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

Current Challenges in Chimeric Antigen Receptor T-cell Therapy in Patients With B-cell Lymphoid Malignancies

Chimeric antigen receptor (CAR) T-cell therapy is a promising immunotherapy based on genetically engineered T cells derived from patients. The introduction of CAR T-cell therapy has changed the treatment paradigm of patients with B-cell lymphoid malignancies. However, challenging issues including managing life-threatening toxicities related to CAR T-cell infusion and resistance to CAR T-cell therapy, leading to progression or relapse, remain. This review summarizes the issues with currently approved CAR T-cell therapies for patients with relapsed or refractory B-cell lymphoid malignancies, including lymphoma and myeloma. We focus on unique toxicities after CAR T-cell therapy, such as cytokine-related events and hematological toxicities, and the mechanisms underlying post-CAR T-cell failure.

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.

Enhanced cellular therapy: revolutionizing adoptive cellular therapy

Enhanced cellular therapy has emerged as a novel concept following the basis of cellular therapy. This treatment modality applied drugs or biotechnology to directly enhance or genetically modify cells to enhance the efficacy of adoptive cellular therapy (ACT). Drugs or biotechnology that enhance the killing ability of immune cells include immune checkpoint inhibitors (ICIs) / antibody drugs, small molecule inhibitors, immunomodulatory factors, proteolysis targeting chimera (PROTAC), oncolytic virus (OV), etc. Firstly, overcoming the inhibitory tumor microenvironment (TME) can enhance the efficacy of ACT, which can be achieved by blocking the immune checkpoint. Secondly, cytokines or cytokine receptors can be expressed by genetic engineering or added directly to adoptive cells to enhance the migration and infiltration of adoptive cells to tumor cells. Moreover, multi-antigen chimeric antigen receptors (CARs) can be designed to enhance the specific recognition of tumor cell-related antigens, and OVs can also stimulate antigen release. In addition to inserting suicide genes into adoptive cells, PROTAC technology can be used as a safety switch or degradation agent of immunosuppressive factors to enhance the safety and efficacy of adoptive cells. This article comprehensively summarizes the mechanism, current situation, and clinical application of enhanced cellular therapy, describing potential improvements to adoptive cellular therapy.

Current Technologies and Future Perspectives in Immunotherapy towards a Clinical Oncology Approach

Immunotherapy is now established as a potent therapeutic paradigm engendering antitumor immune response against a wide range of malignancies and other diseases by modulating the immune system either through the stimulation or suppression of immune components such as CD4+ T cells, CD8+ T cells, B cells, monocytes, macrophages, dendritic cells, and natural killer cells. By targeting several immune checkpoint inhibitors or blockers (e.g., PD-1, PD-L1, PD-L2, CTLA-4, LAG3, and TIM-3) expressed on the surface of immune cells, several monoclonal antibodies and polyclonal antibodies have been developed and already translated clinically. In addition, natural killer cell-based, dendritic cell-based, and CAR T cell therapies have been also shown to be promising and effective immunotherapeutic approaches. In particular, CAR T cell therapy has benefited from advancements in CRISPR-Cas9 genome editing technology, allowing the generation of several modified CAR T cells with enhanced antitumor immunity. However, the emerging SARS-CoV-2 infection could hijack a patient's immune system by releasing pro-inflammatory interleukins and cytokines such as IL-1β, IL-2, IL-6, and IL-10, and IFN-γ and TNF-α, respectively, which can further promote neutrophil extravasation and the vasodilation of blood vessels. Despite the significant development of advanced immunotherapeutic technologies, after a certain period of treatment, cancer relapses due to the development of resistance to immunotherapy. Resistance may be primary (where tumor cells do not respond to the treatment), or secondary or acquired immune resistance (where tumor cells develop resistance gradually to ICIs therapy). In this context, this review aims to address the existing immunotherapeutic technologies against cancer and the resistance mechanisms against immunotherapeutic drugs, and explain the impact of COVID-19 on cancer treatment. In addition, we will discuss what will be the future implementation of these strategies against cancer drug resistance. Finally, we will emphasize the practical steps to lay the groundwork for enlightened policy for intervention and resource allocation to care for cancer patients.

Chimeric antigen receptor T-cell therapy-induced nervous system toxicity: a real-world study based on the FDA Adverse Event Reporting System database

BACKGROUND

Nervous system toxicity (NST) is one of the most frequent and dangerous side effects of chimeric antigen receptor T-cell (CAR-T) therapy, which is an effective treatment for related tumors in most relapsed/refractory (r/r) hematologic malignancies. Current clinical trial data do not fully reflect the real-world situation. Therefore, this study evaluated the NST of CAR-T therapy using the FDA Adverse Event Reporting System (FAERS).

METHODS

Data were retrieved from FAERS for the period from January 1, 2017 to March 31, 2023. Disproportionality analysis and Bayesian analysis were used for data mining. The reporting odds ratio (ROR) for NST with 95% confidence interval (CI) was calculated for each CAR-T product. The time to onset (TTO) and clinical outcomes due to CAR-T therapy-associated NST were assessed.

RESULTS

Overall, 6946 cases of NST associated with CAR-T therapy were identified. The patients had a median age of 61 years (interquartile range [IQR]: 47-69 years). Significant signals were observed for all CAR-T products (ROR: 2.19, 95% CI: 2.13-2.44). Anti-CD19 CAR-T products showed a higher NST signal than anti-B cell maturation antigen (BCMA) CAR-T products (ROR025 2.13 vs. 1.98). Brexucabtagene autoleucel (ROR: 3.17, 95% CI: 2.90-3.47) and axicabtagene ciloleucel (ROR: 2.92, 95% CI: 2.81-3.03) had the two highest NST signals. For the preferred term "brain edema," the highest signals were obtained for CD28 CAR-T products. The median TTO of NST for all CAR-T products was 7 days (IQR: 3-17 days). The proportion of death, life-threatening and hospitalization adverse events associated with NST was 20.06%, 7.21%, and 32.70%, respectively. The proportion of death outcomes was higher in patients treated with tisagenlecleucel (30.36%) than in those treated with other CAR-T products, except ciltacabtagene autoleucel (P < 0.001). The proportion of hospitalizations was significantly higher for lisocabtagene maraleucel-associated NST (53.85%) than for other drugs, except for ciltacabtagene autoleucel (P < 0.001).

CONCLUSIONS

NST is more closely associated with anti-CD19 CAR-Ts and CAR-Ts containing CD28. Serious NST (brain oedema) is likely to occur with CAR-Ts that contain CD28. CAR-T-related NST warrants greater attention owing to the high proportion of serious adverse events and delayed NST.

Cytokine Release Syndrome in Patients Treated With Chimeric Antigen Receptor T-cell Therapy: A Retrospective Study Analyzing Risks, Outcomes, and Healthcare Burden

Background Chimeric antigen receptor T-cell (CAR-T) therapy has emerged as a promising immunotherapy for various malignancies. However, its use is associated with challenges, including cytokine release syndrome (CRS), a potentially severe complication. This retrospective study aims to analyze the risks, outcomes, and healthcare burden of CRS in patients undergoing CAR-T therapy. Method Data from the 2020 National Inpatient Sample (NIS) were utilized, comprising 415 CAR-T-related hospitalizations. They were categorized into those with CRS (n = 68) and those without CRS (n = 347). Baseline characteristics, including age, gender, race, income, insurance status, and comorbidities, were compared. Outcomes of interest included in-hospital mortality, length of stay (LOS), total hospital charges, and access to complications, associations, and interventions. Statistical analyses, including multivariable models, were employed to assess associations. Results Hospitalizations with CRS did not exhibit significant differences in age, gender, race, income, or insurance status compared to those without CRS. The multivariable analysis showed no statistically significant difference in mortality (adjusted odds ratio (aOR) = 2.48, 95% confidence interval (CI): 0.71 to 8.69, p = 0.151), LOS (coefficient = -2.1 days, 95% CI: -5.43 to 1.21, p = 0.207), or total hospital charges (coefficient = $207,456, 95% CI: $6119 to $421,031, p = 0.057) between the two groups. The CRS group had a higher incidence of fever (aOR = 1.91, 95% CI: 1.15 to 3.17, p = 0.014), acute respiratory failure (aOR = 2.10, 95% CI: 1.01 to 4.40, p= 0.049), and the need for intubation/mechanical ventilation (aOR = 2.59, 95% CI: 1.14 to 5.88, p = 0.024). Hemophagocytic lymphohistiocytosis (HLH) was significantly associated with CRS (aOR = 6.72, 95% CI: 2.03 to 22.18, p = 0.002). Conclusion While the development of CRS in CAR-T-treated patients did not significantly increase mortality, LOS, or total hospital charges, it was associated with specific risks and outcomes, including fever, respiratory failure, and HLH. This study emphasizes the importance of vigilance in recognizing and managing CRS in CAR-T therapy to optimize patient outcomes. The findings contribute valuable insights to guide clinical decision-making in the context of CAR-T therapy.

Complete spectrum of adverse events associated with chimeric antigen receptor (CAR)-T cell therapies

Chimeric antigen receptor (CAR)-T cell therapies have been approved by FDA to treat relapsed or refractory hematological malignancies. However, the adverse effects of CAR-T cell therapies are complex and can be challenging to diagnose and treat. In this review, we summarize the major adverse events, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and CAR T-cell associated HLH (carHLH), and discuss their pathophysiology, symptoms, grading, and diagnosis systems, as well as management. In a future outlook, we also provide an overview of measures and modifications to CAR-T cells that are currently being explored to limit toxicity.

Cervical Local Cytokine Release Syndrome Following Chimeric Antigen Receptor T-cell Therapy in Patients With Relapsed or Refractory Diffuse Large B-cell Lymphoma

The use of chimeric antigen receptor T-cell (CAR-T) therapy for hematologic malignancies is rapidly increasing, and appropriately managing adverse events (AEs) is crucial. Cytokine release syndrome (CRS) is a common AE of CAR-T therapy, characterized by systemic symptoms such as fever and respire-circulatory failure. We present two cases with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) accompanied by a rare complication of cervical local CRS as an acute inflammatory reaction at a specific site after CAR-T infusion. Case 1: A 60-year-old gentleman with diffuse large B cell lymphoma (DLBCL) developed grade 1 CRS on day one that required three doses of tocilizumab. Then he developed remarkable cervical edema as local CRS on day five. His local CRS spontaneously improved from day seven without additional therapy. Case 2: A 70-year-old gentleman with DLBCL developed grade 1 CRS on day two that required three doses of tocilizumab. Then he developed remarkable cervical edema and muffled voice as local CRS on day three. He received dexamethasone because of concerns about airway obstruction, and his local CRS improved immediately after dexamethasone administration. Before Tisa-Cel infusion, neither patients had a lymphoma lesion in their necks. To summarize, local CRS may occur at the site without lymphoma involvement after CAR-T therapy. An appropriate diagnosis and careful observation are required to determine the need for additional treatment.