Practical guidelines for monitoring and management of coagulopathy following tisagenlecleucel CAR T-cell therapy

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.

Coagulopathy in CAR-T: Critical concern or mere blip?

Despite Peng and colleagues providing an extensive review of the clinical and laboratory aspects of CAR-T-associated coagulopathy, the current literature often lacks specificity in nomenclature and gradings, and the clinical implications of coagulopathy may remain unclear. Clear recommendations on stratification and prophylaxis are still required to standardize the clinical approach to this topic. Commentary on: Peng et al. Coagulation abnormalities associated with CAR-T therapy in hematological malignancies: A review. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19583.

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.

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

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

Recognizing, defining, and managing CAR-T hematologic toxicities

Autologous CAR-T cell therapy (CAR-T) has improved outcomes for patients with B-cell malignancies. It is associated with the well-described canonical toxicities cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), which may be abrogated by corticosteroids and the anti-IL6 receptor antagonist tocilizumab. Practitioners and researchers should be aware of additional toxicities. Here we review current understanding and management of hematologic toxicities after CAR-T, including cytopenias, coagulopathies, bleeding and clotting events, hemophagocytic-lymphohistiocytosis, and tumor lysis syndrome. We pay particular attention to cytopenias, recently termed immune effector cell-associated hematological toxicity (ICAHT). While the "H" is silent, hematotoxicity is not: ICAHT has the highest cumulative incidence of all immune adverse events following CAR-T. Early cytopenia (day 0-30) is closely linked to lymphodepleting chemotherapy and CRS-related inflammatory stressors. Late ICAHT (after day 30) can present either with or without antecedent count recovery (e.g., "intermittent" vs "aplastic" phenotype), and requires careful evaluation and management strategies. Growth factor support is the mainstay of treatment, with recent evidence demonstrating safety and feasibility of early granulocyte colony-stimulating factor (G-CSF) (e.g., within week 1). In G-CSF refractory cases, autologous stem cell boosts represent a promising treatment avenue, if available. The CAR-HEMATOTOX scoring system, validated for use across lymphoid malignancies (B-NHL, multiple myeloma), enables pretherapeutic risk assessment and presents the potential for risk-adapted management. Recent expert panels have led to diagnostic scoring criteria, severity grading systems, and management strategies for both ICAHT and the recently termed immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS), now clarified and defined as a distinct entity from CRS.

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.

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.

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.

A comprehensive analysis of adverse events in the first 30 days of phase 1 pediatric CAR T-cell trials

The tremendous success of chimeric antigen receptor (CAR) T cells in children and young adults (CAYAs) with relapsed/refractory B-cell acute lymphoblastic leukemia is tempered by toxicities such as cytokine release syndrome (CRS). Despite expansive information about CRS, profiling of specific end-organ toxicities secondary to CAR T-cell therapy in CAYAs is limited. This retrospective, single-center study sought to characterize end-organ specific adverse events (AEs) experienced by CAYAs during the first 30 days after CAR T-cell infusion. AEs graded using Common Terminology Criteria for Adverse Events were retrospectively analyzed for 134 patients enrolled in 1 of 3 phase 1 CAR T-cell trials (NCT01593696, NCT02315612, and NCT03448393), targeting CD19 and/or CD22. A total of 133 patients (99.3%) experienced at least 1 grade ≥3 (≥Gr3) AE across 17 organ systems, of which 75 (4.4%) were considered dose- or treatment-limiting toxicities. Excluding cytopenias, 109 patients (81.3%) experienced a median of 3 ≥Gr3 noncytopenia (NC) AEs. The incidence of ≥Gr3 NC AEs was associated with the development and severity of CRS as well as preinfusion disease burden (≥ 25% marrow blasts). Although those with complete remission trended toward experiencing more ≥Gr3 NC AEs than nonresponders (median, 4 vs 3), nonresponders experiencing CRS (n = 17; 37.8%) had the highest degree of NC AEs across all patients (median, 7 vs 4 in responders experiencing CRS). Greater understanding of these toxicities and the ability to predict which patients may experience more toxicities is critical as the array of CAR T-cell therapies expand. This retrospective study was registered at www.clinicaltrials.gov as NCT03827343.

Immunotherapy in hematologic malignancies: achievements, challenges and future prospects

The immune-cell origin of hematologic malignancies provides a unique avenue for the understanding of both the mechanisms of immune responsiveness and immune escape, which has accelerated the progress of immunotherapy. Several categories of immunotherapies have been developed and are being further evaluated in clinical trials for the treatment of blood cancers, including stem cell transplantation, immune checkpoint inhibitors, antigen-targeted antibodies, antibody-drug conjugates, tumor vaccines, and adoptive cell therapies. These immunotherapies have shown the potential to induce long-term remission in refractory or relapsed patients and have led to a paradigm shift in cancer treatment with great clinical success. Different immunotherapeutic approaches have their advantages but also shortcomings that need to be addressed. To provide clinicians with timely information on these revolutionary therapeutic approaches, the comprehensive review provides historical perspectives on the applications and clinical considerations of the immunotherapy. Here, we first outline the recent advances that have been made in the understanding of the various categories of immunotherapies in the treatment of hematologic malignancies. We further discuss the specific mechanisms of action, summarize the clinical trials and outcomes of immunotherapies in hematologic malignancies, as well as the adverse effects and toxicity management and then provide novel insights into challenges and future directions.

Immune Effector Cell-Associated Hemophagocytic Lymphohistiocytosis-Like Syndrome

T cell-mediated hyperinflammatory responses, such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), are now well-established toxicities of chimeric antigen receptor (CAR) T cell therapy. As the field of CAR T cells advances, however, there is increasing recognition that hemophagocytic lymphohistiocytosis (HLH)-like toxicities following CAR T cell infusion are occurring broadly across patient populations and CAR T cell constructs. Importantly, these HLH-like toxicities are often not as directly associated with CRS and/or its severity as initially described. This emergent toxicity, however ill-defined, is associated with life-threatening complications, creating an urgent need for improved identification and optimal management. With the goal of improving patient outcomes and formulating a framework to characterize and study this HLH-like syndrome, we established an American Society for Transplantation and Cellular Therapy panel composed of experts in primary and secondary HLH, pediatric and adult HLH, infectious disease, rheumatology and hematology, oncology, and cellular therapy. Through this effort, we provide an overview of the underlying biology of classical primary and secondary HLH, explore its relationship with similar manifestations following CAR T cell infusions, and propose the term "immune effector cell-associated HLH-like syndrome (IEC-HS)" to describe this emergent toxicity. We also delineate a framework for identifying IEC-HS and put forward a grading schema that can be used to assess severity and facilitate cross-trial comparisons. Additionally, given the critical need to optimize outcomes for patients experiencing IEC-HS, we provide insight into potential treatment approaches and strategies to optimize supportive care and delineate alternate etiologies that should be considered in a patient presenting with IEC-HS. By collectively defining IEC-HS as a hyperinflammatory toxicity, we can now embark on further study of the pathophysiology underlying this toxicity profile and make strides toward a more comprehensive assessment and treatment approach.

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.

Safety and efficacy of autologous and allogeneic humanized CD19-targeted CAR-T cell therapy for patients with relapsed/refractory B-ALL

BACKGROUND

Murine chimeric antigen receptor T (CAR-T) cell therapy has demonstrated clinical benefit in patients with relapsed/refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). However, the potential immunogenicity of the murine single-chain variable fragment domain may limit the persistence of CAR-T cell, leading to relapse.

METHODS

We performed a clinical trial to determine the safety and efficacy of autologous and allogeneic humanized CD19-targeted CAR-T cell (hCART19) for R/R B-ALL. Fifty-eight patients (aged 13-74 years) were enrolled and treated between February 2020 and March 2022. The endpoints were complete remission (CR) rate, overall survival (OS), event-free survival (EFS), and safety.

RESULTS

Overall, 93.1% (54/58) of patients achieved CR or CR with incomplete count recovery (CRi) by day 28, with 53 patients having minimal residual disease negativity. With a median follow-up of 13.5 months, the estimated 1-year OS and EFS were 73.6% (95% CI 62.1% to 87.4%) and 46.0% (95% CI 33.7% to 62.8%), with a median OS and EFS of 21.5 months and 9.5 months, respectively. No significant increase in human antimouse antibodies was observed following infusion (p=0.78). Duration of B-cell aplasia in the blood was observed for as long as 616 days, which was longer than that in our prior mCART19 trial. All toxicities were reversible, including severe cytokine release syndrome, which developed in 36% (21/58) of patients and severe neurotoxicity, which developed in 5% (3/58) of patients. Compared with our prior mCART19 trial, patients treated with hCART19 had longer EFS without increased toxicity. Additionally, our data also suggest that patients treated with consolidation therapy, including allogeneic hematopoietic stem cell transplantation or CD22-targeted CAR-T cell, following hCART19 therapy had a longer EFS than those without consolidation therapy.

CONCLUSION

hCART19 has good short-term efficacy and manageable toxicity in R/R B-ALL patients.

TRIAL REGISTRATION NUMBER

NCT04532268.

Predictive Nomogram for Hyperprogressive Disease During Anti-PD-1/PD-L1 Treatment in Patients with Advanced Non-Small Cell Lung Cancer

Introduction

Various studies have reported that anti-PD-1/PD-L1 treatment may lead to the rapid development of tumors called hyperprogressive disease (HPD). A nomogram for HPD prediction in NSCLC patients is urgently needed.

Methods

This retrospective cohort study included 176 cases for establishing a model of HPD prediction and 85 cases for validation in advanced NSCLC patients treated with PD-1/PD-L1 inhibitors. HPD was defined as tumor growth rate (TGR, ≥ 2), tumor growth kinetics (TGK, ≥ 2) or time to treatment failure (TTF, ≤ 2 months). Univariate and multivariate logistic regression were used to estimate the specified factors associated with HPD. Then, the nomogram was developed and validated.

Results

Anti-PD-1/PD-L1 therapy resulted in a 9.66% (17/176) incidence of HPD in advanced NSCLC. The overall survival (OS) and progression-free survival (PFS) in patients with HPD were significantly shorter than those in patients without HPD (OS: 7.00 vs 12.00 months, P<0.01; PFS: 2.00 vs 5.00 months, P<0.001, respectively). The HPD prediction nomogram included APTT (P<0.01), CD4+ CD25+ CD127-low cells (Treg cells) (P<0.01), the presence of liver metastasis (P<0.05), and more than two metastatic sites (P<0.05). Then, patients were divided into two groups by the "HPD score" calculated by the nomogram. The C-index was 0.845, while the area under the curve (AUC) was 0.830 (sensitivity 75.00%, specificity 91.70%). The calibration plot of HPD probability showed an optimal agreement between the actual observation and prediction by the nomogram. In the validation cohort, the AUC was up to 0.960 (sensitivity 88.70%, specificity 89.80%).

Conclusions

The nomogram was constructed with the presence of liver metastasis, more than two metastatic sites, lengthened APTT and a high level of Treg cells, which could be used to predict HPD risk.

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.

Cardiotoxicity Associated With Chimeric Antigen Receptor (CAR)-T Cell Therapy for Hematologic Malignancies: A Systematic Review

Chimeric Antigen Receptor (CAR)-T cell therapy has been one of the most important breakthroughs for treating hematologic malignancies. On the other hand, the therapy had many toxicities. One of the toxicities of the CAR-T therapy is cardiotoxicity. The goal of the systematic review is to elaborate on the cardiotoxicities related to CAR-T therapy for hematologic malignancies. The systematic review is following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) 2020 guidelines. The systematic search was done using PubMed, PubMed Central (PMC), Google Scholar, Cochrane Library, ScienceDirect, and clinicaltrial.gov. The search and selection of studies were done on April 28, 2022, and May 6, 2022, respectively. The studies were selected based upon participants, intervention, and outcomes (PIO) elements and the articles that were included were, full-text articles published within the last ten years, clinical trials, meta-analyses, randomized controlled trial, review, and systematic review. The exclusion criteria were non-hematologic malignancy, non-English-language articles. The initial search had 2,159 publications. The publications were assessed with assessment tools of Scale of the Assessment of Narrative Review Articles (SANRA), Newcastle-Ottawa Scale (NCOS), and Cochrane Collaboration Risk of Bias Tool (CCRBT), which led to selection of eight publications. The systematic review concludes that cardiotoxicity happened in adults and pediatric patients receiving the CAR-T cell therapy and that those cardiac adverse events had many risk factors. Therefore, monitoring these cardiotoxicities is highly essential.

Chimeric Antigen Receptor T-cell Therapy: Current Status and Clinical Outcomes in Pediatric Hematologic Malignancies

Chimeric antigen receptor T-cell (CART) therapy has transformed the treatment paradigm for pediatric patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL), with complete remission rates in key pivotal CD19-CART trials ranging from 65% to 90%. Alongside this new therapy, new toxicity profiles and treatment limitations have emerged, necessitating toxicity consensus grading systems, cooperative group trials, and novel management approaches. This review highlights the results of key clinical trials of CART for pediatric hematologic malignancies, discusses the most common toxicities seen to date, and elucidates challenges, opportunities, and areas of active research to optimize this therapy.

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.

Cytokine Release Syndrome and Associated Acute Toxicities in Pediatric Patients Undergoing Immune Effector Cell Therapy or Hematopoietic Cell Transplantation

Immune effector cells (IEC) are a powerful and increasingly targeted tool, particularly for the control and eradication of malignant diseases. However, the infusion, expansion, and persistence of autologous or allogeneic IEC or engagement of endogenous immune cells can be associated with significant systemic multi-organ toxicities. Here we review the signs and symptoms, grading and pathophysiology of immune-related toxicities arising in the context of pediatric immunotherapies and haploidentical T cell replete Hematopoietic Cell Transplantation (HCT). Principles of management are discussed with particular focus on the intersection of these toxicities with the requirement for pediatric critical care level support.

CAR-T cell: Toxicities issues: Mechanisms and clinical management

CAR-T cells are modified T cells expressing a chimeric antigen receptor targeting a specific antigen. They have revolutionized the treatment of B cell malignancies (aggressive lymphomas, B-ALL), and this has raised hopes for application in many other pathologies (myeloma, AML, solid tumors, etc.). However, these therapies are associated with novel and specific toxicities (cytokine release syndrome and neurotoxicity). These complications, although mostly managed in a conventional hospitalization unit, can sometimes be life threatening, leading to admission of patients to the intensive care unit. Management relies mainly on anti-IL6R (tocilizumab) and corticosteroids. However, the optimal treatment regimen is still a matter of debate, and the management of the most severe forms is even less well codified. In addition to CRS and ICANS, infections, cytopenia and hypogammaglobulinemia are other frequent complications. This article reviews the mechanisms, risk factors, clinical presentation, and management of these toxicities.

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.

Identifying and managing CAR T-cell-mediated toxicities: on behalf of an Italian CAR-T multidisciplinary team

INTRODUCTION

Chimeric antigen receptor (CAR)-T-cell therapy is a new treatment for patients with hematologic malignancies in which other therapies have failed.

AREAS COVERED

The review provides an overview for recognizing and managing the most acute toxicities related to CAR-T cells.

EXPERT OPINION

The development of immune-mediated toxicities is a common challenge of CAR-T therapy. The mechanism that determines this toxicity is still unclear, although an unfavorable tumor microenvironment and a pro-inflammatory state put patients at risk. The monitoring, diagnosis, and treatment of post-CAR-T toxicities must be determined and based on international guidelines and internal clinical practice. It is urgent to identify biomarkers that can identify patients at greater risk of developing complications. The adoption of consistent grading criteria is necessary to improve toxicity management strategies continually. The first-line therapy consists of supportive care and treatment with tocilizumab or corticosteroids. An early start of cytokine blockade therapies could mitigate toxicity. The plan will include cytokine release prophylaxis, a risk-adapted treatment, prevention of on-target/off-tumor effect, and a switch on/off CAR-T approach.

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.

CAR T-Cell Therapy in Hematologic Malignancies: Clinical Role, Toxicity, and Unanswered Questions

At the time of writing, five anti-CD19 CAR T-cell products are approved by the U.S. Food and Drug Administration for seven different indications in lymphoid malignancies, including B-cell non-Hodgkin lymphoma, pediatric B-cell acute lymphoblastic leukemia, and multiple myeloma. CAR T cells for chronic lymphocytic leukemia, acute myeloid leukemia, and less common malignancies such as T-cell lymphomas and Hodgkin lymphoma are being tested in early-phase clinical trials worldwide. The purpose of this overview is to describe the current landscape of CAR T cells in hematologic malignancies, outline their outcomes and toxicities, and explain the outstanding questions that remain to be addressed.