rates were calculated using a random-effects model. We performed subgroup analyses stratified by follow-up duration, CAR T-cell target antigen, and underlying hematologic malignancy.

RESULTS

We included 47 studies with a total of 7040 patients. High heterogeneity between studies precluded reporting of overall pooled rates of thrombotic and bleeding events. In studies with follow-up duration of ≤6 months, the pooled incidence of venous thrombotic events was 2.4% (95% CI, 1.4%-3.4%; I2 = 0%) per patient-month, whereas the rate was 0.1% (95% CI, 0%-0.1%; I2 = 0%) per patient-month for studies with longer follow-up periods (>6 months). The pooled incidences of any bleeding events per patient-month in studies with follow-up duration of ≤6 months and >6 months were 1.9% (95% CI, 0.6%-3.1%; I2 = 78%) and 0.3% (95% CI: 0%-0.8%, I2 = 40%), respectively. Secondary analyses by CAR T-cell target antigen, underlying malignancy, and primary outcome of the studies did not reveal significant differences in the rates of thromboembolism, any bleeding events, or major bleeding events.

CONCLUSION

The risk of both thrombosis and bleeding following CAR T-cell therapy appears to be highest in the initial months following infusion.

Scalable intracellular delivery via microfluidic vortex shedding enhances the function of chimeric antigen receptor T-cells

Adoptive chimeric antigen receptor T-cell (CAR-T) therapy is transformative and approved for hematologic malignancies, as well being developed for treatment of solid tumors, autoimmune disorders, heart disease and aging. Despite unprecedented clinical outcomes, CAR-T and other engineered cell therapies face a variety of manufacturing and safety challenges. Traditional methods, like lentivirus transduction and electroporation, result in random integration or cause significant cellular damage, which can limit the safety and efficacy of engineered cell therapies, such as CAR-T. We present hydroporation as a gentle and effective alternative for intracellular delivery. Hydroporation resulted in 1.7 to 2x higher CAR-T yields compared to electroporation with superior cell viability and recovery. Hydroporated cells exhibited rapid proliferation, robust target cell lysis and increased pro-inflammatory and regulatory cytokine secretion in addition to improved CAR-T yield by day 5 post-transfection. We demonstrated scaled-up hydroporation can process 5 × 10 8 cells in less than 10 s, showcasing the platform as a viable solution for high-yield CAR-T cell manufacturing with the potential for improved therapeutic outcomes.

CAR-T cell-derived exosomes: a new perspective for cancer therapy

Chimeric antigen receptor (CAR)-T cell adoptive immunotherapy is a promising cancer treatment that uses genetically engineered T cells to attack tumors. However, this therapy can have some adverse effects. CAR-T cell-derived exosomes are a potential alternative to CAR-T cells that may overcome some limitations. Exosomes are small vesicles released by cells and can carry a variety of molecules, including proteins, RNA, and DNA. They play an important role in intercellular communication and can be used to deliver therapeutic agents to cancer cells. The application of CAR-T cell-derived exosomes could make CAR-T cell therapy more clinically controllable and effective. Exosomes are cell-free, which means that they are less likely to cause adverse reactions than CAR-T cells. The combination of CAR-T cells and exosomes may be a more effective way to treat cancer than either therapy alone. Exosomes can deliver therapeutic agents to cancer cells where CAR-T cells cannot reach. The appropriate application of both cellular and exosomal platforms could make CAR-T cell therapy a more practicable treatment for cancer. This combination therapy could offer a safe and effective way to treat a variety of cancers.

Hemophagocytic lymphohistiocytosis/cytokine release syndrome secondary to neoadjuvant pembrolizumab for triple-negative breast cancer: a case study

As indications for immune checkpoint inhibitors for breast cancer continue to expand, rare toxicities will emerge that require careful consideration and multidisciplinary management. We report the case of a 40-year-old female receiving neoadjuvant pembrolizumab and chemotherapy for locally advanced triple-negative breast cancer who developed cytokine release syndrome (CRS)/hemophagocytic lymphohistiocytosis (HLH). CRS/HLH secondary to pembrolizumab are scarcely documented in the literature and, to our knowledge, have never been reported in the context of neoadjuvant treatment for breast cancer.

Self-regulating CAR-T cells modulate cytokine release syndrome in adoptive T-cell therapy

Cytokine release syndrome (CRS) is a frequently observed side effect of chimeric antigen receptor (CAR)-T cell therapy. Here, we report self-regulating T cells that reduce CRS severity by secreting inhibitors of cytokines associated with CRS. With a humanized NSG-SGM3 mouse model, we show reduced CRS-related toxicity in mice treated with CAR-T cells secreting tocilizumab-derived single-chain variable fragment (Toci), yielding a safety profile superior to that of single-dose systemic tocilizumab administration. Unexpectedly, Toci-secreting CD19 CAR-T cells exhibit superior in vivo antitumor efficacy compared with conventional CD19 CAR-T cells. scRNA-seq analysis of immune cells recovered from tumor-bearing humanized mice revealed treatment with Toci-secreting CD19 CAR-T cells enriches for cytotoxic T cells while retaining memory T-cell phenotype, suggesting Toci secretion not only reduces toxicity but also significantly alters the overall T-cell composition. This approach of engineering T cells to self-regulate inflammatory cytokine production is a clinically compatible strategy with the potential to simultaneously enhance safety and efficacy of CAR-T cell therapy for cancer.

Acute kidney injury after CAR-T cell therapy: exploring clinical patterns, management, and outcomes

Background

Acute kidney injury (AKI) has been reported after CAR-T cells, but available data are limited. We sought to describe the incidence of AKI in a cohort of patients hospitalized in the intensive care unit (ICU) following CAR-T cell reinjection, identify the primary factors linked to the onset of AKI, and ascertain the key determinants associated with kidney outcomes and mortality.

Methods

We retrospectively analyzed 119 patients hospitalized in ICU after CAR-T cell therapy between 2017 and 2023. Factors associated with AKI, mortality, and kidney sequelae were identified using multivariate analyses.

Results

Of the 119 patients, 41 patients fulfilled diagnostic criteria of AKI (34%). By multivariate analysis, grade ≥3 cytokine release syndrome (CRS) [OR = 1.20 CI95% (1.01-1.43)] and elevated lactate dehydrogenase (LDH) levels at admission [OR = 1.44 CI95% (1.04-1.99)] were significantly associated with the occurrence of AKI during ICU stay. AKI KDIGO ≥2 was an independent risk factor for hospital mortality [OR = 1.50 (1.22-1.85), P < 0.001]. Nine out of 12 (75%) and 6/9 (67%) patients who had experienced AKI and survived had chronic kidney disease (CKD) at 6 months and 1 year, respectively. We did not identify any specific factor associated with kidney recovery.

Conclusion

AKI may occur in ICU patients receiving CAR-T cell therapy, especially those who experience CRS and exhibit elevated LDH levels. Early recognition of AKI is of utmost importance as it substantially compromises survival in these patients. Future studies should aim to elucidate the underlying pathophysiological mechanisms of AKI in this context and pinpoint predictive factors for long-term risks of CKD.

Bispecific antibodies and autologous chimeric antigen receptor T cell therapies for treatment of hematological malignancies

In recent years, the therapeutic landscape for hematological malignancies has markedly advanced, particularly since the inaugural approval of autologous chimeric antigen receptor T cell (CAR-T) therapy in 2017 for relapsed/refractory acute lymphoblastic leukemia (ALL). Autologous CAR-T therapy involves the genetic modification of a patient's T cells to specifically identify and attack cancer cells, while bispecific antibodies (BsAbs) function by binding to both cancer cells and immune cells simultaneously, thereby triggering an immune response against the tumor. The subsequent approval of various CAR-T therapies and BsAbs have revolutionized the treatment of multiple hematological malignancies, highlighting high response rates and a subset of patients achieving prolonged disease control. This review explores the mechanisms underlying autologous CAR-T therapies and BsAbs, focusing on their clinical application in multiple myeloma, ALL, and non-Hodgkin lymphoma. We provide comprehensive insights into their individual efficacy, limitations concerning broad application, and the potential of combination therapies. These upcoming strategies aim to propel the field forward, paving the way for safer and more effective therapeutic interventions in hematological malignancies.

Frontiers and hotspots evolution in cytokine storm: A bibliometric analysis from 2004 to 2022

Background

As a fatal disease, cytokine storm has garnered research attention in recent years. Nonetheless, as the body of related studies expands, a thorough and impartial evaluation of the current status of research on cytokine storms remains absent. Consequently, this study aimed to thoroughly explore the research landscape and evolution of cytokine storm utilizing bibliometric and knowledge graph approaches.

Methods

Research articles and reviews centered on cytokine storms were retrieved from the Web of Science Core Collection database. For bibliometric analysis, tools such as Excel 365, CiteSpace, VOSviewer, and the Bibliometrix R package were utilized.

Results

This bibliometric analysis encompassed 6647 articles published between 2004 and 2022. The quantity of pertinent articles and citation frequency exhibited a yearly upward trend, with a sharp increase starting in 2020. Network analysis of collaborations reveals that the United States holds a dominant position in this area, boasting the largest publication count and leading institutions. Frontiers in Immunology ranks as the leading journal for the largest publication count in this area. Stephan A. Grupp, a prominent researcher in this area, has authored the largest publication count and has the second-highest citation frequency. Research trends and keyword evaluations show that the connection between cytokine storm and COVID-19, as well as cytokine storm treatment, are hot topics in research. Furthermore, research on cytokine storm and COVID-19 sits at the forefront in this area.

Conclusion

This study employed bibliometric analysis to create a visual representation of cytokine storm research, revealing current trends and burgeoning topics in this area for the first time. It will provide valuable insights, helping scholars pinpoint critical research areas and potential collaborators.

Development of a chimeric cytokine receptor that captures IL-6 and enhances the antitumor response of CAR-T cells

The efficacy of chimeric antigen receptor (CAR)-engineered T cell therapy is suboptimal in most cancers, necessitating further improvement in their therapeutic actions. However, enhancing antitumor T cell response inevitably confers an increased risk of cytokine release syndrome associated with monocyte-derived interleukin-6 (IL-6). Thus, an approach to simultaneously enhance therapeutic efficacy and safety is warranted. Here, we develop a chimeric cytokine receptor composed of the extracellular domains of GP130 and IL6RA linked to the transmembrane and cytoplasmic domain of IL-7R mutant that constitutively activates the JAK-STAT pathway (G6/7R or G6/7R-M452L). CAR-T cells with G6/7R efficiently absorb and degrade monocyte-derived IL-6 in vitro. The G6/7R-expressing CAR-T cells show superior expansion and persistence in vivo, resulting in durable antitumor response in both liquid and solid tumor mouse models. Our strategy can be widely applicable to CAR-T cell therapy to enhance its efficacy and safety, irrespective of the target antigen.

Targeting TGFβ-activated kinase-1 activation in microglia reduces CAR T immune effector cell-associated neurotoxicity syndrome

Cancer immunotherapy with chimeric antigen receptor (CAR) T cells can cause immune effector cell-associated neurotoxicity syndrome (ICANS). However, the molecular mechanisms leading to ICANS are not well understood. Here we examined the role of microglia using mouse models and cohorts of individuals with ICANS. CD19-directed CAR (CAR19) T cell transfer in B cell lymphoma-bearing mice caused microglia activation and neurocognitive deficits. The TGFβ-activated kinase-1 (TAK1)-NF-κB-p38 MAPK pathway was activated in microglia after CAR19 T cell transfer. Pharmacological TAK1 inhibition or genetic Tak1 deletion in microglia using Cx3cr1CreER:Tak1fl/fl mice resulted in reduced microglia activation and improved neurocognitive activity. TAK1 inhibition allowed for potent CAR19-induced antilymphoma effects. Individuals with ICANS exhibited microglia activation in vivo when studied by translocator protein positron emission tomography, and imaging mass cytometry revealed a shift from resting to activated microglia. In summary, we prove a role for microglia in ICANS pathophysiology, identify the TAK1-NF-κB-p38 MAPK axis as a pathogenic signaling pathway and provide a rationale to test TAK1 inhibition in a clinical trial for ICANS prevention after CAR19 T cell-based cancer immunotherapy.

Finding Your CAR: The Road Ahead for Engineered T Cells

Adoptive cellular therapy using chimeric antigen receptors (CARs) has transformed immunotherapy by engineering T cells to target specific antigens on tumor cells. As the field continues to advance, pathology laboratories will play increasingly essential roles in the complicated multi-step process of CAR T-cell therapy. These include detection of targetable tumor antigens by flow cytometry or immunohistochemistry at the time of disease diagnosis and the isolation and infusion of CAR T cells. Additional roles include: i) detecting antigen loss or heterogeneity that renders resistance to CAR T cells as well as identifying alternative targetable antigens on tumor cells, ii) monitoring the phenotype, persistence, and tumor infiltration properties of CAR T cells and the tumor microenvironment for factors that predict CAR T-cell therapy success, and iii) evaluating side effects and biomarkers of CAR T-cell cytotoxicity such as cytokine release syndrome. This review highlights existing technologies that are applicable to monitoring CAR T-cell persistence, target antigen identification, and loss. Also discussed are emerging technologies that address new challenges such as how to put a brake on CAR T cells. Although pathology laboratories have already provided companion diagnostic tests important in immunotherapy (eg, programmed death-ligand 1, microsatellite instability, and human epidermal growth factor receptor 2 testing), we draw attention to the exciting new translational research opportunities in adoptive cellular therapy.

The Unprecedented Success of Chimeric Antigen Receptor T-Cell Therapy in the Treatment of Hematological Malignancies

Chimeric antigen receptor (CAR) therapy is one of the most unprecedented advancements in the treatment of hematological malignancies, especially B-cell malignancies. The fundamental notion behind the success of this therapy is to generate a synthetic protein (CAR) capable of redirecting T lymphocytes to act against cancer cells. New insights into the genetic and molecular base of hematological malignancies have more recently given rise to the development of targeted treatments. CAR T-cell therapy is one of these immunological treatment techniques that has recently received a lot of attention and paved a light of hope for the effective cure of relapsed and refractory hematological malignancies and some solid malignancies. Researchers of today might not know what the future holds for CAR T-cell therapy, but from whatever research has been done so far, this therapy has proven to be a success despite its limitations, and it can be assumed that the spectrum of its application is expanding with each passing day.

Autologous stem cell boost improves persistent immune effector cell associated hematotoxicity following BCMA directed chimeric antigen receptor T (CAR T) cell therapy in multiple myeloma

Persistent Immune Effector Cell Associated Hematotoxicity (ICAHT) is a significant side effect of BCMA CAR T-Cell therapy in patients with relapsed multiple myeloma (MM). The use of stem cell boosts in ICAHT has been described, however studies have been limited by small patient numbers and short follow up. Herein, we report on our multi-institutional experience of ICAHT, defined by an absolute neutrophil count (ANC) of ≤ 1000, thrombocytopenia with a platelet count ≤ 50,000 or/and anemia as hemoglobin (hgb) ≤9 g/dL, in patients who received BCMA CAR T therapy, and the effects of subsequent stem cell boost on hematopoietic reconstitution and clinical outcome. In this study, ICAHT was observed in 60% (n = 61/101) of patients at D + 21, and risk factors for its development included history of a prior ASCT, higher number of prior lines of therapy, a decreased platelet count prior to lymphodepletion and history of ICANS. 28% of patients with ICAHT received a stem cell boost at a median of 116 days due to profound and prolonged cytopenias often requiring ongoing transfusion support. Stem cell boost significantly improved cytopenias at 3 and 6 months follow up without any adverse effects on PFS and OS, underscoring the safety of this procedure.

CAR T-cell therapy and the onco-nephrologist

Cell therapy, specifically the revolutionary chimeric antigen receptor (CAR) T-cell therapy, has transformed the landscape of oncology, making substantial strides in practical treatment approaches. Today, established guidelines for diseases such as lymphomas, myelomas, and leukemias actively advocate the utilization of these once-unconventional therapies. The practical impact of these therapies is underscored by their unparalleled efficacy, reshaping the way we approach and implement treatments in the realm of oncology. However, CAR T-cell therapy, with its performance in anti-tumor aggression through cellular action and inflammatory response, also comes with various adverse events, one of which is kidney injury. Therefore, the management of these side effects is extremely important. The integration of knowledge between oncologists and specialized nephrologists has led to the emergence of a new sub-area of expertise for onco-nephrologists specializing in managing kidney complications from immune effector therapies.

Incorporating IL7 receptor alpha signaling in the endodomain of B7H3-targeting chimeric antigen receptor T cells mediates antitumor activity in glioblastoma

CAR-T-cell therapy has shown promise in treating hematological malignancies but faces challenges in treating solid tumors due to impaired T-cell function in the tumor microenvironment. To provide optimal T-cell activation, we developed a B7 homolog 3 protein (B7H3)-targeting CAR construct consisting of three activation signals: CD3ζ (signal 1), 41BB (signal 2), and the interleukin 7 receptor alpha (IL7Rα) cytoplasmic domain (signal 3). We generated B7H3 CAR-T cells with different lengths of the IL7Rα cytoplasmic domain, including the full length (IL7R-L), intermediate length (IL7R-M), and short length (IL7R-S) domains, and evaluated their functionality in vitro and in vivo. All the B7H3-IL7Rα CAR-T cells exhibited a less differentiated phenotype and effectively eliminated B7H3-positive glioblastoma in vitro. Superiority was found in B7H3 CAR-T cells contained the short length of the IL7Rα cytoplasmic domain. Integration of the IL7R-S cytoplasmic domain maintained pSTAT5 activation and increased T-cell proliferation while reducing activation-induced cell death. Moreover, RNA-sequencing analysis of B7H3-IL7R-S CAR-T cells after coculture with a glioblastoma cell line revealed downregulation of proapoptotic genes and upregulation of genes associated with T-cell proliferation compared with those in 2nd generation B7H3 CAR-T cells. In animal models, compared with conventional CAR-T cells, B7H3-IL7R-S CAR-T cells suppressed tumor growth and prolonged overall survival. Our study demonstrated the therapeutic potential of IL7Rα-incorporating CAR-T cells for glioblastoma treatment, suggesting a promising strategy for augmenting the effectiveness of CAR-T cell therapy.

A novel safer CD19CAR with shRNA interference of IFN-γ can reduce multiple cytokine levels without significantly compromising its killing efficacy

Cytokine release syndrome (CRS) is a great challenge for the application of anti-CD19 CAR-T cell therapy. The aim of this study was to investigate the effect of knocking down interferon gamma (IFN-γ) by shRNA as a potential strategy to reduce the cytokine storms. A newly designed short hairpin interference RNA of IFN-γ (shIFN-γ) in CD19CAR gene was constructed. Several cellular model systems of approach using Nalm-6 cell lines including Nalm-6CD19pos and Nalm-6CD19neg with or without monocytes and endothelial cells were used to analyze the different levels of cytokines after shIFN-γ-anti-CD19CAR-T cell targeted therapy. The activity of this novel CD19CAR-T was evaluated both in vitro and in NSG mouse model. The killing efficacy of shIFN-γ-anti-CD19CAR-T at the E:T ratio of 2:1 was similar to that of regular anti-CD19CAR-T at the E:T ratio of 1:1. The IFN-γ level in the shIFN-γ-anti-CD19CAR-T cell group was (2673.1 ± 307.4) pg/ml at the E:T ratio of 2:1 which was significantly lower than that ((8261.5 ± 345.5) pg/ml) in the regular anti-CD19CAR-T group at the E:T ratio of 1:1. Cytotoxicity experiments in vitro showed significantly reduced concentrations of IFN-γ, IL-6 and TNFα in the shIFN-γ-anti-CD19CAR-T cell group compared to regular anti-CD19CAR-T cell group. Both regular anti-CD19CAR and shIFN-γ-CD19CAR-T exerted bystander killing effect in vitro. We conclude that shIFN-γ-anti-CD19CAR-T cells can reduce the generation of cytokine storms without significantly compromising their therapeutic efficacy in the preclinical setting. In mouse model, 3 × 106 shIFN-γ-anti-CD19CAR-T cells/mouse generated the similar killing efficacy to that with 2 × 106 regular anti-CD19CAR-T cells/mouse.

Important Considerations in the Intensive Care Management of Acute Leukemias

In the realm of hematologic disorders, acute leukemia is approached as an emergent disease given the multitude of complications and challenges that present both as a result of inherent disease pathology and adverse events associated with antineoplastic therapies and interventions. The heavy burden of leukemic cells may lead to complications including tumor lysis syndrome, hyperleukocytosis, leukostasis, and differentiation syndrome, and the initiation of treatment can further exacerbate these effects. Capillary leak syndrome is observed as a result of antineoplastic agents used in acute leukemia, and L-asparaginase, a bacterial-derived enzyme, has a unique side effect profile including association with thrombosis. Thrombohemorrhagic syndrome and malignancy-associated thrombosis are also commonly observed complications due to direct disequilibrium in coagulant and anticoagulant factors. Due to inherent effects on the white blood cell milieu, leukemia patients are inherently immunocompromised and vulnerable to life-threatening sepsis. Lastly, the advents of newer therapies such as chimeric antigen receptor (CAR) T-cells have clinicians facing the management of related toxicities on unfamiliar territory. This review aims to discuss these acute leukemia-associated complications, their pathology, and management recommendations.

Engineering self-propelled tumor-infiltrating CAR T cells using synthetic velocity receptors

Chimeric antigen receptor (CAR) T cells express antigen-specific synthetic receptors, which upon binding to cancer cells, elicit T cell anti-tumor responses. CAR T cell therapy has enjoyed success in the clinic for hematological cancer indications, giving rise to decade-long remissions in some cases. However, CAR T therapy for patients with solid tumors has not seen similar success. Solid tumors constitute 90% of adult human cancers, representing an enormous unmet clinical need. Current approaches do not solve the central problem of limited ability of therapeutic cells to migrate through the stromal matrix. We discover that T cells at low and high density display low- and high-migration phenotypes, respectively. The highly migratory phenotype is mediated by a paracrine pathway from a group of self-produced cytokines that include IL5, TNFα, IFNγ, and IL8. We exploit this finding to "lock-in" a highly migratory phenotype by developing and expressing receptors, which we call velocity receptors (VRs). VRs target these cytokines and signal through these cytokines' cognate receptors to increase T cell motility and infiltrate lung, ovarian, and pancreatic tumors in large numbers and at doses for which control CAR T cells remain confined to the tumor periphery. In contrast to CAR therapy alone, VR-CAR T cells significantly attenuate tumor growth and extend overall survival. This work suggests that approaches to the design of immune cell receptors that focus on migration signaling will help current and future CAR cellular therapies to infiltrate deep into solid tumors.

Need for standardization of cytokine profiling in CAR T cell therapy

With expansion of chimeric antigen receptor (CAR) T cell therapy and broader utilization of anti-cytokine directed therapeutics for toxicity mitigation, the routine assessment of cytokines may enhance understanding of toxicity profiles, guide therapeutic interventions, and facilitate cross-trial comparisons. As specific cytokine elevations can correlate with and provide insights into CAR T cell toxicity, mitigation strategies, and response, we explored the reporting of cytokine detection methods and assessed for the correlation of cytokines to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) across clinical trials. In this analysis, we reviewed 21 clinical trials across 60 manuscripts that featured a US Food and Drug Administration-approved CAR T cell construct or one of its predecessors. We highlight substantial variability and limited reporting of cytokine measurement platforms and panels used across CAR T cell clinical trials. Specifically, across 60 publications, 28 (46.7%) did not report any cytokine data, representing 6 of 21 (28.6%) clinical trials. In the 15 trials reporting cytokine data, at least 4 different platforms were used. Furthermore, correlation of cytokines with ICANS, CRS, and CRS severity was limited. Considering the fundamental role of cytokines in CAR T cell toxicity, our manuscript supports the need to establish standardization of cytokine measurements as a key biomarker essential to improving outcomes of CAR T cell therapy.

Targeting the gut microbiota to enhance the antitumor efficacy and attenuate the toxicity of CAR-T cell therapy: a new hope?

Chimeric antigen receptor (CAR) -T cell therapy has achieved tremendous efficacy in the treatment of hematologic malignancies and represents a promising treatment regimen for cancer. Despite the striking response in patients with hematologic malignancies, most patients with solid tumors treated with CAR-T cells have a low response rate and experience major adverse effects, which indicates the need for biomarkers that can predict and improve clinical outcomes with future CAR-T cell treatments. Recently, the role of the gut microbiota in cancer therapy has been established, and growing evidence has suggested that gut microbiota signatures may be harnessed to personally predict therapeutic response or adverse effects in optimizing CAR-T cell therapy. In this review, we discuss current understanding of CAR-T cell therapy and the gut microbiota, and the interplay between the gut microbiota and CAR-T cell therapy. Above all, we highlight potential strategies and challenges in harnessing the gut microbiota as a predictor and modifier of CAR-T cell therapy efficacy while attenuating toxicity.

Manufacture of CD22 CAR T cells following positive versus negative selection results in distinct cytokine secretion profiles and γδ T cell output

Chimeric antigen receptor T cells (CART) have demonstrated curative potential for hematological malignancies, but the optimal manufacturing has not yet been determined and may differ across products. The first step, T cell selection, removes contaminating cell types that can potentially suppress T cell expansion and transduction. While positive selection of CD4/CD8 T cells after leukapheresis is often used in clinical trials, it may modulate signaling cascades downstream of these co-receptors; indeed, the addition of a CD4/CD8-positive selection step altered CD22 CART potency and toxicity in patients. While negative selection may avoid this drawback, it is virtually absent from good manufacturing practices. Here, we performed both CD4/CD8-positive and -negative clinical scale selections of mononuclear cell apheresis products and generated CD22 CARTs per our ongoing clinical trial (NCT02315612NCT02315612). While the selection process did not yield differences in CART expansion or transduction, positively selected CART exhibited a significantly higher in vitro interferon-γ and IL-2 secretion but a lower in vitro tumor killing rate. Notably, though, CD22 CART generated from both selection protocols efficiently eradicated leukemia in NSG mice, with negatively selected cells exhibiting a significant enrichment in γδ CD22 CART. Thus, our study demonstrates the importance of the initial T cell selection process in clinical CART manufacturing.

In Vivo mRNA CAR T Cell Engineering via Targeted Ionizable Lipid Nanoparticles with Extrahepatic Tropism

With six therapies approved by the Food and Drug Association, chimeric antigen receptor (CAR) T cells have reshaped cancer immunotherapy. However, these therapies rely on ex vivo viral transduction to induce permanent CAR expression in T cells, which contributes to high production costs and long-term side effects. Thus, this work aims to develop an in vivo CAR T cell engineering platform to streamline production while using mRNA to induce transient, tunable CAR expression. Specifically, an ionizable lipid nanoparticle (LNP) is utilized as these platforms have demonstrated clinical success in nucleic acid delivery. Though LNPs often accumulate in the liver, the LNP platform used here achieves extrahepatic transfection with enhanced delivery to the spleen, and it is further modified via antibody conjugation (Ab-LNPs) to target pan-T cell markers. The in vivo evaluation of these Ab-LNPs confirms that targeting is necessary for potent T cell transfection. When using these Ab-LNPs for the delivery of CAR mRNA, antibody and dose-dependent CAR expression and cytokine release are observed along with B cell depletion of up to 90%. In all, this work conjugates antibodies to LNPs with extrahepatic tropism, evaluates pan-T cell markers, and develops Ab-LNPs capable of generating functional CAR T cells in vivo.

Targeting the activated microenvironment with endosialin (CD248)-directed CAR-T cells ablates perivascular cells to impair tumor growth and metastasis

BACKGROUND

Targeting of solid cancers with chimeric antigen receptor (CAR)-T cells is limited by the lack of suitable tumor-specific antigens and the immunosuppressive, desmoplastic tumor microenvironment that impedes CAR-T cell infiltration, activity and persistence. We hypothesized that targeting the endosialin (CD248) receptor, strongly expressed by tumor-associated pericytes and perivascular cancer-associated fibroblasts, would circumvent these challenges and offer an exciting antigen for CAR-T cell therapy due to the close proximity of target cells to the tumor vasculature, the limited endosialin expression in normal tissues and the lack of phenotype observed in endosialin knockout mice.

METHODS

We generated endosialin-directed E3K CAR-T cells from three immunocompetent mouse strains, BALB/c, FVB/N and C57BL/6. E3K CAR-T cell composition (CD4+/CD8+ ratio), activity in vitro against endosialin+ and endosialin- cells, and expansion and activity in vivo in syngeneic tumor models as well as in tumor-naive healthy and wounded mice and tumor-bearing endosialin knockout mice was assessed.

RESULTS

E3K CAR-T cells were active in vitro against both mouse and human endosialin+, but not endosialin-, cells. Adoptively transferred E3K CAR-T cells exhibited no activity in endosialin knockout mice, tumor-naive endosialin wildtype mice or in wound healing models, demonstrating an absence of off-target and on-target/off-tumor activity. By contrast, adoptive transfer of E3K CAR-T cells into BALB/c, FVB/N or C57BL/6 mice bearing syngeneic breast or lung cancer lines depleted target cells in the tumor stroma resulting in increased tumor necrosis, reduced tumor growth and a substantial impairment in metastatic outgrowth.

CONCLUSIONS

Together these data highlight endosialin as a viable antigen for CAR-T cell therapy and that targeting stromal cells closely associated with the tumor vasculature avoids CAR-T cells having to navigate the harsh immunosuppressive tumor microenvironment. Further, the ability of E3K CAR-T cells to recognize and target both mouse and human endosialin+ cells makes a humanized and optimized E3K CAR a promising candidate for clinical development applicable to a broad range of solid tumor types.

Recent advances in CAR T-cell engineering using synthetic biology: Paving the way for next-generation cancer treatment

This book chapter highlights a comprehensive exploration of the transformative innovations in the field of cancer immunotherapy. CAR (Chimeric Antigen Receptor) T-cell therapy represents a groundbreaking approach to treat cancer by reprogramming a patient immune cells to recognize and destroy cancer cells. This chapter underscores the critical role of synthetic biology in enhancing the safety and effectiveness of CAR T-cell therapies. It begins by emphasizing the growing importance of personalized medicine in cancer treatment, emphasizing the shift from one-size-fits-all approaches to patient-specific solutions. Synthetic biology, a multidisciplinary field, has been instrumental in customizing CAR T-cell therapies, allowing for fine-tuned precision and minimizing unwanted side effects. The chapter highlights recent advances in gene editing, synthetic gene circuits, and molecular engineering, showcasing how these technologies are optimizing CAR T-cell function. In summary, this book chapter sheds light on the remarkable progress made in the development of CAR T-cell therapies using synthetic biology, providing hope for cancer patients and hinting at a future where highly personalized and effective cancer treatments are the norm.

Enhancing the safety of CAR-T cell therapy: Synthetic genetic switch for spatiotemporal control

Chimeric antigen receptor T (CAR-T) cell therapy is a promising and precise targeted therapy for cancer that has demonstrated notable potential in clinical applications. However, severe adverse effects limit the clinical application of this therapy and are mainly caused by uncontrollable activation of CAR-T cells, including excessive immune response activation due to unregulated CAR-T cell action time, as well as toxicity resulting from improper spatial localization. Therefore, to enhance controllability and safety, a control module for CAR-T cells is proposed. Synthetic biology based on genetic engineering techniques is being used to construct artificial cells or organisms for specific purposes. This approach has been explored in recent years as a means of achieving controllability in CAR-T cell therapy. In this review, we summarize the recent advances in synthetic biology methods used to address the major adverse effects of CAR-T cell therapy in both the temporal and spatial dimensions.

Bendamustine lymphodepletion before axicabtagene ciloleucel is safe and associates with reduced inflammatory cytokines

ABSTRACT

Lymphodepletion (LD) is an integral component of chimeric antigen receptor T-cell (CART) immunotherapies. In this study, we compared the safety and efficacy of bendamustine (Benda) to standard fludarabine/cyclophosphamide (Flu/Cy) LD before CD19-directed, CD28-costimulated CART axicabtagene ciloleucel (axi-cel) for patients with large B-cell lymphoma (LBCL) and follicular lymphoma (FL). We analyzed 59 patients diagnosed with LBCL (n = 48) and FL (n = 11) consecutively treated with axi-cel at the University of Pennsylvania. We also analyzed serum samples for cytokine levels and metabolomic changes before and after LD. Flu/Cy and Benda demonstrated similar efficacy, with complete remission rates of 51.4% and 50.0% (P = .981), respectively, and similar progression-free and overall survivals. Any-grade cytokine-release syndrome occurred in 91.9% of patients receiving Flu/Cy vs 72.7% of patients receiving Benda (P = .048); any-grade neurotoxicity after Flu/Cy occurred in 45.9% of patients and after Benda in 18.2% of patients (P = .031). In addition, Flu/Cy was associated with a higher incidence of grade ≥3 neutropenia (100% vs 54.5%; P < .001), infections (78.4% vs 27.3%; P < .001), and neutropenic fever (78.4% vs 13.6%; P < .001). These results were confirmed both in patients with LBCL and those with FL. Mechanistically, patients with Flu/Cy had a greater increase in inflammatory cytokines associated with neurotoxicity and reduced levels of metabolites critical for redox balance and biosynthesis. This study suggests that Benda LD may be a safe alternative to Flu/Cy for CD28-based CART CD19-directed immunotherapy with similar efficacy and reduced toxicities. Benda is associated with reduced levels of inflammatory cytokines and increased anabolic metabolites.

INSPIRED Symposium Part 4B: Chimeric Antigen Receptor T Cell Correlative Studies-Established Findings and Future Priorities

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of B cell malignancies, with multiple CAR T cell products approved for numerous indications by regulatory agencies worldwide. However, significant work remains to be done to enhance these treatments. In March 2023, a group of experts in CAR T cell therapy assembled at the National Institutes of Health in Bethesda, Maryland at the Insights in Pediatric CAR T Cell Immunotherapy: Recent Advances and Future Directions (INSPIRED) Symposium to identify key areas for research for the coming years. In session 4B, correlative studies to be incorporated into future clinical trials and real-world settings were discussed. Active areas of research identified included (1) optimizing CAR T cell product manufacturing; (2) ensuring adequate lymphodepletion prior to CAR T cell administration; (3) overcoming immunoregulatory cells and tumor stroma present in the tumor microenvironment, particularly in solid tumors; (4) understanding tumor intrinsic properties that lead to CAR T cell immunotherapy resistance; and (5) uncovering biomarkers predictive of treatment resistance, treatment durability, or immune-related adverse events. Here we review the results of previously published clinical trials and real-world studies to summarize what is currently known about each of these topics. We then outline priorities for future research that we believe will be important for improving our understanding of CAR T cell therapy and ultimately leading to better outcomes for patients.

Current and emerging pharmacotherapies for cytokine release syndrome, neurotoxicity, and hemophagocytic lymphohistiocytosis-like syndrome due to CAR T cell therapy

INTRODUCTION

Chimeric antigen receptor (CAR) T cells have revolutionized the treatment of multiple hematologic malignancies. Engineered cellular therapies now offer similar hope to transform the management of solid tumors and autoimmune diseases. However, toxicities can be serious and often require hospitalization.

AREAS COVERED

We review the two chief toxicities of CAR T therapy, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), and the rarer immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome. We discuss treatment paradigms and promising future pharmacologic strategies. Literature and therapies reviewed were identified by PubMed search, cited references therein, and review of registered trials.

EXPERT OPINION

Management of CRS and ICANS has improved, aided by consensus definitions and guidelines that facilitate recognition and timely intervention. Further data will define optimal timing of tocilizumab and corticosteroids, current foundations of management. Pathophysiologic understanding has inspired off-label use of IL-1 receptor antagonism, IFNγ and IL-6 neutralizing antibodies, and janus kinase inhibitors, with data emerging from ongoing clinical trials. Further strategies to reduce toxicities include novel pharmacologic targets and safety features engineered into CAR T cells themselves. As these potentially curative therapies are used earlier in oncologic therapy and even in non-oncologic indications, effective accessible strategies to manage toxicities are critical.

Hematopoiesis and immune reconstitution after CD19 directed chimeric antigen receptor T-cells (CAR-T): A comprehensive review on incidence, risk factors and current management

Impaired function of hematopoiesis after treatment with chimeric antigen T-cells (CAR-T) is a frequent finding and can interest a wide range of patients, regardless of age and underlying disease. Trilinear cytopenias, as well as hypogammaglobulinemia, B-cell aplasia, and T-cell impairment, can severely affect the infectious risk of CAR-T recipients, as well as their quality of life. In this review, we provide an overview of defects in hematopoiesis after CAR-T, starting with a summary of different definitions and thresholds. We then move to summarize the main pathogenetic mechanisms of cytopenias, and we offer insight into cytomorphological aspects, the role of clonal hematopoiesis, and the risk of secondary myeloid malignancies. Subsequently, we expose the major findings and reports on T-cell and B-cell quantitative and functional impairment after CAR-T. Finally, we provide an overview of current recommendations and leading experiences regarding the management of cytopenias and defective B- and T-cell function.

Bridging treatment prior to chimeric antigen receptor T-cell therapy in multiple myeloma

Autologous patient-derived adoptive T-cell therapies have revolutionized the management of relapsed multiple myeloma (MM). However, the current manufacturing and quality control processes result in lengthy vein-to-vein time, making bridging therapy necessary for most patients. Yet the decision and choice of optimal bridging therapy are complex in the heavily pretreated relapsed MM patient. In this perspective piece, the authors provide their approach and considerations while selecting an optimal bridging regimen before autologous chimeric antigen receptor T-cell therapy.

Optimizing CAR-T cell therapy in adults with B-cell acute lymphoblastic leukemia

Chimeric antigen receptor T-cell (CAR-T) therapy has demonstrated unprecedented success in the treatment of various hematologic malignancies including relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Currently, there are two FDA-approved CD19-directed CAR-T cell products for the treatment of adults with R/R B-ALL. Despite high remission rates following CD19 CAR-T cell therapy in R/R B-ALL, remission durability remains limited in most adult patients, with relapse observed frequently in the absence of additional consolidation therapy. Furthermore, the burden of CAR-T cell toxicity remains significant in adults with R/R B-ALL and further limits the wide utilization of this effective therapy. In this review, we discuss patient and disease factors that are linked to CAR-T cell therapy outcomes in R/R B-ALL and strategies to optimize durability of response to reduce relapse and mitigate toxicity in the adult population. We additionally discuss future approaches being explored to maximize the benefit of CAR-T in adults with B-ALL.

Epigenetic targets to enhance antitumor immune response through the induction of tertiary lymphoid structures

Tertiary lymphoid structures (TLS) are ectopic lymphoid aggregates found in sites of chronic inflammation such as tumors and autoimmune diseases. The discovery that TLS formation at tumor sites correlated with good patient prognosis has triggered extensive research into various techniques to induce their formation at the tumor microenvironment (TME). One strategy is the exogenous induction of specific cytokines and chemokine expression in murine models. However, applying such systemic chemokine expression can result in significant toxicity and damage to healthy tissues. Also, the TLS formed from exogenous chemokine induction is heterogeneous and different from the ones associated with favorable prognosis. Therefore, there is a need to optimize additional approaches like immune cell engineering with lentiviral transduction to improve the TLS formation in vivo. Similarly, the genetic and epigenetic regulation of the different phases of TLS neogenesis are still unknown. Understanding these molecular regulations could help identify novel targets to induce tissue-specific TLS in the TME. This review offers a unique insight into the molecular checkpoints of the different stages and mechanisms involved in TLS formation. This review also highlights potential epigenetic targets to induce TLS neogenesis. The review further explores epigenetic therapies (epi-therapy) and ongoing clinical trials using epi-therapy in cancers. In addition, it builds upon the current knowledge of tools to generate TLS and TLS phenotyping biomarkers with predictive and prognostic clinical potential.

Brief research report: in-depth immunophenotyping reveals stability of CD19 CAR T-cells over time

Variability or stability might have an impact on treatment success and toxicity of CD19 CAR T-cells. We conducted a prospective observational study of 12 patients treated with Tisagenlecleucel for CD19+ B-cell malignancies. Using a 31-color spectral flow cytometry panel, we analyzed differentiation stages and exhaustion markers of CAR T-cell subsets prior to CAR T-cell infusion and longitudinally during 6 months of follow-up. The majority of activation markers on CAR T-cells showed stable expression patterns over time and were not associated with response to therapy or toxicity. Unsupervised cluster analysis revealed an immune signature of CAR T-cell products associated with the development of immune cell-associated neurotoxicity syndrome. Warranting validation in an independent patient cohort, in-depth phenotyping of CAR T-cell products as well as longitudinal monitoring post cell transfer might become a valuable tool to increase efficacy and safety of CAR T-cell therapy.

Safety and feasibility of anti-CD19 CAR T cells expressing inducible IL-7 and CCL19 in patients with relapsed or refractory large B-cell lymphoma

Although CD19-specific chimeric antigen receptor (CAR) T cells are curative for patients with relapsed or refractory large B-cell lymphoma (R/R LBCL), disease relapse with tumor antigen-positive remains a challenge. Cytokine/chemokine-expressing CAR-T cells could overcome a suppressive milieu, but the clinical safety and efficacy of this CAR-T therapy remain unclear. Here we report the preclinical development of CD19-specific CAR-T cells capable of expressing interleukin (IL)-7 and chemokine (C-C motif) ligand (CCL)-19 upon CD19 engagement (referred to as 7 × 19 CAR-T cells) and results from a phase 1 and expansion phase trial of 7 × 19 CAR-T cell therapy in patients with R/R LBCL (NCT03258047). In dose-escalation phase, there were no dose-limiting toxicities observed. 39 patients with R/R LBCL received 7 × 19 CAR-T with doses ranged from 0.5 × 106-4.0 × 106 cells per kg body weight. Grade 3 cytokine release syndrome occurred in 5 (12.8%) patients and ≥ grade 3 neurotoxicity in 4 (10.3%) patients. The overall response rate at 3 months post-single infusion was 79.5% (complete remission, 56.4%; partial response, 23.1%). With a median follow-up of 32 months, the median progression-free survival was 13 months, and median overall survival was not reached, with an estimated rate of 53.8% (95% CI, 40.3% to 72.0%) at two years. Together, these long-term follow-up data from the multicenter clinical study suggest that 7 × 19 CAR-T cells can induce durable responses with a median overall survival of greater than 2 years, and have a manageable safety profile in patients with R/R LBCL.

Neutrophil activation and clonal CAR-T re-expansion underpinning cytokine release syndrome during ciltacabtagene autoleucel therapy in multiple myeloma

Cytokine release syndrome (CRS) is the most common complication of chimeric antigen receptor redirected T cells (CAR-T) therapy. CAR-T toxicity management has been greatly improved, but CRS remains a prime safety concern. Here we follow serum cytokine levels and circulating immune cell transcriptomes longitudinally in 26 relapsed/refractory multiple myeloma patients receiving the CAR-T product, ciltacabtagene autoleucel, to understand the immunological kinetics of CRS. We find that although T lymphocytes and monocytes/macrophages are the major overall cytokine source in manifest CRS, neutrophil activation peaks earlier, before the onset of severe symptoms. Intracellularly, signaling activation dominated by JAK/STAT pathway occurred prior to cytokine cascade and displayed regular kinetic changes. CRS severity is accurately described and potentially predicted by temporal cytokine secretion signatures. Notably, CAR-T re-expansion is found in three patients, including a fatal case characterized by somatic TET2-mutation, clonal expanded cytotoxic CAR-T, broadened cytokine profiles and irreversible hepatic toxicity. Together, our findings show that a latent phase with distinct immunological changes precedes manifest CRS, providing an optimal window and potential targets for CRS therapeutic intervention and that CAR-T re-expansion warrants close clinical attention and laboratory investigation to mitigate the lethal risk.

Prophylactic use of interleukin 6 monoclonal antibody can reduce CRS response of CAR-T cell therapy

Background

Chimeric antigen receptor T (CAR-T) cell immunotherapy is becoming one of the most promising treatments for hematological malignancies, however, complications such as cytokine release syndrome (CRS) seriously threaten the lives of patients. Interleukin 6(IL-6) monoclonal antibody is the common and useful treatment of CRS, however, it is not clear whether prophylactic use IL-6 monoclonal antibody before CAR-T therapy can reduce the incidence of CRS.

Purpose

This study aims to systematically evaluate whether the prophylactic use of IL-6 monoclonal antibody can reduce the incidence of CRS.

Data sources and methods

We searched the PubMed, Embase, web of Science, and Cochrane Library databases for studies that reported the prophylactic use of IL-6 monoclonal antibody in the treatment of CRS-related complications of CAR-T cell immunotherapy before December 2022. The literature is screened according to the established inclusion and exclusion criteria, relevant data are extracted, and the quality of the literature is evaluated using the scale Cochrane bias risk assessment tool, and the Review Manager 5.3 is used to draw for related charts. Since the two experimental data only provide the median, the maximum and minimum values of the data, the mean and standard (Standard Deviation, SD) are calculated by this document Delai, and finally use Review Manager for data processing, and STATA software for supplementation.

Results

A total of 2 trials with a total of 37 participants were included in this study. Meta-analysis showed that compared with no use of IL-6 monoclonal antibody to prevent CRS, IL-6 monoclonal antibody was given to patients at 8 mg/kg one hour before CAR-T cell infusion, which reduced the incidence of CRS [RR: 0.41 95% confidence interval (0.20, 0.86) I[2] = 0.0% P = 0.338 z = -2.369 (p = 0.018)]. In subgroup analysis, compared with those who did not use IL-6 monoclonal antibody to prevent CRS, IL-6 monoclonal antibody was given to patients at 8 mg/kg one hour before CAR-T cell infusion, which reduced lactate dehydrogenase (LDH)[MD: -617.21, 95% confidence interval (-1104.41, -130.01) I[2] = 0% P = 0.88 Z = 2.48 (P = 0.01)], prophylactic use of IL-6 monoclonal antibody has a significant effect on reducing peak C-reactive protein (CRP) after CAR-T therapy [MD: -11.58, 95% confidence interval (-15.28, -7.88) I[2] = 0.0% P = 0.73 z = 6.14 (p < 0.00001)].

Conclusion

The prophylactic use of IL-6 monoclonal antibody can significantly reduce the incidence of CRS complications after CAR-T therapy, can also reduce LDH vaule and peak CRP vaule after CAR-T therapy.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023487662, identifier CRD42023487662.

Chimeric antigen receptor T-cell therapy-induced nervous system toxicity: a real-world study based on the FDA Adverse Event Reporting System database

BACKGROUND

Nervous system toxicity (NST) is one of the most frequent and dangerous side effects of chimeric antigen receptor T-cell (CAR-T) therapy, which is an effective treatment for related tumors in most relapsed/refractory (r/r) hematologic malignancies. Current clinical trial data do not fully reflect the real-world situation. Therefore, this study evaluated the NST of CAR-T therapy using the FDA Adverse Event Reporting System (FAERS).

METHODS

Data were retrieved from FAERS for the period from January 1, 2017 to March 31, 2023. Disproportionality analysis and Bayesian analysis were used for data mining. The reporting odds ratio (ROR) for NST with 95% confidence interval (CI) was calculated for each CAR-T product. The time to onset (TTO) and clinical outcomes due to CAR-T therapy-associated NST were assessed.

RESULTS

Overall, 6946 cases of NST associated with CAR-T therapy were identified. The patients had a median age of 61 years (interquartile range [IQR]: 47-69 years). Significant signals were observed for all CAR-T products (ROR: 2.19, 95% CI: 2.13-2.44). Anti-CD19 CAR-T products showed a higher NST signal than anti-B cell maturation antigen (BCMA) CAR-T products (ROR025 2.13 vs. 1.98). Brexucabtagene autoleucel (ROR: 3.17, 95% CI: 2.90-3.47) and axicabtagene ciloleucel (ROR: 2.92, 95% CI: 2.81-3.03) had the two highest NST signals. For the preferred term "brain edema," the highest signals were obtained for CD28 CAR-T products. The median TTO of NST for all CAR-T products was 7 days (IQR: 3-17 days). The proportion of death, life-threatening and hospitalization adverse events associated with NST was 20.06%, 7.21%, and 32.70%, respectively. The proportion of death outcomes was higher in patients treated with tisagenlecleucel (30.36%) than in those treated with other CAR-T products, except ciltacabtagene autoleucel (P < 0.001). The proportion of hospitalizations was significantly higher for lisocabtagene maraleucel-associated NST (53.85%) than for other drugs, except for ciltacabtagene autoleucel (P < 0.001).

CONCLUSIONS

NST is more closely associated with anti-CD19 CAR-Ts and CAR-Ts containing CD28. Serious NST (brain oedema) is likely to occur with CAR-Ts that contain CD28. CAR-T-related NST warrants greater attention owing to the high proportion of serious adverse events and delayed NST.

Tebentafusp as a Promising Drug for the Treatment of Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults and commonly occurs in the Caucasian population. The malignancy involves the uvea of the eye, which includes the iris, ciliary body, and choroid. The etiology of UM is still not well understood, but age is a risk factor. Symptoms include blurred vision, redness of the eye, floaters, dark spots, a change in the size of the pupil, and loss of vision. The location, shape, and size of the tumor are important for therapeutic purposes. Treating metastasis is always a challenge in UM cases. In cases of lung metastasis, the survival rate decreases. Treatment includes surgery, laser therapy, immunotherapy, hormone therapy, and chemotherapy. Recently, in 2022, the United States Food and Drug Administration (FDA) approved the drug tebentafusp. Tebentafusp was developed to target the most common HLA complex in humans. The present review discusses the indications for the use of a new drug tebentafusp, its mechanism of action, dose, pharmacokinetics, results of clinical trials conducted, and adverse effects like cytokine release syndrome. Hence, tebentafusp is the first T cell receptor (TCR) therapeutic drug that could be considered for the treatment of UM.

The role of podoplanin inhibitors in controlling oral cancer progression

OBJECTIVE

In this article, we review the current studies on the role of podoplanin in oral cancer and the potential application of podoplanin inhibitors as a therapeutic agent for oral cancer.

DESIGN

The narrative review approach was conducted, providing a comprehensive perspective of related literature. Publications addressing podoplanin and its inhibitors in the context of oral cancer were retrieved from PubMed and Scopus databases.

RESULTS

Podoplanin has emerged as a biomarker and therapeutic agent for oral cancer. Numerous studies have reported high podoplanin expression in oral cancer and pre-cancerous lesions compared to normal cells. A specific inhibitor targeting podoplanin may have the potential to prevent oral carcinogenesis via interfering with the pathway of cancerous cells involved in cell proliferation and metastasis. Antibodies, chimeric antigen receptor (CAR)-T cells, cancer-specific mAb (CasMab), synthetic molecules, and lectins are among the materials used as anticancer agents targeting podoplanin. Plant-derived lectins appear to demonstrate a unique advantage against alternative candidates.

CONCLUSIONS

The use of podoplanin inhibitors in place of existing therapeutic approaches could be a promising and novel approach to the prevention and treatment of oral cancer. Nevertheless, further research is required to investigate the practical application of such inhibitors.

Implications of High Tumor Burden on Chimeric Antigen Receptor T-Cell Immunotherapy: A Review

Importance

Chimeric antigen receptor (CAR) T-cell therapy has redefined the therapeutic landscape of several hematologic malignant tumors. Despite its clinical efficacy, many patients with cancer experience nonresponse to CAR T-cell treatment, disease relapse within months, or severe adverse events. Furthermore, CAR T-cell therapy has demonstrated minimal to no clinical efficacy in the treatment of solid tumors in clinical trials.

Observations

A complex interplay between high tumor burden and the systemic and local tumor microenvironment on clinical outcomes of CAR T-cell therapy is emerging from preclinical and clinical data. The hallmarks of advanced cancers-namely, inflammation and immune dysregulation-sustain cancer progression. They negatively affect the production, expansion, antitumor activity, and persistence of CAR T-cell products. Understanding of CAR T-cell therapy, mechanisms underlying its failure, and adverse events under conditions of high tumor burden is critical for realizing the full potential of this novel treatment approach.

Conclusions and Relevance

This review focuses on linking the efficacy and safety of CAR T-cell therapy with tumor burden. Its limitations relative to high tumor burden, systemic inflammation, and immune dysregulation are discussed. Emerging clinical approaches to overcome these obstacles and more effectively incorporate this therapeutic strategy into the treatment paradigm of patients with solid malignant tumors are also described.

Baseline [18F]FDG PET features are associated with survival and toxicity in patients treated with CAR T cells for large B cell lymphoma

PURPOSE

Chimeric antigen receptor (CAR) T cells have established themselves as an effective treatment for refractory or relapsed large B cell lymphoma (LBCL). Recently, the sDmax, which corresponds to the distance separating the two farthest lesions standardized by the patient's body surface area, has appeared as a prognostic factor in LBCL. This study aimed to identify [18F]FDG-PET biomarkers associated with prognosis and predictive of adverse events in patients treated with CAR T cells.

METHODS

Patients were retrospectively included from two different university hospitals. They were being treated with CAR T cells for LBCL and underwent [18F]FDG-PET just before CAR T cell infusion. Lesions were segmented semi-automatically with a threshold of 41% of the maximal uptake. In addition to clinico-biological features, sDmax, total metabolic tumor volume (TMTV), SUVmax, and uptake intensity of healthy lymphoid organs and liver were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The occurrence of adverse events, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), was reported.

RESULTS

Fifty-six patients were included. The median follow-up was 9.7 months. Multivariate analysis showed that TMTV (cut-off of 36 mL) was an independent prognostic factor for PFS (p < 0.001) and that sDmax (cut-off of 0.15 m-1) was an independent prognostic factor for OS (p = 0.008). Concerning the occurrence of adverse events, a C-reactive protein level > 35 mg/L (p = 0.006) and a liver SUVmean > 2.5 (p = 0.027) before CAR T cells were associated with grade 2 to 4 CRS and a spleen SUVmean > 1.9 with grade 2 to 4 ICANS.

CONCLUSION

TMTV and sDmax had independent prognostic values, respectively, on PFS and OS. Regarding adverse events, the mean liver and spleen uptakes were associated with the occurrence of grade 2 to 4 CRS and ICANS, respectively. Integrating these biomarkers into the clinical workflow could be useful for early adaptation of patients management.

INSPIRED Symposium Part 3: Prevention and Management of Pediatric Chimeric Antigen Receptor T Cell-Associated Emergent Toxicities

Chimeric antigen receptor (CAR) T cell (CAR-T) therapy has emerged as a revolutionary cancer treatment modality, particularly in children and young adults with B cell malignancies. Through clinical trials and real-world experience, much has been learned about the unique toxicity profile of CAR-T therapy. The past decade brought advances in identifying risk factors for severe inflammatory toxicities, investigating preventive measures to mitigate these toxicities, and exploring novel strategies to manage refractory and newly described toxicities, infectious risks, and delayed effects, such as cytopenias. Although much progress has been made, areas needing further improvements remain. Limited guidance exists regarding initial administration of tocilizumab with or without steroids and the management of inflammatory toxicities refractory to these treatments. There has not been widespread adoption of preventive strategies to mitigate inflammation in patients at high risk of severe toxicities, particularly children. Additionally, the majority of research related to CAR-T toxicity prevention and management has focused on adult populations, with only a few pediatric-specific studies published to date. Given that children and young adults undergoing CAR-T therapy represent a unique population with different underlying disease processes, physiology, and tolerance of toxicities than adults, it is important that studies be conducted to evaluate acute, delayed, and long-term toxicities following CAR-T therapy in this younger age group. In this pediatric-focused review, we summarize key findings on CAR-T therapy-related toxicities over the past decade, highlight emergent CAR-T toxicities, and identify areas of greatest need for ongoing research.

IL-6 Mutation Attenuates Liver Injury Caused by Aeromonas hydrophila Infection by Reducing Oxidative Stress in Zebrafish

Interleukin-6 (IL-6), a pleiotropic cytokine, plays a crucial role in acute stress induced by bacterial infection and is strongly associated with reactive oxygen species (ROS) production. However, the role of IL-6 in the liver of fish after Aeromonas hydrophila infection remains unclear. Therefore, this study constructed a zebrafish (Danio rerio) il-6 knockout line by CRISPR/Cas9 to investigate the function of IL-6 in the liver post bacterial infection. After infection with A. hydrophila, pathological observation showed that il-6-/- zebrafish exhibited milder liver damage than wild-type (WT) zebrafish. Moreover, liver transcriptome sequencing revealed that 2432 genes were significantly up-regulated and 1706 genes were significantly down-regulated in il-6-/- fish compared with WT fish after A. hydrophila infection. Further, gene ontology (GO) analysis showed that differentially expressed genes (DEGs) were significantly enriched in redox-related terms, including oxidoreductase activity, copper ion transport, etc. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were significantly enriched in pathways such as the PPAR signaling pathway, suggesting that il-6 mutation has a significant effect on redox processes in the liver after A. hydrophila infection. Additionally, il-6-/- zebrafish exhibited lower malondialdehyde (MDA) levels and higher superoxide dismutase (SOD) activities in the liver compared with WT zebrafish following A. hydrophila infection, indicating that IL-6 deficiency mitigates oxidative stress induced by A. hydrophila infection in the liver. These findings provide a basis for further studies on the role of IL-6 in regulating oxidative stress in response to bacterial infections.

Toxicities of CAR T-cell therapy: a review of current literature

The chimeric antigen receptor (CAR) design, first invented by Zelig Eshhar, paved the way for the use of genetically modified T-cells in targeted therapy against cancer cells. Since then, it has gone through many generations, especially with the integration of co-stimulation in the second and third-generation CARs. However, it also mounts a hyperactive immune response named as cytokine release syndrome with the release of several cytokines eventually resulting in multiple end-organ toxicities. The severity of cytokine release syndrome depends upon certain factors such as the tumor burden, choice of co-stimulation, and degree of lymphodepletion, and can manifest as pulmonary edema, vascular leak, renal dysfunction, cardiac problems, hepatic failure, and coagulopathy. Many grading criteria have been used to define these clinical manifestations but they lack harmonization. Neurotoxicity has also been significantly associated with CAR T-cell therapy but it has not been studied much in previous literature. This review aims to provide a comprehensive account of the clinical manifestations, diagnosis, management, and treatment of CAR T-cell associated neurotoxicity.

Harnessing CD3 diversity to optimize CAR T cells

Current US Food and Drug Administration-approved chimeric antigen receptor (CAR) T cells harbor the T cell receptor (TCR)-derived ζ chain as an intracellular activation domain in addition to costimulatory domains. The functionality in a CAR format of the other chains of the TCR complex, namely CD3δ, CD3ε and CD3γ, instead of ζ, remains unknown. In the present study, we have systematically engineered new CD3 CARs, each containing only one of the CD3 intracellular domains. We found that CARs containing CD3δ, CD3ε or CD3γ cytoplasmic tails outperformed the conventional ζ CAR T cells in vivo. Transcriptomic and proteomic analysis revealed differences in activation potential, metabolism and stimulation-induced T cell dysfunctionality that mechanistically explain the enhanced anti-tumor performance. Furthermore, dimerization of the CARs improved their overall functionality. Using these CARs as minimalistic and synthetic surrogate TCRs, we have identified the phosphatase SHP-1 as a new interaction partner of CD3δ that binds the CD3δ-ITAM on phosphorylation of its C-terminal tyrosine. SHP-1 attenuates and restrains activation signals and might thus prevent exhaustion and dysfunction. These new insights into T cell activation could promote the rational redesign of synthetic antigen receptors to improve cancer immunotherapy.