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

Strategies for Reducing Toxicity and Enhancing Efficacy of Chimeric Antigen Receptor T Cell Therapy in Hematological Malignancies

Chimeric antigen receptor T cell (CAR-T) therapy in hematologic malignancies has made great progress, but there are still some problems. First, T cells from tumor patients show an exhaustion phenotype; thus, the persistence and function of the CAR-Ts are poor, and achieving a satisfactory curative effect is difficult. Second, some patients initially respond well but quickly develop antigen-negative tumor recurrence. Thirdly, CAR-T treatment is not effective in some patients and is accompanied by severe side effects, such as cytokine release syndrome (CRS) and neurotoxicity. The solution to these problems is to reduce the toxicity and enhance the efficacy of CAR-T therapy. In this paper, we describe various strategies for reducing the toxicity and enhancing the efficacy of CAR-T therapy in hematological malignancies. In the first section, strategies for modifying CAR-Ts using gene-editing technologies or combining them with other anti-tumor drugs to enhance the efficacy of CAR-T therapy are introduced. The second section describes some methods in which the design and construction of CAR-Ts differ from the conventional process. The aim of these methods is to enhance the anti-tumor activity of CAR-Ts and prevent tumor recurrence. The third section describes modifying the CAR structure or installing safety switches to radically reduce CAR-T toxicity or regulating inflammatory cytokines to control the symptoms of CAR-T-associated toxicity. Together, the knowledge summarized herein will aid in designing better-suited and safer CAR-T treatment strategies.

Understanding CAR T cell therapy and its role in ovarian cancer and peritoneal carcinomatosis from ovarian cancer

Ovarian cancer is the seventh most common cancer worldwide in women and the most lethal gynecologic malignancy due to the lack of accurate screening tools for early detection and late symptom onset. The absence of early-onset symptoms often delays diagnosis until the disease has progressed to advanced stages, frequently when there is peritoneal involvement. Although ovarian cancer is a heterogeneous malignancy with different histopathologic types, treatment for advanced tumors is usually based on chemotherapy and cytoreduction surgery. CAR T cells have shown promise for the treatment of hematological malignancies, though their role in treating solid tumors remains unclear. Outcomes are less favorable owing to the low capacity of CAR T cells to migrate to the tumor site, the influence of the protective tumor microenvironment, and the heterogeneity of surface antigens on tumor cells. Despite these results, CAR T cells have been proposed as a treatment approach for peritoneal carcinomatosis from colorectal and gastric origin. Local intraperitoneal administration of CAR T cells has been found to be superior to systemic administration, as this route is associated with increased tumor reduction, a more durable effect, protection against local relapse and distant metastases, and fewer systemic adverse effects. In this article we review the application of CAR T cells for the treatment of ovarian cancer and peritoneal carcinomatosis from ovarian cancer.

How I treat refractory CRS and ICANS after CAR T-cell therapy

The clinical use of chimeric antigen receptor (CAR) T-cell therapy is growing rapidly because of the expanding indications for standard-of-care treatment and the development of new investigational products. The establishment of consensus diagnostic criteria for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), alongside the steady use of both tocilizumab and corticosteroids for treatment, have been essential in facilitating the widespread use. Preemptive interventions to prevent more severe toxicities have improved safety, facilitating CAR T-cell therapy in medically frail populations and in those at high risk of severe CRS/ICANS. Nonetheless, the development of persistent or progressive CRS and ICANS remains problematic because it impairs patient outcomes and is challenging to treat. In this case-based discussion, we highlight a series of cases of CRS and/or ICANS refractory to front-line interventions. We discuss our approach to managing refractory toxicities that persist or progress beyond initial tocilizumab or corticosteroid administration, delineate risk factors for severe toxicities, highlight the emerging use of anakinra, and review mitigation strategies and supportive care measures to improve outcomes in patients who develop these refractory toxicities.

How I treat cytopenias after CAR T-cell therapy

Increasing use of chimeric antigen receptor T-cell therapy (CAR-T) has unveiled diverse toxicities warranting specific recognition and management. Cytopenias occurring after CAR-T infusion invariably manifest early (<30 days), commonly are prolonged (30-90 days), and sometimes persist or occur late (>90 days). Variable etiologies of these cytopenias, some of which remain incompletely understood, create clinical conundrums and uncertainties about optimal management strategies. These cytopenias may cause additional sequelae, decreased quality of life, and increased resource use. Early cytopenias are typically attributed to lymphodepletion chemotherapy, however, infections and hyperinflammatory response such as immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome may occur. Early and prolonged cytopenias often correlate with severity of cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome. Bone marrow biopsy in patients with prolonged or late cytopenias is important to evaluate for primary disease and secondary marrow neoplasm in both pediatric and adult patients. Commonly, cytopenias resolve over time and evidence for effective interventions is often anecdotal. Treatment strategies, which are limited and require tailoring based upon likely underlying etiology, include growth factors, thrombopoietin-receptor agonist, stem cell boost, transfusion support, and abrogation of infection risk. Here we provide our approach, including workup and management strategies, for cytopenias after CAR-T.

Derivation and validation of a novel score for early prediction of severe CRS after CAR-T therapy in haematological malignancy patients: A multi-centre study

Chimeric antigen receptor T (CAR-T) cell therapy is highly effective in inducing complete remission in haematological malignancies. Severe cytokine release syndrome (CRS) is the most significant and life-threatening adverse effect of this therapy. This multi-centre study was conducted at six hospitals in China. The training cohort included 87 patients with multiple myeloma (MM), an external validation cohort of 59 patients with MM and another external validation cohort of 68 patients with acute lymphoblastic leukaemia (ALL) or non-Hodgkin lymphoma (NHL). The levels of 45 cytokines on days 1-2 after CAR-T cell infusion and clinical characteristics of patients were used to develop the nomogram. A nomogram was developed, including CX3CL1, GZMB, IL4, IL6 and PDGFAA. Based on the training cohort, the nomogram had a bias-corrected AUC of 0.876 (95% CI = 0.871-0.882) for predicting severe CRS. The AUC was stable in both external validation cohorts (MM, AUC = 0.907, 95% CI = 0.899-0.916; ALL/NHL, AUC = 0.908, 95% CI = 0.903-0.913). The calibration plots (apparent and bias-corrected) overlapped with the ideal line in all cohorts. We developed a nomogram that can predict which patients are likely to develop severe CRS before they become critically ill, improving our understanding of CRS biology, and may guide future cytokine-directed therapies.

Management and Prevention of Cellular-Therapy-Related Toxicity: Early and Late Complications

Chimeric Antigen Receptor T (CAR-T) cell therapy has dramatically changed prognosis and treatment of relapsed and refractory hematologic malignancies. Currently the 6 FDA approved products target various surface antigens. While CAR-T therapy achieves good response, life-threatening toxicities have been reported. Mechanistically, can be divided into two categories: (1) toxicities related to T-cell activation and release of high levels of cytokines: or (2) toxicities resulting from interaction between CAR and CAR targeted antigen expressed on non-malignant cells (i.e., on-target, off-tumor effects). Variations in conditioning therapies, co-stimulatory domains, CAR T-cell dose and anti-cytokine administration, pose a challenge in distinguishing cytokine mediated related toxicities from on-target, off-tumor toxicities. Timing, frequency, severity, as well as optimal management of CAR T-cell-related toxicities vary significantly between products and are likely to change as newer therapies become available. Currently the FDA approved CARs are targeted towards the B-cell malignancies however the future holds promise of expanding the target to solid tumor malignancies. Further highlighting the importance of early recognition and intervention for early and late onset CAR-T related toxicity. This contemporary review aims to describe presentation, grading and management of commonly encountered toxicities, short- and long-term complications, discuss preventive strategies and resource utilization.

Meta-analysis informed machine learning: Supporting cytokine storm detection during CAR-T cell Therapy

Cytokine release syndrome (CRS), also known as cytokine storm, is one of the most consequential adverse effects of chimeric antigen receptor therapies that have shown otherwise promising results in cancer treatment. When emerging, CRS could be identified by the analysis of specific cytokine and chemokine profiles that tend to exhibit similarities across patients. In this paper, we exploit these similarities using machine learning algorithms and set out to pioneer a meta-review informed method for the identification of CRS based on specific cytokine peak concentrations and evidence from previous clinical studies. To this end we also address a widespread challenge of the applicability of machine learning in general: reduced training data availability. We do so by augmenting available (but often insufficient) patient cytokine concentrations with statistical knowledge extracted from domain literature. We argue that such methods could support clinicians in analyzing suspect cytokine profiles by matching them against the said CRS knowledge from past clinical studies, with the ultimate aim of swift CRS diagnosis. We evaluate our proposed methods under several design choices, achieving performance of more than 90% in terms of CRS identification accuracy, and showing that many of our choices outperform a purely data-driven alternative. During evaluation with real-world CRS clinical data, we emphasize the potential of our proposed method of producing interpretable results, in addition to being effective in identifying the onset of cytokine storm.

Potentiating antibody-dependent killing of cancers with CAR T cells secreting CD47-SIRPα checkpoint blocker

Chimeric antigen receptor (CAR) T-cell therapy has shown success in the treatment of hematopoietic malignancies; however, relapse remains a significant issue. To overcome this, we engineered "Orexi" CAR T cells to locally secrete a high-affinity CD47 blocker, CV1, at the tumor and treated tumors in combination with an orthogonally targeted monoclonal antibody. Traditional CAR T cells plus the antibody had an additive effect in xenograft models, and this effect was potentiated by CAR T-cell local CV1 secretion. Furthermore, OrexiCAR-secreted CV1 reversed the immunosuppression of myelomonocytoid cells both in vitro and within the tumor microenvironment. Local secretion of the CD47 inhibitor bypasses the CD47 sink found on all cells in the body and may prevent systemic toxicities. This combination of CAR T-cell therapy, local CD47 blockade, and orthogonal antibody may be a combinatorial strategy to overcome the limitations of each monotherapy.

Safety of CAR-T Cell Therapy in Patients With Renal Failure/Acute Kidney Injury: Focused Review

Chimeric antigen receptor (CAR) T-cell therapy is novel immunotherapy targeting specifically cancerous cells, and has been shown to induce durable remissions in some refractory hematological malignancies. However, CAR T-cell therapy has adverse effects, such as cytokine release syndrome (CRS), immune effector-associated neurotoxicity syndrome (ICANS), tumor lysis syndrome (TLS), and acute kidney injury (AKI), among others. Not many studies have covered the repercussions of CAR T-cell therapy on the kidneys. In this review, we summarized the available evidence on the safety profile of CAR T-cell therapy in patients with pre-existing renal insufficiency/AKI and in those who develop AKI as a result of CAR T-cell therapy. With a 30% incidence of AKI post-CAR T-cell, various pathophysiological mechanisms, such as CRS, hemophagocytic lymphohistiocytosis (HLH), TLS, serum cytokines, and inflammatory biomarkers, have been shown to play a role. However, CRS is commonly reported as an underlying mechanism. Overall, 18% of patients in our included studies developed AKI after receiving CAR T-cell therapy, and most cases were reversible with appropriate therapy. While phase-1 clinical trials exclude patients with significant renal toxicity, two studies (Mamlouk et al. and Hunter et al.) reported successful treatment of dialysis-dependent patients with refractory diffuse large B-cell lymphoma, and demonstrated that CAR T-cell therapy and lymphodepletion (Flu/Cy) can be safely administered.

RNA silencing of GM-CSF in CAR-T cells reduces the secretion of multiple inflammatory cytokines

Chimeric antigen receptor T (CAR-T) cell therapy has become a research hotspot in the field of hematological malignancies. However, CAR-T cell therapy can lead to immunotherapy-associated side effects including cytokine release syndrome and neurotoxicity. Gene depletion of GM-CSF in CAR-T cells was found preventive against adverse effects, but additional transfections were required to produce CAR-T cells. In this study, we interrupted GM-CSF expression in CAR-T cells by inserting the GM-CSF shRNA-expression cassette in the CAR vector. Reduction of GM-CSF in CAR-T cells could decrease the level of several proinflammatory cytokines without hampering the killing capacity. The manufacture of GM-CSF knockdown CAR-T cells does not require complicated transfections, which makes it more practical and feasible for clinical application.

CAR-T Cell Therapy: the Efficacy and Toxicity Balance

PURPOSE OF REVIEW

Chimeric antigen receptor (CAR) T cell therapy is an immunotherapy that has resulted in tremendous progress in the treatment of patients with B cell malignancies. However, the remarkable efficacy of therapy is not without significant safety concerns. Herein, we will review the unique and potentially life-threatening toxicities associated with CAR-T cell therapy and their association with treatment efficacy.

RECENT FINDINGS

Currently, CAR-T cell therapy is approved for the treatment of B cell relapsed or refractory leukemia and lymphoma, and most recently, multiple myeloma (MM). In these different diseases, it has led to excellent complete and overall response rates depending on the patient population and therapy. Despite promising efficacy, CAR-T cell therapy is associated with significant side effects; the two most notable toxicities are cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). The treatment of CAR-T-induced toxicity is supportive; however, as higher-grade adverse events occur, toxicity-directed therapy with tocilizumab, an IL-6 receptor antibody, and steroids is standard practice. Overall, a careful risk-benefit balance exists between the efficacy and toxicities of therapies. The challenge lies in the underlying pathophysiology of CAR-T-related toxicity which relies upon the activation of CAR-T cells. Some degree of toxicity is expected to achieve an effective response to therapy, and certain aspects of treatment are also associated with toxicity. As progress is made in the investigation and approval of new CARs, novel toxicity-directed therapies and toxicity-limited constructs will be the focus of attention.

Neurological Adverse Effects of Immune Checkpoint Inhibitors and Chimeric Antigen Receptor T-Cell Therapy

Immune checkpoint inhibitors (ICPIs) and chimeric antigen receptor (CAR) T-cell constitute recently approved novel therapies targeted to treat a wide number of malignancies. Both the treatments modulate the immune system and can cause a number of immune-related adverse events (irAEs), including polyendocrinopathies, gastrointestinal and neurological complications. This literature review focuses on the neurological side effects of these therapies as these are uncommon and alter the course of the treatment. Neurological complications involve the peripheral and central nervous system, including polyneuropathy, myositis, myasthenia gravis, demyelinating polyradiculopathy, myelitis, and encephalitis. If early recognized, the neurological complications can be treated effectively with steroids to reduce the potential of short-term and long-term complications. Therefore, early identification and treatment of irAEs are needed to optimize the outcomes associated with ICPI and CAR T-cell therapies.

Cytokine Release Syndrome in the Pediatric Population and Implications for Intensive Care Management

Cytokine release syndrome represents a spectrum of disease varying from fever alone to multiorgan system failure. Most commonly seen following treatment with chimeric antigen receptor T cell therapy, it is increasingly being described with other immunotherapies as well as following hematopoietic stem cell transplant. As its symptoms are nonspecific, awareness is key to timely diagnosis and initiation of treatment. Given the high risk of cardiopulmonary involvement, critical care providers must be familiar with the cause, symptoms, and therapeutic options. Current treatment modalities focus on immunosuppression and targeted cytokine therapy.

Advancing CAR T cell therapy through the use of multidimensional omics data

Despite the notable success of chimeric antigen receptor (CAR) T cell therapies in the treatment of certain haematological malignancies, challenges remain in optimizing CAR designs and cell products, improving response rates, extending the durability of remissions, reducing toxicity and broadening the utility of this therapeutic modality to other cancer types. Data from multidimensional omics analyses, including genomics, epigenomics, transcriptomics, T cell receptor-repertoire profiling, proteomics, metabolomics and/or microbiomics, provide unique opportunities to dissect the complex and dynamic multifactorial phenotypes, processes and responses of CAR T cells as well as to discover novel tumour targets and pathways of resistance. In this Review, we summarize the multidimensional cellular and molecular profiling technologies that have been used to advance our mechanistic understanding of CAR T cell therapies. In addition, we discuss current applications and potential strategies leveraging multi-omics data to identify optimal target antigens and other molecular features that could be exploited to enhance the antitumour activity and minimize the toxicity of CAR T cell therapy. Indeed, fully utilizing multi-omics data will provide new insights into the biology of CAR T cell therapy, further accelerate the development of products with improved efficacy and safety profiles, and enable clinicians to better predict and monitor patient responses.

Identifying Early Infections in the Setting of CRS With Routine and Exploratory Serum Proteomics and the HT10 Score Following CD19 CAR-T for Relapsed/Refractory B-NHL

Early fever after chimeric antigen receptor T-cell (CAR-T) therapy can reflect both an infection or cytokine release syndrome (CRS). Identifying early infections in the setting of CRS and neutropenia represents an unresolved clinical challenge. In this retrospective observational analysis, early fever events (day 0-30) were characterized as infection versus CRS in 62 patients treated with standard-of-care CD19.CAR-T for relapsed/refractory B-cell non-Hodgkin lymphoma. Routine serum inflammatory markers (C-reactive protein [CRP], interleukin-6 [IL-6], procalcitonin [PCT]) were recorded daily. Exploratory plasma proteomics were performed longitudinally in 52 patients using a multiplex proximity extension assay (Olink proteomics). Compared with the CRS^only cohort, we noted increased event-day IL-6 (median 2243 versus 64 pg/mL, P = 0.03) and particularly high PCT levels (median 1.6 versus 0.3 µg/L, P < 0.0001) in the patients that developed severe infections. For PCT, an optimal discriminatory threshold of 1.5 µg/L was established (area under the receiver operating characteristic curve [AUC_ROC] = 0.78). Next, we incorporated day-of-fever PCT levels with the patient-individual CAR-HEMATOTOX score. In a multicenter validation cohort (n = 125), we confirmed the discriminatory capacity of this so-called HT10 score for early infections at first fever (AUC_ROC = 0.87, P < 0.0001, sens. 86%, spec. 86%). Additionally, Olink proteomics revealed pronounced immune dysregulation and endothelial dysfunction in patients with severe infections as evidenced by an increased ANGPT2/1 ratio and an altered CD40/CD40L-axis. In conclusion, the high discriminatory capacity of the HT10 score for infections highlights the advantage of dynamic risk assessment and supports the incorporation of PCT into routine inflammatory panels. Candidate markers from Olink proteomics may further refine risk-stratification. If validated prospectively, the score will enable risk-adapted decisions on antibiotic use.

Impact of Preemptive Use of Tocilizumab on Chimeric Antigen Receptor T Cell Outcomes in Non-Hodgkin Lymphoma

Despite the impressive results of chimeric antigen receptor (CAR) T cell treatment for lymphomas, adverse events such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and infections are major issues that can lead to intensive care unit (ICU) admission and death. Current guidelines recommend tocilizumab for treating patients with CRS grade (G) ≥2; however, the optimal timing of intervention has yet to be determined. Our institution adopted the preemptive use of tocilizumab in cases of persistent G1 CRS, defined as fever (≥38 °C) for >24 hours. This preemptive tocilizumab treatment aimed to reduce evolution to severe (G≥3) CRS, ICU admission, or death. We report on 48 prospectively collected consecutive patients with non-Hodgkin lymphoma treated with autologous CD19-targeted CAR T cells. In total, 39 patients (81%) developed CRS. CRS started as G1 in 28 patients, as G2 in patients, and as G3 in 1 patient. Tocilizumab was administered in 34 patients, including 23 patients who received "preemptive" tocilizumab and 11 patients who received tocilizumab for G2 or G3 CRS from the onset of symptoms. CRS resolved without worsening severity in 19 patients out of 23 (83%) who received preemptive tocilizumab; 4 patients (17%) progressed from G1 to G2 for the development of hypotension and quickly responded to the introduction of steroids. No patients treated with a preemptive approach developed G3 or G4 CRS. Ten out of 48 patients (21%) were diagnosed with ICANS, including 5 patients with G3 or G4. Six infectious events occurred. The overall ICU admission rate was 19%. ICANS management was the most relevant reason for ICU admission (7 patients), and no patient required ICU to manage CRS. No deaths from CAR-T toxicity were observed. Our data indicate that preemptive tocilizumab use is feasible and useful in reducing severe CRS and CRS-related ICU admission, with no impact on neurotoxicity or infection rate. Therefore, early use of tocilizumab can be considered, especially for patients at high risk of CRS.

Novel Immunotherapeutic Approaches to Treating HPV-Related Head and Neck Cancer

Head and neck cancer (HNC) is the seventh most common malignancy, with oropharyngeal squamous cell carcinoma (OPSCC) accounting for a majority of cases in the western world. While HNC accounts for only 5% of all cancers in the United States, the incidence of a subset of OPSCC caused by human papillomavirus (HPV) is increasing rapidly. The treatment for OPSCC is multifaceted, with a recently emerging focus on immunotherapeutic approaches. With the increased incidence of HPV-related OPSCC and the approval of immunotherapy in the management of recurrent and metastatic HNC, there has been rising interest in exploring the role of immunotherapy in the treatment of HPV-related OPSCC specifically. The immune microenvironment in HPV-related disease is distinct from that in HPV-negative OPSCC, which has prompted further research into various immunotherapeutics. This review focuses on HPV-related OPSCC, its immune characteristics, and current challenges and future opportunities for immunotherapeutic applications in this virus-driven cancer.

How I use risk factors for success or failure of CD19 CAR T cells to guide management of children and AYA with B-cell ALL

By overcoming chemotherapeutic resistance, chimeric antigen receptor (CAR) T cells facilitate deep, complete remissions and offer the potential for long-term cure in a substantial fraction of patients with chemotherapy refractory disease. However, that success is tempered with 10% to 30% of patients not achieving remission and over half of patients treated eventually experiencing relapse. With over a decade of experience using CAR T cells in children, adolescents, and young adults (AYA) to treat relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) and 5 years since the first US Food and Drug Administration approval, data defining the nuances of patient-specific risk factors are emerging. With the commercial availability of 2 unique CD19 CAR T-cell constructs for B-ALL, in this article, we review the current literature, outline our approach to patients, and discuss how individual factors inform strategies to optimize outcomes in children and AYA receiving CD19 CAR T cells. We include data from both prospective and recent large retrospective studies that offer insight into understanding when the risks of CAR T-cell therapy failure are high and offer perspectives suggesting when consolidative hematopoietic cell transplantation or experimental CAR T-cell and/or alternative immunotherapy should be considered. We also propose areas where prospective trials addressing the optimal use of CAR T-cell therapy are needed.

Associations of granulocyte colony-stimulating factor with toxicities and efficacy of chimeric antigen receptor T-cell therapy in relapsed or refractory multiple myeloma

BACKGROUND AIMS

Few studies have reported the associations of granulocyte colony-stimulating factor (G-CSF) with cytokine release syndrome (CRS), neurotoxic events (NEs) and efficacy after chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory (R/R) multiple myeloma (MM). We present a retrospective study performed on 113 patients with R/R MM who received single anti-BCMA CAR T-cell, combined with anti-CD19 CAR T-cell or anti-CD138 CAR T-cell therapy.

METHODS

Eight patients were given G-CSF after successful management of CRS, and no CRS re-occurred thereafter. Of the remaining 105 patients that were finally analyzed, 72 (68.6%) received G-CSF (G-CSF group), and 33 (31.4%) did not (non G-CSF group). We mainly analyzed the incidence and severity of CRS or NEs in two groups of patients, as well as the associations of G-CSF timing, cumulative dose and cumulative time with CRS, NEs and efficacy of CAR T-cell therapy.

RESULTS

Both groups of patients had similar duration of grade 3-4 neutropenia, and the incidence and severity of CRS or NEs.There were also no differences in the incidence and severity of CRS or NEs between patients with the timing of G-CSF administration ≤3 days and those >3 days after CAR T-cell infusion. The incidence of CRS was greater in patients receiving cumulative doses of G-CSF >1500 μg or cumulative time of G-CSF administration >5 days. Among patients with CRS, there was no difference in the severity of CRS between patients who used G-CSF and those who did not. The duration of CRS in anti-BCMA and anti-CD19 CAR T-cell-treated patients was prolonged after G-CSF administration. There were no significant differences in the overall response rate at 1 and 3 months between the G-CSF group and the non-G-CSF group.

CONCLUSIONS

Our results showed that low-dose or short-time use of G-CSF was not associated with the incidence or severity of CRS or NEs, and G-CSF administration did not influence the antitumor activity of CAR T-cell therapy.

CAR T-cells and macrophages in large B-cell lymphoma: impact on toxicity and efficacy

Chimeric antigen receptor (CAR) T-cell therapy targeting CD19 is the current standard of care for the treatment of relapsed refractory large B cell lymphoma, demonstrating impressive response rates in the second- and third-line setting. Despite these advances, this treatment strategy can result in significant toxicities, such as cytokine release syndrome or immune effector cell associated neurotoxicity syndrome. While the exact mechanisms of these immune-mediated toxicities are not clearly understood, emerging pre-clinical and clinical studies have revealed the pivotal role of myeloid cells, particularly macrophages, as key contributors to the efficacy of treatments and as crucial mediators of toxicity. In this review, we discuss the current understanding of how macrophages mediate these effects, highlighting specific mechanisms of macrophage biology relevant to CAR T-cell therapy activity and side effects. These findings are resulting in novel treatment strategies that target macrophages, and able to mitigate toxicity while preserving CAR T-cell therapy efficacy.

T cell-dependent bispecific antibodies alter organ-specific endothelial cell-T cell interaction

Preclinical and clinical studies demonstrate that T cell-dependent bispecific antibodies (TDBs) induce systemic changes in addition to tumor killing, leading to adverse events. Here, we report an in-depth characterization of acute responses to TDBs in tumor-bearing mice. Contrary to modest changes in tumors, rapid and substantial lymphocyte accumulation and endothelial cell (EC) activation occur around large blood vessels in normal organs including the liver. We hypothesize that organ-specific ECs may account for the differential responses in normal tissues and tumors, and we identify a list of genes selectively upregulated by TDB in large liver vessels. Using one of the genes as an example, we demonstrate that CD9 facilitates ICAM-1 to support T cell-EC interaction in response to soluble factors released from a TDB-mediated cytotoxic reaction. Our results suggest that multiple factors may cooperatively promote T cell infiltration into normal organs as a secondary response to TDB-mediated tumor killing. These data shed light on how different vascular beds respond to cancer immunotherapy and may help improve their safety and efficacy.

MIP3α as an early prognostic predictor for patients with B-cell malignancies receiving CD19/CD22-redirected CAR-T cell cocktail therapy

PURPOSE

Identifying the temporal pattern of recurrence and prognostic biomarkers would further help improve the efficacy of chimeric antigen receptor (CAR) -T therapy.

METHODS

We examined the prognoses of 119 patients after sequential infusion of anti-CD19 and anti-CD22, a cocktail of 2 single-target CAR (CAR19/22) T cells in an open-label, single-center clinical trial (ChiCTR-OPN-16008526). And we, from a 70-biomarker panel, identified candidate cytokines that might predict the treatment failure, including primary non-response (NR) and early relapse (ER).

RESULTS

In our study, 3 (11.5%) patients with B-cell acute lymphoblastic leukemia (B-ALL) and 9 (12.2%) cases of B-cell non-Hodgkin lymphoma (NHL) failed to respond to sequential CAR19/22 T-cell infusion (NR). A total of 11 (42.3%) B-ALL patients and 30 (52.7%) B-NHL patients had relapses during follow-up. Most recurrence events (67.5%) occurred within six months of sequential CAR T-cell infusion (ER). We found that macrophage inflammatory protein (MIP)-3α was a highly sensitive and specific prognostic predictor for patients with NR/ER and those attaining over-6-month remission. Patients who had higher MIP3α levels after sequential CAR19/22 T-cell infusion had significantly favorable progression-free survival (PFS) than their counterparts with relatively lower MIP3α expression. Our experiments demonstrated that MIP3α could enhance the therapeutic effect of CAR-T cells by promoting T-cell infiltration into and enriching memory-phenotype T cells in the tumor environment.

CONCLUSION

This study showed that relapse occurred mainly within six months after sequential CAR19/22 T-cell infusion. Moreover, MIP3α could act as a valuable post-infusion biomarker for identifying patients with NR/ER.

2022 Chinese expert consensus and guidelines on clinical management of toxicity in anti-CD19 chimeric antigen receptor T-cell therapy for B-cell non-Hodgkin lymphoma

Adoptive cellular immunotherapy with chimeric antigen receptor (CAR) T cells has emerged as a novel modality for treating relapsed and/or refractory B-cell non-Hodgkin lymphoma (B-NHL). With increasing approval of CAR T-cell products and advances in CAR T cell therapy, CAR T cells are expected to be used in a growing number of cases. However, CAR T-cell-associated toxicities can be severe or even fatal, thus compromising the survival benefit from this therapy. Standardizing and studying the clinical management of these toxicities are imperative. In contrast to other hematological malignancies, such as acute lymphoblastic leukemia and multiple myeloma, anti-CD19 CAR T-cell-associated toxicities in B-NHL have several distinctive features, most notably local cytokine-release syndrome (CRS). However, previously published guidelines have provided few specific recommendations for the grading and management of toxicities associated with CAR T-cell treatment for B-NHL. Consequently, we developed this consensus for the prevention, recognition, and management of these toxicities, on the basis of published literature regarding the management of anti-CD19 CAR T-cell-associated toxicities and the clinical experience of multiple Chinese institutions. This consensus refines a grading system and classification of CRS in B-NHL and corresponding measures for CRS management, and delineates comprehensive principles and exploratory recommendations for managing anti-CD19 CAR T-cell-associated toxicities in addition to CRS.

The convergence of pharmacometrics and quantitative systems pharmacology in pharmaceutical research and development

Quantitative systems pharmacology (QSP) models are an important facet of pharmaceutical and clinical research as they combine mechanistic models of physiology in health and disease with pharmacokinetics/pharmacodynamics to predict systems-level effects. The quantitative clinical pharmacology toolbox has traditionally included both mechanistic modeling and population approaches, collectively called pharmacometrics, but the current landscape requires the optimization and use of multiple models together. Here, we explore several case studies in drug development that exemplify three approaches for using QSP and pharmacometrics models together - parallel synchronization, cross-informative use, and sequential integration. While these approaches are increasingly applied in drug development, achieving a true convergence of QSP and pharmacometrics that fully exploits their synergy will require new tools and methods that enable greater technical integration, in addition to nurturing scientists with diverse modeling expertise that enable cross-discipline strategy. Extensions of existing methods used in each approach as well as additional resources including machine learning models, data-at-scale, end-to-end computation platforms, and real-time analytics will enable this convergence.

Non-viral precision T cell receptor replacement for personalized cell therapy

T cell receptors (TCRs) enable T cells to specifically recognize mutations in cancer cells1-3. Here we developed a clinical-grade approach based on CRISPR-Cas9 non-viral precision genome-editing to simultaneously knockout the two endogenous TCR genes TRAC (which encodes TCRα) and TRBC (which encodes TCRβ). We also inserted into the TRAC locus two chains of a neoantigen-specific TCR (neoTCR) isolated from circulating T cells of patients. The neoTCRs were isolated using a personalized library of soluble predicted neoantigen-HLA capture reagents. Sixteen patients with different refractory solid cancers received up to three distinct neoTCR transgenic cell products. Each product expressed a patient-specific neoTCR and was administered in a cell-dose-escalation, first-in-human phase I clinical trial ( NCT03970382 ). One patient had grade 1 cytokine release syndrome and one patient had grade 3 encephalitis. All participants had the expected side effects from the lymphodepleting chemotherapy. Five patients had stable disease and the other eleven had disease progression as the best response on the therapy. neoTCR transgenic T cells were detected in tumour biopsy samples after infusion at frequencies higher than the native TCRs before infusion. This study demonstrates the feasibility of isolating and cloning multiple TCRs that recognize mutational neoantigens. Moreover, simultaneous knockout of the endogenous TCR and knock-in of neoTCRs using single-step, non-viral precision genome-editing are achieved. The manufacture of neoTCR engineered T cells at clinical grade, the safety of infusing up to three gene-edited neoTCR T cell products and the ability of the transgenic T cells to traffic to the tumours of patients are also demonstrated.

Assessment of Chimeric Antigen Receptor T Cell-Associated Toxicities Using an Acute Lymphoblastic Leukemia Patient-derived Xenograft Mouse Model

Chimeric antigen receptor T (CART) cell therapy has emerged as a powerful tool for the treatment of multiple types of CD19+ malignancies, which has led to the recent FDA approval of several CD19-targeted CART (CART19) cell therapies. However, CART cell therapy is associated with a unique set of toxicities that carry their own morbidity and mortality. This includes cytokine release syndrome (CRS) and neuroinflammation (NI). The use of preclinical mouse models has been crucial in the research and development of CART technology for assessing both CART efficacy and CART toxicity. The available preclinical models to test this adoptive cellular immunotherapy include syngeneic, xenograft, transgenic, and humanized mouse models. There is no single model that seamlessly mirrors the human immune system, and each model has strengths and weaknesses. This methods paper aims to describe a patient-derived xenograft model using leukemic blasts from patients with acute lymphoblastic leukemia as a strategy to assess CART19-associated toxicities, CRS, and NI. This model has been shown to recapitulate CART19-associated toxicities as well as therapeutic efficacy as seen in the clinic.

Interleukin-6 and cytokine release syndrome: A new understanding in drug hypersensitivity reactions

Immediate drug hypersensitivity reactions (DHRs) are historically thought to be because of immunoglobulin E (IgE) cross-linking, causing mast cell degranulation and release of mediators like tryptase and histamine. With the increasing use of monoclonal antibodies, it has become apparent that some patients present atypical features during immediate DHRs, including occurrence in initial exposure, a lack of urticaria and angioedema, and the presence of fever, chills, rigors and musculoskeletal pain as the predominant symptoms. This observation led to the recognition of a novel phenotype of immediate DHRs called cytokine release syndrome (CRS). Other types of immediate DHRs include infusion-related reactions (which present similarly to CRS), and mixed reactions (which share overlapping features of both type 1 reactions and CRS). Desensitization to culprit drugs can be a lifesaving option in patients who develop immediate DHRs to first-line treatment. Whereas robust data are supporting the safety and efficacy of drug desensitization, breakthrough reactions can still occur and CRS seems to be a more common cause than type 1 reactions. Tryptase has been the only available biomarker for immediate DHRs and is associated with type 1 reactions. Emerging evidence consistently found the association between increased serum interleukin 6 level and DHR-related CRS, suggesting that interleukin 6 can be a novel biomarker, in addition to tryptase, to distinguish various types of DHRs. In the era of precision medicine, phenotyping and endotyping hypersensitivity reactions to chemotherapy and monoclonal antibodies using validated biomarkers should be part of routine drug allergy care.

CAR-T Cell Therapy and the Gut Microbiota

Chimeric antigen receptor (CAR) - T cell cancer therapy has yielded promising results in treating hematologic malignancies in clinical studies, and a growing number of CAR-T regimens are approved for clinical usage. While the therapy is considered of great potential in expanding the cancer immunotherapy arsenal, more than half of patients receiving CAR-T infusions do not respond, while others develop significant adverse effects, collectively indicating a need for optimization of CAR-T treatment to the individual. The microbiota is increasingly suggested as a major modulator of immunotherapy responsiveness. Studying causal microbiota roles possibly contributing to CAR-T therapy efficacy, adverse effects reduction, and prediction of patient responsiveness constitutes an exciting area of active research. Herein, we discuss the latest developments implicating human microbiota involvement in CAR-T therapy, while highlighting challenges and promises in harnessing the microbiota as a predictor and modifier of CAR-T treatment towards optimized efficacy and minimization of treatment-related adverse effects.

Dose fractionation of CAR-T cells. A systematic review of clinical outcomes

CAR-T cells are widely recognized for their potential to successfully treat hematologic cancers and provide durable response. However, severe adverse events such as cytokine release syndrome (CRS) and neurotoxicity are concerning. Our goal is to assess CAR-T cell clinical trial publications to address the question of whether administration of CAR-T cells as dose fractions reduces toxicity without adversely affecting efficacy. Systematic literature review of studies published between January 2010 and May 2022 was performed on PubMed and Embase to search clinical studies that evaluated CAR-T cells for hematologic cancers. Studies published in English were considered. Studies in children (age < 18), solid tumors, bispecific CAR-T cells, and CAR-T cell cocktails were excluded. Data was extracted from the studies that met inclusion and exclusion criteria. Review identified a total of 18 studies that used dose fractionation. Six studies used 2-day dosing schemes and 12 studies used 3-day schemes to administer CAR-T cells. Three studies had both single dose and fractionated dose cohorts. Lower incidence of Grade ≥ 3 CRS and neurotoxicity was seen in fractionated dose cohorts in 2 studies, whereas 1 study reported no difference between single and fractionated dose cohorts. Dose fractionation was mainly recommended for high tumor burden patients. Efficacy of CAR-T cells in fractionated dose was comparable to single dose regimen within the same or historical trial of the same agent in all the studies. The findings suggest that administering dose fractions of CAR-T cells over 2-3 days instead of single dose infusion may mitigate the toxicity of CAR-T cell therapy including CRS and neurotoxicity, especially in patients with high tumor burden. However, controlled studies are likely needed to confirm the benefits of dose fractionation.

Genome Editing for Engineering the Next Generation of Advanced Immune Cell Therapies

Our current genetic engineering capacity through synthetic biology and genome editing is the foundation of a revolution in biomedical science: the use of genetically programmed cells as therapeutics. The prime example of this paradigm is the adoptive transfer of genetically engineered T cells to express tumor-specific receptors, such as chimeric antigen receptors (CARs) or engineered T-cell receptors (TCR). This approach has led to unprecedented complete remission rates in patients with otherwise incurable hematological malignancies. However, this approach is still largely ineffective against solid tumors, which comprise the vast majority of neoplasms. Also, limitations associated with the autologous nature of this therapy and shared markers between cancer cells and T cells further restrict the access to these therapies. Here, we described how cutting-edge genome editing approaches have been applied to unlock the full potential of these revolutionary therapies, thereby increasing therapeutic efficacy and patient accessibility.

Safety evaluation of axicabtagene ciloleucel for relapsed or refractory large B-cell lymphoma

INTRODUCTION

CD19-directed chimeric antigen receptor (CAR) T-cell therapy is a highly effective therapy for patients with relapsed/refractory large B-cell lymphoma (LBCL) and three CD19 CAR T-cell products (axicabtagene ciloleucel, tisagenlecleucel and lisocabtagene maraleucel) are currently approved for this indication. Despite the clinical benefit of CD19 directed CAR T-cell therapy, this treatment is associated with significant morbidity from treatment-emergent toxicities.

AREAS COVERED

This Review discusses the safety considerations of axicabtagene ciloleucel in patients with LBCL. This includes discussion of the frequently observed immune-mediated toxicities of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. Additionally, we review CAR T-cell therapy related cytopenias, infection, organ dysfunction and the more recently described hemophagocytic lymphohistiocytosis.

EXPERT OPINION

A thorough understanding of the toxicities associated with CD19-directed CAR T-cell therapy will facilitate the optimal selection of patients for this therapy. Furthermore, knowledge of preventative measures of CAR T-cell related complications, and early recognition and appropriate intervention will lead to the safe administration of these therapies, and ultimately improved outcomes for our patients.

Antitumor effect of CAR-T cells targeting transmembrane tumor necrosis factor alpha combined with PD-1 mAb on breast cancers

BACKGROUND

Our previous study showed that transmembrane tumor necrosis factor alpha (tmTNF-α) is overexpressed in primary breast cancers including triple-negative breast cancers (TNBCs). Chimeric antigen receptor engineered-T (CAR-T) cells have been successfully used mainly in B-cell malignancies.

METHODS

We generated CAR-T cells targeting tmTNF-α but not secreted tumor necrosis factor alpha and assessed the antitumor effect of the CAR-T cells on tmTNF-α-expressing breast cancer cells in vitro and in vivo.

RESULTS

Our tmTNF-α CAR-T cells showed potent cytotoxicity against tmTNF-α-expressing breast cancer cells but not tmTNF-α-negative tumor cells with increased secretion of interferon gamma (IFN-γ) and interleukin (IL)-2 in vitro. In tmTNF-α-overexpressing TNBC-bearing mice, the tmTNF-α CAR-T therapy induced evident tumor regression, prolonged survival and increased serum concentrations of IFN-γ and IL-2. However, we found thattmTNF-α induced programmed death-ligand 1 (PD-L1) expression through the p38 pathway via TNF receptor (TNFR) and through the NF-κB and AKT pathways via outside-to-inside (reverse) signaling, which might limit the efficacy of the CAR-T cell therapy. Blockage of the PD-L1/programmed death-1 (PD-1) pathway by PD-1 monoclonal antibody significantly enhanced the antitumor effect of the tmTNF-α CAR-T cell therapy in vitro and in vivo, and the combination was effective for antiprimary tumors and had a tendency to increase the antimetastasis effect of the CAR-T cell therapy.

CONCLUSION

Our findings suggest a potent antitumor efficacy of the tmTNF-α CAR-T cells that can be enhanced by anti-PD-L1/PD-1 because high PD-L1 expression in TNBC was induced by the tmTNF-α signaling, indicating a promising individual therapy for tmTNF-α-positive breast cancers including TNBC.

A combination of pre-infusion serum ferritin, CRP and IL-6 predicts outcome in relapsed/refractory multiple myeloma patients treated with CAR-T cells

Background

Chimeric antigen receptor - T (CAR-T) cell therapy has shown remarkable efficacy in patients with relapsed/refractory multiple myeloma (R/R MM). However, a subset of patients still experienced progression or relapse, and the predictors of prognosis are little known. We analyzed the inflammatory markers before CAR-T cell infusion, to clarify their correlation with survival and toxicity.

Methods

This study involved 109 R/R MM patients who received CAR-T therapy between June 2017 and July 2021. Inflammatory markers, including ferritin, c-reactive protein (CRP), and interleukin-6 (IL-6) before CAR-T cell infusion were detected and then categorized by quartiles. Adverse events and clinical outcomes were compared between patients with upper quartile of inflammatory markers and patients with lower three quartiles of inflammatory markers. An inflammatory prognostic index (InPI) based on these three inflammatory markers was developed in this study. Patients were divided into 3 groups according to the InPI score, progression-free survival (PFS) and overall survival (OS) were compared among the groups. In addition, we explored the correlation between cytokine release syndrome (CRS) and pre-infusion inflammatory markers.

Results

We found that the pre-infusion high ferritin (hazard ratio [HR], 3.382; 95% confidence interval [CI], 1.667 to 6.863; P = .0007), high CRP (HR, 2.043; 95% CI, 1.019 to 4.097; P = .044), and high IL-6 (HR, 3.298; 95% CI, 1.598 to 6.808; P = .0013) were significantly associated with inferior OS. The formula of the InPI score was based on the HR value of these 3 variables. Three risk groups were formed: (good, 0 to 0.5 point; intermediate, 1 to 1.5 points; poor, 2 to 2.5 points). Median OS for patients with good, intermediate, and poor InPI was not reached, 24 months, and 4 months, respectively, and median PFS was 19.1 months, 12.3 months, and 2.9 months, respectively. In the cox proportional hazards model, poor InPI remained an independent prognostic factor for PFS and OS. Pre-infusion ferritin was negatively associated with CAR T-cell expansion normalized to baseline tumor burden. Spearman correlation analysis showed that pre-infusion ferritin and IL-6 levels positively correlated with the grade of CRS (P = .0369 and P = .0117, respectively). The incidence of severe CRS was higher in patients with high IL-6 compared with patients with low IL-6 (26% vs. 9%, P = .0405). Pre-infusion ferritin, CRP and IL-6 were positively correlated with each peak values within the first month after infusion.

Conclusions

Our results suggest that patients with elevated inflammation markers before CAR-T cell infusion are more likely to have poor prognosis.

The impact of early versus late tocilizumab administration in patients with cytokine release syndrome secondary to immune effector cell therapy

INTRODUCTION

Cytokine release syndrome is a life-threatening hyper-inflammatory state induced by immune effector cell therapy. Anti-interleukin 6-(IL-6) therapy, such as tocilizumab, is the standard treatment for cytokine release syndrome since it reverses symptoms without compromising immune effector cell therapy efficacy. Glucocorticoids are reserved for refractory or severe cytokine release syndrome due to concern for attenuating antitumor activity. Optimizing the timing of tocilizumab could avoid glucocorticoid use and improve outcomes. This study assesses tocilizumab timing on patient outcomes and healthcare resource utilization.

METHODS

This is a retrospective single-institution analysis of 28 patients who received tocilizumab for cytokine release syndrome secondary to immune effector cell therapy. Patients were categorized into two groups: Early Tocilizumab (within 24 h) or Late Tocilizumab groups (more than 24 h) from fever onset. The composite primary endpoint was glucocorticoid use, intensive care unit admission, or inpatient mortality. Secondary outcomes include comparing the various presentations of cytokine release syndrome, need for vasopressors, length of stay, rates of neurotoxicity, and C-reactive protein and ferritin trends.

RESULTS

The Early Tocilizumab group presented with more rapid fever onset (35 vs.113 h, P = 0.017) and higher maximum cytokine release syndrome grade (Median, Grade 2 vs. Grade 1, P = 0.025). Additionally, the Early Tocilizumab group required more doses of tocilizumab (Median, 2 vs. 1, P = 0.037). Despite the difference in cytokine release syndrome presentation, the primary composite endpoint was not statistically different between groups.

CONCLUSION

Earlier onset of fever appears to be associated with more severe, progressive cytokine release syndrome requiring multiple doses of anti-interleukin-6 therapy. Prompt and aggressive tocilizumab treatment could be protective against the negative consequences of cytokine release syndrome.

Nano-Biohybrid DNA Engager That Reprograms the T-Cell Receptor

Although engineered T cells with transgenic chimeric antigen receptors (CARs) have made a breakthrough in cancer therapeutics, this approach still faces many challenges in the specificity, efficacy, and self-safety of genetic engineering. Here, we developed a nano-biohybrid DNA engager-reprogrammed T-cell receptor (EN-TCR) system to improve the specificity and efficacy, mitigate the excessive activation, and shield against risks from transgenesis, thus achieving a diversiform and precise control of the T-cell response. Utilizing modular assembly, the EN-TCR system can graft different specificities on T cells via antibody assembly. Besides, the designability of DNA hybridization enables precise target recognition by the library of multiantigen cell recognition circuits and allows gradual tuning of the T-cell activation level by the signaling switch and independent control over different types of T cells. Furthermore, we demonstrated the effectiveness of the system in tumor models. Together, this study provides a nongenetic T-cell engineering strategy to overcome major hindrances in T-cell therapy and may be extended to a general and convenient cell engineering strategy.

Serious adverse events and coping strategies of CAR-T cells in the treatment of malignant tumors

Chimeric antigen receptor T (CAR-T) cells technology has been successfully used in the treatment of B cell-derived hematological tumors and multiple myeloma. CAR-T cells are also being studied in a variety of solid tumors. Current clinical reports on CAR-T cells in the treatment of malignant tumors are abundant. The tumor-killing activity of CAR-T cells and the unique adverse effects of CAR-T cells have been confirmed by many studies. There is evidence that serious adverse events can be life-threatening. CAR-T cells therapy is increasingly used in clinical settings, so it is important to pay attention to its serious adverse events. In this review, we summarized the serious adverse events of CAR-T cells in the treatment of malignant tumors by reading literature and searching relevant clinical studies, and discussed the management and treatment of serious adverse events in an effort to provide theoretical support for clinicians who deal with such patients.

Evaluation of the Tocilizumab therapy in human cancers: Latest evidence and clinical potential

Tocilizumab (Actemra®), as the first human interleukin-6 receptor (IL-6R) antagonist, has been used in treating moderate to severe active rheumatoid arthritis (RA) patients who were undertreatment with one or more disease-modifying anti-rheumatic drugs (DMARDs) and did not improve significantly. Tocilizumab also has been administrated and confirmed in several inflammatory-based diseases. Recently, tocilizumab has been prescribed to treat patients with advanced coronavirus disease (COVID-19) and is used as one of the effective drugs in reducing the increased inflammation in these patients. On the other hand, cancer treatment has been considered by researchers one of the most important challenges to human health. Regarding inflammatory-associated malignancies, it has been shown that inflammatory mediators such as interleukin-1 beta (IL-1β), IL-6, and tumour necrosis factor-alpha (TNF-α) may play a role in tumorigenesis, thus targeting these cytokines as evidence suggested can be useful in the treatment of these types of cancers. This review summarized the role of the IL-6/IL-6R axis in inflammation-based cancers and discussed the effectiveness and challenges of treating cancer with tocilizumab.

Advances in CAR T cell immunotherapy for paediatric brain tumours

Brain tumours are the most common solid tumour in children and the leading cause of cancer related death in children. Current treatments include surgery, chemotherapy and radiotherapy. The need for aggressive treatment means many survivors are left with permanent severe disability, physical, intellectual and social. Recent progress in immunotherapy, including genetically engineered T cells with chimeric antigen receptors (CARs) for treating cancer, may provide new avenues to improved outcomes for patients with paediatric brain cancer. In this review we discuss advances in CAR T cell immunotherapy, the major CAR T cell targets that are in clinical and pre-clinical development with a focus on paediatric brain tumours, the paediatric brain tumour microenvironment and strategies used to improve CAR T cell therapy for paediatric tumours.

A phase I dose-escalation study of neoantigen-activated haploidentical T cell therapy for the treatment of relapsed or refractory peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a type of highly heterogeneous non-Hodgkin lymphoma with a poor prognosis and lack of effective targeted therapies. Adoptive T-cell therapy has been successfully used in the treatment of B-cell malignancies. We first used adoptive transfer of haploidentical T cells activated by patient-specific neoantigens in vitro to treat an elderly patient with refractory angioimmunoblastic T-cell lymphoma (AITL) in 2017, and the patient achieved long-term complete remission (CR). Here we report on early results from this first-in-human phase 1 clinical trial that aims to assess the safety and tolerability of neoantigen-activated haploidentical T cell therapy (NAHTC) for relapsed/refractory PTCL.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/index.aspx, identifier [ChiCTR1800017440].

EBAG9 silencing exerts an immune checkpoint function without aggravating adverse effects

Chimeric antigen receptor (CAR) T cells have revolutionized treatment of B cell malignancies. However, enhancing the efficacy of engineered T cells without compromising their safety is warranted. The estrogen receptor-binding fragment-associated antigen 9 (EBAG9) inhibits release of cytolytic enzymes from cytotoxic T lymphocytes. Here, we examined the potency of EBAG9 silencing for the improvement of adoptive T cell therapy. MicroRNA (miRNA)-mediated EBAG9 downregulation in transplanted cytolytic CD8+ T cells (CTLs) from immunized mice improved their cytolytic competence in a tumor model. In tolerant female recipient mice that received organ transplants, a minor histocompatibility antigen was turned into a rejection antigen by Ebag9 deletion, indicating an immune checkpoint function for EBAG9. Considerably fewer EBAG9-silenced human CAR T cells were needed for tumor growth control in a xenotransplantation model. Transcriptome profiling did not reveal additional risks regarding genotoxicity or aberrant differentiation. A single-step retrovirus transduction process links CAR or TCR expression with miRNA-mediated EBAG9 downregulation. Despite higher cytolytic efficacy, release of cytokines associated with cytokine release syndrome remains unaffected. Collectively, EBAG9 silencing enhances effector capacity of TCR- and CAR-engineered T cells, results in improved tumor eradication, facilitates efficient manufacturing, and decreases the therapeutic dose.

Cytokine Release Syndrome after Chimeric Antigen Receptor Transduced T-Cell Therapy in Cancers: A Systematic Review

Patients with refractory or relapsed malignant disorders are in desperate condition, with few therapeutic options left, if any. Chimeric antigen receptor (CAR) transduced T-cell transplantation is a novel approach that has shown promising results as well as serious adverse events. This study aimed to systematically review the current data on the cytokine release syndrome (CRS) as a major side effect of CAR therapy. A systematic literature review was conducted to find reports of CAR T-cell therapy in the context of cancer patients and to extract reports of severe CRS. The factors that could significantly affect the incidence of CRS were investigated. Mortality rates were also compared regarding the occurrence of CRS. The incidence of severe CRS was 9.4% (95% confidence interval: 8.3-10.5) in the reviewed studies. Younger and older patients (vs. adults), higher doses of CAR T-cell infusions, lymphodepletion (LD) before CAR T-cell infusions, specific LD regimens, the source of allogeneic cells for the construction of CAR, chronic lymphocytic leukemia as the tumor type (vs. lymphoma), and CD28 as costimulatory domain in the structure of CAR were significantly associated with CRS events. Patients experiencing severe CRS had a significantly higher mortality rate within 2 and 3 months after transplantation. In conclusion, this study found many factors that could predict severe CRS and future clinical trials could reveal the relevance of appropriate interventions to the incidence and outcomes of CRS in cancer patients undergoing CAR T-cell transduced infusions.

Clinical Pharmacology Perspectives for Adoptive Cell Therapies in Oncology

Adoptive cell therapies (ACTs) have shown transformative efficacy in oncology with five US Food and Drug Administration (FDA) approvals for chimeric antigen receptor (CAR) T-cell therapies in hematological malignancies, and promising activity for T cell receptor T-cell therapies in both liquid and solid tumors. Clinical pharmacology can play a pivotal role in optimizing ACTs, aided by modeling and simulation toolboxes and deep understanding of the underlying biological and immunological processes. Close collaboration and multilevel data integration across functions, including chemistry, manufacturing, and control, biomarkers, bioanalytical, and clinical science and safety teams will be critical to ACT development. As ACT is comprised of alive, polyfunctional, and heterogeneous immune cells, its overall physicochemical and pharmacological property is vastly different from other platforms/modalities, such as small molecule and protein therapeutics. In this review, we first describe the unique kinetics of T cells and the appropriate bioanalytical strategies to characterize cellular kinetics. We then assess the distinct aspects of clinical pharmacology for ACTs in comparison to traditional small molecule and protein therapeutics. Additionally, we provide a review for the five FDA-approved CAR T-cell therapies and summarize their properties, cellular kinetic characteristics, dose-exposure-response relationship, and potential baseline factors/variables in product, patient, and regimen that may affect the safety and efficacy. Finally, we probe into existing empirical and mechanistic quantitative techniques to understand how various modeling and simulation approaches can support clinical pharmacology strategy and propose key considerations to be incorporated and explored in future models.

Adverse Cardiac Effects of CAR T-Cell Therapy: Characteristics, Surveillance, Management, and Future Research Directions

This review summarizes the current literature on the adverse cardiac effects of CAR T-cell therapy. Case reports and series suggest that major adverse cardiovascular events are not uncommon after CAR T-cell therapy; however, limited data exist regarding incidence, pathophysiology, and prevention strategies related to CAR T-associated cardiovascular events. As cellular therapy advances and the indications for its use continue to expand, it is essential to better understand its associated cardiovascular toxicities. Biomarkers, cardiac imaging, longitudinal data from larger populations, and translational research are all essential areas for further research. Interestingly, CAR T-cell therapy can also be used to reverse cardiac fibrosis in murine models. Altogether this underscores the need to broadly understand how T-cells, endogenous and engineered, may impact cardiovascular diseases.

Antitumor immunity induced by antibody-based natural killer cell engager therapeutics armed with not-alpha IL-2 variant

Harnessing innate immunity is emerging as a promising therapeutic approach in cancer. We report here the design of tetraspecific molecules engaging natural killer (NK) cell-activating receptors NKp46 and CD16a, the β-chain of the interleukin-2 receptor (IL-2R), and a tumor-associated antigen (TAA). In vitro, these tetraspecific antibody-based natural killer cell engager therapeutics (ANKETs) induce a preferential activation and proliferation of NK cells, and the binding to the targeted TAA triggers NK cell cytotoxicity and cytokine and chemokine production. In vivo, tetraspecific ANKETs induce NK cell proliferation and their accumulation at the tumor bed, as well as the control of local and disseminated tumors. Treatment of non-human primates with CD20-directed tetraspecific ANKET leads to CD20⁺ circulating B cell depletion, with minimal systemic cytokine release and no sign of toxicity. Tetraspecific ANKETs, thus, constitute a technological platform for harnessing NK cells as next-generation cancer immunotherapies.

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Tetraspecific ANKETs constitute a technological platform to harness NK cells in cancer

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Tetraspecific ANKETs target NKp46, CD16a, IL-2Rβ, and a tumor antigen

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Tetraspecific ANKETs stimulate NK cell proliferation, activation, and antitumor functions

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In vivo, tetraspecific ANKETs promote NK cell tumor accumulation and antitumor activity

The pathogenesis, diagnosis, prevention, and treatment of CAR-T cell therapy-related adverse reactions

Chimeric antigen receptor (CAR)-T cell therapy is effective in the treatment of refractory/relapsed (r/r) hematological malignancies (r/r B-cell lymphoblastic leukemia, B-cell lymphoma, and multiple myeloma). In addition, it is being explored as a treatment option for solid tumors. As of 31 March 2022, seven CAR-T therapies for hematological malignancies have been approved worldwide. Although CAR-T therapy is an effective treatment for many malignancies, it also causes adverse effects. The incidence of cytokine release syndrome (CRS), the most common adverse reaction after infusion of CAR-T cells, is as high as 93%.CRS, is the leading risk factor of immune effector cell-associated neurotoxicity syndrome (ICANS), as well as cardiovascular, hematological, hepatorenal, skin, pulmonary, and gastrointestinal toxicity. Severe adverse reactions complicated by CRS severely impede the widespread application of CAR-T therapy. The CAR-T product was initially approved in 2017; however, only limited studies have investigated the adverse reactions owing to CAR-T therapy compared to that of clinically approved drugs. Thus, we aimed to elucidate the mechanisms, risk factors, diagnostic criteria, and treatment of toxicities concurrent with CRS, thereby providing a valuable reference for the safe, effective, and widespread application of CAR-T therapy.

A Computational Model of Cytokine Release Syndrome during CAR T-cell Therapy

Cytokine release syndrome (CRS) is a lethal adverse event in chimeric antigen receptor (CAR) T-cell therapy, hindering this promising therapy for cancers, such as B-cell acute lymphoblastic leukemia (B-ALL). Clinical management of CRS requires a better understanding of its underlying mechanisms. In this study, a computational model of CRS during CAR T-cell therapy is built to depict how the cellular interactions among CAR T-cells, B-ALL cells, and bystander monocytes, as well as the accompanying molecular interactions among various inflammatory cytokines, influence the severity of CRS. The model successfully defines the factors related to severe CRS and studied the effects of immunomodulatory therapy on CRS. The use of the model is also demonstrated as a precision medicine tool to optimize the treatment scheme, including personalized choice of CAR T-cell products and control of switchable CAR T-cell activity, for a more efficient and safer immunotherapy. This new computational oncology model can serve as a precision medicine tool to guide the clinical management of CRS during CAR T cell therapy.

Emerging approaches for preventing cytokine release syndrome in CAR-T cell therapy

Chimeric antigen receptor (CAR) T cells have demonstrated remarkable anti-tumor efficacy against hematological malignancies, such as leukemia and lymphoma. However, patients treated with CAR-T cells frequently experience cytokine release syndrome (CRS), one of the most life-threatening adverse events of the therapy induced by systemic concentrations of pro-inflammatory cytokines throughout the body. Immunosuppressants such as tocilizumab are currently administered to treat the onset and progression of CRS symptoms. In order to reduce the risk of CRS, newly designed next-generation CAR-T treatments are being developed for both hematopoietic malignancies and solid tumors. In this review, we discuss six classes of interesting approaches that control cytokine production of CAR-T cell therapy: adaptor-based strategies, orthogonal cytokine-receptor pairs, regulation of macrophage cytokine activity, autonomous neutralization of key cytokines, kill switches and methods of reversible suppression of CARs. With these strategies, future CAR-T cell therapies will be designed to preemptively inhibit CRS, minimize the patients' suffering, and maximize the number of benefiting patients.