Enhancing Glioblastoma Immunotherapy with Integrated Chimeric Antigen Receptor T Cells through the Re-Education of Tumor-Associated Microglia and Macrophages

Glioblastoma (GBM) is an aggressive brain cancer that is highly resistant to treatment including chimeric antigen receptor (CAR)-T cells. Tumor-associated microglia and macrophages (TAMs) are major contributors to the immunosuppressive GBM microenvironment, which promotes tumor progression and treatment resistance. Hence, the modulation of TAMs is a promising strategy for improving the immunotherapeutic efficacy of CAR-T cells against GBM. Molecularly targeting drug pexidartinib (PLX) has been reported to re-educate TAMs toward the antitumorigenic M1-like phenotype. Here, we developed a cell-drug integrated technology to reversibly conjugate PLX-containing liposomes (PLX-Lip) to CAR-T cells and establish tumor-responsive integrated CAR-T cells (PLX-Lip/AZO-T cells) as a combination therapy for GBM. We used a mouse model of GBM to show that PLX-Lip was stably maintained on the surface of PLX-Lip/AZO-T cells in circulation and these cells could transmigrate across the blood-brain barrier and deposit PLX-Lip at the tumor site. The uptake of PLX-Lip by TAMs effectively re-educated them into the M1-like phenotype, which in turn boosted the antitumor function of CAR-T cells. GBM tumor growth was completely eradicated in 60% of the mice after receiving PLX-Lip/AZO-T cells and extended their overall survival time beyond 50 days; in comparison, the median survival time of mice in other treatment groups did not exceed 35 days. Overall, we demonstrated the successful fusion of CAR-T cells and small-molecule drugs with the cell-drug integrated technology. These integrated CAR-T cells provided a superior combination strategy for GBM treatment and presented a reference for the construction of integrated cell-based drugs.

Inhibitory CARs fail to protect from immediate T cell cytotoxicity

Chimeric antigen receptors (CARs) equipped with an inhibitory signaling domain (iCARs) have been proposed as strategy to increase on-tumor specificity of CAR-T cell therapies. iCARs inhibit T cell activation upon antigen recognition and thereby program a Boolean NOT gate within the CAR-T cell. If cancer cells do not express the iCAR target antigen while it is highly expressed on healthy tissue, CAR/iCAR coexpressing T cells are supposed to kill cancer cells but not healthy cells expressing the CAR antigen. In this study, we employed a well-established reporter cell system to demonstrate high potency of iCAR constructs harboring BTLA-derived signaling domains. We then created CAR/iCAR combinations for the clinically relevant antigen pairs B7-H3/CD45 and CD123/CD19 and show potent reporter cell suppression by iCARs targeting CD45 or CD19. In primary human T cells αCD19-iCARs were capable of suppressing T cell proliferation and cytokine production. Surprisingly, the iCAR failed to veto immediate CAR-mediated cytotoxicity. Likewise, T cells overexpressing PD-1 or BTLA did not show impaired cytotoxicity toward ligand-expressing target cells, indicating that inhibitory signaling by these receptors does not mediate protection against cytotoxicity by CAR-T cells. Future approaches employing iCAR-equipped CAR-T cells for cancer therapy should therefore monitor off-tumor reactivity and potential CAR/iCAR-T cell dysfunction.

Efficient combination of radiotherapy and CAR-T - A systematic review

Chimeric antigen receptor T (CAR-T) cell therapy, a groundbreaking immunotherapy. However, it faces formidable challenges in treating solid tumors, grappling with issues like poor trafficking, limited penetration, and insufficient persistence within the tumor microenvironment (TME). CAR-T cells are engineered to express receptors that target specific cancer antigens, enhancing their ability to recognize and eliminate cancer cells. This review paper explores the intricate interplay between CAR-T therapy and radiotherapy (RT), investigating their synergistic potential. Radiotherapy, a standard cancer treatment, involves using high doses of radiation to target and damage cancer cells, disrupting their ability to grow and divide. We highlight that RT modulates the TME, augments antigen presentation, and promotes immune cell infiltration, bolstering CAR-T cell-mediated tumor eradication. Molecular insights shed light on RT-induced alterations in tumor stroma, T cell recruitment promotion, and induction of immunogenic cell death. Noteworthy, strategies, such as combining hypofractionated radiotherapy with myeloid-derived suppressor cell blockade, underscore innovative approaches to enhance CAR-T cell therapy in solid tumors. Bridging indications for RT and CAR-T cells in hematological malignancies are discussed, emphasizing scenarios where RT strategically enhances CAR-T cell efficacy. The paper critically evaluates the RT as a bridge compared to traditional chemotherapy, highlighting timing and dosage considerations crucial for optimizing CAR-T therapy outcomes. In summary, the paper provides valuable insights into the intricate molecular mechanisms activated by RT and innovative strategies to improve CAR-T cell therapy, fostering a deeper understanding of their combined potential in cancer treatment.

Targeted chemotherapy via HER2-based chimeric antigen receptor (CAR) engineered T-cell membrane coated polymeric nanoparticles

Cell membrane-derived nanoparticles (NPs) have recently gained popularity due to their desirable features in drug delivery such as mimicking properties of native cells, impeding systemic clearance, and altering foreign body responses. Besides NP technology, adoptive immunotherapy has emerged due to its promise in cancer specificity and therapeutic efficacy. In this research, we developed a biomimetic drug carrier based on chimeric antigen receptor (CAR) transduced T-cell membranes. For that purpose, anti-HER2 CAR-T cells were engineered via lentiviral transduction of anti-HER2 CAR coding lentiviral plasmids. Anti-HER2 CAR-T cells were characterized by their specific activities against the HER2 antigen and used for cell membrane extraction. Anti-cancer drug Cisplatin-loaded poly (D, l-lactide-co-glycolic acid) (PLGA) NPs were coated with anti-human epidermal growth factor receptor 2 (HER2)-specific CAR engineered T-cell membranes. Anti-HER2 CAR-T-cell membrane-coated PLGA NPs (CAR-T-MNPs) were characterized and confirmed via fluorescent microscopy and flow cytometry. Membrane-coated NPs showed a sustained drug release over the course of 21 days in physiological conditions. Cisplatin-loaded CAR-T-MNPs also inhibited the growth of multiple HER2+ cancer cells in vitro. In addition, in vitro uptake studies revealed that CAR-T-MNPs showed an increased uptake by A549 cells. These results were also confirmed via in vivo biodistribution and therapeutic studies using a subcutaneous lung cancer model in nude mice. CAR-T-MNPs localized preferentially at tumor areas compared to those of other studied groups and consisted of a significant reduction in tumor growth in tumor-bearing mice. In Conclusion, the new CAR modified cell membrane-coated NP drug-delivery platform has demonstrated its efficacy both in vitro and in vivo. Therefore, CAR engineered membrane-coated NP system could be a promising cell-mimicking drug carrier that could improve therapeutic outcomes of lung cancer treatments.

Targeting solid tumor antigens with chimeric receptors: cancer biology meets synthetic immunology

Chimeric antigen receptor (CAR) T cell therapy is a medical breakthrough in the treatment of B cell malignancies. There is intensive focus on developing solid tumor-targeted CAR-T cell therapies. Although clinically approved CAR-T cell therapies target B cell lineage antigens, solid tumor targets include neoantigens and tumor-associated antigens (TAAs) with diverse roles in tumor biology. Multiple early-stage clinical trials now report encouraging signs of efficacy for CAR-T cell therapies that target solid tumors. We review the landscape of solid tumor target antigens from the perspective of cancer biology and gene regulation, together with emerging clinical data for CAR-T cells targeting these antigens. We then discuss emerging synthetic biology strategies and their application in the clinical development of novel cellular immunotherapies.

CD19-targeted chimeric antigen receptor T cell therapy in two patients with multiple sclerosis

BACKGROUND

Progressive multiple sclerosis (MS) is characterized by compartmentalized smoldering neuroinflammation caused by the proliferation of immune cells residing in the central nervous system (CNS), including B cells. Although inflammatory activity can be prevented by immunomodulatory therapies during early disease, such therapies typically fail to halt disease progression. CD19 chimeric antigen receptor (CAR)-T cell therapies have revolutionized the field of hematologic malignancies. Although generally considered efficacious, serious adverse events associated with CAR-T cell therapies such as immune effector cell-associated neurotoxicity syndrome (ICANS) have been observed. Successful use of CD19 CAR-T cells in rheumatic diseases like systemic lupus erythematosus and neuroimmunological diseases like myasthenia gravis have recently been observed, suggesting possible application in other autoimmune diseases.

METHODS

Here, we report the first individual treatment with a fully human CD19 CAR-T cell therapy (KYV-101) in two patients with progressive MS.

FINDINGS

CD19 CAR-T cell administration resulted in acceptable safety profiles for both patients. No ICANS was observed despite detection of CD19 CAR-T cells in the cerebrospinal fluid. In case 1, intrathecal antibody production in the cerebrospinal fluid decreased notably after CAR-T cell infusion and was sustained through day 64.

CONCLUSIONS

CD19 CAR-T cell administration in progressive MS resulted in an acceptable safety profile. CAR-T cell presence and expansion were observed in the cerebrospinal fluid without clinical signs of neurotoxicity, which, along with intrathecal antibody reduction, indicates expansion-dependent effects of CAR-T cells on CD19+ target cells in the CNS. Larger clinical studies assessing CD19 CAR-T cells in MS are warranted.

FUNDING

Both individual treatments as well the generated data were not based on external funding.

Prospects and challenges of CAR-T cell therapy combined with ICIs

Immune checkpoint molecules are a group of molecules expressed on the surface of immune cells that primarily regulate their immune homeostasis. Chimeric antigen receptor (CAR) T cell therapy is an immunotherapeutic technology that realizes tumor-targeted killing by constructing synthetic T cells expressing specific antigens through biotechnology. Currently, CAR-T cell therapy has achieved good efficacy in non-solid tumors, but its treatment of solid tumors has not yielded the desired results. Immune checkpoint inhibitors (ICIs) combined with CAR-T cell therapy is a novel combination therapy with high expectations to defeat solid tumors. This review addresses the challenges and expectations of this combination therapy in the treatment of solid tumors.

Emerging Strategies to Overcome Current CAR-T Therapy Dilemmas - Exosomes Derived from CAR-T Cells

Adoptive T cells immunotherapy, specifically chimeric antigen receptor T cells (CAR-T), has shown promising therapeutic efficacy in the treatment of hematologic malignancies. As extensive research on CAR-T therapies has been conducted, various challenges have emerged that significantly hampered their clinical application, including tumor recurrence, CAR-T cell exhaustion, and cytokine release syndrome (CRS). To overcome the hurdles of CAR-T therapy in clinical treatment, cell-free emerging therapies based on exosomes derived from CAR-T cells have been developed as an effective and promising alternative approach. In this review, we present CAR-T cell-based therapies for the treatment of tumors, including the features and benefits of CAR-T therapies, the limitations that exist in this field, and the measures taken to overcome them. Furthermore, we discuss the notable benefits of utilizing exosomes released from CAR-T cells in tumor treatment and anticipate potential issues in clinical trials. Lastly, drawing from previous research on exosomes from CAR-T cells and the characteristics of exosomes, we propose strategies to overcome these restrictions. Additionally, the review discusses the plight in large-scale preparation of exosome and provides potential solutions for future clinical applications.

CAR-T cell expansion platforms yield distinct T cell differentiation states

With investigators looking to expand engineered T cell therapies such as CAR-T to new tumor targets and patient populations, a variety of cell manufacturing platforms have been developed to scale manufacturing capacity using closed and/or automated systems. Such platforms are particularly useful for solid tumor targets, which typically require higher CAR-T cell doses. Although T cell phenotype and function are key attributes that often correlate with therapeutic efficacy, how manufacturing platforms influence the final CAR-T cell product is currently unknown. We compared 4 commonly used T cell manufacturing platforms (CliniMACS Prodigy, Xuri W25 rocking platform, G-Rex gas-permeable bioreactor, static bag culture) using identical media, stimulation, culture length, and donor starting material. Selected CD4+CD8+ cells were transduced with lentiviral vector incorporating a CAR targeting FGFR4, a promising target for pediatric sarcoma. We observed significant differences in overall expansion over the 14-day culture; bag cultures had the highest capacity for expansion while the Prodigy had the lowest (481-fold versus 84-fold, respectively). Strikingly, we also observed considerable differences in the phenotype of the final product, with the Prodigy significantly enriched for CCR7+CD45RA+ naïve/stem central memory (Tn/scm)-like cells at 46% compared to bag and G-Rex with 16% and 13%, respectively. Gene expression analysis also showed that Prodigy CAR-Ts are more naïve, less cytotoxic and less exhausted than bag, G-Rex, and Xuri CAR-Ts, and pointed to differences in cell metabolism that were confirmed via metabolic assays. We hypothesized that dissolved oxygen level, which decreased substantially during the final 3 days of the Prodigy culture, may contribute to the observed differences in T cell phenotype. By culturing bag and G-Rex cultures in 1% O2 from day 5 onward, we could generate >60% Tn/scm-like cells, with longer time in hypoxia correlating with a higher percentage of Tn/scm-like cells. Intriguingly, our results suggest that oxygenation is responsible, at least in part, for observed differences in T cell phenotype among bioreactors and suggest hypoxic culture as a potential strategy prevent T cell differentiation during expansion. Ultimately, our study demonstrates that selection of bioreactor system may have profound effects not only on the capacity for expansion, but also on the differentiation state of the resulting CAR-T cells.

CAR-Aptamers Enable Traceless Enrichment and Monitoring of CAR-Positive Cells and Overcome Tumor Immune Escape

Chimeric antigen receptor (CAR)-positive cell therapy, specifically with anti-CD19 CAR-T (CAR19-T) cells, achieves a high complete response during tumor treatment for hematological malignancies. Large-scale production and application of CAR-T therapy can be achieved by developing efficient and low-cost enrichment methods for CAR-T cells, expansion monitoring in vivo, and overcoming tumor escape. Here, novel CAR-specific binding aptamers (CAR-ap) to traceless sort CAR-positive cells and obtain a high positive rate of CAR19-T cells is identified. Additionally, CAR-ap-enriched CAR19-T cells exhibit similar antitumor capacity as CAR-ab (anti-CAR antibody)-enriched CAR-T cells. Moreover, CAR-ap accurately monitors the expansion of CAR19-T cells in vivo and predicts the prognosis of CAR-T treatment. Essentially, a novel class of stable CAR-ap-based bispecific circular aptamers (CAR-bc-ap) is constructed by linking CAR-ap with a tumor surface antigen (TSA): protein tyrosine kinase 7 (PTK7) binding aptamer Sgc8. These CAR-bc-aps significantly enhance antitumor cytotoxicity with a loss of target antigens by retargeting CAR-T cells to the tumor in vitro and in vivo. Overall, novel CAR-aptamers are screened for traceless enrichment, monitoring of CAR-positive cells, and overcoming tumor cell immune escape. This provides a low-cost and high-throughput approach for CAR-positive cell-based immunotherapy.

FLT3 Mutated Acute Myeloid Leukemia after CD19 CAR-t Cells

Chimeric Antigen Receptor T-cells have improved the life expectancy of severely pretreated patients with aggressive hematological cancers; for this reason, therapy-related myeloid leukemias are becoming of great concern in this field, despite their clonal phylogenesis and mutational landscape have not been fully explored yet. This case discusses a 33-year-old man with refractory large B-cell lymphoma, treated with Chimeric Antigen Receptor T-cell (CAR-T) therapy as the 7th line of treatment. Despite a persistent partial response, the patient developed therapy-related acute myeloid leukemia (t-AML) six months post-CAR-T, revealing pre-existing clonal hematopoiesis. The myeloid malignancy exhibited an unusual hypocellular/dysplastic pattern, progressing to an established blast phase with cytopenia. Treatment with demethylating agents and BCL2 inhibitors proved ineffective, leading to t-AML with hyperleukocytosis and FLT3-ITD gain, resulting in the patient's death. This case underscores the impact of severe pretreatment and bone marrow impairment in CAR-T-associated t-AML, emphasizing their role over insertional mutagenesis. Furthermore, it highlights the retention of classic therapy-related leukemia characteristics, including the potential for acquiring FLT3 mutations and displaying dysplastic morphology in these secondary leukemias.

Digital PCR Improves Sensitivity and Quantification in Monitoring CAR-T Cells in B Cell Lymphoma Patients

Chimeric antigen receptor T cells (CAR-T) has emerged as a promising therapy, over 60% of patients fail to sustain a long-term response. The underlying factors that leads to the effectiveness of this therapy are not completely understood, CAR-T cell persistence and monitoring seems to be pivotal for ensuring a successful response. Various monitoring methods such as multiparametric flow cytometry (MFC) or quantitative PCR (qPCR) have been applied. Our objective is to develop digital PCR (dPCR) assays for detection and quantification of CAR-T cells, comparing them with MFC and qPCR. Samples taken at different follow-up times from 45 patients treated with CAR-T therapy were analyzed to assess the correlation between the different methodologies. dPCR presented a high correlation with MFC and qPCR (r = 0.97 and r = 0.87, respectively), while offering a higher sensitivity (0.01%) compared to MFC (0.1%) and qPCR (1%). dPCR emerged as an alternative and highly sensitivity method for monitoring CAR-T cell dynamics. This technique is well-suited for implementation in clinical practice as a complementary technique to MFC.

Unlocking Predictive Power: Quantitative Assessment of CAR-T Expansion with Digital Droplet Polymerase Chain Reaction (ddPCR)

Flow cytometry (FCM) and quantitative PCR (qPCR) are conventional methods for assessing CAR-T expansion, while digital droplet PCR (ddPCR) is emerging as a promising alternative. We monitored CAR-T transcript expansion in 40 B-NHL patients post-infusion of CAR-T products (axi-cel; tisa-cel; and brexu-cel) with both His-Tag FCM and ddPCR techniques. Sensitivity and predictive capacity for efficacy and safety outcomes of ddPCR were analyzed and compared with FCM. A significant correlation between CAR-T counts determined by FCM and CAR transcripts assessed by ddPCR (p < 0.001) was observed. FCM revealed median CD3+CAR+ cell counts at 7, 14, and 30 days post-infusion with no significant differences. In contrast, ddPCR-measured median copies of CAR-T transcripts demonstrated significant lower copy numbers in tisa-cel recipients compared to the other products at day 7 and day 14. Patients with a peak of CAR transcripts at day 7 exceeding 5000 copies/microg gDNA, termed "good CAR-T expanders", were more likely to achieve a favorable response at 3 months (HR 10.79, 95% CI 1.16-100.42, p = 0.036). Good CAR-T expanders showed superior progression-free survival at 3, 6, and 12 months compared to poor CAR-T expanders (p = 0.088). Those reaching a peak higher than 5000 copies/microg gDNA were more likely to experience severe CRS and ICANS. DdPCR proves to be a practical method for monitoring CAR-T expansion, providing quantitative information that better predicts both treatment outcomes and toxicity.

Challenges in Global Access to CAR-T cells: an Asian Perspective

The use of cell therapy for clinical applications has seen a dramatic increase in recent years, primarily in oncology, especially with the use of chimeric antigen receptor (CAR) T-cell therapies. However, there are some barriers to the widespread adoption of CAR-T cell therapies globally, primarily because of the high cost of manufacturing these cells and clinical infrastructure considerations. We reviewed the different strategies adopted across Asia to implement CAR-T cell therapy and found that these included patient assistance programs, close engagement with funders, cost-effectiveness studies, on-site manufacturing of CAR-T cells, and joint ventures between local partners and foreign pharmaceutical companies. Although on-site manufacturing can reduce the cost of genetic engineering and expansion, it does not address many other hidden costs and quality considerations. Future growth in large-scale regional manufacturing, facilitated by cutting-edge science and innovation, could reduce costs through economies of scale and facilitate the eagerly needed global access.

Systemic sclerosis, silica exposure and cellular therapies: The sand in the gears?

Systemic sclerosis (SSc) is a chronic orphan autoimmune disease with the highest mortality rate among rheumatic diseases. SSc-related interstitial-lung disease (ILD) remains among the leading causes of SSc-related mortality with still few therapeutic effective strategies. In patients with crystallin silica exposure, SSc is recognized as an occupational disease according to the French social security system (Table 25A of the general insurance regimen). Lympho-ablative or myeloablative immunosuppression followed by autologous hematopoietic stem-cell transplantation (aHSCT) is the only therapeutic approach with demonstrated efficacy, improved survival with disease modifying effects on SSc-fibrotic manifestations (skin disease and ILD) and quality of life. A documented past and/or present occupational silica exposure, with extensive exposure and/or silica-related ILD and/or with persistent silica content in the broncho-alveolar lavage fluid are contra-indications to aHSCT in SSc patients, due to the risk of silica-related malignancy or of SSc relapse. This article aims to discuss alternative options in SSc patients with a history of silica exposure, and how innovative cellular therapies (mesenchymal stromal cells, CAR cells) could represent new therapeutic options for these patients.

Treatment of secondary CNS lymphoma using CD19-targeted chimeric antigen receptor (CAR) T cells

BACKGROUND

Aggressive B cell lymphoma with secondary central nervous system (CNS) involvement (SCNSL) carries a dismal prognosis. Chimeric antigen receptor (CAR) T cells (CAR-T) targeting CD19 have revolutionized the treatment for B cell lymphomas; however, only single cases with CNS manifestations successfully treated with CD19 CAR-T have been reported.

METHODS

We prospectively enrolled 4 patients with SCNSL into our study to assess clinical responses and monitor T cell immunity.

RESULTS

Two of four SNCSL patients responded to the CD19-targeted CAR-T. Only one patient showed a substantial expansion of peripheral (PB) CAR-T cells with an almost 100-fold increase within the first week after CAR-T. The same patient also showed marked neurotoxicity and progression of the SNCSL despite continuous surface expression of CD19 on the lymphoma cells and an accumulation of CD4+ central memory-type CAR-T cells in the CNS. Our studies indicate that the local production of chemokine IP-10, possibly through its receptor CXCR3 expressed on our patient's CAR-T, could potentially have mediated the local accumulation of functionally suboptimal anti-tumor T cells.

CONCLUSIONS

Our results demonstrate expansion and homing of CAR-T cells into the CNS in SNCSL patients. Local production of chemokines such as IP-10 may support CNS infiltration by CAR-T cells but also carry the potential of amplifying local toxicity. Future studies investigating numbers, phenotype, and function of CAR-T in the different body compartments of SNSCL patients receiving CAR-T will help to improve local delivery of "fit" and highly tumor-reactive CAR-T with low off-target reactivity into the CNS.

Mesenchymal stromal cells and CAR-T cells in regenerative medicine: The homing procedure and their effective parameters

Mesenchymal stromal cells (MSCs) and chimeric antigen receptor (CAR)-T cells are two core elements in cell therapy procedures. MSCs have significant immunomodulatory effects that alleviate inflammation in the tissue regeneration process, while administration of specific chemokines and adhesive molecules would primarily facilitate CAR-T cell trafficking into solid tumors. Multiple parameters affect cell homing, including the recipient's age, the number of cell passages, proper cell culture, and the delivery method. In addition, several chemokines are involved in the tumor microenvironment, affecting the homing procedure. This review discusses parameters that improve the efficiency of cell homing and significant cell therapy challenges. Emerging comprehensive mechanistic strategies such as non-systemic and systemic homing that revealed a significant role in cell therapy remodeling were also reviewed. Finally, the primary implications for the development of combination therapies that incorporate both MSCs and CAR-T cells for cancer treatment were discussed.

Injectable Supramolecular Hydrogels for In Situ Programming of Car-T Cells toward Solid Tumor Immunotherapy

Chimeric antigen receptor (CAR)-T cell immunotherapy is approved in the treatment of hematological malignancies, but remains far from satisfactory in solid tumor treatment due to inadequate intra-tumor CAR-T cell infiltration. Herein, an injectable supramolecular hydrogel system, based on self-assembly between cationic polymer mPEG-PCL-PEI (PPP) conjugated with T cell targeting anti-CD3e f(ab')2 fragment and α-cyclodextrin (α-CD), is designed to load plasmid CAR (pCAR) with a T cell specific CD2 promoter, which successfully achieves in situ fabrication and effective accumulation of CAR-T cells at the tumor site in humanized mice models. More importantly, due to this tumor microenvironment reprogramming, secretion of cellular inflammatory cytokines (interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ)) or tumor killer protein granzyme B is significantly promoted, which reverses the immunosuppressive microenvironment and significantly enhances the intra-tumor CAR-T cells and cytotoxic T cells infiltration. To the best of the current knowledge, this is a pioneer report of using injectable supramolecular hydrogel for in situ reprogramming CAR-T cells, which might be beneficial for solid tumor CAR-T immunotherapy.

Immunotherapy Strategy for Systemic Autoimmune Diseases: Betting on CAR-T Cells and Antibodies

Systemic autoimmune diseases (SAIDs), such as systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and rheumatoid arthritis (RA), are fully related to the unregulated innate and adaptive immune systems involved in their pathogenesis. They have similar pathogenic characteristics, including the interferon signature, loss of tolerance to self-nuclear antigens, and enhanced tissue damage like necrosis and fibrosis. Glucocorticoids and immunosuppressants, which have limited specificity and are prone to tolerance, are used as the first-line therapy. A plethora of novel immunotherapies have been developed, including monoclonal and bispecific antibodies, and other biological agents to target cellular and soluble factors involved in disease pathogenesis, such as B cells, co-stimulatory molecules, cytokines or their receptors, and signaling molecules. Many of these have shown encouraging results in clinical trials. CAR-T cell therapy is considered the most promising technique for curing autoimmune diseases, with recent successes in the treatment of SLE and SSc. Here, we overview novel therapeutic approaches based on CAR-T cells and antibodies for targeting systemic autoimmune diseases.

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.

Recent advances and current challenges in CAR-T cell therapy

Rapid advancements in the field of immunotherapy have significantly improved cancer treatments. Specifically, an individualized cell-based modality which involves the removal of some of the patient's own white blood cells, including T cells, has revolutionized research in this field. This study focuses on the recent advances and current challenges of Chimeric Antigen Receptor- T (CAR-T) cell therapy and its regulations in the United States (US) and European Union (EU). Understanding the regulatory regimes of CAR-T cell therapy is critical for researchers and manufacturers as they navigate the hurdles of bringing CAR-T cell therapy to the global market. Benefits of CAR-T cell therapy include high response rates and the potential of long-term remissions in some haematological malignancies. However, the drawbacks are still evident including high costs, adverse reactions, and limited efficacy to solid tumours. CAR-T cell therapy is rapidly advancing, with 1231 clinical trials launched globally according to www.clinicalTrial.gov . The future of CAR-T cell therapy holds enormous promise but improving its safety, effectiveness, and availability are still barriers to its successful implementation.

[Role of advanced practice nurse within a cellular therapy unit: Guidelines from the Francophone Society of Bone Marrow Transplantation and cellular therapy (SFGM-TC)]

Like the "nurse practitioner" in Anglo-Saxon countries, the French health authority validated on January 2016 the creation of an intermediate grade called advanced practice nurse (APN). They are authorized to carry out an assessment of the person's state of health, through a complete clinical examination. They can also prescribe additional examinations necessary for the monitoring of the pathology, and carry out certain acts for diagnostic and/or therapeutic purposes. Given the specificities of cellular therapy patients, the content of university professional training doesn't seem sufficient to assure an optimal management by the APN of these patients. The Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC) had already published two works regarding what was initially called "the transfer of skills" between doctors and nurses in the follow-up of transplant patients. In the same way, this workshop attempts to address the question of the place of APNs in the management of patients undergoing cellular therapy treatment. Beyond a delegation of tasks as proposed by the cooperation protocols, this workshop produces recommendations to allow an autonomous activity of the IPA in the follow-up of these patients, in close collaboration with the medical team.

In Vitro Functionality and Endurance of GMP-Compliant Point-of-Care BCMA.CAR-T Cells at Different Timepoints of Cryopreservation

The search for target antigens for CAR-T cell therapy against multiple myeloma defined the B-cell maturation antigen (BCMA) as an interesting candidate. Several studies with BCMA-directed CAR-T cell therapy showed promising results. Second-generation point-of-care BCMA.CAR-T cells were manufactured to be of a GMP (good manufacturing practice) standard using the CliniMACS Prodigy® device. Cytokine release in BCMA.CAR-T cells after stimulation with BCMA positive versus negative myeloma cell lines, U266/HL60, was assessed via intracellular staining and flow cytometry. The short-term cytotoxic potency of CAR-T cells was evaluated by chromium-51 release, while the long-term potency used co-culture (3 days/round) at effector/target cell ratios of 1:1 and 1:4. To evaluate the activation and exhaustion of CAR-T cells, exhaustion markers were assessed via flow cytometry. Stability was tested through a comparison of these evaluations at different timepoints: d0 as well as d + 14, d + 90 and d + 365 of cryopreservation. As results, (1) Killing efficiency of U266 cells correlated with the dose of CAR-T cells in a classical 4 h chromium-release assay. There was no significant difference after cryopreservation on different timepoints. (2) In terms of endurance of BCMA.CAR-T cell function, BCMA.CAR-T cells kept their ability to kill all tumor cells over six rounds of co-culture. (3) BCMA.CAR-T cells released high amounts of cytokines upon stimulation with tumor cells. There was no significant difference in cytokine release after cryopreservation. According to the results, BCMA.CAR-T cells manufactured under GMP conditions exerted robust and specific killing of target tumor cells with a high release of cytokines. Even after 1 year of cryopreservation, cytotoxic functions were maintained at the same level. This gives clinicians sufficient time to adjust the timepoint of BCMA.CAR-T cell application to the patient's course of the underlying disease.

Activation of Notch-1 signaling pathway in macrophages to secrete PD-L1 and regulate cytotoxicity of CAR-T cells in diffuse large B-cell lymphoma

OBJECTIVE

To investigate the mechanism of action of the Notch-1/IRE1/XBP1s signaling pathway in diffuse large B-cell lymphoma (DLBCL).

METHODS

The expressions of relevant proteins were detected by Western blotting. The effect of myeloid-specific knockout of Notch-1 on lymphoma progression was observed by mouse tumor transplantation and imaging. The apoptosis of chimeric antigen receptor T-cell therapy (CAR-T) cells were detected by flow cytometry, and the proliferation of CAR-T cells was detected by wound healing assay and cell counting kit-8 (CCK8) assay.

RESULTS

Lymphoma cells mediated the Notch-1 signaling pathway in bone marrow-derived macrophages and promoted the activation of STAT3 and STAT6 in bone marrow-derived macrophages. Myeloid-specific knockout of Notch-1 could inhibit the progression of lymphoma. Lymphoma cells enhanced the expression of p-PERK, p-IRE1α, ATF6, IL-6, IL-4, p-AKT, CD9, CD63 and PD-L1 in bone marrow-derived macrophages by mediating the Notch-1 signaling pathway. Knockout of Notch-1 in macrophages alleviated, to some extent, the suppression of killing activity of CAR-T cells, while activation of Notch-1 in macrophages inhibited proliferation and promoted apoptosis of CAR-T cells. The PD-L1 antibody significantly restored the cytotoxicity and proliferation of CAR-T cells, and inhibited their apoptosis.

CONCLUSION

Activation of the Notch-1/IRE1/XBP1s signaling pathway in myeloid macrophages promotes the secretion of IL-6 and IL-4 as well as PD-L1, thereby inhibiting the activity and proliferation of CAR-T cells and promoting their apoptosis.

Childhood leukemias in Mexico: towards implementing CAR-T cell therapy programs

Leukemias are the most common type of pediatric cancer around the world. Prognosis has improved during the last decades, and many patients are cured with conventional treatment as chemotherapy; however, many patients still present with a refractory disease requiring additional treatments, including hematopoietic stem cell transplantation. Immunotherapy with monoclonal antibodies or cellular therapy is a promising strategy for treating refractory or relapsed hematological malignancies. Particularly, CAR-T cells have shown clinical efficacy in clinical trials, and different products are now commercially approved by regulatory agencies in the USA and Europe. Many challenges still need to be solved to improve and optimize the potential of these therapies worldwide. Global access to cell therapy is a significant concern, and different strategies are being explored in the middle- and low-income countries. In Mexico, leukemias represent around 50% of total cancer diagnosed in pediatric patients, and the rate of relapsed or refractory disease is higher than reported in other countries, a multi-factorial problem. Although significant progress has been made during the last decades in leukemia diagnosis and treatment, making new therapies available to Mexican patients is a priority, and cell and gene therapies are on the horizon. Efforts are ongoing to make CAR-T cell therapy accessible for patients in Mexico. This article summarizes a general landscape of childhood leukemias in Mexico, and we give a perspective about the current strategies, advances, and challenges ahead to make gene and cell therapies for leukemia clinically available.

Immunotherapy in multiple myeloma

Patients with multiple myeloma who present with refractory disease or relapse after receiving the main classes of available drugs -immunomodulators, proteasome inhibitors and antibodies against CD38- do not have satisfactory therapeutic alternatives. New treatments based on the redirection of T lymphocytes to act directly against tumor cells, such as bispecific antibodies and T cells with chimeric antigen receptors, are changing this scenario. The published information confirms unprecedented antitumor activity of these agents in patients with refractory myeloma and they will certainly represent the backbone of the treatment of these patients in the immediate future. However, these therapies also present specific characteristics and medium or long-term toxicities that pose new healthcare challenges. In this review, we address the current results and future challenges of the administration of these treatments in patients with relapsed or refractory multiple myeloma.

Management of Patients Undergoing CAR-T Cell Therapy in Germany

INTRODUCTION

Chimeric antigen receptor positive T cell (CAR-T cell) treatment became standard therapy for relapsed or refractory hematologic malignancies, such as non-Hodgkin's lymphoma and multiple myeloma. Owing to the rapidly progressing field of CAR-T cell therapy and the lack of generally accepted treatment guidelines, we hypothesized significant differences between centers in the prevention, diagnosis, and management of short- and long-term complications.

METHODS

To capture the current CAR-T cell management among German centers to determine the medical need and specific areas for future clinical research, the DAG-HSZT (Deutsche Arbeitsgemeinschaft für Hämatopoetische Stammzelltransplantation und Zelluläre Therapie; German Working Group for Hematopoietic Stem Cell Transplantation and Cellular Therapy) performed a survey among 26 German CAR-T cell centers.

RESULTS

We received answers from 17 centers (65%). The survey documents the relevance of evidence in the CAR-T cell field with a homogeneity of practice in areas with existing clinical evidence. In contrast, in areas with no - or low quality - clinical evidence, we identified significant variety in management in between the centers: management of cytokine release syndrome, immune effector cell-related neurotoxicity syndrome, IgG substitution, autologous stem cell backups, anti-infective prophylaxis, and vaccinations.

CONCLUSION

The results indicate the urgent need for better harmonization of supportive care in CAR-T cell therapies including clinical research to improve clinical outcome.

Immune determinants of CAR-T cell expansion in solid tumor patients receiving GD2 CAR-T cell therapy

Chimeric antigen receptor T cells (CAR-Ts) have remarkable efficacy in liquid tumors, but limited responses in solid tumors. We conducted a Phase I trial (NCT02107963) of GD2 CAR-Ts (GD2-CAR.OX40.28.z.iC9), demonstrating feasibility and safety of administration in children and young adults with osteosarcoma and neuroblastoma. Since CAR-T efficacy requires adequate CAR-T expansion, patients were grouped into good or poor expanders across dose levels. Patient samples were evaluated by multi-dimensional proteomic, transcriptomic, and epigenetic analyses. T cell assessments identified naive T cells in pre-treatment apheresis associated with good expansion, and exhausted T cells in CAR-T products with poor expansion. Myeloid cell assessment identified CXCR3+ monocytes in pre-treatment apheresis associated with good expansion. Longitudinal analysis of post-treatment samples identified increased CXCR3- classical monocytes in all groups as CAR-T numbers waned. Together, our data uncover mediators of CAR-T biology and correlates of expansion that could be utilized to advance immunotherapies for solid tumor patients.

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.

In Vivo Bioluminescence and Fluorescence Imaging: Optical Tool for Cancer Research

In vivo whole-body imaging, using optical tools based on bioluminescence and fluorescence detection, offers tremendous opportunities to specifically determine the spatiotemporal resolution of cancer cells within the tested animals. This enables the study of many aspects of cancer biology, including cell proliferation, trafficking, and invasions. The antitumor therapeutic properties of various tested compounds (e.g., CD19 CAR-T cells, used for cancer immunotherapy) can be monitored within the same animal at different time points, significantly reducing the number of animals used in the study as indicated in this method.

Case Report: CAR-T cells and subsequent maintenance with ponatinib in an adult Philadelphia acute lymphoblastic leukemia patient with hematological and extramedullary relapse after allogeneic stem cell transplantation

Relapsed or refractory (r/r) Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) still represent an unmet clinical need despite the new immune therapies available for these patients. We report the case of a Ph + ALL relapsed one year after allogeneic stem cell transplant. After one DLI was started CAR-T program with brexucabtageneautoleucel, using as bridging treatment ponatinib, vincristine and prednisone. Brexu-cel infusion was performed in 2023, without CRS or ICANS onset. One month after Brexu-cel infusion BM aspirate and CT-PET showed recovery of full donor chimerism, MRD negativity and complete metabolic remission. Subsequently was started maintenance with ponatinib: at last follow-up, the patient persisted in leukemia-free status. CAR-T cells represent the most powerful treatment for r/r Ph + ALL but there is no consensus about the optimal bridging strategy and also regarding the management algorithm during "post CAR-T phase". Here, we report the efficacy of ponatinib as a bridge to anti-CD19 CAR-T cell therapy and as post CAR-T maintenance. Our experience suggests that a preserving approach with TKI associated to low-dose chemotherapy can be the optimal bridging therapy prior to CAR-T and that an "MRD-guided" and "TKI-based" maintenance strategy can represent the best choice for Ph + ALL which satisfactorily responds to CAR-T.

The many facets of immune-mediated thrombocytopenia: Principles of immunobiology and immunotherapy

Immune thrombocytopenia (ITP) is a rare autoimmune condition, due to peripheral platelet destruction through antibody-dependent cellular phagocytosis, complement-dependent cytotoxicity, cytotoxic T lymphocyte-mediated cytotoxicity, and megakaryopoiesis alteration. This condition may be idiopathic or triggered by drugs, vaccines, infections, cancers, autoimmune disorders and systemic diseases. Recent advances in our understanding of ITP immunobiology support the idea that other forms of thrombocytopenia, for instance, occurring after immunotherapy or cellular therapies, may share a common pathophysiology with possible therapeutic implications. If a decent pipeline of old and new agents is currently deployed for classical ITP, in other more complex immune-mediated thrombocytopenic disorders, clinical management is less harmonized and would deserve further prospective investigations. Here, we seek to provide a fresh overview of pathophysiology and current therapeutical algorithms for adult patients affected by this disorder with specific insights into poorly codified scenarios, including refractory ITP and post-immunotherapy/cellular therapy immune-mediated thrombocytopenia.

Cell-Surface GRP78-Targeted Chimeric Antigen Receptor T Cells Eliminate Lung Cancer Tumor Xenografts

Lung cancer is one of the most common and intractable malignancies. It is associated with low survival rates despite existing treatments, indicating that new and more effective therapies are urgently needed such as the chimeric antigen receptor-T (CAR-T) cell immunotherapy. The cell-surface glucose-regulated protein 78 (csGRP78) is expressed in various hematological malignancies and solid tumor cells including lung cancer in response to cancer-related endoplasmic reticulum stress, while GRP78 is restricted to inside the normal cells. Here, we detected the prominent expression of csGRP78 in both lung cancer cell lines, A549 and H1299, as well as cancer stemlike cells derived from A549 by immunofluorescence. Next, a csGRP78-targeted CAR was constructed, and the transduced CAR-T cells were tested for their potency to kill the two lung cancer cell lines and derived stemlike cells, which was correlated with specific interferon γ release in vitro. Finally, we found that csGRP78 CAR-T cells also efficiently killed both lung cancer cells and cancer stemlike cells, resulting into the elimination of tumor xenografts in vivo, neither with any evidence of relapse after 63 days of tumor clearance nor any detrimental impact on other body organs we examined. Our study reveals the capacity of csGRP78 as a therapeutic target and offers valuable insight into the development of csGRP78 CAR-T cells as potential therapy for lung cancer.

Enhanced efficacy of CD19/CD22 bispecific CAR-T cells with EAAAK linker on B-cell malignancies

OBJECTIVES

Despite the great success of CD19 CAR-T cell therapy, its clinical efficacy has been greatly hampered by the high relapse rate. In this study, we designed and compared four structures of CD19/CD22 bispecific CAR-T cells with different linkers and different orders of the antibody sequences.

METHODS

We detected the cytotoxicity, cytokine secretion levels, sustainable killing ability, differentiation, exhaustion of these four CAR-T cells in vitro. The optimal Bis-C CAR-T cells were evaluated the efficacy using NSG mice.

RESULTS

The two structures of CD19/CD22 bispecific CAR-T cells using (EAAAK)3 as linker had more significant cytotoxicity and cytokine secretion levels. In the process of continuous killing, Bis-C CAR-T cells showed better sustained killing ability, memory phenotype differentiation, and exhaustion. In the in vivo experiment mimicking CD19-negative relapse, Bis-C CAR-T was more able to control the tumor progression of mice in the CD19 low expression or no expression groups than CD19 CAR-T.

CONCLUSIONS

This study has generated a novel bispecific CAR-T cell that can simultaneously target CD19 or CD22 positive tumor cells, providing a new strategy to address the limitations of single-targeted CAR-T therapy in B-cell tumors (limited response or relapse).

Advancements in chimeric antigen receptor-expressing T-cell therapy for glioblastoma multiforme: Literature review and future directions

Glioblastoma multiforme (GBM) is an aggressive cancer that has been difficult to treat and often requires multimodal therapy consisting of surgery, radiotherapy, and chemotherapy. Chimeric antigen receptor-expressing (CAR-T) cells have been efficacious in treating hematological malignancies, resulting in several FDA-approved therapies. CAR-T cells have been more recently studied for the treatment of GBM, with some promising preclinical and clinical results. The purpose of this literature review is to highlight the commonly targeted antigens, results of clinical trials, novel modifications, and potential solutions for challenges that exist for CAR-T cells to become more widely implemented and effective in eradicating GBM.

Genome Editing in CAR-T Cells Using CRISPR/Cas9 Technology

CAR-T cell therapy is revolutionizing the treatment of hematologic malignancies. However, there are still many challenges ahead before CAR-T cells can be used effectively to treat solid tumors and certain hematologic cancers, such as T-cell malignancies. Next-generation CAR-T cells containing further genetic modifications are being developed to overcome some of the current limitations of this therapy. In this regard, genome editing is being explored to knock out or knock in genes with the goal of enhancing CAR-T cell efficacy or increasing access. In this chapter, we describe in detail a protocol to knock out genes on CAR-T cells using CRISPR-Cas9 technology. Among various gene editing protocols, due to its simplicity, versatility, and reduced toxicity, we focused on the electroporation of ribonucleoprotein complexes containing the Cas9 protein together with sgRNA. All together, these protocols allow for the design of the knockout strategy, CAR-T cell expansion and genome editing, and analysis of knockout efficiency.

Lymphodepletion - an essential but undervalued part of the chimeric antigen receptor T-cell therapy cycle

Lymphodepletion (LD) or conditioning is an essential step in the application of currently used autologous and allogeneic chimeric antigen receptor T-cell (CAR-T) therapies as it maximizes engraftment, efficacy and long-term survival of CAR-T. Its main modes of action are the depletion and modulation of endogenous lymphocytes, conditioning of the microenvironment for improved CAR-T expansion and persistence, and reduction of tumor load. However, most LD regimens provide a broad and fairly unspecific suppression of T-cells as well as other hematopoietic cells, which can also lead to severe side effects, particularly infections. We reviewed 1271 published studies (2011-2023) with regard to current LD strategies for approved anti-CD19 CAR-T products for large B cell lymphoma (LBCL). Fludarabine (Flu) and cyclophosphamide (Cy) (alone or in combination) were the most commonly used agents. A large number of different schemes and combinations have been reported. In the respective schemes, doses of Flu and Cy (range 75-120mg/m2 and 750-1.500mg/m2) and wash out times (range 2-5 days) differed substantially. Furthermore, combinations with other agents such as bendamustine (benda), busulfan or alemtuzumab (for allogeneic CAR-T) were described. This diversity creates a challenge but also an opportunity to investigate the impact of LD on cellular kinetics and clinical outcomes of CAR-T. Only 21 studies explicitly investigated in more detail the influence of LD on safety and efficacy. As Flu and Cy can potentially impact both the in vivo activity and toxicity of CAR-T, a more detailed analysis of LD outcomes will be needed before we are able to fully assess its impact on different T-cell subsets within the CAR-T product. The T2EVOLVE consortium propagates a strategic investigation of LD protocols for the development of optimized conditioning regimens.

Chimeric Antigen Receptor-T Cell Therapy for Lymphoma: New Settings and Future Directions

In the last decade, anti-CD19 CAR-T cell therapy has led to a treatment paradigm shift for B-cell non-Hodgkin lymphomas, first with the approval for relapsed/refractory (R/R) large B-cell lymphomas and subsequently for R/R mantle cell and follicular lymphoma. Many efforts are continuously being made to extend the therapeutic setting in the lymphoma field. Several reports are supporting the safety and efficacy of CAR-T cells in patients with central nervous system disease involvement. Anti-CD30 CAR-T cells for the treatment of Hodgkin lymphoma are in development and early studies looking for the optimal target for T-cell malignancies are ongoing. Anti-CD19/CD20 and CD19/CD22 dual targeting CAR-T cells are under investigation in order to increase anti-lymphoma activity and overcome tumor immune escape. Allogeneic CAR product engineering is on the way, representing a rapidly accessible 'off-the-shelf' and potentially more fit product. In the present manuscript, we will focus on recent advances in CAR-T cell therapy for lymphomas, including new settings and future perspectives in the field, reviewing data reported in literature in the last decade up to October 2023.

Harnessing immunotherapy for brain metastases: insights into tumor-brain microenvironment interactions and emerging treatment modalities

Brain metastases signify a deleterious milestone in the progression of several advanced cancers, predominantly originating from lung, breast and melanoma malignancies, with a median survival timeframe nearing six months. Existing therapeutic regimens yield suboptimal outcomes; however, burgeoning insights into the tumor microenvironment, particularly the immunosuppressive milieu engendered by tumor-brain interplay, posit immunotherapy as a promising avenue for ameliorating brain metastases. In this review, we meticulously delineate the research advancements concerning the microenvironment of brain metastases, striving to elucidate the panorama of their onset and evolution. We encapsulate three emergent immunotherapeutic strategies, namely immune checkpoint inhibition, chimeric antigen receptor (CAR) T cell transplantation and glial cell-targeted immunoenhancement. We underscore the imperative of aligning immunotherapy development with in-depth understanding of the tumor microenvironment and engendering innovative delivery platforms. Moreover, the integration with established or avant-garde physical methodologies and localized applications warrants consideration in the prevailing therapeutic schema.

A bibliometric and knowledge-map study of CAR-T cell-related cytokine release syndrome (CRS) from 2012 to 2023

CAR-T cell therapy has demonstrated efficacy in treating certain hematological malignancies. However, the administration of CAR-T cells is accompanied by the occurrence of adverse events. Among these, cytokine release syndrome (CRS) has garnered significant attention. In this descriptive study, we set the search criteria to retrieve and obtain articles regarding CAR-T cell-related CRS from the Web of Science Core Collection (WoSCC). The bibliometric and knowledge-map analysis of these documents was conducted using Microsoft Excel 2019, GraphPad Prism 8, CtieSpace, and VOSviewer. 6,623 authors from 295 institutions in 49 countries coauthored a total of 1,001 publications. The leading country in this field was the United States. The most productive institution was the University of Pennsylvania. Carl H. June had the most citations, while Daniel W. Lee had the most co-citations. Research hotspots primarily concentrated on the pathogenesis, serum biomarkers, management, and therapeutic drugs of CRS, alongside neurotoxicity. Emerging topics within this discipline encompassed the following: a. Drugs for effective treatment and intervention of CRS; b. Conducting pertinent clinical trials to acquire real-world data; c. Management of toxicity (CRS and neurotoxicity) associated with CAR-T cell therapy; d. The study of BCMA-CAR-T cells in multiple myeloma (MM); e. Optimizing the CAR framework structure to enhance the effectiveness and safety of CAR-T cells. A bibliometric and scientific knowledge-map analysis provided a unique and objective perspective for exploring the field of CAR-T cell-related CRS, and may provide some new clues and valuable references for researchers.

Universal ddPCR-based assay for the determination of lentivirus infectious titer and lenti-modified cell vector copy number

The translation of cell-based therapies from research to clinical setting requires robust analytical methods that successfully adhere to current good manufacturing practices and regulatory guidelines. Lentiviral vectors are commonly used for gene delivery to generate genetically modified therapeutic cell products. For some cell therapy products, standardized characterization assays for potency and safety have gained momentum. Translational applications benefit from assays that can be deployed broadly, such as for lentiviral vectors with various transgenes of interest. Development of a universal method to determine lentivirus infectious titer and vector copy number (VCN) of lenti-modified cells was performed using droplet digital PCR (ddPCR). Established methods relied on a ubiquitous lenti-specific target and a housekeeping gene that demonstrated comparability among flow cytometry-based methods. A linearized plasmid control was used to determine assay linearity/range, sensitivity, accuracy, and limits of quantification. Implementing this assay, infectious titer was assessed for various production runs that demonstrated comparability to the flow cytometry titer. The ddPCR assay described here also indicates suitability in the determination of VCN for genetically modified CAR-T cell products. Overall, the development of these universal assays supports the implementation of standardized characterization methods for quality control.

The Limitations of Current T Cell-Driven Anticancer Immunotherapies Can Be Overcome with an Original Extracellular-Vesicle-Based Vaccine Strategy

The emergence of tumors associated with defects in immune surveillance often involve the impairment of key functions of T lymphocytes. Therefore, several anticancer immunotherapies have focused on the induction/strengthening of the tumor-specific activity of T cells. In particular, strategies based on immune checkpoint inhibitors, CAR-T cells, and mRNA vaccines share a common goal of inducing/recovering an effective antitumor cytotoxic activity, often resulting in either exhausted or absent in patients' lymphocytes. In many instances, these approaches have been met with success, becoming part of current clinic protocols. However, the most practiced strategies sometimes also pay significant tolls in terms of adverse events, a lack of target specificity, tumor escape, and unsustainable costs. Hence, new antitumor immunotherapies facing at least some of these issues need to be explored. In this perspective article, the characteristics of a novel CD8+ T cell-specific anticancer vaccine strategy based on in vivo-engineered extracellular vesicles are described. How this approach can be exploited to overcome at least some of the limitations of current antitumor immunotherapies is also discussed.

[Organizational and budgetary impacts of the implementation of CAR-T cell therapies in a French academic hospital]

Belonging to the family of advanced therapy medicinal products, CAR-T cells have changed the management of hematological malignancies. These treatments are known to involve many actors in a complex process. The quotation of hospital stays associated with this therapeutic strategy is also unusual since there is currently no specific quotation. From November 2021 to May 2022, a study was conducted at the Nancy University Hospital to evaluate the organizational impact of CAR-T cell therapy on hospital actors and the budgetary impact of stays in care centers. Through this study, we have shown significant and variable organizational impacts: from 3.12% of an additional full-time equivalent for an administrative manager to 41.5% for a clinical research associate. These times, when compared to the hourly rates of the actors, generated high costs: 6582.81 € per patient, i.e. 15.60% of the total cost of hospitalization. Taking into account the current refund of hospital stays and the costs calculated above, the balance of an average hospital stay is a deficit of 674.10 € [±10,224.79] with a median of 1334.97 €. This study highlighted the workload generated by the management of these new therapies, as well as the fragile balance of financing hospital stays. To date, it seems necessary and even essential to adapt the quotations of the acts dedicated to CAR-T cells activity and to provide adequate funding through an adapted pricing system.

Incidence of MACE in Patients Treated With CAR-T Cell Therapy: A Prospective Study

Background

Previous retrospective studies have shown that chimeric antigen receptor T (CAR-T) cell therapy may be associated with major adverse cardiovascular events (MACE), especially in the context of cytokine-release syndrome (CRS) events.

Objectives

The aim of this prospective observational study was to define the occurrence of MACE in adults undergoing treatment with CAR-T cell therapy and identify associated risk factors.

Methods

Vital signs, blood samples, and an echocardiogram were collected prior to and 2 days, 1 week, 1 month, and 6 months after CAR-T cell infusion, and charts were consulted at 12 months. In the event of CRS, echocardiography was repeated within 72 hours. MACE were defined as cardiovascular death, symptomatic heart failure, acute coronary syndrome, ischemic stroke, and de novo cardiac arrhythmia.

Results

A total of 44 patients were enrolled (mean age 58 ± 11 years, 77% men). The median follow-up duration was 487 days (Q1-Q3: 258-622 days). There were 24 episodes of CRS in 23 patients (52%) (13 grade 1, 10 grade 2, and 1 grade 3), with a median time to CRS of 4 days. Two patients had MACE (heart failure with preserved ejection fraction and atrial fibrillation) within 1 year and 6 and 7 days after CAR-T cell infusion. There was no change in left ventricular ejection fraction, but a modest decrease in global longitudinal strain was noted.

Conclusions

There were few cardiac effects associated with contemporary CAR-T cell therapy. As MACE occurred after CRS episodes, aggressive treatment and close follow-up during CRS events are essential.

Translational research of new developments in targeted therapy of colorectal cancer

A severe global health concern is the rising incidence and mortality rate of colorectal cancer (CRC). Chemotherapy, which is typically used to treat CRC, is known to have limited specificity and can have noticeable side effects. A paradigm shift in cancer treatment has been brought about by the development of targeted therapies, which has led to the appearance of pharmacological agents with improved efficacy and decreased toxicity. Epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER2), and BRAF are among the molecular targets covered in this review that are used in targeted therapy for CRC. The current discussion also covers advancements in targeted therapeutic approaches, such as antibody-drug conjugates, immune checkpoint inhibitors, and chimeric antigen receptor (CAR) T-cell therapy. A review of the clinical trials and application of these particular therapies in treating CRC is also done. Despite the improvements in targeted therapy for CRC, problems such as drug resistance and patient selection remain to be solved. Despite this, targeted therapies have offered fresh possibilities for identifying and treating CRC, paving the way for the development of personalized medicine and extending the life expectancy and general well-being of CRC patients.

DIALing-up the preclinical characterization of gene-modified adoptive cellular immunotherapies

The preclinical characterization of gene modified adoptive cellular immunotherapy candidates for clinical development often requires the use of mouse models. Gene-modified lymphocytes (GML) incorporating chimeric antigen receptors (CAR) and T-cell receptors (TCR) into immune effector cells require in vivo characterization of biological activity, mechanism of action, and preclinical safety. Typically, this characterization involves the assessment of dose-dependent, on-target, on-tumor activity in severely immunocompromised mice. While suitable for the purpose of evaluating T cell-expressed transgene function in a living host, this approach falls short in translating cellular therapy efficacy, safety, and persistence from preclinical models to humans. To comprehensively characterize cell therapy products in mice, we have developed a framework called "DIAL". This framework aims to enable an end-to-end understanding of genetically engineered cellular immunotherapies in vivo, from infusion to tumor clearance and long-term immunosurveillance. The acronym DIAL stands for Distribution, Infiltration, Accumulation, and Longevity, compartmentalizing the systemic attributes of gene-modified cellular therapy and providing a platform for optimization with the ultimate goal of improving therapeutic efficacy. This review will discuss both existent and emerging examples of DIAL characterization in mouse models, as well as opportunities for future development and optimization.

CAR-T Cell Therapy in the Treatment of Pediatric Non-Hodgkin Lymphoma

Non-Hodgkin lymphomas (NHL) are a group of cancers that originate in the lymphatic system, especially from progenitor or mature B-cells, T-cells, or natural killer (NK) cells. NHL is the most common hematological malignancy worldwide and also the fourth most frequent type of cancer among pediatric patients. This cancer can occur in children of any age, but it is quite rare under the age of 5 years. In recent decades, available medicines and therapies have significantly improved the prognosis of patients with this cancer. However, some cases of NHL are treatment resistant. For this reason, immunotherapy, as a more targeted and personalized treatment strategy, is becoming increasingly important in the treatment of NHL in pediatric patients. The objective of the following review is to gather the latest available research results, conducted among pediatric and/or adult patients with NHL, regarding one immunotherapy method, i.e., chimeric antigen receptor (CAR) T cell therapy. We focus on assessing the effectiveness of CAR-T cell therapy, which mainly targets B cell markers, CD19, CD20, and CD22, their connections with one another, sequential treatment, or connections with co-stimulatory molecules. In addition, we also evaluate the safety, aftermath (especially neurotoxicities) and limitations of CAR-T cell therapy.

Optimized peptide nanofibrils as efficient transduction enhancers for in vitro and ex vivo gene transfer

Chimeric antigen receptor (CAR)-T cell therapy is a groundbreaking immunotherapy for cancer. However, the intricate and costly manufacturing process remains a hurdle. Improving the transduction rate is a potential avenue to cut down costs and boost therapeutic efficiency. Peptide nanofibrils (PNFs) serve as one such class of transduction enhancers. PNFs bind to negatively charged virions, facilitating their active engagement by cellular protrusions, which enhances virion attachment to cells, leading to increased cellular entry and gene transfer rates. While first-generation PNFs had issues with aggregate formation and potential immunogenicity, our study utilized in silico screening to identify short, endogenous, and non-immunogenic peptides capable of enhancing transduction. This led to the discovery of an 8-mer peptide, RM-8, which forms PNFs that effectively boost T cell transduction rates by various retroviral vectors. A subsequent structure-activity relationship (SAR) analysis refined RM-8, resulting in the D4 derivative. D4 peptide is stable and assembles into smaller PNFs, avoiding large aggregate formation, and demonstrates superior transduction rates in primary T and NK cells. In essence, D4 PNFs present an economical and straightforward nanotechnological tool, ideal for refining ex vivo gene transfer in CAR-T cell production and potentially other advanced therapeutic applications.