Axicabtagene Ciloleucel CAR T-Cell Therapy in Refractory Large B-Cell Lymphoma

CAR T-cells for pediatric solid tumors: where to go from here?

Despite the great success that chimeric antigen receptor (CAR) T-cells have had in patients with B-cell malignancies and multiple myeloma, they continue to have limited efficacy against most solid tumors. Especially in the pediatric population, pre- and post-treatment biopsies are rarely performed due to ethical reasons, and thus, our understanding is still very limited regarding the mechanisms in the tumor microenvironment by which tumor cells exclude effectors and attract immune-suppressive cells. Nevertheless, based on the principles that are known, current T-cell engineering has leveraged some of these processes and created more potent CAR T-cells. The recent discovery of new oncofetal antigens and progress made in CAR design have expanded the potential pool of candidate antigens for therapeutic development. The most promising approaches to enhance CAR T-cells are novel CAR gating strategies, creative ways of cytokine delivery to the TME without enhancing systemic toxicity, and hijacking the chemokine axis of tumors for migratory purposes. With these new modifications, the next step in the era of CAR T-cell development will be the clinical validation of these promising preclinical findings.

Outcomes of patients with R/R B-cell NHL and limited (<5 sites) pre-CART disease bridged with or without radiotherapy

ABSTRACT

Unirradiated patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (NHL) who undergo anti-CD19 chimeric antigen receptor T-cell therapy (CART) have a predominant localized pattern of relapse, the significance of which is heightened in individuals with limited/localized disease before CART. This study reports on the outcomes of patients with R/R NHL and limited (<5 involved sites) disease bridged with or without radiotherapy. A multicenter retrospective review of 150 patients with R/R NHL who received CART with <5 disease sites before leukapheresis was performed. Bridging treatment, if any, was administered between leukapheresis and CART infusion. Study end points included relapse-free survival (RFS), event-free survival (EFS), and overall survival. Before CART infusion, 48 patients (32%) received bridging radiotherapy (BRT), and 102 (68%) did not. The median follow-up was 21 months. After CART infusion, BRT patients had higher objective response (92% vs 78%; P = .046) and sustained complete response rates (54% vs 33%; P = .015). Local relapse in sites present before CART was lower in the BRT group (21% vs 46%; P = .003). BRT patients had improved 2-year RFS (53% vs 44%; P = .023) and 2-year EFS (37% vs 34%; P = .039) compared with patients who did not receive BRT. The impact of BRT was most prominent in patients who had ≤2 pre-CART involved disease sites, with 2-year RFS of 62% in patients who received BRT compared with 42% in those who did not (P = .002). BRT before CART for patients with limited (<5 involved disease sites) R/R NHL improves response rate, local control, RFS, and EFS without causing significant toxicities.

Validation of a PD-1/CD28 chimeric switch receptor to augment CAR-T function in dogs with spontaneous B cell lymphoma

Chimeric antigen receptor (CAR) T cell therapy has achieved unprecedented clinical outcomes in patients with relapsed/refractory B cell leukemias; however, response rates in patients with large B cell lymphoma (LBCL) are less impressive. Expression of PD-1 on activated T cells and PD-L1 on malignant, stromal, and immune cells within the tumor microenvironment (TME) contribute to CAR-T exhaustion, hypofunction, and treatment failures. Here, a comparative approach is taken to develop a chimeric switch receptor (CSR) with potential to augment CAR-T persistence, function, and clinical efficacy in immune competent, pet dogs with spontaneous B cell lymphoma (BCL). We show that similar to human CAR-T cells, expression of a PD-1/CD28 CSR in canine CAR-T cells results in enhanced function against PD-L1+ targets and preserves central memory phenotype. We also demonstrate that these effects depend upon active CSR signaling. This work paves the way for in vivo studies in canine BCL patients to inform human trial design.

Development of an antigen-based approach to noninvasively image CAR T cells in real time and as a predictive tool

CAR T cell therapy has revolutionized the treatment of a spectrum of blood-related malignancies. However, treatment responses vary among cancer types and patients. Accurate monitoring of CAR T cell dynamics is crucial for understanding and evaluating treatment efficacy. Positron emission tomography (PET) offers a comprehensive view of CAR T cell homing, especially in critical organs such as lymphoid structures and bone marrow. This information will help assess treatment response and predict relapse risk. Current PET imaging methods for CAR T require genetic modifications, limiting clinical use. To overcome this, we developed an antigen-based imaging approach enabling whole-body CAR T cell imaging. The probe detects CAR T cells in vivo without affecting their function. In an immunocompetent B cell leukemia model, CAR-PET signal in the spleen predicted early mortality risk. The antigen-based CAR-PET approach allows assessment of CAR T therapy responses without altering established clinical protocols. It seamlessly integrates with FDA-approved and future CAR T cell generations, facilitating broader clinical application.

A general pHLA-CD80 scaffold fusion protein to promote efficient antigen-specific T cell-based immunotherapy

Inadequate antigen-specific T cells activation hampers immunotherapy due to complex antigen presentation. In addition, therapeutic in vivo T cell expansion is constrained by slow expansion rates and limited functionality. Herein, we introduce a model fusion protein termed antigen-presenting cell-mimic fusion protein (APC-mimic), designed to greatly mimicking the natural antigen presentation pattern of antigen-presenting cells and directly expand T cells both in vitro and in vivo. The APC-mimic comprises the cognate peptide-human leukocyte antigen (pHLA) complex and the co-stimulatory marker CD80, which are natural ligands on APCs. Following a single stimulation, APC-mimic leads to an approximately 400-fold increase in the polyclonal expansion of antigen-specific T cells compared with the untreated group in vitro without the requirement for specialized antigen-presenting cells. Through the combination of single-cell TCR sequencing (scTCR-seq) and single-cell RNA sequencing (scRNA-seq), we identify an approximately 600-fold monoclonal expansion clonotype among these polyclonal clonotypes. It also exhibits suitability for in vivo applications confirmed in the OT-1 mouse model. Furthermore, T cells expanded by APC-mimic effectively inhibits tumor growth in adoptive cell transfer (ACT) murine models. These findings pave the way for the versatile APC-mimic platform for personalized therapeutics, enabling direct expansion of polyfunctional antigen-specific T cell subsets in vitro and in vivo.

Co-stimulation of CD28/CD40 signaling molecule potentiates CAR-T cell efficacy and stemness

CD19 chimeric antigen receptor T (CD19CAR-T) cells have achieved promising outcomes in relapsed/refractory B cell malignancies. However, recurrences occur due to the loss of CAR-T cell persistence. We developed dual T/B cell co-stimulatory molecules (CD28 and CD40) in CAR-T cells to enhance intense tumoricidal activity and persistence. CD19.28.40z CAR-T cells promoted pNF-κB and pRelB downstream signaling while diminishing NFAT signaling upon antigen exposure. CD19.28.40z CAR-T cells demonstrated greater proliferation, which translated into effective anti-tumor cytotoxicity in long-term co-culture assay. Repetitive weekly antigen stimulation unveiled continuous CAR-T cell expansion while preserving central memory T cell subset and lower expression of exhaustion phenotypes. The intrinsic genes underlying CD19.28.40z CAR-T cell responses were compared with conventional CARs and demonstrated the up-regulated genes associated with T cell proliferation and memory as well as down-regulated genes related to apoptosis, exhaustion, and glycolysis pathway. Enrichment of genes toward T cell stemness, particularly SELL, IL-7r, TCF7, and KLF2, was observed. Effective and continuing anti-tumor cytotoxicity in vivo was exhibited in both B cell lymphoblastic leukemia and B cell non-Hodgkin lymphoma xenograft models while demonstrating persistent T cell memory signatures. The functional enhancement of CD37.28.40z CAR-T cell activities against CD37+ tumor cells was further validated. The modification of dual T/B cell signaling molecules remarkably maximized the efficacy of CAR-T cell therapy.

Prospective Assessment of Quality of Life and Patient-Reported Toxicities Over the First Year After Chimeric Antigen Receptor T-Cell Therapy

Chimeric antigen receptor (CAR) T-cell therapy has transformed survival outcomes in patients with relapsed and refractory large B-cell lymphoma (LBCL), but it is associated with a variety of side effects. This study examined changes in patient-reported quality of life (QoL) and toxicities, as well as risk factors for worse QoL and toxicities, in the first year after treatment. Patients with LBCL completed questionnaires assessing QoL and toxicity severity before infusion, and 90, 180, and 360 days after infusion. Mixed models were used to examine changes in QoL and toxicities over time, and clinical moderators of change in QoL and toxicities. Patients reported improvements in physical functioning and fatigue in the year after treatment (P values <.01), but there were no changes in pain, anxiety, or depression over time. Patients with active disease at day 90 reported more physical dysfunction at all postinfusion timepoints (Ps ≤ .01) compared to patients who responded to treatment. Similarly, patients with active disease at day 90 reported worsening depression over time, such that at day 360, depressive symptoms were worse for patients with active disease than patients without active disease (P = .02). Patients treated with 4+ lines of prior therapy reported worsening pain and anxiety over time, such that at day 360, both pain and anxiety were significantly worse for patients previously treated with 4 of more lines of therapy than patients treated with fewer lines of therapy (Ps ≤ .01). Regarding toxicities, patients reported decreasing overall toxicity burden up to day 180, with subsequent worsening at day 360 (P = .02). Most patients reported at least one or two grade 2 toxicities at each timepoint. Patients demonstrated unchanging or improved QoL after treatment with CAR T-cell therapy, but active disease and greater prior lines of therapy were associated with worse QoL outcomes over time. Toxicity severity also improved during the first 6 months post-treatment, but worsened thereafter, particularly among patients with active disease after treatment.

Strategies to Overcome Hurdles in Cancer Immunotherapy

Despite marked advancements in cancer immunotherapy over the past few decades, there remains an urgent need to develop more effective treatments in humans. This review explores strategies to overcome hurdles in cancer immunotherapy, leveraging innovative technologies including multi-specific antibodies, chimeric antigen receptor (CAR) T cells, myeloid cells, cancer-associated fibroblasts, artificial intelligence (AI)-predicted neoantigens, autologous vaccines, and mRNA vaccines. These approaches aim to address the diverse facets and interactions of tumors' immune evasion mechanisms. Specifically, multi-specific antibodies and CAR T cells enhance interactions with tumor cells, bolstering immune responses to facilitate tumor infiltration and destruction. Modulation of myeloid cells and cancer-associated fibroblasts targets the tumor's immunosuppressive microenvironment, enhancing immunotherapy efficacy. AI-predicted neoantigens swiftly and accurately identify antigen targets, which can facilitate the development of personalized anticancer vaccines. Additionally, autologous and mRNA vaccines activate individuals' immune systems, fostering sustained immune responses against cancer neoantigens as therapeutic vaccines. Collectively, these strategies are expected to enhance efficacy of cancer immunotherapy, opening new horizons in anticancer treatment.

High specificity of engineered T cells with third generation CAR (CD28-4-1BB-CD3-ζ) based on biotin-bound monomeric streptavidin for potential tumor immunotherapy

Introduction

Immunotherapy has revolutionized cancer treatment, and Chimeric Antigen Receptor T cell therapy (CAR-T) is a groundbreaking approach. Traditional second-generation CAR-T therapies have achieved remarkable success in hematological malignancies, but there is still room for improvement, particularly in developing new targeting strategies. To address this limitation, engineering T cells with multi-target universal CARs (UniCARs) based on monomeric streptavidin has emerged as a versatile approach in the field of anti-tumor immunotherapy. However, no studies have been conducted on the importance of the intracellular signaling domains of such CARs and their impact on efficiency and specificity.

Method

Here, we developed second-generation and third-generation UniCARs based on an extracellular domain comprising an affinity-enhanced monomeric streptavidin, in addition to CD28 and 4-1BB co-stimulatory intracellular domains. These UniCAR structures rely on a biotinylated intermediary, such as an antibody, for recognizing target antigens. In co-culture assays, we performed a functional comparison between the third-generation UniCAR construct and two second-generation UniCAR variants, each incorporating either the CD28 or 4-1BB as co-stimulatory domain.

Results

We observed that components in culture media could inhibit the binding of biotinylated antibodies to monomeric streptavidin-CARs, potentially compromising their efficacy. Furthermore, third-generation UniCAR-T cells showed robust cytolytic activity against cancer cell lines upon exposure to specific biotinylated antibodies like anti-CD19 and anti-CD20, underscoring their capability for multi-targeting. Importantly, when assessing engineered UniCAR-T cell activation upon encountering their target cells, third-generation UniCAR-T cells exhibited significantly enhanced specificity compared to second-generation CAR-T cells.

Discussion

First, optimizing culture conditions would be essential before deploying UniCAR-T cells clinically. Moreover, we propose that third-generation UniCAR-T cells are excellent candidates for preclinical research due to their high specificity and multi-target anti-tumor cytotoxicity.

Efficient combinatorial adaptor-mediated targeting of acute myeloid leukemia with CAR T-cells

CAR T-cell products targeting lineage-specific cell-of-origin antigens, thereby eliminating both tumor and healthy counterpart cells, are currently clinically approved therapeutics in B- and plasma-cell malignancies. While they represent a major clinical improvement, they are still limited in terms of efficacy by e.g. single, sometimes low-expressed antigen targeting, and in terms of safety by e.g., lack of on-off activity. Successful cell-of-origin non-discriminative targeting of heterogeneous hematopoietic stem and progenitor cell malignancies, such as acute myeloid leukemia (AML), will require antigen-versatile targeting and off-switching of effectors in order to then allow rescue by hematopoietic stem cell transplantation (HSCT), preventing permanent myeloablation. To address this, we developed adaptor-CAR (AdFITC-CAR) T-cells targeting fluoresceinated AML antigen-binding diabody adaptors. This platform enables the use of adaptors matching the AML-antigen-expression profile and conditional activity modulation. Combining adaptors significantly improved lysis of AML cells in vitro. In therapeutic xenogeneic mouse models, AdFITC-CAR T-cells co-administered with single diabody adaptors were as efficient as direct CAR T-cells, and combinatorial use of adaptors further enhanced therapeutic efficacy against both, cell lines and primary AML. Collectively, this study provides proof-of-concept that AdFITC-CAR T-cells and combinations of adaptors can efficiently enhance immune-targeting of AML.

Pembrolizumab in Japanese patients with primary mediastinal large B-cell lymphoma: results from the KEYNOTE-A33 study

BACKGROUND

KEYNOTE-A33 (NCT04317066) is an open-label, single-arm, phase 1 trial designed to evaluate the safety and efficacy of pembrolizumab in Japanese patients with relapsed or refractory (R/R) primary mediastinal large B-cell lymphoma (PMBCL).

METHODS

Patients received pembrolizumab 200 mg every 3 weeks for up to 35 cycles. The primary endpoints were safety and objective response rate (ORR) per International Working Group 2007 criteria by independent central review. The secondary endpoint was disease control rate (DCR). Duration of response (DOR), progression-free survival (PFS), and overall survival (OS) were exploratory.

RESULTS

Seven patients were enrolled and treated; the median age was 32 years (range 26-43) and 86% were female. The median time from the first dose to data cutoff (April 12, 2022) was 5.6 months (range 2.4-21.2). Grade 3-5 treatment-related adverse events (AEs) occurred in 2 patients (29%; 2 grade 4 neutropenia, 1 grade 3 febrile neutropenia); however, no patient discontinued pembrolizumab or died because of treatment-related AEs. The ORR was 43% [95% confidence interval (CI) 10-82]. DCR was 57% (95% CI 18-90). Median DOR was not reached (NR). Four (57%) patients had a reduction in target lesion size of ≥ 50%. The median PFS was 2.9 months (95% CI 2.6-NR). The median OS was 17.5 months (95% CI NE-NE), and the 12 months OS rate was 100%.

CONCLUSION

Overall, pembrolizumab had manageable safety and clinically meaningful antitumor activity in Japanese patients with R/R PMBCL, results that were consistent with those observed in prior global studies.

TRIAL REGISTRY

Registry and the Registration No. of the study/trial: Clinicaltrials.gov: NCT04317066.

Targeting TAG-72 in cutaneous T cell lymphoma

Purpose

Current monoclonal antibody-based treatment approaches for cutaneous T cell lymphoma (CTCL) rely heavily on the ability to identify a tumor specific target that is essentially absent on normal cells. Herein, we propose tumor associated glycoprotein-72 (TAG-72) as one such target. TAG-72 is a mucin-associated, truncated O-glycan that has been identified as a chimeric antigen receptor (CAR)-T cell target in solid tumor indications. To date, TAG-72 targeting has not been considered in the setting of hematological malignancies.

Experimental design

CD3+ cells from patients with CTCL were analyzed for TAG-72 expression by flow cytometry. Immunohistochemistry was used to assess TAG-72 expression in CTCL patient skin lesions and a TAG-72 ELISA was employed to assess soluble TAG-72 (CA 72-4) in patient plasma. TAG-72 CAR transduction was performed on healthy donor (HD) and CTCL T cells and characterized by flow cytometry. In vitro CAR-T cell function was assessed by flow cytometry and xCELLigence® using patient peripheral blood mononuclear cells and proof-of-concept ovarian cancer cell lines. In vivo CAR-T cell function was assessed in a proof-of-concept, TAG-72+ ovarian cancer xenograft mouse model.

Results

TAG-72 expression was significantly higher on total CD3+ T cells and CD4+ subsets in CTCL donors across disease stages, compared to that of HDs. TAG-72 was also present in CTCL patient skin lesions, whereas CA 72-4 was detected at low levels in both CTCL patient and HD plasma with no differences between the two groups. In vitro cytotoxicity assays showed that anti-TAG-72 CAR-T cells significantly, and specifically reduced CD3+TAG-72+ expressing CTCL cells, compared to culture with unedited T cells (no CAR). CTCL CAR-T cells had comparable function to HD CAR-T cells in vitro and CAR-T cells derived from CTCL patients eradicated cancer cells in vivo.

Conclusion

This study shows the first evidence of TAG-72 as a possible target for the treatment of CTCL.

Logistical challenges of CAR T-cell therapy in non-Hodgkin lymphoma: a survey of healthcare professionals

Aim: Characterize the logistical challenges faced by healthcare professionals (HCPs), patients and caregivers during the chimeric antigen receptor T-cell (CAR T) treatment process for non-Hodgkin lymphoma patients.Materials & methods: HCPs in the US and UK experienced with CAR T administration participated in interviews and completed a web-based survey.Results: A total of 133 (80 US, 53 UK) HCPs participated. Two or more logistical challenges were identified by ≥60% of respondents across all stages of the CAR T process. Commonly reported challenges were lengthy waiting periods, administrative and payer-related barriers, limited healthcare capacity, caregiver support and (particularly in the US) patient out-of-pocket costs.Conclusion: The CAR T treatment process presents numerous challenges, highlighting an unmet need for more convenient therapies.

Protocol for a clinically annotated biorepository of samples from Australian immune-compromised patients to investigate the host-microbiome interaction

INTRODUCTION

The human gut microbiota has the potential to modulate the outcomes of several human diseases. This effect is likely to be mediated through interaction with the host immune system. This protocol details the establishment of a biorepository of clinically annotated samples, which we will use to explore correlations between the gut microbiota and the immune system of immune-compromised patients. We aim to identify microbiome-related risk factors for adverse outcomes.

METHODS AND ANALYSES

This is a protocol for the development of a biorepository of clinically annotated samples collected prospectively across three centres in Melbourne, Australia. Participants will be recruited across the following clinical streams: (1) acute leukaemia and allogeneic stem cell transplant; (2) end-stage liver disease and liver transplant; (3) patients receiving any cancer immunotherapies (eg, chimeric antigen receptor therapy); (4) deceased organ donors and (5) healthy adult controls. Participants will be asked to provide paired peripheral blood and microbiota samples (stool and saliva) at either (1) single time point for healthy controls and deceased organ donors or (2) longitudinally over multiple prespecified or event-driven time points for the remaining cohorts. Sampling of fluid from bronchoalveolar lavage and colonoscopy or biopsy of tissues undertaken during routine care will also be performed.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the relevant local ethics committee (The Royal Melbourne Hospital Human Research Ethics Committee). The results of this study will be disseminated by various scientific platforms including social media, international presentations and publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12623001105639. Date registered 20 October 2023.

Advancing CAR T-cell therapies: Preclinical insights and clinical translation for hematological malignancies

Chimeric antigen receptor (CAR) T-cell therapy has achieved significant success in achieving durable and potentially curative responses in patients with hematological malignancies. CARs are tailored fusion proteins that direct T cells to a specific antigen on tumor cells thereby eliciting a targeted immune response. The approval of several CD19-targeted CAR T-cell therapies has resulted in a notable surge in clinical trials involving CAR T cell therapies for hematological malignancies. Despite advancements in understanding response mechanisms, resistance patterns, and adverse events associated with CAR T-cell therapy, the translation of these insights into robust clinical efficacy has shown modest outcomes in both clinical trials and real-world scenarios. Therefore, the assessment of CAR T-cell functionality through rigorous preclinical studies plays a pivotal role in refining therapeutic strategies for clinical applications. This review provides an overview of the various in vitro and animal models used to assess the functionality of CAR T-cells. We discuss the findings from preclinical research involving approved CAR T-cell products, along with the implications derived from recent preclinical studies aiming to optimize the functionality of CAR T-cells. The review underscores the importance of robust preclinical evaluations and the need for models that accurately replicate human disease to bridge the gap between preclinical success and clinical efficacy.

Phase 1 study of CAR-37 T cells in patients with relapsed or refractory CD37+ lymphoid malignancies

ABSTRACT

We report a first-in-human clinical trial using chimeric antigen receptor (CAR) T cells targeting CD37, an antigen highly expressed in B- and T-cell malignancies. Five patients with relapsed or refractory CD37+ lymphoid malignancies were enrolled and infused with autologous CAR-37 T cells. CAR-37 T cells expanded in the peripheral blood of all patients and, at peak, comprised >94% of the total lymphocytes in 4 of 5 patients. Tumor responses were observed in 4 of 5 patients with 3 complete responses, 1 mixed response, and 1 patient whose disease progressed rapidly and with relative loss of CD37 expression. Three patients experienced prolonged and severe pancytopenia, and in 2 of these patients, efforts to ablate CAR-37 T cells, which were engineered to coexpress truncated epidermal growth factor receptor, with cetuximab were unsuccessful. Hematopoiesis was restored in these 2 patients after allogeneic hematopoietic stem cell transplantation. No other severe, nonhematopoietic toxicities occurred. We investigated the mechanisms of profound pancytopenia and did not observe activation of CAR-37 T cells in response to hematopoietic stem cells in vitro or hematotoxicity in humanized models. Patients with pancytopenia had sustained high levels of interleukin-18 (IL-18) with low levels of IL-18 binding protein in their peripheral blood. IL-18 levels were significantly higher in CAR-37-treated patients than in both cytopenic and noncytopenic cohorts of CAR-19-treated patients. In conclusion, CAR-37 T cells exhibited antitumor activity, with significant CAR expansion and cytokine production. CAR-37 T cells may be an effective therapy in hematologic malignancies as a bridge to hematopoietic stem cell transplant. This trial was registered at www.ClinicalTrials.gov as #NCT04136275.

Engineering potent chimeric antigen receptor T cells by programming signaling during T-cell activation

Programming cell signaling during T-cell activation represents a simple strategy for improving the potency of therapeutic T-cell products. Stim-R technology (Lyell Immunopharma) is a customizable, degradable synthetic cell biomimetic that emulates physiologic, cell-like presentation of signal molecules to control T-cell activation. A breadth of Stim-R formulations with different anti-CD3/anti-CD28 (αCD3/αCD28) antibody densities and stoichiometries were screened for their effects on multiple metrics of T-cell function. We identified an optimized formulation that produced receptor tyrosine kinase-like orphan receptor 1 (ROR1)-targeted chimeric antigen receptor (CAR) T cells with enhanced persistence and polyfunctionality in vitro, as assessed in repeat-stimulation assays, compared with a benchmark product generated using a conventional T-cell-activating reagent. In transcriptomic analyses, CAR T cells activated with Stim-R technology showed downregulation of exhaustion-associated gene sets and retained a unique subset of stem-like cells with effector-associated gene signatures following repeated exposure to tumor cells. Compared with the benchmark product, CAR T cells activated using the optimized Stim-R technology formulation exhibited higher peak expansion, prolonged persistence, and improved tumor control in a solid tumor xenograft model. Enhancing T-cell products with Stim-R technology during T-cell activation may help improve therapeutic efficacy against solid tumors.

Identification of early predictive biomarkers for severe cytokine release syndrome in pediatric patients with chimeric antigen receptor T-cell therapy

CAR-T cell therapy is a revolutionary new treatment for hematological malignancies, but it can also result in significant adverse effects, with cytokine release syndrome (CRS) being the most common and potentially life-threatening. The identification of biomarkers to predict the severity of CRS is crucial to ensure the safety and efficacy of CAR-T therapy. To achieve this goal, we characterized the expression profiles of seven cytokines, four conventional biochemical markers, and five hematological markers prior to and following CAR-T cell infusion. Our results revealed that IL-2, IFN-γ, IL-6, and IL-10 are the key cytokines for predicting severe CRS (sCRS). Notably, IL-2 levels rise at an earlier stage of sCRS and have the potential to serve as the most effective cytokine for promptly detecting the condition's onset. Furthermore, combining these cytokine biomarkers with hematological factors such as lymphocyte counts can further enhance their predictive performance. Finally, a predictive tree model including lymphocyte counts, IL-2, and IL-6 achieved an accuracy of 85.11% (95% CI = 0.763-0.916) for early prediction of sCRS. The model was validated in an independent cohort and achieved an accuracy of 74.47% (95% CI = 0.597-0.861). This new prediction model has the potential to become an effective tool for assessing the risk of CRS in clinical practice.

IL-4 drives exhaustion of CD8+ CART cells

Durable response to chimeric antigen receptor T (CART) cell therapy remains limited in part due to CART cell exhaustion. Here, we investigate the regulation of CART cell exhaustion with three independent approaches including: a genome-wide CRISPR knockout screen using an in vitro model for exhaustion, RNA and ATAC sequencing on baseline and exhausted CART cells, and RNA and ATAC sequencing on pre-infusion CART cell products from responders and non-responders in the ZUMA-1 clinical trial. Each of these approaches identify interleukin (IL)-4 as a regulator of CART cell dysfunction. Further, IL-4-treated CD8+ CART cells develop signs of exhaustion independently of the presence of CD4+ CART cells. Conversely, IL-4 pathway editing or the combination of CART cells with an IL-4 monoclonal antibody improves antitumor efficacy and reduces signs of CART cell exhaustion in mantle cell lymphoma xenograft mouse models. Therefore, we identify both a role for IL-4 in inducing CART exhaustion and translatable approaches to improve CART cell therapy.

Quantification of circulating TCR-engineered T cells targeting a human endogenous retrovirus post-adoptive transfer using nanoplate digital PCR

In vivo expansion of genetically modified T cells in cancer patients following adoptive transfer has been linked to both anti-tumor activity and T cell-mediated toxicities. The development of digital PCR has improved the accuracy in quantifying the in vivo status of adoptively infused T cells compared to qPCR or flow cytometry. Here, we developed and evaluated the feasibility and performance of nanoplate-based digital PCR (ndPCR) to quantify adoptively infused T cells engineered with a T cell receptor (TCR) that recognizes a human endogenous retrovirus type E (HERV-E) antigen. Analysis of blood samples collected from patients with metastatic kidney cancer following the infusion of HERV-E TCR-transduced T cells established the limit of detection of ndPCR to be 0.3 transgene copies/μL of reaction. The lower limit of quantification for ndPCR was one engineered T cell per 10,000 PBMCs, which outperformed both qPCR and flow cytometry by 1 log. High inter-test and test-retest reliability was confirmed by analyzing blood samples collected from multiple patients. In conclusion, we demonstrated the feasibility of ndPCR for detecting and monitoring the fate of TCR-engineered T cells in adoptive cell therapy.

Advancements and Challenges in Personalized Therapy for BRAF-Mutant Melanoma: A Comprehensive Review

Over the past several decades, advancements in the treatment of BRAF-mutant melanoma have led to the development of BRAF inhibitors, BRAF/MEK inhibitor combinations, anti-PD-1 therapy, and anti-CTLA4 therapy. Although these therapies have shown substantial efficacy in clinical trials, their sustained effectiveness is often challenged by the tumor microenvironment, which is a highly heterogeneous and complex milieu of immunosuppressive cells that affect tumor progression. The era of personalized medicine holds substantial promise for the tailoring of treatments to individual genetic profiles. However, tumor heterogeneity and immune evasion mechanisms contribute to the resistance to immunotherapy. Despite these challenges, tumor-infiltrating lymphocyte (TIL) therapy, as exemplified by lifileucel, has demonstrated notable efficacy against BRAF V600-mutant melanoma. Additionally, early response biomarkers, such as COX-2 and MMP2, along with FDG-PET imaging, offer the potential to improve personalized immunotherapy by predicting patient responses and determining the optimal treatment duration. Future efforts should focus on reducing the T-cell harvesting periods and costs associated with TIL therapy to enhance efficiency and accessibility.

Chimeric antigen receptor T-cell therapy for haematological malignancies: Insights from fundamental and translational research to bedside practice

Autologous chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of lymphoid malignancies, leading to the approval of CD19-CAR T cells for B-cell lymphomas and acute leukaemia, and more recently, B-cell maturation antigen-CAR T cells for multiple myeloma. The long-term follow-up of patients treated in the early clinical trials demonstrates the possibility for long-term remission, suggesting a cure. This is associated with a low incidence of significant long-term side effects and a rapid improvement in the quality of life for responders. In contrast, other types of immunotherapies require prolonged treatments or carry the risk of long-term side effects impairing the quality of life. Despite impressive results, some patients still experience treatment failure or ultimately relapse, underscoring the imperative to improve CAR T-cell therapies and gain a better understanding of their determinants of efficacy to maximize positive outcomes. While the next-generation of CAR T cells will undoubtingly be more potent, there are already opportunities for optimization when utilizing the currently available CAR T cells. This review article aims to summarize the current evidence from clinical, translational and fundamental research, providing clinicians with insights to enhance their understanding and use of CAR T cells.

The rules of T-cell engagement: current state of CAR T cells and bispecific antibodies in B-cell lymphomas

ABSTRACT

T-cell engaging-therapies have transformed the treatment landscape of relapsed and refractory B-cell non-Hodgkin lymphomas by offering highly effective treatments for patients with historically limited therapeutic options. This review focuses on the advances in chimeric antigen receptor-modified T cells and bispecific antibodies, first providing an overview of each product type, followed by exploring the primary data for currently available products in large B-cell lymphoma, follicular lymphoma, and mantle cell lymphoma. This review also highlights key logistical and sequencing considerations across diseases and product types that can affect clinical decision-making.

Safety and Efficacy of Bispecific Antibodies in Adults with Large B-Cell Lymphomas: A Systematic Review of Clinical Trial Data

Bispecific antibodies (bsAbs) are an emerging therapy in the treatment of large B-cell lymphomas (LBCLs). There is a gap in the research on the safety and efficacy of bsAbs in adults with LBCL, with current research focusing on the wider non-Hodgkin's lymphoma population. To address this research gap, we conducted a systematic review aiming to evaluate the safety and efficacy outcomes of bsAbs in adults with LBCL. A systematized search was conducted in PubMed, EMBASE, and CENTRAL on 10 April 2024. Interventional clinical trials were eligible for inclusion. Observational studies, reviews, and meta-analyses were excluded. According to the Revised Risk of Bias Assessment Tool for Nonrandomized Studies, the included studies were largely of a high quality for safety outcome reporting, but of mixed quality for efficacy outcome reporting. Due to the heterogeneity of the included studies, the results were discussed as a narrative synthesis. Nineteen early phase studies were evaluated in the final analysis, with a pooled sample size of 1332 patients. Nine bsAbs were investigated across the studies as monotherapy (nine studies) or in combination regimes (10 studies). The rates of cytokine release syndrome were variable, with any grade events ranging from 0 to 72.2%. Infection rates were consistently high across the reporting studies (38-60%). Cytopenias were found to be common, in particular, anemia (4.4-62%), thrombocytopenia (3.3-69%), and neutropenia (4.4-70%). Immune effector cell-associated neurotoxicity syndrome (ICANS) and grade ≥3 adverse events were not commonly reported. Promising efficacy outcomes were reported, with median overall response rates of 95-100% in the front-line and 36-91% in terms of relapsed/refractory disease. The results of this systematic review demonstrate that bsAbs are generally well-tolerated and effective in adults with LBCL. BsAbs appear to have superior tolerability, but inferior efficacy to CAR T-cell therapies in adults with LBCL. Future research on safety and efficacy should focus on evaluating adverse event timing and management, the impact on the patient's quality of life, the burden on the healthcare system, and overall survival outcomes.

From the mechanism of action to clinical management: A review of cardiovascular toxicity in adult treated with CAR-T therapy

Chimeric antigen receptor T-cell therapy represents an innovative approach to immunotherapy and currently stands out, particularly for oncohematological patients refractory to traditional treatments. Ongoing trials are further expanding its clinical use for new oncological and non-oncological indications, potentially leading to newer treatment options soon. This new approach, however, also presents challenges, including cardiovascular toxicity. Little is reported in pivotal studies, and some recent retrospective observations suggest a non-negligible incidence of side effects with presentation ranging from mild adverse cardiovascular events to fatal complications in which, in most cases, there is a direct or indirect association with cytokine release syndrome. In this literature review, the hypotheses of an important interface between cytokine release syndrome and cardiotoxicity by chimeric antigen receptor T-cell therapy will be addressed, as will current knowledge about risk factors for cardiotoxicity and recommendations for pre-therapy evaluation, post-infusion monitoring and clinical management of these complications.

Transformed follicular lymphoma with laryngeal edema requiring tracheal intubation after tisagenlecleucel treatment: A case report

RATIONALE

Cytokine release syndrome (CRS) is a common adverse event of chimeric antigen receptor T (CAR-T) cell therapy. CRS is generally a systemic inflammatory reaction, but in rare cases, it can occur in specific body areas and is referred to as "local CRS (L-CRS)." A case of laryngeal edema due to L-CRS that required tracheal intubation because of the lack of response to tocilizumab (TCZ) and dexamethasone (DEX) is reported.

PATIENT CONCERNS

A 67-year-old woman with relapsed transformed follicular lymphoma was treated with CAR-T cell therapy. Although she had been given TCZ and DEX for CRS, neck swelling appeared on day 4 after infusion.

DIAGNOSES

Laryngoscopy showed severe laryngeal edema, which was presumed to be due to L-CRS, since there were no other apparent triggers based on history, physical examination, and computed tomography.

INTERVENTIONS

Tracheal intubation was performed because of the risk of upper airway obstruction. Ultimately, 4 doses of tocilizumab (8 mg/kg) and 6 doses of dexamethasone (10 mg/body) were required to improve the L-CRS.

OUTCOMES

On day 7, laryngeal edema improved, and the patient could be extubated.

LESSONS

The lessons from this case are, first, that CAR-T cell therapy may induce laryngeal edema in L-CRS. Second, TCZ alone may be ineffective in cervical L-CRS. Third, TCZ, as well as DEX, may be inadequate. In such cases, we should recognize L-CRS and manage it early because it may eventually progress to laryngeal edema that requires securing the airway.

Emerging and Biological Concepts in Pediatric High-Grade Gliomas

Primary central nervous system tumors are the most frequent solid tumors in children, accounting for over 40% of all childhood brain tumor deaths, specifically high-grade gliomas. Compared with pediatric low-grade gliomas (pLGGs), pediatric high-grade gliomas (pHGGs) have an abysmal survival rate. The WHO CNS classification identifies four subtypes of pHGGs, including Grade 4 Diffuse midline glioma H3K27-altered, Grade 4 Diffuse hemispheric gliomas H3-G34-mutant, Grade 4 pediatric-type high-grade glioma H3-wildtype and IDH-wildtype, and infant-type hemispheric gliomas. In recent years, we have seen promising advancements in treatment strategies for pediatric high-grade gliomas, including immunotherapy, CAR-T cell therapy, and vaccine approaches, which are currently undergoing clinical trials. These therapies are underscored by the integration of molecular features that further stratify HGG subtypes. Herein, we will discuss the molecular features of pediatric high-grade gliomas and the evolving landscape for treating these challenging tumors.

A Multicenter Real-life Prospective Study of Axicabtagene Ciloleucel versus Tisagenlecleucel Toxicity and Outcomes in Large B-cell Lymphomas

This real-world prospective observational study across 21 Italian centers (CART-SIE) compares axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) outcomes in 485 patients with relapsed/refractory large B-cell lymphoma with baseline characteristics matched by stabilized inverse propensity score weighting. Axi-cel versus tisa-cel had higher all-grade cytokine release syndrome (78.6% vs. 89.3%, P = 0.0017) and neurotoxicity (9.9% vs. 32.2%, P < 0.0001) but also superior progression-free survival (PFS) at 1 year (46.5% vs. 34.1%, P = 0.0009). Even among patients who failed bridging therapy, axi-cel PFS was superior to tisa-cel (37.5% vs. 22.7%, P = 0.0059). Differences in overall survival and high-grade immune toxicities were not significant. The CAR-HEMATOTOX score not only predicted hematologic toxicity but also 1-year survival outcomes (51.5% in CAR-HEMATOTOX high vs. 77.2% in CAR-HEMATOTOX low, P < 0.0001). Twenty patients developed second primary malignancies, including two cases of T-cell neoplasms. These findings enable more informed selection of anti-CD19 CAR T-cell therapy, balancing bridging, safety, and efficacy considerations for individual patients. Significance: The findings of this study on 485 patients with relapsed/refractory large B-cell lymphoma treated with commercial axi-cel and tisa-cel indicate axi-cel's superior PFS after propensity score weighting. The predictive utility of CAR-HEMATOTOX in assessing not only toxicity but also outcomes across both CAR T-cell products may guide future risk-stratified management strategies.

Knocking Out CD70 Rescues CD70-Specific NanoCAR T Cells from Antigen-Induced Exhaustion

CD70 is an attractive target for chimeric antigen receptor (CAR) T-cell therapy for the treatment of both solid and liquid malignancies. However, the functionality of CD70-specific CAR T cells is modest. We optimized a CD70-specific VHH-based CAR (nanoCAR). We evaluated the nanoCARs in clinically relevant models in vitro, using co-cultures of CD70-specific nanoCAR T cells with malignant rhabdoid tumor organoids, and in vivo, using a diffuse large B-cell lymphoma patient-derived xenograft (PDX) model. Although the nanoCAR T cells were highly efficient in organoid co-cultures, they showed only modest efficacy in the PDX model. We determined that fratricide was not causing this loss in efficacy but rather CD70 interaction in cis with the nanoCAR-induced exhaustion. Knocking out CD70 in nanoCAR T cells using CRISPR/Cas9 resulted in dramatically enhanced functionality in the diffuse large B-cell lymphoma PDX model. Through single-cell transcriptomics, we obtained evidence that CD70 knockout CD70-specific nanoCAR T cells were protected from antigen-induced exhaustion. In addition, we demonstrated that wild-type CD70-specific nanoCAR T cells already exhibited signs of exhaustion shortly after production. Their gene signature strongly overlapped with gene signatures of exhausted CAR T cells. Conversely, the gene signature of knockout CD70-specific nanoCAR T cells overlapped with the gene signature of CAR T-cell infusion products leading to complete responses in chronic lymphatic leukemia patients. Our data show that CARs targeting endogenous T-cell antigens negatively affect CAR T-cell functionality by inducing an exhausted state, which can be overcome by knocking out the specific target.

Recent updates on allogeneic CAR-T cells in hematological malignancies

CAR-T cell therapy is known as an effective therapy in patients with hematological malignancies. Since 2017, several autologous CAR-T cell (auto-CAR-T) drugs have been approved by the US Food and Drug Administration (FDA) for the treatment of some kinds of relapsed/refractory hematological malignancies. However, some patients fail to respond to these drugs due to high manufacturing time, batch-to-batch variation, poor quality and insufficient quantity of primary T cells, and their insufficient expansion and function. CAR-T cells prepared from allogeneic sources (allo-CAR-Ts) can be an alternative option to overcome these obstacles. Recently, several allo-CAR-Ts have entered into the early clinical trials. Despite their promising preclinical and clinical results, there are two main barriers, including graft-versus-host disease (GvHD) and allo-rejection that may decline the safety and efficacy of allo-CAR-Ts in the clinic. The successful development of these products depends on the starter cell source, the gene editing method, and the ability to escape immune rejection and prevent GvHD. Here, we summarize the gene editing technologies and the potential of various cell sources for developing allo-CAR-Ts and highlight their advantages for the treatment of hematological malignancies. We also describe preclinical and clinical data focusing on allo-CAR-T therapy in blood malignancies and discuss challenges and future perspectives of allo-CAR-Ts for therapeutic applications.

Case report: Bridging radiation therapy before chimeric antigen receptor T-cell therapy induces sustained remission in patients with relapsed/refractory double-expressor diffuse large B-cell lymphoma with localized compressive symptoms

Background

High-risk double-expressor diffuse large B-cell lymphoma has an inferior prognosis following standard first-line therapy. After failure of second-line therapy, treatment options are limited if accompanied by localized compressive symptoms. Chimeric Antigen Receptor T cell (CAR-T) therapy preceded by bridging radiotherapy may be an effective emerging therapy.

Case presentation

We report a 66-year-old female patient diagnosed with stage IV double-expressor diffuse large B-cell lymphoma. The patient achieved progressive disease after two cycles of rituximab, cyclophosphamide, liposomal doxorubicin, vincristine, and prednisone and continued to develop cervical lymph node recurrence after second-line therapy. The patient was infused with CAR-T cells after receiving focal bridging radiotherapy and remained in complete response more than 9 months after treatment. In addition, the patients did not experience serious adverse reactions related to radiotherapy as well as CAR-T cell therapy.

Conclusions

In this article, we describe a patient with double-expressor diffuse large B-cell lymphoma with localized compression symptoms after second-line treatment failure who benefited from CAR-T combined with focal bridging radiotherapy.

AI in cellular engineering and reprogramming

During the last decade, artificial intelligence (AI) has increasingly been applied in biophysics and related fields, including cellular engineering and reprogramming, offering novel approaches to understand, manipulate, and control cellular function. The potential of AI lies in its ability to analyze complex datasets and generate predictive models. AI algorithms can process large amounts of data from single-cell genomics and multiomic technologies, allowing researchers to gain mechanistic insights into the control of cell identity and function. By integrating and interpreting these complex datasets, AI can help identify key molecular events and regulatory pathways involved in cellular reprogramming. This knowledge can inform the design of precision engineering strategies, such as the development of new transcription factor and signaling molecule cocktails, to manipulate cell identity and drive authentic cell fate across lineage boundaries. Furthermore, when used in combination with computational methods, AI can accelerate and improve the analysis and understanding of the intricate relationships between genes, proteins, and cellular processes. In this review article, we explore the current state of AI applications in biophysics with a specific focus on cellular engineering and reprogramming. Then, we showcase a couple of recent applications where we combined machine learning with experimental and computational techniques. Finally, we briefly discuss the challenges and prospects of AI in cellular engineering and reprogramming, emphasizing the potential of these technologies to revolutionize our ability to engineer cells for a variety of applications, from disease modeling and drug discovery to regenerative medicine and biomanufacturing.

The prognostic utility of 18F-FDG PET parameters in lymphoma patients under CAR-T-cell therapy: a systematic review and meta-analysis

Background

Chimeric antigen receptor (CAR) T-cell therapy has attracted considerable attention since its recent endorsement by the Food and Drug Administration, as it has emerged as a promising immunotherapeutic modality within the landscape of oncology. This study explores the prognostic utility of [18F]Fluorodeoxyglucose positron emission tomography ([18F]FDG PET) in lymphoma patients undergoing CAR T-cell therapy. Through meta-analysis, pooled hazard ratio (HR) values were calculated for specific PET metrics in this context.

Methods

PubMed, Scopus, and Ovid databases were explored to search for relevant topics. Dataset retrieval from inception until March 12, 2024, was carried out. The primary endpoints were impact of specific PET metrics on overall survival (OS) and progression-free survival (PFS) before and after treatment. Data from the studies were extracted for a meta-analysis using Stata 17.0.

Results

Out of 27 studies identified for systematic review, 15 met the criteria for meta-analysis. Baseline OS analysis showed that total metabolic tumor volume (TMTV) had the highest HR of 2.66 (95% CI: 1.52-4.66), followed by Total-body total lesion glycolysis (TTLG) at 2.45 (95% CI: 0.98-6.08), and maximum standardized uptake values (SUVmax) at 1.30 (95% CI: 0.77-2.19). TMTV and TTLG were statistically significant (p < 0.0001), whereas SUVmax was not (p = 0.33). For PFS, TMTV again showed the highest HR at 2.65 (95% CI: 1.63-4.30), with TTLG at 2.35 (95% CI: 1.40-3.93), and SUVmax at 1.48 (95% CI: 1.08-2.04), all statistically significant (p ≤ 0.01). The ΔSUVmax was a significant predictor for PFS with an HR of 2.05 (95% CI: 1.13-3.69, p = 0.015).

Conclusion

[18F]FDG PET parameters are valuable prognostic tools for predicting outcome of lymphoma patients undergoing CAR T-cell therapy.

Antigen escape in CAR-T cell therapy: Mechanisms and overcoming strategies

Chimeric antigen receptor T (CAR-T) cell therapy has shown promise in treating hematological malignancies and certain solid tumors. However, its efficacy is often hindered by negative relapses resulting from antigen escape. This review firstly elucidates the mechanisms underlying antigen escape during CAR-T cell therapy, including the enrichment of pre-existing target-negative tumor clones, antigen gene mutations or alternative splicing, deficits in antigen processing, antigen redistribution, lineage switch, epitope masking, and trogocytosis-mediated antigen loss. Furthermore, we summarize various strategies to overcome antigen escape, evaluate their advantages and limitations, and propose future research directions. Thus, we aim to provide valuable insights to enhance the effectiveness of CAR-T cell therapy.

Advances in biology, diagnosis and treatment of DLBCL

Diffuse large B-cell lymphoma (DLBCL), with approximately 150,000 new cases worldwide each year, represent nearly 30% of all cases of non-Hodgkin lymphoma (NHL) and are phenotypically and genetically heterogeneous. A gene-expression profile (GEP) has identified at least three major subtypes of DLBCL, each of which has distinct clinical, biological, and genetic features: activated B-cell (ABC)-like DLBCL, germinal-center B-cell (GCB)-like DLBCL, and unclassified. Different origins are associated with different responses to chemotherapy and targeted agents. Despite DLBCL being a highly heterogeneous disease, more than 60% of patients with DLBCL can be cured after using rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) to inhibit the growth of cancer cells while targeting the CD20 receptor. In recent decades, the improvement of diagnostic levels has led to a refinement classification of DLBCL and the development of new therapeutic approaches. The objective of this review was to summarize the latest studies examining genetic lesions and therapies for DLBCL.

Rational formulation and industrial manufacturing of lipid-based complex injectables: Landmarks and trends

Lipid-based complex injectables are renowned for their effectiveness in delivering drugs, with many approved products. While significant strides have been made in formulating nanosystems for small molecular weight drugs, a pivotal breakthrough emerged with the recognition of lipid nanoparticles as a promising platform for delivering nucleic acids. This finding has paved the way for tackling long-standing challenges in molecular and delivery aspects (e.g., mRNA stability, intracellular delivery) that have impeded the clinical translation of gene therapy, especially in the realm of immunotherapy. Nonetheless, developing and implementing new lipid-based delivery systems pose significant challenges, as industrial manufacturing of these formulations often involves complex, multi-batch processes, giving rise to issues related to scalability, stability, sterility, and regulatory compliance. To overcome these obstacles, embracing the principles of quality-by-design (QbD) is imperative. Furthermore, adopting cutting-edge manufacturing and process analytical tools (PAT) that facilitate the transition from batch to continuous production is essential. Herein, the key milestones and insights derived from the development of currently approved lipid- nanosystems will be explored. Additionally, a comprehensive and critical overview of the latest technologies and regulatory guidelines that underpin the creation of more efficient, scalable, and flexible manufacturing processes for complex lipid-based nanoformulations will be provided.

The Role of Chimeric Antigen Receptor T-Cell Therapy in Immune-Mediated Neurological Diseases

Despite the use of 'high efficacy' disease-modifying therapies, disease activity and clinical progression of different immune-mediated neurological diseases continue for some patients, resulting in accumulating disability, deteriorating social and mental health, and high economic cost to patients and society. Although autologous hematopoietic stem cell transplant is an effective treatment modality, it is an intensive chemotherapy-based therapy with a range of short- and long-term side-effects. Chimeric antigen receptor T-cell therapy (CAR-T) has revolutionized the treatment of B-cell and other hematological malignancies, conferring long-term remission for otherwise refractory diseases. However, the toxicity of this treatment, particularly cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and the complexity of production necessitate the need for a high level of specialization at treating centers. Early-phase trials of CAR-T therapies in immune-mediated B cell driven conditions, such as systemic lupus erythematosus, neuromyelitis optica spectrum disorder and myasthenia gravis, have shown dramatic clinical response with few adverse events. Based on the common physiopathology, CAR-T therapy in other immune-mediated neurological disease, including multiple sclerosis, chronic inflammatory polyradiculopathy, autoimmune encephalitis, and stiff person syndrome, might be an effective option for patients, avoiding the need for long-term immunosuppressant medications. It may prove to be a more selective immunoablative approach than autologous hematopoietic stem cell transplant, with potentially increased efficacy and lower adverse events. In this review, we present the state of the art and future directions of the use of CAR-T in such conditions. ANN NEUROL 2024;96:441-452.

Frontiers in CAR-T cell therapy for autoimmune diseases

Chimeric antigen receptor (CAR)-engineered T (CAR-T) cell therapy has demonstrated significant success in treating cancers. The potential of CAR-T cells is now being explored in the context of autoimmune diseases. Recent clinical trials have shown sustained and profound elimination of autoreactive B cells by CAR-T cells, leading to promising autoimmune disease control with minimal safety concerns. These encouraging results have inspired further investigation into CAR-T cell applications for a broader range of autoimmune diseases and the development of advanced cell products with improved efficacy and safety. In this review, we discuss the mechanisms by which CAR-T cells target autoimmune conditions, summarize current preclinical models, and highlight ongoing clinical trials, including CAR-T therapy design, clinical outcomes, and challenges. Additionally, we discuss the limitations and future directions of CAR-T therapy in the treatment of autoimmune diseases.

Acute kidney injury following chimeric antigen receptor T-cell therapy: Epidemiology, mechanism and prognosis

Chimeric antigen receptor T cell (CAR-T) therapy is a promising treatment for hematologic tumors, and adverse events of acute kidney injury (AKI) have been reported. However, its incidence, clinical characteristics, and prognosis remained unclear. We searched PubMed, EMBASE, and Web of Science for study about AKI after CAR-T therapy, a total of 15 studies, comprising 694 patients, were included. Among the 694 patients, 154 (22%) developed AKI, of which 89 (57.8%) were in stage 1, 59 (38.3%) were in stage 2 or 3, and 6 (3.9%) were not reported. Cytokine release syndrome is considered to be the most common cause of AKI. Of the 154 AKI patients, only 16 (10.4%) received renal replacement therapy, most AKI recovered renal function after symptomatic treatment. Although the occurrence of AKI after CAR-T therapy is rare and mostly mild, active knowledge of its pathogenesis, timely diagnosis and treatment are necessary for clinicians.

How can we improve the successful identification of patients suitable for CAR-T cell therapy?

INTRODUCTION

In recent years, chimeric antigen receptor T (CAR-T) cell therapy has resulted in a breakthrough in the treatment of patients with refractory or relapsed hematological malignancies. However, the identification of patients suitable for CAR-T cell therapy needs to be improved.

AREAS COVERED

CAR-T cell therapy has demonstrated excellent efficacy in hematological malignancies; however, views on determining when to apply CAR-T cells in terms of the evaluation of patient characteristics remain controversial.

EXPERT OPINION

We reviewed the current feasibility and challenges of CAR-T cell therapy in the most common hematological malignancies and classified them according to the disease type and treatment priority, to guide clinicians and researchers in applying and investigating CAR-T cells furtherly.

Anti-CD19 chimeric antigen receptor T-cell therapy in older patients with relapsed or refractory large B-cell lymphoma: A multicenter study

Chimeric antigen receptor T-cell (CAR-T) therapy, despite being a potentially curative therapy in relapsed or refractory (RR) large B-cell lymphoma (LBCL), remains underutilized in older patients due to limited clinical data. We therefore studied the safety and efficacy of CAR-T therapy in older patients with RR LBCL in the real-world setting. Patients aged ≥65 years with RR LBCL, treated with anti-CD19 CAR-T therapy at 7 US institutions were included in this multicenter, retrospective, observational study. In total, 226 patients were included. Median age at infusion was 71 years (range 65-89). Best objective and complete response rates were 86% and 62%, respectively. Median follow-up after infusion was 18.3 months. The median progression-free survival (PFS) was 6.9 months, with 6- and 12-month PFS estimates of 54% and 44%, respectively. The nonrelapse mortality (NRM) rate was 10.9% at day 180, primarily due to infections, and not impacted by the age groups. Grade ≥3 cytokine release syndrome and neurotoxicity occurred in 7% and 26%, respectively. In univariate analysis, no significant difference in PFS was seen regardless of the age groups or CAR-T type, whereas ECOG PS ≥2, elevated LDH, bulky disease, advanced stage, extranodal involvement, the need for bridging therapy, and prior bendamustine exposure were associated with shorter PFS. These findings support the use of CAR-T in older patients, including those aged ≥80 years. The age at CAR-T therapy did not influence safety, survival, and NRM outcomes. Older patients should not be excluded from receiving CAR-T therapy solely based on their chronological age.

Adaptive bridging radiation therapy for relapsed/refractory B-cell lymphoma patient undergoing CAR T-cell therapy: Case report

Radiation therapy (RT) is utilized as a bridging strategy for patients with aggressive B-cell lymphoma prior to CD19-targeted chimeric antigen receptor (CAR T)-cell therapy. RT has been shown to provide local control without exacerbating the toxicities associated with subsequent CAR T-cell infusion. However, a consensus on the optimal radiation dose and fractionation for bridging purposes has yet to be established. We present a case of a patient with relapsed aggressive B-cell lymphoma who underwent bridging adaptive RT on a CT-linac prior to receiving CAR T-cell therapy. At month 6 post-CAR T infusion, the patient demonstrates no signs of disease recurrence or relapse, nor any unexpected toxicities attributable to the combined treatment. This underscores the feasibility and success of this innovative approach in treating lymphoma patients undergoing CAR T-cell therapy.

Several factors that predict the outcome of large B-cell lymphoma patients who relapse/progress after chimeric antigen receptor (CAR) T-cell therapy can be identified before cell administration

AIM

The aim of this study was to analyse the outcomes of patients with large B-cell lymphoma (LBCL) treated with chimeric antigen receptor T-cell therapy (CAR-Tx), with a focus on outcomes after CAR T-cell failure, and to define the risk factors for rapid progression and further treatment.

METHODS

We analysed 107 patients with LBCL from the Czech Republic and Slovakia who were treated in ≥3rd-line with tisagenlecleucel or axicabtagene ciloleucel between 2019 and 2022.

RESULTS

The overall response rate (ORR) was 60%, with a 50% complete response (CR) rate. The median progression-free survival (PFS) and overall survival (OS) were 4.3 and 26.4 months, respectively. Sixty-three patients (59%) were refractory or relapsed after CAR-Tx. Of these patients, 39 received radiotherapy or systemic therapy, with an ORR of 22% (CR 8%). The median follow-up of surviving patients in whom treatment failed was 10.6 months. Several factors predicting further treatment administration and outcomes were present even before CAR-Tx. Risk factors for not receiving further therapy after CAR-Tx failure were high lactate dehydrogenase (LDH) levels before apheresis, extranodal involvement (EN), high ferritin levels before lymphodepletion (LD) and ECOG PS >1 at R/P. The median OS-2 (from R/P after CAR-Tx) was 6.7 months (6-month 57.9%) for treated patients and 0.4 months (6-month 4.2%) for untreated patients (p < 0.001). The median PFS-2 (from R/P after CAR-Tx) was 3.2 months (6-month 28.5%) for treated patients. The risk factors for a shorter PFS-2 (n = 39) included: CRP > limit of the normal range (LNR) before LD, albumin < LNR and ECOG PS > 1 at R/P. All these factors, together with LDH > LNR before LD and EN involvement at R/P, predicted OS-2 for treated patients.

CONCLUSION

Our findings allow better stratification of CAR-Tx candidates and stress the need for a proactive approach (earlier restaging, intervention after partial remission achievement).

Targeting endothelial cell anergy to improve CAR T cell therapy for solid tumors

Chimeric antigen receptor (CAR) T cell therapy presents significant results, especially for the treatment of hematologic malignancies. However, there are limitations and challenges to be overcome to achieve similar success for the treatment of solid tumors. These challenges involve selection of the target, infiltration into the tumor microenvironment and maintenance of functionality. The tumor vasculature is a major barrier for leukocytes to enter the tumor parenchyma. Due to the exposure of the vasculature to angiogenic growth factors during tumor progression, the endothelial cells become anergic to inflammatory cytokines, resulting in reduced leukocyte adhesion molecule expression. As such adhesion molecules are a prerequisite for leukocyte extravasation, endothelial cell anergy allows tumors to escape from endogenous immunity, as well as from cellular immunotherapies such as CAR T cells. Hence, overcoming endothelial cell anergy, e.g. through the administration of angiogenesis inhibitors, is believed to restore anti-tumor immunity. Concomitantly, both endogenous immune cells as well as cellular therapeutics such as CAR T cells can permeate into the tumor parenchyma. Here, we discuss how prior or concomitant treatment with an antiangiogenic drug can improve CAR T cell therapy, to become an attractive strategy for the treatment of solid tumors.

Investigating the Influence of Covariates on Axicabtagene Ciloleucel (axi-cel) Kinetics in Patients with Non-Hodgkin's Lymphoma

BACKGROUND AND OBJECTIVE

Axicabtagene ciloleucel (axi-cel, Yescarta) is an autologous, anti-CD19, chimeric antigen receptor (CAR) T-cell therapy approved for patients with relapsed and refractory non-Hodgkin's lymphoma. Substantial inter-individual variability in cellular kinetics has been observed with CAR-T therapies and factors impacting CAR-T cellular kinetics remain poorly understood. This work reports a population cellular kinetic model of axi-cel in relapsed and patients with refractory non-Hodgkin's lymphoma and investigated the impact of covariates on early and late kinetic phases of CAR-T exposure.

METHODS

A population cellular kinetic model (NONMEM® version 7.4) for axi-cel was developed using data from 410 patients (2050 transgene observations) after a single intravenous infusion of 2 × 106 anti-CD19 CAR+ T cells/kg in patients with non-Hodgkin's lymphoma (ZUMA-1, ZUMA-5, and ZUMA-7 clinical studies). A large panel of covariates was assessed to decipher the variability of CAR-T cell kinetics including patient characteristics, product characteristics, and disease types.

RESULTS

Axi-cel cellular kinetics were well described by a piecewise model of cellular growth kinetics characterized by an exponential growth phase followed by a triphasic decline phase including a long-term persistence phase. The final cellular kinetic model retained in vitro doubling time during CAR-T cell manufacturing and total number of T cells infused as covariates impacting the duration of the growth phase, which, however, did not substantially influence maximum concentration, area under the concentration-time curve over the first 28 days, or long-term persistence. A statistically significant relationship was observed between maximum concentration and the probability to receive tocilizumab and/or corticosteroids.

CONCLUSIONS

No covariates considered in this study were found to significantly and substantially predict the exposure profile of axi-cel. Tocilizumab and steroid use were related to maximum concentration, but they were used reactively to treat toxicities that are associated with a higher maximum concentration. Further CAR-T kinetic analyses should consider additional factors to explain the observed variability in cellular kinetics or help establish a dose-exposure relationship.

CLINICAL TRIAL REGISTRATION

NCT02348216 (ZUMA-1), NCT03105336 (ZUMA-5), and NCT03391466 (ZUMA-7).

CAR-T Cell Therapy in Pancreatic and Biliary Tract Cancers: An Updated Review of Clinical Trials

BACKGROUND

Pancreatic and biliary tract cancers are digestive system tumors with dismal prognosis and limited treatment options. The effectiveness of conventional surgical interventions, radiation therapy, and systemic therapy is restricted in these cases. Furthermore, clinical trials have shown that immunotherapy using immune checkpoint inhibitors has only demonstrated modest clinical results when applied to patients with pancreatobiliary tumors. This highlights the importance of implementing combination immunotherapy approaches or exploring alternative therapeutic strategies to improve treatment outcomes.

MATERIALS AND METHODS

We reviewed the relevant literature on chimeric antigen receptor (CAR)-T cell therapy for pancreatobiliary cancers from PubMed/Medline and ClinicalTrials.gov and retrieved the relevant data accordingly. Attention was additionally given to the examination of grey literature with the aim of obtaining additional details regarding ongoing clinical trials. We mainly focused on abstracts and presentations and e-posters and slides of recent important annual meetings (namely ESMO Immuno-Oncology Congress, ESMO Congress, ASCO Virtual Scientific Program, ASCO Gastrointestinal Cancers Symposium).

RESULTS

CAR-T cell therapy has emerged as a promising and evolving treatment approach for pancreatic and biliary tract cancer. This form of adoptive cell therapy utilizes genetic engineering to modify the expression of specific antibodies on the surface of T cells enabling them to target specific cancer-associated antigens and to induce potent anti-tumor activity. The aim of this review is to provide an updated summary of the available evidence from clinical trials that have explored the application of CAR-T cell therapy in treating pancreatobiliary cancers.

CONCLUSIONS

While the utilization of CAR-T cell therapy in pancreatobiliary cancers is still in its initial phases with only a limited amount of clinical data available, the field is advancing rapidly, incorporating novel technologies to mitigate potential toxicities and enhance antigen-directed tumor eradication.

Atrial arrhythmias following CAR-chimeric antigen receptor T-cell therapy: Incidence, risk factors and biomarker profile

Recent reports have raised concerns about the association of chimeric antigen receptor T cell (CAR-T) with non-negligible cardiotoxicity, particularly atrial arrhythmias. First, we conducted a pharmacovigilance study to assess the reporting of atrial arrhythmias following CD19-directed CAR-T. Subsequently, to determine the incidence, risk factors and outcomes of atrial arrhythmias post-CAR-T, we compiled a retrospective single-centre cohort of non-Hodgkin lymphoma patients. Only commercial CAR-T products were considered. Atrial arrhythmias were nearly fourfold more likely to be reported after CAR-T therapy compared to all other cancer patients in the FAERS (adjusted ROR = 3.76 [95% CI 2.67-5.29]). Of the 236 patients in our institutional cohort, 23 (10%) developed atrial arrhythmias post-CAR-T, including 12 de novo arrhythmias, with most (83%) requiring medical intervention. Atrial arrhythmias frequently co-occurred with cytokine release syndrome and were associated with higher post-CAR-T infusion peak levels of IL-10, TNF-alpha and LDH, and lower trough levels of fibrinogen. In a multivariable analysis, risk factors for atrial arrhythmia were history of atrial arrhythmia (OR = 6.80 [2.39-19.6]) and using CAR-T product with a CD28-costimulatory domain (OR = 5.17 [1.72-18.6]). Atrial arrhythmias following CD19-CAR-T therapy are prevalent and associated with elevated inflammatory biomarkers, a history of atrial arrhythmia and the use of a CAR-T product with a CD28 costimulatory domain.

Radiation Therapy Dose Response in Bulky Relapsed/Refractory Large B-Cell Lymphoma

PURPOSE

To assess whether a radiation therapy (RT) dose affects response in bulky tumors in relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL).

METHODS AND MATERIALS

Data from patients with r/r DLBCL treated with salvage- or palliative-intent RT (2008-2020) at a single institution were examined. Index lesion size ≥7.5 cm was defined as bulky. Equivalent doses in 2-Gy fractions (EQD2) were calculated to compare doses between conventional and hypofractionated (≥2.5 Gy/fraction) schemes. Objective response rates (ORRs) were compared using nonparametric Mann-Whitney U test or Kruskal-Wallis test with Dunn's multiple comparison corrections. Freedom from local progression (FFLP) was assessed using Kaplan-Meier and Cox proportional hazard regression analyses.

RESULTS

One hundred eighty-three courses of 151 unique patients were included (salvage: 37% and palliative: 63%). Nonbulky and bulky tumors were irradiated in 109 (60%) and 74 (40%) courses, respectively. Median EQD2 was 33 Gy (IQR, 23-39 Gy) with hypofractionation in 84 (46%) cases. Of those with post-RT imaging (80%), the ORR was 59%, with a trend toward worsened ORR in bulky tumors (50% vs 65%, P = .077). For bulky tumors, RT regimens with EQD2s >30 Gy were associated with better ORR (≤30 Gy vs >30 Gy: 27% vs 64%, P = .0073), whereas a lower EQD2 cutoff was sufficient for nonbulky tumors (≤20 Gy vs >20 Gy: 38% vs 75%, P = .0011). On multivariable regression analysis, bulky tumor size was associated with worsened FFLP (hazard ratio, 2.07; 95% CI, 1.16-3.68; P = .014), whereas high EQD2s >30 Gy were associated with better FFLP (hazard ratio, 0.48; 95% CI, 0.25-0.93; P = .031). Bulky tumors treated with EQD2s ≤30 Gy had the lowest median FFLP (4.0 months), whereas EQD2s >30 Gy had an unreached median FFLP (P = .0047).

CONCLUSIONS

Bulky r/r DLBCL tumors were associated with less favorable tumor control outcomes in the salvage and palliative settings. RT regimens with higher EQD2s (>30 Gy) should be considered if durable local control of bulky tumors is desired.

Targeting chronic lymphocytic leukemia with B-cell activating factor receptor CAR T cells

The challenge of disease relapsed/refractory (R/R) remains a therapeutic hurdle in chimeric antigen receptor (CAR) T-cell therapy, especially for hematological diseases, with chronic lymphocytic leukemia (CLL) being particularly resistant to CD19 CAR T cells. Currently, there is no approved CAR T-cell therapy for CLL patients. In this study, we aimed to address this unmet medical need by choosing the B-cell activating factor receptor (BAFF-R) as a promising target for CAR design against CLL. BAFF-R is essential for B-cell survival and is consistently expressed on CLL tumors. Our research discovered that BAFF-R CAR T-cell therapy exerted the cytotoxic effects on both CLL cell lines and primary B cells derived from CLL patients. In addition, the CAR T cells exhibited cytotoxicity against CD19-knockout CLL cells that are resistant to CD19 CAR T therapy. Furthermore, we were able to generate BAFF-R CAR T cells from small blood samples collected from CLL patients and then demonstrated the cytotoxic effects of these patient-derived CAR T cells against autologous tumor cells. Given these promising results, BAFF-R CAR T-cell therapy has the potential to meet the long-standing need for an effective treatment on CLL patients.