Coagulation Disorders after Chimeric Antigen Receptor T Cell Therapy: Analysis of 100 Patients with Relapsed and Refractory Hematologic Malignancies

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Dermatologic adverse events associated with chimeric antigen receptor T-cell therapy: a pharmacovigilance analysis of the FDA reporting system

BACKGROUND

Chimeric antigen receptor T-cell (CAR-T) therapy, including axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel), has demonstrated significant efficacy in treating refractory or relapsed diffuse large B-cell lymphoma and B-cell acute lymphoblastic leukemia. Though adverse events such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are well characterized, the dermatologic adverse event (DAE) profile is less thoroughly described.

OBJECTIVES

This study aims to provide the first comprehensive analysis of DAEs associated with axi-cel and tisa-cel using real-world data from the FDA Adverse Event Reporting System (FAERS) database.

STUDY DESIGN

FAERS database reports citing axi-cel or tisa-cel in patients aged 16 years or older were included, excluding duplicate reports and off-label indications. Disproportionality analysis by reporting odds ratio (ROR) was utilized to detect increased reporting of drug-adverse event combinations.

RESULTS

Of the 11,256,845 reports in the FAERS database, 5,559 identified CAR-T therapy as the primary suspected drug. After exclusions, 3,666 reports were analyzed (2,168 for axi-cel and 1,498 for tisa-cel). Among these, 2.7% of axi-cel and 5.1% of tisa-cel cases reported DAEs. There was a statistically significant increased reporting of 2 DAE groups associated with CAR-T therapy: severe cutaneous eruptions (ROR 5.18, 95% CI 1.29, 20.76) and vascular cutaneous (ROR 2.91, 95% CI 1.51, 5.60). The median time to DAE onset was 3 days after CAR T-cell infusion. Death was a reported outcome in 11.9% and 13.0% of axi-cel and tisa-cel DAE cases, respectively, and in 50% and 25% of severe cutaneous eruptions and vascular cutaneous cases, respectively.

CONCLUSIONS

This study reveals a significantly increased reporting rate of severe cutaneous eruptions and vascular cutaneous DAEs associated with CAR-T therapy, with both event groups associated with high mortality. These results emphasize the importance of monitoring dermatologic toxicities in clinical practice to ensure timely identification and management of potentially severe adverse events.

Coagulation abnormalities associated with CAR-T-cell therapy in haematological malignancies: A review

Chimeric antigen receptor (CAR)-T-cell therapy has demonstrated considerable efficacy and safety in the treatment of patients with relapsed/refractory haematological malignancies. Owing to significant advances, CAR-T-cell therapeutic modality has undergone substantial shifts in its clinical application. Coagulation abnormalities, which are prevalent complications in CAR-T-cell therapy, can range in severity from simple abnormalities in coagulation parameters to serious haemorrhage or disseminated intravascular coagulation associated with life-threatening multiorgan dysfunction. Nonetheless, there is a lack of a comprehensive overview concerning the coagulation abnormalities associated with CAR-T-cell therapy. With an aim to attract heightened clinical focus and to enhance the safety of CAR-T-cell therapy, this review presents the characteristics of the coagulation abnormalities associated with CAR-T-cell therapy, including clinical manifestations, coagulation parameters, pathogenesis, risk factors and their influence on treatment efficacy in patients receiving CAR-T-cell infusion. Due to limited data, these conclusions may undergo changes as more experience accumulates.

Gastrointestinal infections and gastrointestinal haemorrhage are underestimated but serious adverse events in chimeric antigen receptor T-cell recipients: A real-world study

Chimeric antigen receptor T-cell (CAR-T) therapy has achieved durable response in patients with hematological malignancies, however, therapy-associated multisystem toxicities are commonly observed. Here, we systematically analyzed CAR-T-related gastrointestinal adverse events (GAEs) using the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) between January 2017 and December 2021. Disproportionality analyses were performed using reporting odds ratios (ROR) and information component (IC). Among 105,087,611 reports in FAERS, 1518 CAR-T-related GAEs reports were identified. 23 GAEs (n = 281, 18.51%) were significantly overreported following CAR-T therapy compared with the full database, of which 11 GAEs (n = 156, 10.28%) were associated with gastrointestinal infections (GI), such as clostridium difficile colitis (n = 44 [2.90%], ROR = 5.55), enterovirus infection (n = 23 [1.52%], ROR = 20.02), and mucormycosis (n = 15 [0.99%], ROR = 3.09). Overall, the fatality rate of 11 GI-related AEs was 29.49%, especially mucormycosis causing substantial mortality with 60%. In addition, 4 of 23 overreported GAEs were related to haemorrhage and the mortality of gastrointestinal haemorrhage was 73.17%. Lastly, 29 death-related GAEs were identified. These findings could help clinicians early alert those rarely reported but lethal GAEs, thus reducing the risk of severe toxicities.

Histiocytic sarcoma following CAR T-cell therapy: a case report

BACKGROUND

Development of secondary tumor after CART treatment is not well investigated. We report a pediatric B-cell acute lymphoblastic leukemia (B-ALL) patient who developed histiocytic sarcoma shortly after CART therapy.

CASE REPORT

A 9-year-old boy diagnosed with relapsed B-ALL presenting the KRAS A146T mutation received autologous mouse-derived CD19 and CD22 chimeric antigen receptor T-cell therapy at our center (Chinese Clinical Trial Registry: ChiCTR2000032211). Thirty days post-CART therapy, the bone marrow showed complete remission. At 85 days post-CART therapy, the boy presented with fever and chills. An abdominal CT scan showed massive hepatomegaly with multiple low-density lesions in the liver. At 130 days post-CART therapy, a bone marrow smear showed abnormal proliferation of macrophages, some of which exhibited phagocytosis. On day 136 post-CART therapy, laparoscopic liver biopsy was performed, revealing multiple yellow-white lesions on the surface of the liver. Microscopically, multifocal lesions were observed, predominantly composed of cells with abundant cytoplasm. Immunohistochemical staining indicated histiocytic origin. Based on the immunohistochemical results, histiocytic sarcoma was diagnosed. The same cytogenetic markers were identified in histiocytic sarcoma.

CONCLUSION

Our case illustrates a rare complication after CART therapy. The diagnosis and treatment of histiocytic sarcoma pose many challenges.

Gp130-HIF1α axis-induced vascular damage is prevented by the short-term inhibition of IL-6 receptor signaling

Protection against endothelial damage is recognized as a frontline approach to preventing the progression of cytokine release syndrome (CRS). Accumulating evidence has demonstrated that interleukin-6 (IL-6) promotes vascular endothelial damage during CRS, although the molecular mechanisms remain to be fully elucidated. Targeting IL-6 receptor signaling delays CRS progression; however, current options are limited by persistent inhibition of the immune system. Here, we show that endothelial IL-6 trans-signaling promoted vascular damage and inflammatory responses via hypoxia-inducible factor-1α (HIF1α)-induced glycolysis. Using pharmacological inhibitors targeting HIF1α activity or mice with the genetic ablation of gp130 in the endothelium, we found that inhibition of IL-6R (IL-6 receptor)-HIF1α signaling in endothelial cells protected against vascular injury caused by septic damage and provided survival benefit in a mouse model of sepsis. In addition, we developed a short half-life anti-IL-6R antibody (silent anti-IL-6R antibody) and found that it was highly effective at augmenting survival for sepsis and severe burn by strengthening the endothelial glycocalyx and reducing cytokine storm, and vascular leakage. Together, our data advance the role of endothelial IL-6 trans-signaling in the progression of CRS and indicate a potential therapeutic approach for burns and sepsis.

Building safety into CAR-T therapy

Chimeric antigen receptor T cell (CAR-T) therapy is an innovative immunotherapeutic approach that utilizes genetically modified T-cells to eliminate cancer cells using the specificity of a monoclonal antibody (mAb) coupled to the potent cytotoxicity of the T-lymphocyte. CAR-T therapy has yielded significant improvements in relapsed/refractory B-cell malignancies. Given these successes, CAR-T has quickly spread to other hematologic malignancies and is being increasingly explored in solid tumors. From early clinical applications to present day, CAR-T cell therapy has been accompanied by significant toxicities, namely cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and on-target off-tumor (OTOT) effects. While medical management has improved for CRS and ICANS, the ongoing threat of refractory symptoms and unanticipated idiosyncratic toxicities highlights the need for more powerful safety measures. This is particularly poignant as CAR T-cell therapy continues to expand into the solid tumor space, where the risk of unpredictable toxicities remains high. We will review CAR-T as an immunotherapeutic approach including emergence of unique toxicities throughout development. We will discuss known and novel strategies to mitigate these toxicities; additional safety challenges in the treatment of solid tumors, and how the inducible Caspase 9 "safety switch" provides an ideal platform for continued exploration.

IL-10 plus the EASIX score predict bleeding events after anti-CD19 CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell-associated coagulopathy can cause bleeding events. To explore risk factors for hemorrhage after CAR T-cell therapy, we retrospectively analyzed routine indicators in 56 patients with non-Hodgkin lymphoma and B-cell acute lymphoblastic leukemia who received anti-CD19 CAR T-cell therapy. Disturbance of coagulation occurred mainly within one month post infusion, especially on day 7 and 14. The cumulative incidence of bleeding events within one month was 32.8%, with the median onset of 7 (range, 0-28) days. All bleeding events were grade 1-3. Patients who experienced bleeding events within one month had longer prothrombin time, higher IL-6, higher IL-10, and lower platelets before lymphodepletion. There were also correlations among coagulation-, inflammatory-, and tumor burden-related markers. Multi-variate analysis showed IL-10 (> 7.98 pg/mL; adjusted odds ratio [OR], 13.84; 95% confidence interval [CI], 2.03-94.36; P = 0.007) and the endothelial activation and stress index (EASIX, defined as dehydrogenase [U/L] × creatinine [mg/dL] / platelets [×109 cells/L]; >7.65; adjusted OR, 7.06; 95% CI, 1.03-48.23; P = 0.046) were significant risk factors for bleeding events. IL-10 plus the EASIX defined three risk groups for bleeding events with cumulative incidence of 100% (hazard ratio [HR], 14.47; 95% CI, 2.78-75.29; P < 0.0001), 38.5% (HR, 3.68; 95% CI, 0.82-16.67; P = 0.089), and 11.8% (reference), respectively. Future studies are needed to verify the risk assessment models for bleeding events after CAR T-cell treatment in larger cohorts.

Broadly neutralizing antibodies targeting HIV: Progress and challenges

Anti-HIV broadly neutralizing antibodies (bNAbs) offer a novel approach to treating, preventing, or curing HIV. Pre-clinical models and clinical trials involving the passive transfer of bNAbs have demonstrated that they can control viremia and potentially serve as alternatives or complement antiretroviral therapy (ART). However, antibody decay, persistent latent reservoirs, and resistance impede bNAb treatment. This review discusses recent advancements and obstacles in applying bNAbs and proposes strategies to enhance their therapeutic potential. These strategies include multi-epitope targeting, antibody half-life extension, combining with current and newer antiretrovirals, and sustained antibody secretion.

Endothelial activation and damage as a common pathological substrate in different pathologies and cell therapy complications

The endothelium is a biologically active interface with multiple functions, some of them common throughout the vascular tree, and others that depend on its anatomical location. Endothelial cells are continually exposed to cellular and humoral factors, and to all those elements (biological, chemical, or hemodynamic) that circulate in blood at a certain time. It can adapt to different stimuli but this capability may be lost if the stimuli are strong enough and/or persistent in time. If the endothelium loses its adaptability it may become dysfunctional, becoming a potential real danger to the host. Endothelial dysfunction is present in multiple clinical conditions, such as chronic kidney disease, obesity, major depression, pregnancy-related complications, septic syndromes, COVID-19, and thrombotic microangiopathies, among other pathologies, but also in association with cell therapies, such as hematopoietic stem cell transplantation and treatment with chimeric antigen receptor T cells. In these diverse conditions, evidence suggests that the presence and severity of endothelial dysfunction correlate with the severity of the associated disease. More importantly, endothelial dysfunction has a strong diagnostic and prognostic value for the development of critical complications that, although may differ according to the underlying disease, have a vascular background in common. Our multidisciplinary team of women has devoted many years to exploring the role of the endothelium in association with the mentioned diseases and conditions. Our research group has characterized some of the mechanisms and also proposed biomarkers of endothelial damage. A better knowledge would provide therapeutic strategies either to prevent or to treat endothelial dysfunction.

CAR-T Cell Therapy: From the Shop to Cancer Therapy

Cancer is a worldwide health problem. Nevertheless, new technologies in the immunotherapy field have emerged. Chimeric antigen receptor (CAR) technology is a novel biological form to treat cancer; CAR-T cell genetic engineering has positively revolutionized cancer immunotherapy. In this paper, we review the latest developments in CAR-T in cancer treatment. We present the structure of the different generations and variants of CAR-T cells including TRUCK (T cells redirected for universal cytokine killing. We explain the approaches of the CAR-T cells manufactured ex vivo and in vivo. Moreover, we describe the limitations and areas of opportunity for this immunotherapy and the current challenges of treating hematological and solid cancer using CAR-T technology as well as its constraints and engineering approaches. We summarize other immune cells that have been using CAR technology, such as natural killer (NK), macrophages (M), and dendritic cells (DC). We conclude that CAR-T cells have the potential to treat not only cancer but other chronic diseases.

Prediction of severe CRS and determination of biomarkers in B cell-acute lymphoblastic leukemia treated with CAR-T cells

Introduction

CAR-T cell therapy is a novel approach in the treatment of hematological tumors. However, it is associated with life-threatening side effects, such as the severe cytokine release syndrome (sCRS). Therefore, predicting the occurrence and development of sCRS is of great significance for clinical CAR-T therapy. The study of existing clinical data by artificial intelligence may bring useful information.

Methods

By analyzing the heat map of clinical factors and comparing them between severe and non-severe CRS, we can identify significant differences among these factors and understand their interrelationships. Ultimately, a decision tree approach was employed to predict the timing of severe CRS in both children and adults, considering variables such as the same day, the day before, and initial values.

Results

We measured cytokines and clinical biomarkers in 202 patients who received CAR-T therapy. Peak levels of 25 clinical factors, including IFN-γ, IL6, IL10, ferritin, and D-dimer, were highly associated with severe CRS after CAR T cell infusion. Using the decision tree model, we were able to accurately predict which patients would develop severe CRS consisting of three clinical factors, classified as same-day, day-ahead, and initial value prediction. Changes in serum biomarkers, including C-reactive protein and ferritin, were associated with CRS, but did not alone predict the development of severe CRS.

Conclusion

Our research will provide significant information for the timely prevention and treatment of sCRS, during CAR-T immunotherapy for tumors, which is essential to reduce the mortality rate of patients.

A comprehensive analysis of coagulopathy during anti-B cell maturation antigen chimeric antigen receptor-T therapy in multiple myeloma, a retrospective study based on LEGEND-2

Chimeric antigen receptor (CAR)-reprogrammed T cell therapy is a novel and powerful treatment against hematological malignancies. Cytokine release syndrome (CRS) and other potentially life-threatening toxicities are known side effects which need appropriate management and supportive care. Coagulopathy is a common and severe CAR-T-related adverse event, while a comprehensive profile of coagulopathy in patients with multiple myeloma (MM) undergoing CAR-T cell therapy has not been reported. Therefore, we performed a comprehensive analysis of coagulopathy in 51 patients with r/r MM given anti-B cell maturation antigen CAR-T cell therapy. We found that 49% of patients had coagulation disorders, and 29% of patients experienced disseminated intravascular coagulation (DIC). Severe CRS, abnormal liver function and higher tumor burden were risk factors for the CAR-T-related coagulopathy. We found that the serum IL-6 level and alanine aminotransferase level were potential indicators for CAR-T-related DIC. Furthermore, we found that coagulation disorders occurred within 1 month after CAR-T cell infusion, mainly between days 10 and 13, which was 2-5 days later than the beginning of CRS and simultaneous with the beginning of abnormal liver function and the peak of CRS. In addition, although patients with coagulation dysfunction had a trend for better outcomes and prognosis, no statistical significance was found. In conclusion, our research provided a comprehensive understanding of CAR-T-related coagulopathy in MM. Upon timely and standardized treatment, coagulopathy was manageable in most cases.

Longitudinal Serum Proteomics Characterization of CD19-CAR-T Cell Therapy for B-Cell Malignancies

Chimeric antigen receptor (CAR)-modified T cells have demonstrated remarkable efficacy in treating B-cell leukemia. However, treated patients may potentially develop side effects, such as cytokine release syndrome (CRS), the mechanisms of which remain unclear. Here, we collected 43 serum samples from eight patients with B-cell acute lymphoblastic leukemia (B-ALL) before and five time points after CD19-specific CAR-T cell treatment. Using TMTpro 16-plex-based quantitative proteomics, we quantified 1151 proteins and profiled the longitudinal proteomes analysis of each patient. Seven days after therapy, we found the most dysregulated inflammatory proteins. Lipid metabolism proteins, including APOA1, decreased after therapy, reached their minimum after 7 days, and then gradually recovered. Hence, APOA1 has been selected as a potential biomarker of the CRS disease progression. Furthermore, we identified CD163 as a potential biomarker of CRS severity. These two biomarkers were successfully validated using targeted proteomics in an independent cohort. Our study provides new insights into CAR-T cell therapy-induced CRS. The biomarkers we identified may help develop targeted drugs and monitoring strategies.

CD22 CAR T-cell associated hematologic toxicities, endothelial activation and relationship to neurotoxicity

BACKGROUND

Hematologic toxicities, including coagulopathy, endothelial activation, and cytopenias, with CD19-targeted chimeric antigen receptor (CAR) T-cell therapies correlate with cytokine release syndrome (CRS) and neurotoxicity severity, but little is known about the extended toxicity profiles of CAR T-cells targeting alternative antigens. This report characterizes hematologic toxicities seen following CD22 CAR T-cells and their relationship to CRS and neurotoxicity.

METHODS

We retrospectively characterized hematologic toxicities associated with CRS seen on a phase 1 study of anti-CD22 CAR T-cells for children and young adults with relapsed/refractory CD22+ hematologic malignancies. Additional analyses included correlation of hematologic toxicities with neurotoxicity and exploring effects of hemophagocytic lymphohistiocytosis-like toxicities (HLH) on bone marrow recovery and cytopenias. Coagulopathy was defined as evidence of bleeding or abnormal coagulation parameters. Hematologic toxicities were graded by Common Terminology Criteria for Adverse Events V.4.0.

RESULTS

Across 53 patients receiving CD22 CAR T-cells who experienced CRS, 43 (81.1%) patients achieved complete remission. Eighteen (34.0%) patients experienced coagulopathy, of whom 16 had clinical manifestations of mild bleeding (typically mucosal bleeding) which generally subsided following CRS resolution. Three had manifestations of thrombotic microangiopathy. Patients with coagulopathy had higher peak ferritin, D-dimer, prothrombin time, international normalized ratio (INR), lactate dehydrogenase (LDH), tissue factor, prothrombin fragment F1+2 and soluble vascular cell adhesion molecule-1 (s-VCAM-1). Despite a relatively higher incidence of HLH-like toxicities and endothelial activation, overall neurotoxicity was generally less severe than reported with CD19 CAR T-cells, prompting additional analysis to explore CD22 expression in the central nervous system (CNS). Single-cell analysis revealed that in contrast to CD19 expression, CD22 is not on oligodendrocyte precursor cells or on neurovascular cells but is seen on mature oligodendrocytes. Lastly, among those attaining CR, grade 3-4 neutropenia and thrombocytopenia were seen in 65% of patients at D28.

CONCLUSION

With rising incidence of CD19 negative relapse, CD22 CAR T-cells are increasingly important for the treatment of B-cell malignancies. In characterizing hematologic toxicities on CD22 CAR T-cells, we demonstrate that despite endothelial activation, coagulopathy, and cytopenias, neurotoxicity was relatively mild and that CD22 and CD19 expression in the CNS differed, providing one potential hypothesis for divergent neurotoxicity profiles. Systematic characterization of on-target off-tumor toxicities of novel CAR T-cell constructs will be vital as new antigens are targeted.

TRIAL REGISTRATION NUMBER

NCT02315612.

Thrombotic Events Are Unusual Toxicities of Chimeric Antigen Receptor T-Cell Therapies

Chimeric antigen receptor (CAR) T-cell therapy has greatly transformed the treatment and prognosis of B-cell hematological malignancies. As CAR T-cell therapy continues to be more readily adopted and indications increase, the field's recognition of emerging toxicities will continue to grow. Among the adverse events associated with CAR T-cell therapy, cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity (ICANS) are the most common toxicities, while thrombotic events represent an under-reported, life-endangering complication. To determine thrombosis incidence post CAR T-cell therapy, we performed a multi-center, retrospective study on CAR T-cell therapy adult patients (N = 140) from Indiana University Simon Cancer Center and the University of North Carolina Medical Center treated from 2017 to 2022 for relapsed and refractory B-cell acute lymphoblastic leukemia (B-ALL, N = 3), diffuse large B-cell lymphoma (DLBCL, N = 92), follicular lymphoma (FL, N = 9), mantle cell lymphoma (MCL, N = 2), and multiple myeloma (MM, N = 34). We report 10 (7.14%) thrombotic events related to CAR T-cell therapy (DLBCL: N = 8, FL: N = 1, MM: N = 1) including 9 primary venous events and 1 arterial event that occurred with median time of 23.5 days post CAR T-cell infusion. In search of parameters associated with such events, we performed multivariate analyses of coagulation parameters (i.e., PT, PTT, and D-Dimer), scoring for adverse events (Padua Score and ISTH DIC Score) and grading for CAR T-cell toxicity severity (CRS grade and ICANS grade) and found that D-Dimer peak elevation and ICANS grade were significantly associated with post-CAR T-cell infusion thrombosis. While the pathophysiology of CAR T-cell associated coagulopathy remains unknown, our study serves to develop awareness of these emerging and unusual complications.

Cross-talk between cancer stem cells and immune cells: potential therapeutic targets in the tumor immune microenvironment

Ongoing research has revealed that the existence of cancer stem cells (CSCs) is one of the biggest obstacles in the current cancer therapy. CSCs make an influential function in tumor progression, recurrence and chemoresistance due to their typical stemness characteristics. CSCs are preferentially distributed in niches, and those niche sites exhibit characteristics typical of the tumor microenvironment (TME). The complex interactions between CSCs and TME illustrate these synergistic effects. The phenotypic heterogeneity within CSCs and the spatial interactions with the surrounding tumor microenvironment led to increased therapeutic challenges. CSCs interact with immune cells to protect themselves against immune clearance by exploiting the immunosuppressive function of multiple immune checkpoint molecules. CSCs also can protect themselves against immune surveillance by excreting extracellular vesicles (EVs), growth factors, metabolites and cytokines into the TME, thereby modulating the composition of the TME. Therefore, these interactions are also being considered for the therapeutic development of anti-tumor agents. We discuss here the immune molecular mechanisms of CSCs and comprehensively review the interplay between CSCs and the immune system. Thus, studies on this topic seem to provide novel ideas for reinvigorating therapeutic approaches to cancer.

Integrated single-cell multiomics reveals novel immune candidate markers for post-traumatic coagulopathy

Introduction

Post-traumatic coagulopathy (PTC) is a critical pathology in traumatic brain injury (TBI), however, its potential mechanism is not clear. To explore this in peripheral samples, we integrated single cell RNA-sequencing and T cell repertoire (TCR)-sequencing across a cohort of patients with TBI.

Methods

Clinical samples from patients with more brain severity demonstrated overexpression of T cell receptor-encoding genes and less TCR diversity.

Results

By mapping TCR clonality, we found patients with PTC have less TCR clones, and the TCR clones are mainly distributed in cytotoxic effector CD8+T cell. In addition, the counts of CD8+ T cell and natural killer (NK) cells are associated with the coagulation parameter by WGCNA, and the granzyme and lectin-like receptor profiles are also decreased in the peripheral blood from TBI patients, suggesting that reduced peripheral CD8+ clonality and cytotoxic profiles may be involved in PTC after TBI.

Conclusion

Our work systematically revealed the critical immune status in PTC patients at the single-cell level.

Factors associated with infection events after chimeric antigen receptor T-cell therapy for relapsed or refractory multiple myeloma

OBJECTIVES

Chimeric antigen receptor (CAR) T-cell therapy is a new and effective method in relapsed or refractory (R/R) multiple myeloma (MM). This study was aimed to explore the risk factors of infection events.

METHODS

We retrospectively analyzed 68 patients with R/R MM who received CAR T-cell therapy at the Affiliated Hospital of Xuzhou Medical University from June 2017 to June 2021.35 patients received anti-CD19 combined with anti-BCMA CAR T-cell therapy and 33 patients received anti-BCMA CAR T-cell therapy alone.

RESULTS

Infection events in patients who received ≥4 prior lines of treatment or with grade 3-5 cytokines released syndrome (CRS) mainly occurred within 4 months after CAR T-cell infusion(CTI). The duration of infection-free survival was positively correlated with progression-free survival of patients with R/R MM (R² = 0.962, p < 0.001) and the first infection event was closely accompanied by the disease relapse or progression. Treatment lines (p = 0.05), duration of ANC<500 cells/mm³ after CTI (p = 0.036), CRS grade (p = 0.007) and treatment response (p < 0.001) were the independent risk factors associated with infection for a multivariable model. The infection incidence was higher in patients with dual CAR T-cell therapy than with mono CAR T-cell therapy18 months after CTI although no statistic differences were observed within 18 months.

CONCLUSIONS

Infections after CTI were closely associated with more lines of prior treatment, longer duration of ANC<500 cells/mm³, higher grade CRS and poor treatment response. Infections tended to occur in the early stage after CTI in patients with more lines of prior treatment and higher grade CRS.

The risk factors for coagulation disorder of chimeric antigen receptor-T cell therapy in patients with hematological tumors: A systematic review and meta-analysis

BACKGROUND

Currently, the frequency of coagulation dysfunction associated with chimeric antigen receptor-T cell (Car-T) therapy cannot yet be determined.

OBJECTIVE

We performed a systematic review and meta-analysis to examine the prevalence of abnormal laboratory tests related to coagulation disorders in patients receiving Car-T therapy and provide a reference for future risk assessment mechanisms.

METHODS

We searched PubMed, Embase, and Web of Science for relevant studies and evaluated their quality using the methodology index of non-random research (MINORS). 2672 quotations were retrieved via systematic searches. After screening of titles, abstracts and full-text, 45 trials involving 2541 patients were ultimately included. 41 studies reported the incidence of thrombocytopenia, 8 studies reported the rate of low fibrin, 4 trials reported the rate of APTT or PT abnormalities and only 3 trials reported the incidence of venous thromboembolism (VTE). We performed a quantitative meta-analysis to explore the incidence of thrombocytopenia following Car-T treatment. The incidence of hypofibrinogenemia, VTE, and abnormal APTT or PT was only qualitatively assessed, as fewer reports were included in this study.

RESULTS

The overall incidence of thrombocytopenia associated with Car-T therapy was 45.8% (95%[CI], 0.384-0.533). The highest rates of thrombocytopenia occurred in patients with multiple myeloma (60.1%, 95%[CI], 0.507-0.688) and aged between 18 to 60 (50%, 95%[CI], 0.367-0.633). There was greater prevalence of thrombocytopenia in BCMA-Car-T therapy of 58.7% (95%[CI], 0.482-0.685). Thrombocytopenia occurred most frequently in Car-T patients treated with a dosage of 1 × 105-1 × 106 cell/kg, at a rate of 66.2% (95%[CI], 0.561-0.749).

CONCLUSION

Overall, 45.8 percent of patients receiving Car-T treatment suffered from thrombocytopenia. Multiple myeloma patients, ages between 18-60, a dose of 1 × 105-1 × 106 cell/kg and BCMA-Car-T therapy are all considered high-risk factors.

Endothelial activation predicts disseminated intravascular coagulopathy, cytokine release syndrome and prognosis in patients treated with anti‐CD19 CAR‐T cells

Cytokine release syndrome (CRS) and consumptive coagulopathy can complicate the treatment with chimeric antigen receptor T (CAR-T) cells. The modified version of the Endothelial Activation and Stress Index (mEASIX), a score derived from haematopoietic stem cell transplantation, combines platelets, C-reactive protein (CRP), and lactate dehydrogenase (LDH) and has been correlated with CRS and endothelial biomarkers. In 38 consecutive patients with aggressive lymphoproliferative disease we measured a coagulative laboratory panel at baseline and early after infusion of anti-CD19 CAR-T. The panel was investigated also in the presence of CRS graded 2 or higher, or immune effector cell-associated neurotoxicity syndrome (ICANS). Moreover, we examined the relationship between mEASIX, coagulation biomarkers, and toxicities of CAR-T cells. During CRS grade 2 or higher, we found increased prothrombin time (PT) and activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, factor VIII (FVIII), and von Willebrand factor (vWF) antigen levels, and decreased platelet count and antithrombin levels. The occurrence of immune effector cell-associated neurotoxicity syndrome was associated with higher PT values, D-dimer, FVIII, and vWF levels, and decreased fibrinogen levels and platelet count. A higher mEASIX score correlated with increased aPTT values, fibrinogen, D-dimer, FVIII and vWF levels, and decreased antithrombin levels. Baseline mEASIX was predictive for consumptive coagulopathy and CRS graded 2 or higher, and for progression-free survival and overall survival.

Acute Kidney Injury in Cancer Immunotherapy Recipients

Cancer immunotherapy has now entered clinical practice and has reshaped the standard of care for many cancer patients. With these new strategies, specific toxicities have emerged, and renal side effects have been described. In this review, we will describe the causes of acute kidney injury in CAR T cell, immune checkpoint inhibitors and other cancer immuno-therapy recipients. CAR T cell therapy and bispecific T cell engaging antibodies can lead to acute kidney injury as a consequence of cytokine release syndrome, tumor lysis syndrome, sepsis or specific CAR T cell infiltration. Immune checkpoint blockade most often results in acute tubular interstitial nephritis, but glomerular diseases have also been described. Although the pathophysiology remains mostly elusive, we will describe the mechanisms of renal damage in these contexts, its prognosis and treatment. As the place of immunotherapy in the anti-cancer armamentarium is exponentially increasing, close collaboration between nephrologists and oncologists is of utmost importance to provide the best standard of care for these patients.

Outcomes of CD19-Targeted Chimeric Antigen Receptor T Cell Therapy for Patients with Reduced Renal Function Including Dialysis

Patients with renal impairment (RI) are typically excluded from trials evaluating chimeric antigen receptor (CAR) T cell therapies. We evaluated the outcomes of patients with RI receiving standard of care (SOC) CAR T cell therapy for relapsed/refractory (R/R) diffuse large B cell lymphoma (DLBCL). In this retrospective, single-center cohort study of patients with R/R DLBCL treated with SOC axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) after 2 or more prior lines of therapy, renal and survival outcomes were compared based on RI and fludarabine dose reduction (DR) status. RI was defined by an estimated glomerular filtration rate <60 mL/min/1.73 m2 as determined by the Modification of Diet in Renal Disease equation using day -5 creatinine (Cr) values. Acute kidney injury (AKI) was identified and graded using standard Kidney Disease: Improving Global Outcomes criteria. Renal recovery was considered to occur if Cr was within .2 mg/mL of baseline by day +30. Fludarabine was considered DR if given at <90% of the recommended Food and Drug Administration label dose. Among 166 patients treated with CAR T cell therapy were 17 patients (10.2%) with baseline RI and 149 (89.8%) without RI. After CAR T cell infusion, the incidence of any grade AKI was not significantly different between patients with baseline RI and those without RI (42% versus 21%; P = .08). Similarly, severe grade 2/3 AKI was seen in 1 of 17 patients (5.8%) with baseline RI and in 11 of 149 patients (7.3%) without RI (P = 1). Decreased renal perfusion (28 of 39; 72%) was the most common cause of AKI, with cytokine release syndrome (CRS) contributing to 17 of 39 AKIs (44%). Progression-free survival (PFS) and overall survival (OS) did not differ between patients with RI and those without RI or between those who received standard-dose fludarabine and those who received reduced-dose fludarabine. In contrast, patients with AKI had worse clinical outcomes than those without AKI (multivariable PFS: hazard ratio [HR], 2.1; 95% confidence interval [CI], 1.2 to 3.7; OS: HR, 3.9; 95% CI, 2.1 to 7.4). Notably, peak inflammatory cytokine levels were higher in patients who experienced AKI. Finally, we describe 2 patients with end-stage renal disease (ESRD) on dialysis who received lymphodepletion and CAR T cell therapy. Baseline renal function did not affect renal or efficacy outcomes after CAR T cell therapy in DLBCL. On the other hand, patients with AKI went on to experience worse clinical outcomes. AKI was commonly related to CRS and high peak inflammatory cytokine levels. CAR T cell therapy is feasible in patients with ESRD and requires careful planning of lymphodepletion.

CAR-T Cell Therapy in Hematological Malignancies: Current Opportunities and Challenges

Chimeric antigen receptor T (CAR-T) cell therapy represents a major breakthrough in cancer treatment, and it has achieved unprecedented success in hematological malignancies, especially in relapsed/refractory (R/R) B cell malignancies. At present, CD19 and BCMA are the most common targets in CAR-T cell therapy, and numerous novel therapeutic targets are being explored. However, the adverse events related to CAR-T cell therapy might be serious or even life-threatening, such as cytokine release syndrome (CRS), CAR-T-cell-related encephalopathy syndrome (CRES), infections, cytopenia, and CRS-related coagulopathy. In addition, due to antigen escape, the limited CAR-T cell persistence, and immunosuppressive tumor microenvironment, a considerable proportion of patients relapse after CAR-T cell therapy. Thus, in this review, we focus on the progress and challenges of CAR-T cell therapy in hematological malignancies, such as attractive therapeutic targets, CAR-T related toxicities, and resistance to CAR-T cell therapy, and provide some practical recommendations.

Relative hypercoagulation induced by suppressed fibrinolysis after tisagenlecleucel infusion in malignant lymphoma

A hypofibrinolytic state with total PAI-1 elevation at the onset of CRS is the initial step of coagulopathy early after CAR-T infusion.

Suppressed fibrinolysis induces hypercoagulable status, which is gradually resolved after CRS remission without any organ damage in DLBCL.

Anti-CD19 chimeric antigen receptor T (CAR-T) cell therapy has facilitated progress in treatment of refractory/relapsed diffuse large B-cell lymphoma (DLBCL). A well-known adverse event after CAR-T therapy is cytokine release syndrome(CRS). However, the etiology and pathophysiology of CRS-related coagulopathy remain unknown. Therefore, we conducted a prospective cohort study to comprehensively analyze coagulation/ fibrinolysis parameters present in peripheral blood of adult DLBCL patients treated with tisagenlecleucel in a single institution. Samples were collected from 25 patients at 3 time points: before lymphocyte-depletion chemotherapy and on days 3 and 13 after CAR-T infusion. After infusion, all patients except 1 experienced CRS, and 13 required the administration of tocilizumab. A significant elevation in the plasma level of total plasminogen activator inhibitor 1 (PAI-1), which promotes the initial step of coagulopathy (mean, 22.5 ng/mL before lymphocyte-depletion and 41.0 on day 3, P = .02), was observed at the onset of CRS. Moreover, this suppressed fibrinolysis-induced relatively hypercoagulable state was gradually resolved after CRS remission with normalization of total PAI-1 to preinfusion levels without any organ damage (mean values of soluble fibrin: 3.16 µg/mL at baseline, 8.04 on day 3, and 9.16 on day 13, P < .01; and mean PAI-1: 25.1 ng/mL on day 13). In conclusion, a hypofibrinolytic and relatively hypercoagulable state concomitant with significant total PAI-1 elevation was observed at the onset of CRS even in DLBCL patients with mild CRS. Our results will facilitate understanding of CRS-related coagulopathy, and they emphasize the importance of monitoring sequential coagulation/fibrinolysis parameters during CAR-T therapy.

Incidence of thrombosis in relapsed/refractory B-cell lymphoma treated with axicabtagene ciloleucel: Mayo Clinic experience

Chimeric antigen receptor (CAR) T-cell therapy is effective in relapsed/refractory large B-cell lymphoma and results in a unique toxicity profile, namely cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome. The hyper-inflammatory state associated with these toxicities has been suggested to increase the risk of thrombosis. We conducted a retrospective analysis of patients treated with axicabtagene ciloleucel (axi-cel) to assess the rate of thrombosis with axi-cel therapy from the time of CAR T-cell infusion until the end of hospitalization, when performed in the inpatient setting, or up to day +30 when performed in the outpatient setting. Ninety-two (95%) of 97 patients were hospitalized during axi-cel therapy and 85 (88%) developed CRS. Fifty-five patients (57%) received concurrent anticoagulation (53 as prophylaxis). Patients with prior VTE did not have progression or evidence of new VTE. Only 2 (2.1%) patients developed VTE. These results demonstrate a low-risk for thrombosis in axi-cel recipients.

Incidence and risk factors associated with bleeding and thrombosis following chimeric antigen receptor T-cell therapy

Clinically significant bleeding occurred in 9% of patients after CAR T therapy and was associated with features of systemic coagulopathy.

Low baseline platelets and possibly high-grade ICANS are risk factors for bleeding and require close monitoring for bleeding up to 1 month.

Bleeding and thrombotic events are an emerging toxicity associated with chimeric antigen receptor (CAR) therapies. To determine their incidence, we retrospectively analyzed consecutive adult patients (N = 127) with large B-cell lymphoma (LBCL) or B-cell acute lymphoblastic leukemia (B-ALL) treated from 2017 through 2020 with axicabtagene ciloleucel (axi-cel; n = 89) or a bispecific CD19/CD22 CAR (n = 38). Twelve (9.4%) and 8 (6.3%) patients developed bleeding and thrombosis within the first 3 months, respectively. In the axi-cel subgroup, these occurred in 11.2% and 6.7%, respectively. Bleeding occurred between days 8 and 30 (median, 17.5) and thrombosis between days 2 and 91 (median, 29). Bleeding sites included genitourinary, soft tissue, intracranial, gastrointestinal, and pulmonary and were associated with features of consumptive coagulopathy. On univariate analysis, patients with bleeding were older, had lower baseline platelets (86 × 10³/μL vs 178 × 10³/μL; P < .01), lower platelet and fibrinogen nadirs , and elevated lactate dehydrogenase. Immune effector cell (IEC)–associated neurotoxicity syndrome (ICANS) grade ≥3 was associated with increased bleeding (50% vs 15%; P = .01), thrombosis (50% vs 16%; P = .04), prothrombin time prolongation, hypofibrinogenemia, and elevated D-dimer. Low pretreatment platelet counts were associated with bleeding in a multivariate logistic regression model. Patients with thrombocytopenia or severe ICANS are at increased risk of bleeding and should be closely monitored, particularly within the first month after CAR therapy. Future studies in larger cohorts should assess risk factors for systemic coagulopathies in CAR T therapy, including their association with neurotoxicity.

Predictive role of endothelial cell activation in cytokine release syndrome after chimeric antigen receptor T cell therapy for acute lymphoblastic leukaemia

CD19-target chimeric antigen receptor (CAR)-T cell therapy is highly effective for relapsed/refractory (R/R) acute lymphoblastic leukaemia (ALL), but is often complicated by cytokine release syndrome (CRS), which is potentially life-threatening. Endothelial cells are the core regulator of CRS in many infectious diseases and may also play a key role after CAR-T cell therapy. We provided a detailed clinical, laboratory description and endothelial cell activation biomarkers in patients with CRS. Endothelial cell activation was associated with occurrence, development and severity of CRS, manifested by decreased serum angiopoietin (Ang)-1 levels and increased levels of von Willebrand Factor (VWF), Ang-2, Ang-2:Ang-1, sE-selectin, soluble intercellular adhesion molecule (sICAM-1) and soluble vascular cell adhesion molecule (sVCAM)-1. Besides, the endothelial activation was correlated with the hepatic, kidney and hematopoietic dysfunction in CRS patients. After infusion of CAR-T cells, we detected changes of endothelial activation-related biomarkers within 36 hours in patients who subsequently developed CRS, especially severe CRS. Using top tree models, we could predict which patients would develop CRS, especially severe CRS, or identify the severity of CRS by certain biomarkers of endothelial activation. These data provide a new idea and will help identify new targets for early intervention and prevention of CRS.

Management of Immune-Related Adverse Events in Patients Treated With Chimeric Antigen Receptor T-Cell Therapy: ASCO Guideline

PURPOSE

To increase awareness, outline strategies, and offer guidance on the recommended management of immune-related adverse events (irAEs) in patients treated with chimeric antigen receptor (CAR) T-cell therapy.

METHODS

A multidisciplinary panel of medical oncology, neurology, hematology, emergency medicine, nursing, trialists, and advocacy experts was convened to develop the guideline. Guideline development involved a systematic literature review and an informal consensus process. The systematic review focused on evidence published from 2017 to 2021.

RESULTS

The systematic review identified 35 eligible publications. Because of the paucity of high-quality evidence, recommendations are based on expert consensus.

RECOMMENDATIONS

The multidisciplinary team issued recommendations to aid in the recognition, workup, evaluation, and management of the most common CAR T-cell-related toxicities, including cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, B-cell aplasia, cytopenias, and infections. Management of short-term toxicities associated with CAR T cells begins with supportive care for most patients, but may require pharmacologic interventions for those without adequate response. Management of patients with prolonged or severe CAR T-cell-associated cytokine release syndrome includes treatment with tocilizumab with or without a corticosteroid. On the basis of the potential for rapid decline, patients with moderate to severe immune effector cell-associated neurotoxicity syndrome should be managed with corticosteroids and supportive care.Additional information is available at www.asco.org/supportive-care-guidelines.

Cancer Stem Cell for Tumor Therapy

Simple Summary

Although many methods have been applied in clinical treatment for tumors, they still always show a poor prognosis. Molecule targeted therapy has revolutionized tumor therapy, and a proper target must be found urgently. With a crucial role in tumor development, metastasis and recurrence, cancer stem cells have been found to be a feasible and potential target for tumor therapy. We list the unique biological characteristics of cancer stem cells and summarize the recent strategies to target cancer stem cells for tumor therapy, through which we hope to provide a comprehensive understanding of cancer stem cells and find a better combinational strategy to target cancer stem cells for tumor therapy.

Abstract

Tumors pose a significant threat to human health. Although many methods, such as operations, chemotherapy and radiotherapy, have been proposed to eliminate tumor cells, the results are unsatisfactory. Targeting therapy has shown potential due to its specificity and efficiency. Meanwhile, it has been revealed that cancer stem cells (CSCs) play a crucial role in the genesis, development, metastasis and recurrence of tumors. Thus, it is feasible to inhibit tumors and improve prognosis via targeting CSCs. In this review, we provide a comprehensive understanding of the biological characteristics of CSCs, including mitotic pattern, metabolic phenotype, therapeutic resistance and related mechanisms. Finally, we summarize CSCs targeted strategies, including targeting CSCs surface markers, targeting CSCs related signal pathways, targeting CSC niches, targeting CSC metabolic pathways, inducing differentiation therapy and immunotherapy (tumor vaccine, CAR-T, oncolytic virus, targeting CSCs–immune cell crosstalk and immunity checkpoint inhibitor). We highlight the potential of immunity therapy and its combinational anti-CSC therapies, which are composed of different drugs working in different mechanisms.

Tumor Burden Measured by 18F-FDG PET/CT in Predicting Efficacy and Adverse Effects of Chimeric Antigen Receptor T-Cell Therapy in Non-Hodgkin Lymphoma

Chimeric antigen receptor (CAR) T-cell therapy has exhibited promising clinical outcomes in treating relapsed/refractory (R/R) B-cell hematologic malignancies. Current studies have shown a close correlation between baseline tumor burden and therapeutic response in CAR-T cell therapy. However, the roles of PET/CT metabolic parameters, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), remain unclear in this setting. In this study, we retrospectively reviewed 41 R/R NHL patients. 18F-FDG PET/CT was used to measure the average standardized uptake value (SUV_avg), MTV, and TLG of the lymphomatous lesions. These patients were divided into two groups according to the optimal cutoff values of respective PET/CT metabolic parameters. The multivariate analysis depicted that early post-therapy SUV_avg (HR: 1.418, 95% CI: 1.029, 1.955; p = 0.033) and MTV (HR: 1.001, 95% CI: 1.000, 1.002; p = 0.041) were independent risk factors associated with OS and PFS, respectively. Patients with baseline SUV_avg < 4.36 achieved a superior 1-year OS rate than the SUV_avg ≥ 4.36 group (100.0% vs. 44.9%, p = 0.019). For the patients with lower values in early post-therapy SUV_avg (<2.60) (51.1% vs. 0%, p < 0.001), MTV (<0.55 cm³) (53.6% vs. 0.0%, p = 0.001), and TLG (<1.54) (53.6% vs. 0.0%, p = 0.001), their 1-year PFS rates were higher than the compared groups. Moreover, patients with higher baseline tumor burdens were found to have significantly increased CRS incidence and cytokine levels. In conclusion, the PET/CT metabolic parameters are closely related to OS, PFS, and CRS in R/R NHL patients treated with CAR-T cells. This study may pave the way for building a comprehensive assessment system of tumor burden using 18F-FDG PET/CT, which can optimize therapeutic and supportive approaches in CAR-T cell therapy.

Pooled safety analysis of tisagenlecleucel in children and young adults with B cell acute lymphoblastic leukemia

BACKGROUND

Tisagenlecleucel, an anti-CD19 chimeric antigen receptor T cell therapy, has demonstrated efficacy in children and young adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL) in two multicenter phase 2 trials (ClinicalTrials.gov, NCT02435849 (ELIANA) and NCT02228096 (ENSIGN)), leading to commercialization of tisagenlecleucel for the treatment of patients up to age 25 years with B-ALL that is refractory or in second or greater relapse.

METHODS

A pooled analysis of 137 patients from these trials (ELIANA: n=79; ENSIGN: n=58) was performed to provide a comprehensive safety profile for tisagenlecleucel.

RESULTS

Grade 3/4 tisagenlecleucel-related adverse events (AEs) were reported in 77% of patients. Specific AEs of interest that occurred ≤8 weeks postinfusion included cytokine-release syndrome (CRS; 79% (grade 4: 22%)), infections (42%; grade 3/4: 19%), prolonged (not resolved by day 28) cytopenias (40%; grade 3/4: 34%), neurologic events (36%; grade 3: 10%; no grade 4 events), and tumor lysis syndrome (4%; all grade 3). Treatment for CRS included tocilizumab (40%) and corticosteroids (23%). The frequency of neurologic events increased with CRS severity (p<0.001). Median time to resolution of grade 3/4 cytopenias to grade ≤2 was 2.0 (95% CI 1.87 to 2.23) months for neutropenia, 2.4 (95% CI 1.97 to 3.68) months for lymphopenia, 2.0 (95% CI 1.87 to 2.27) months for leukopenia, 1.9 (95% CI 1.74 to 2.10) months for thrombocytopenia, and 1.0 (95% CI 0.95 to 1.87) month for anemia. All patients who achieved complete remission (CR)/CR with incomplete hematologic recovery experienced B cell aplasia; however, as nearly all responders also received immunoglobulin replacement, few grade 3/4 infections occurred >1 year postinfusion.

CONCLUSIONS

This pooled analysis provides a detailed safety profile for tisagenlecleucel during the course of clinical trials, and AE management guidance, with a longer follow-up duration compared with previous reports.

Cytokine Release Syndrome Is an Independent Risk Factor Associated With Platelet Transfusion Refractoriness After CAR-T Therapy for Relapsed/Refractory Acute Lymphoblastic Leukemia

Background: Chimeric antigen receptor T cell (CAR-T) therapy is successful in improving treatment outcomes for relapsed/refractory acute lymphoblastic leukemia (R/R ALL). However, toxicities associated with CAR-T therapy are being increasingly identified. Pancytopenia is one of the most common complications after CAR-T therapy, and platelet transfusions are an essential part of its supportive care. Study Design and Methods: This study aimed to assess the effectiveness of platelet transfusions for R/R ALL patients at our single center and identify associated risk factors. Overall, 44 R/R ALL patients were enrolled in this study, of whom 26 received CAR-T therapy and 18 received salvage chemotherapy. Result: Patients in the CAR-T group had a higher incidence of platelet transfusion refractoriness (PTR) (15/26, 57.7%) than those in the chemotherapy group (3/18, 16.7%) (p = 0.007). For patients receiving CAR-T therapy, multivariate analysis showed that the grade of cytokine release syndrome (CRS) was the only independent risk factor associated with PTR (p = 0.007). Moreover, higher peak serum IL-6 and IFN-γ levels suggested a higher risk of PTR (p = 0.024 and 0.009, respectively). Patients with PTR received more platelet infusion doses than those without PTR (p = 0.0426). Patients with PTR had more grade 3-4 bleeding events than those without PTR (21.4 vs. 0%, p = 0.230), and the cumulative incidence of grade 3-4 bleeding event was different (p = 0.023). Conclusion: We found for the first time that PTR is associated with the CRS grade. Improved knowledge on the mechanisms of PTR after CAR-T therapy is needed to design a rational therapeutic strategy that aims to improve the efficiency of transfusions.

CRS-related coagulopathy in BCMA targeted CAR-T therapy: a retrospective analysis in a phase I/II clinical trial

Chimeric antigen receptor (CAR) T-cell therapy that targets B-cell maturation antigen (BCMA) has shown promising effects in the treatment of patients with refractory/relapsed multiple myeloma (R/R MM) patients. In this retrospective analysis of phase I/II clinical trial (ChiCTR1800017404), 37 patients with R/R MM received their first BCMA-targeted CAR T-cells following lymphodepletion chemotherapy. The response rate was high (97%), while accompanied by a high incidence of adverse events including coagulation dysfunction. Of 37 patients, all (100%) had cytokine release syndrome (CRS) and 34 (91%) developed at least one abnormal coagulation parameter. The values of coagulation parameters were positively correlated with the severity of CRS as well as with the levels of some cytokines, such as interleukin (IL)-6, IL-10, and interferon (IFN)-γ, etc. Furthermore, levels of the plasma tissue factor (TF), Factor X (FX), Factor XII (FXII), and P-selectin also showed a positive correlation with severity of CRS as well as some specific cytokines, which indicates that these factors are likely to play important roles in CRS-related coagulopathy. Our study suggests that there exists relationship in some extent between coagulation disorder and CRS. Moreover, coagulation dysfunction can be managed with daily monitoring and early intervention despite high incidence.

An Analysis of Cardiac Disorders Associated With Chimeric Antigen Receptor T Cell Therapy in 126 Patients: A Single-Centre Retrospective Study

Introduction

Chimeric antigen receptor T (CAR-T) cells are effective in treating hematological malignancies. However, in patients receiving CAR-T therapy, data characterizing cardiac disorders are limited.

Methods

126 patients with hematologic malignancies receiving CAR-T cell therapy were analyzed to determine the impact of CAR-T therapy on occurrence of cardiac disorders, including heart failure, arrhythmias, myocardial infarction, which were defined by the Common Terminology Criteria for Adverse Events (CTCAE). Parameters related to cardiac disorders were detected including myocardial enzyme, NT-proBNP and ejection fraction (EF). Cardiovascular (CV) events included decompensated heart failure (HF), clinically significant arrhythmias and CV death.

Results

The median age of patients was 56 years (6 to 72 years). 58% patients were male, 62% had multiple myeloma, 20% had lymphoma and 18% had ALL. 33 (26%) patients had cardiac disorders, most of which were grade 1-2. 13 patients (10%) were observed with cardiac disorders grade 3-5, which comprised 5(4%) patients with new-onset HF, 2 (2%) patients with new-onset arrhythmias, 4 (3%) patients with the acute coronary syndrome, 1(1%) patient with myocardial infarction and 1(1%) patient with left ventricular systolic dysfunction. There were 9 CV events (7%) including 6 decompensated heart failure, 1 clinically significant arrhythmias and 2 CV deaths. Among the 33 patients with cardiac disorders, the patients with cardiac disorders CTCAE grade 3-5 had higher grade CRS (grade ≥ 3) than those with cardiac disorders CTCAE grade ≤ 2 (P <0.001). More patients with cardiac disorders CTCAE grade 3-5 were observed in the cohort who did not receive corticosteroids and/or tocilizumab therapy timely comparing with those who received corticosteroids and/or tocilizumab therapy timely (P =0.0004).

Conclusions

Cardiac disorders CAR-T cell therapy were common and associated with occurrence of CRS. However, most cases were mild. For patients with CRS grade 3-5, timely administration of corticosteroids and/or tocilizumab can effectively prevent the occurrence and progression of cardiac disorders.

Bilateral anterior cerebral artery occlusion following CD19- and BCMA-targeted chimeric antigen receptor T-cell therapy for a myeloma patient

Chimeric antigen receptor T (CAR-T)-cell therapy is a promising treatment for relapsed/refractory multiple myeloma (RRMM). In our previous report, CD19- and BCMA-targeted CAR-T co-administration was associated with a high response rate. Although cytokine release syndrome (CRS) and neurotoxicity are frequent complications following CAR-T treatment, cerebral infarction is rarely reported as a CAR-T-related complication. We reported a 73-year-old female MM patient who received CD19- and BCMA-targeted CAR-T for refractory disease. Her disease responded to CAR-T therapy, but she developed neurological symptoms following CRS. Cranial CT and MRI demonstrated multiple cerebral infarctions and bilateral anterior cerebral artery (ACA) occlusion. We suggest that cerebral infarction other than CAR-T-related neurotoxicity is the underlying cause of abnormal neuropsychological symptoms, and diagnostic imaging tests should be actively performed to exclude ischemic cerebrovascular events.

Reactions Related to CAR-T Cell Therapy

The application of chimeric antigen receptor (CAR) T-cell therapy as a tumor immunotherapy has received great interest in recent years. This therapeutic approach has been used to treat hematological malignancies solid tumors. However, it is associated with adverse reactions such as, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), off-target effects, anaphylaxis, infections associated with CAR-T-cell infusion (CTI), tumor lysis syndrome (TLS), B-cell dysplasia, hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) and coagulation disorders. These adverse reactions can be life-threatening, and thus they should be identified early and treated effectively. In this paper, we review the adverse reactions associated with CAR-T cells, the mechanisms driving such adverse reactions, and strategies to subvert them. This review will provide important reference data to guide clinical application of CAR-T cell therapy.

Management of Disseminated Intravascular Coagulation in Acute Leukemias

Disseminated intravascular coagulation (DIC) is characterized by the intravascular activation of coagulation with loss of localization arising from different causes, and is diagnosed using scoring systems which rely upon the presence of an underlying disorder compatible with DIC alongside hemostatic derangements such as low platelet count, prolonged prothrombin time, and elevated fibrinogen degradation products. DIC is common in patients with acute leukemia, with prevalence ranging from 17 to 100% in acute promyelocytic leukemia (APL) and 8.5 to 25% in acute lymphoblastic leukemia (ALL) and non-APL acute myeloid leukemia (AML). The pathophysiology is complex and varies between the leukemia subtypes, and is not fully reflected by the laboratory markers currently used to classify DIC. Similarly, the clinical consequence of DIC in acute leukemia also varies across the types of leukemia. DIC is primarily associated with bleeding in APL, while thrombosis is the dominant phenotype in ALL and non-APL AML. The cornerstone of managing DIC is the treatment of the underlying disease, as exemplified by the important role of early administration of all-trans retinoic acid in APL. Other aspects of management focus on supportive care aimed at minimizing the risk of bleeding, via transfusion of blood products. The use of blood products is more liberal in APL, due to the hemorrhagic phenotype and unacceptably high rates of early hemorrhagic death. This review will focus on the pathophysiology, risk factors, clinical implications, and the management of DIC in patients across the spectrum of acute leukemias.

Biomarkers for Chimeric Antigen Receptor T Cell Therapy in Acute Lymphoblastic Leukemia: Prospects for Personalized Management and Prognostic Prediction

Chimeric antigen receptor (CAR) T cell therapy represents a breakthrough in immunotherapy with the potential of ushering in a new era in cancer treatment. Remarkable therapeutic response and complete remission of this innovative management have been observed in patients with relapse/refractory acute lymphoblastic leukemia. With CAR-T cell therapy becoming widely used both in multicenter clinical trials and as a commercial treatment, therapeutic efficacy monitoring and management of toxicities will be indispensable for ensuring safety and improving overall survival. Biomarkers can act not only as effective indicators reflecting patients' baseline characteristics, CAR-T cell potency, and the immune microenvironment, but can also assess side effects during treatment. In this review, we will elaborate on a series of biomarkers associated with therapeutic response as well as treatment-related toxicities, and present their current condition and latent value with respect to the clinical utility. The combination of biomarker research and CAR-T cell therapy will contribute to establishing a safer and more powerful monitoring system and prolonging the event-free survival of patients.

Advances in the diagnosis and treatment of disseminated intravascular coagulation in haematological malignancies

Haematological malignancies, including acute leukaemia and non-Hodgkin lymphoma, are one of the underlying diseases that frequently cause disseminated intravascular coagulation (DIC), an acquired thrombotic disorder. Concomitant DIC is associated with the severity of the underlying disease and poor prognosis. The Japanese Society on Thrombosis and Hemostasis released the new DIC diagnostic criteria in 2017. This criteria include coagulation markers such as soluble fibrin and the thrombin-antithrombin complex to more accurately evaluate the hypercoagulable state in patients. Among several groups of anticoagulants available, recombinant human soluble thrombomodulin is most frequently used to treat DIC caused by haematological malignancies in Japan. DIC is remitted in parallel with the improvement of the underlying haematological diseases; thus, there is room for debate regarding whether the treatment of DIC would improve the prognosis of patients. Haematopoietic stem cell transplantation as well as the recently introduced chimeric antigen receptor (CAR)-T-cell therapy are innovative therapies to produce a cure in a subset of patients with haematological malignancies. However, coagulopathy frequently occurs after these therapies, which limits the success of the treatment. For example, DIC is noted in approximately 50% of patients after CAT-T-cell therapy in conjunction with cytokine release syndrome. Hematopoietic stem cell transplantation (HSCT) causes endotheliitis, which triggers coagulopathy and the development of potentially lethal complications, such as sinusoidal obstruction syndrome/veno-occlusive disease and transplant-associated thrombotic microangiopathy. This review article describes the pathogenesis, clinical manifestation, diagnosis, and treatment of DIC caused by haematological malignancies, CAR-T-cell therapy, and HSCT.

Acute Kidney Injury after CAR-T Cell Therapy: Low Incidence and Rapid Recovery

Chimeric antigen receptor (CAR) T cell therapy using engineered cytotoxic T cells has shown promising responses in various hematologic malignancies. Cytokine release syndrome (CRS) and immune effector cell-associated neurologic syndrome (ICANS) are recognized toxicities of CAR-T, whereas kidney injury remains less well recognized. The objective of the present study was to identify the incidence of acute kidney injury (AKI) after CAR-T cell therapy, potential risk factors, and recovery of kidney function. We performed a retrospective review of 46 adult patients with non-Hodgkin lymphoma treated with CAR-T therapy between February 2018 and February 2019 at our institution. Serum creatinine values before CAR-T therapy through day 100 were used to assess AKI, as defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria: grade 1, 1.5- to <2-fold of baseline; grade 2, 2- to <3-fold of baseline; grade 3, ≥3-fold of baseline. CRS and ICANS were graded using the consensus criteria of the American Society of Transplantation and Cellular Therapy. The overall incidence of CRS was 78.3% (95% confidence interval [CI], 66% to 90.5%), of whom 13% (95% CI, 3.3% to 22.8%) developed grade 3-4 CRS, whereas the overall incidence of ICANS was lower at 45.7% (95% CI, 3.1% to 60.3%). The cumulative incidence of any grade AKI by day 100 was 30% (95% CI, 16.9% to 43.9%), with a grade 1 AKI incidence of 21.7% (95% CI, 9.7% to 33.8%) and a grade 2-3 AKI incidence of 8.7% (95% CI, .4% to 17%). No patients developed severe AKI necessitating renal replacement therapy. Patients with previous autologous or allogeneic stem cell transplantation, those requiring intensive care unit level care and with grade 3-4 CRS had a higher incidence of AKI. Most patients recovered, with kidney function returning to baseline within 30 days. We conclude that with early recognition and management of CAR-T complications, the incidence of AKI is low, the severity of injury is mild, and most patients recover kidney function within 30 days.