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

MARC, a novel modular chimeric antigen receptor, improves T cell-based cancer immunotherapies by preventing early T cell exhaustion and enhancing persistence

BACKGROUND

Chimeric antigen receptor T cell (CAR-T)-based immunotherapies have reshaped the therapeutic landscape of cancer treatment, in particular for patients afflicted with leukemia. However, defects in CAR behaviors and clinical complications have hindered their widespread application across diverse cancer types. Chief among these defects is high tonic signaling, absent in native activating immune receptors, which accelerates T cell exhaustion and undermines treatment efficacy. We hypothesized that these limitations arise because current CAR architectures fail to replicate the modular design of native activating immune receptors, which integrate distinct receptor and signaling modules. This modular assembly is crucial for maintaining proper receptor regulation and function.

METHODS

Therefore, we set forth to develop a modular chimeric antigen receptor leveraging the same assembly principles found in native activating immune receptors to reestablish the intrinsic safeguards in receptor expression and signaling.

RESULTS

The resulting Modular Actuation Receptor Complex (MARC) displayed surface expression levels akin to its native immune receptor counterpart, the NK cell receptor KIR2DS3, while eliminating tonic signaling. In a clinically relevant mouse leukemia model, MARC-T cells exhibited remarkable long-term persistence and a less exhausted phenotype compared with conventional CAR-T cells.

CONCLUSIONS

With its modular architecture, the MARC offers unparalleled opportunities for optimization and broad applicability across different cell types, paving the way for transformative advancements in cell-based therapies. This innovation holds immense promise as a next-generation therapeutic tool in clinical settings.

CAR-T for multiple myeloma: practice pearls

The CAR-T cell products ciltacabtagene autoleucel and idecabtagene vicleucel have transformed the management of patients with multiple myeloma. Here, we present a practical guide highlighting clinical pearls on the incorporation of CAR-T into clinical practice. Topics addressed include expected outcomes, recommendations for referral timing, bridging therapy, treatment complications, therapeutic sequencing, and management of relapse.

Immunotherapy in chronic lymphocytic leukemia: advances and challenges

Chronic lymphocytic leukemia (CLL) is characterized as a clonal proliferation of mature B lymphocytes with distinct immunophenotypic traits, predominantly affecting the middle-aged and elderly population. This condition is marked by an accumulation of lymphocytes within the peripheral blood, bone marrow, spleen, and lymph nodes. The associated immune dysregulation predisposes CLL patients to a higher risk of secondary malignancies and infections, which significantly contribute to morbidity and mortality rates. The advent of immunotherapy has revolutionized the prognosis of CLL, advancing treatment modalities and offering substantial benefits to patient outcomes. This review endeavors to synthesize and scrutinize the efficacy, merits, and limitations of the current immunotherapeutic strategies for CLL. The aim is to inform the selection of optimal treatment regimens tailored to individual patient needs. Furthermore, the review juxtaposes various therapeutic combinations to elucidate the comparative advantages of each approach, with the ultimate objective of enhancing patient prognosis and quality of life.

Neurotoxic complications of chimeric antigen receptor (CAR) T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy has revolutionised the treatment of haematological malignancies and has demonstrated efficacy in early trials for solid tumours, neurological and rheumatological autoimmune diseases. However, CAR-T is complicated in some patients by neurotoxicity syndromes including immune-effector cell-associated neurotoxicity syndrome, and the more recently described movement and neurocognitive treatment-emergent adverse events, and tumour inflammation-associated neurotoxicity. These neurotoxic syndromes remain poorly understood and are associated with significant morbidity and mortality. A multidisciplinary approach, including neurologists, haematologists and oncologists, is critical for the diagnosis and management of CAR-T neurotoxicity. This approach will be of increasing importance as the use of CAR-T expands, its applications increase and as novel neurotoxic syndromes emerge.

Case Report: Successful use of emapalumab in adult B-cell acute lymphoblastic leukemia experiencing severe neurotoxicity and hemophagocytic lymphohistiocytosis-like features after CAR-T cell therapy

Chimeric antigen receptor (CAR)-T cell therapy is a powerful adoptive immunotherapy associated with significant toxicity, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). As CAR-T usage expands, hyperinflammatory toxicities resembling hemophagocytic lymphohistiocytosis (HLH) syndrome are increasingly recognized. Immune effector cell-associated HLH-like syndrome (IEC-HS) describes HLH-like symptoms attributable to CAR-T cell therapy, often presenting as CRS resolves. Treatments for IEC-HS are adapted from primary HLH, including corticosteroids, the recombinant human interleukin (IL)-1 receptor antagonist anakinra and the Janus Kinase inhibitor ruxolitinib. Emapalumab, an anti-IFN-γ antibody, is promising but underexplored in adult IEC-HS cases. We report an adult B-cell acute lymphoblastic leukemia (B-ALL) patient treated with brexucabtagene autoleucel (brexu-cel). The patient developed CRS, refractory neurotoxicity, and IEC-HS with worsening multiorgan failure and hyperinflammatory markers. Treatment included tocilizumab, high-dose corticosteroids, anakinra, siltuximab, and ruxolitinib. Despite aggressive management, hyperinflammation and neurotoxicity persisted. Emapalumab was initiated on day +11, resulting in normalization of the biochemical parameters and full neurological recovery by day +21. The patient recovered from IEC-HS and underwent allogeneic stem cell transplantation. This case highlights the role of emapalumab in managing refractory IEC-HS and persistent neurotoxicity in adults, underscoring the need for targeted interventions in severe CAR-T complications.

Emapalumab for severe cytokine release syndrome in solid tumor CAR-T: a case report

Chimeric Antigen Receptor T (CAR-T) cell therapy significantly and rapidly changed the treatment paradigm for lymphoma, myeloma and leukemia, and the recent approvals of the first cellular immunotherapies in melanoma and synovial sarcoma demonstrate the potential success of this approach in solid tumors. Though the therapeutic potential of CAR-T is impressive, severe cytokine release syndrome (CRS) remains an ongoing challenge. Here we report a patient who received an investigational CAR-T product for metastatic castration-resistant prostate cancer who developed multi-drug refractory, life-threatening CRS, which was successfully treated with the interferon (IFN)-γ antagonist emapalumab. Within 12 hours after the first dose of emapalumab, there was a dramatic improvement in hemodynamic status and the patient was weaned off all four vasopressors. The hemodynamic improvement was associated with a decrease in IFN-γ and CXCL10 levels but no other cytokines. Not only was emapalumab the only drug effective at treating this case of refractory CRS, but it did not appear to reduce the activity of the CAR-T product, as the CAR-T vector copy numbers remained persistent and the patient's PSA levels remained low. This case demonstrates the clinical use of emapalumab to treat refractory cytokine release syndrome in a solid tumor CAR-T while potentially preserving therapeutic efficacy of CAR-T therapy. Further studies with larger patient populations are needed to evaluate the use of emapalumab as a treatment for CRS.

Recent Advances in Aging and Immunosenescence: Mechanisms and Therapeutic Strategies

Cellular senescence is an irreversible state of cell cycle arrest. Senescent cells (SCs) accumulate in the body with age and secrete harmful substances known as the senescence-associated secretory phenotype (SASP), causing chronic inflammation; at the same time, chronic inflammation leads to a decrease in immune system function, known as immunosenescence, which further accelerates the aging process. Cellular senescence and immunosenescence are closely related to a variety of chronic diseases, including cardiovascular diseases, metabolic disorders, autoimmune diseases, and neurodegenerative diseases. Studying the mechanisms of cellular senescence and immunosenescence and developing targeted interventions are crucial for improving the immune function and quality of life of elderly people. Here, we review a series of recent studies focusing on the molecular mechanisms of cellular senescence and immunosenescence, the regulation of aging by the immune system, and the latest advances in basic and clinical research on senolytics. We summarize the cellular and animal models related to aging research, as well as the mechanisms, strategies, and future directions of aging interventions from an immunological perspective, with the hope of laying the foundation for developing novel and practical anti-aging therapies.

Multi-targeted, NOT gated CAR-T cells as a strategy to protect normal lineages for blood cancer therapy

Introduction

Despite advances in treatment of blood cancers, several-including acute myeloid leukemia (AML)-continue to be recalcitrant. Cell therapies based on chimeric antigen receptors (CARs) have emerged as promising approaches for blood cancers. However, current CAR-T treatments suffer from on-target, off-tumor toxicity, because most familiar blood cancer targets are also expressed in normal lineages. In addition, they face the common problem of relapse due to target-antigen loss. Cell therapeutics engineered to integrate more than one signal, often called logic-gated cells, can in principle achieve greater selectivity for tumors.

Methods

We applied such a technology, a NOT gated system called Tmod™ that is being developed to treat solid-tumor patients, to the problem of therapeutic selectivity for blood cancer cells.

Results

Here we show that Tmod cells can be designed to target 2-4 antigens to provide different practical and conceptual options for a blood cancer therapy: (i) mono- and bispecific activating receptors that target CD33, a well-known AML antigen expressed on the majority of AML tumors (as well as healthy myeloid cells) and CD43 (SPN), an antigen expressed on many hematopoietic cancers (and normal blood lineages); and (ii) mono- and bispecific inhibitory receptors that target CD16b (FCGR3B) and CLEC9A, antigens expressed on key normal blood cells but not on most blood cancers.

Discussion

These results further demonstrate the robust modularity of the Tmod system and generalize the Tmod approach beyond solid tumors.

Mitigation and Management of Common Toxicities Associated with the Administration of CAR-T Therapies in Oncology Patients

Chimeric antigen receptor T-cell (CAR-T) therapies are one of the main approaches among targeted cellular therapies. Despite the potential benefit and durable responses observed in some patients receiving CAR-T therapies, serious and potentially fatal toxicities remain a major challenge. The most common CAR-T-associated toxicities include cytokine release syndrome (CRS), neurotoxicity, cytopenias, and infections. While CRS and neurotoxicity are generally managed with tocilizumab and corticosteroids, respectively, high-grade toxicities can be life-threatening. Close postinfusion monitoring and assessment of clinical laboratory parameters, patient-related and clinical risk factors (e.g., age, tumor burden, comorbidities, baseline laboratory parameters, and underlying abnormalities), and therapy-related risk factors (e.g., CAR-T type, dose, and CAR-T-induced toxicity) are effective strategies to mitigate the toxicities. Clinical laboratory parameters, including various cytokines, have been identified for CRS (interleukin [IL]-1, IL-2, IL-5, IL-6, IL-8, IL-10, C-reactive protein [CRP], interferon [IFN]-γ, ferritin, granulocyte-macrophage colony-stimulating factor [GM-CSF], and monocyte chemoattractant protein-1), neurotoxicity (IL-1, IL-2, IL-6, IL-15, tumor necrosis factor [TNF]-α, GM-CSF, and IFN-γ), cytopenias (IL-2, IL-4, IL-6, IL-10, IFN-γ, ferritin, and CRP), and infections (IL-8, IL-1β, CRP, IFN-γ, and procalcitonin). CAR-T-associated toxicities can be monitored and treated to mitigate the risk to patients. Assessment of alterations in clinical laboratory parameter values that are correlated with CAR-T-associated toxicities may predict development and/or severity of a given toxicity, which can improve patient management strategies and ultimately enable the patients to better tolerate these therapies.

Multi-Targeting CAR-T Cell Strategies to Overcome Immune Evasion in Lymphoid and Myeloid Malignancies

BACKGROUND

Chimeric antigen receptor (CAR)-T cell therapy has become a groundbreaking treatment for hematological malignancies, particularly lymphomas and multiple myeloma, with high remission rates in refractory and relapsed patients. However, most CAR-T therapies target a single antigen, such as CD19, which can result in immune evasion through antigen escape. This mechanism describes the downregulation or complete loss of the targeted antigen by the tumor cells, eventually leading to relapse. To address this issue, multi-targeting strategies like logic-gated CARs, adapter CARs, or combination therapies can increase the potency of CAR-T cells. These approaches aim to minimize immune evasion by targeting multiple antigens simultaneously, thereby increasing treatment durability. Additionally, advanced tools such as next-generation sequencing (NGS), direct stochastic optical reconstruction microscopy (dSTORM), or multiparametric flow cytometry are helping to identify novel tumor-specific targets and improve therapy designs.

SUMMARY

This review explores the current landscape of CAR-T cell therapies in lymphoid and myeloid malignancies, highlights ongoing clinical trials, and discusses the future of these innovative multi-targeting approaches to improve patient outcome.

KEY MESSAGES

Antigen escape limits CAR-T cell therapy success, but multi-targeting strategies like logic gates and adapter CARs offer solutions. Optimizing antigen selection and CAR design, along with larger clinical trials, is essential for improving patient outcomes. Personalization using advanced technologies like CRISPR screening and single-cell RNA sequencing can enhance durability and effectiveness of treatments for heavily pretreated patients.

Cellular Kinetics and Biodistribution of Adoptive T Cell Therapies: from Biological Principles to Effects on Patient Outcomes

Cell-based immunotherapy has revolutionized cancer treatment in recent years and is rapidly expanding as one of the major therapeutic options in immuno-oncology. So far ten adoptive T cell therapies (TCTs) have been approved by the health authorities for cancer treatment, and they have shown remarkable anti-tumor efficacy with potent and durable responses. While adoptive T cell therapies have shown success in treating hematological malignancies, they are lagging behind in establishing promising efficacy in treating solid tumors, partially due to our incomplete understanding of the cellular kinetics (CK) and biodistribution (including tumoral penetration) of cell therapy products. Indeed, recent clinical studies have provided ample evidence that CK of TCTs can influence clinical outcomes in both hematological malignancies and solid tumors. In this review, we will discuss the current knowledge on the CK and biodistribution of anti-tumor TCTs. We will first describe the typical CK and biodistribution characteristics of these "living" drugs, and the biological factors that influence these characteristics. We will then review the relationships between CK and pharmacological responses of TCT, and potential strategies in enhancing the persistence and tumoral penetration of TCTs in the clinic. Finally, we will also summarize bioanalytical methods, preclinical in vitro and in vivo tools, and in silico modeling approaches used to assess the CK and biodistribution of TCTs.

Co-targeting of the thymic stromal lymphopoietin receptor to decrease immunotherapeutic resistance in CRLF2-rearranged Ph-like and Down syndrome acute lymphoblastic leukemia

CRLF2 rearrangements occur in >50% of Ph-like and Down syndrome (DS)-associated B-acute lymphoblastic leukemia (ALL) and induce constitutive kinase signaling targetable by the JAK1/2 inhibitor ruxolitinib under current clinical investigation. While chimeric antigen receptor T cell (CART) immunotherapies have achieved remarkable remission rates in children with relapsed/refractory B-ALL, ~50% of CD19CART-treated patients relapse again, many with CD19 antigen loss. We previously reported preclinical activity of thymic stromal lymphopoietin receptor-targeted cellular immunotherapy (TSLPRCART) against CRLF2-overexpressing ALL as an alternative approach. In this study, we posited that combinatorial TSLPRCART and ruxolitinib would have superior activity and first validated potent TSLPRCART-induced inhibition of leukemia proliferation in vitro in CRLF2-rearranged ALL cell lines and in vivo in Ph-like and DS-ALL patient-derived xenograft (PDX) models. However, simultaneous TSLPRCART/ruxolitinib or CD19CART/ruxolitinib treatment during initial CART expansion diminished T cell proliferation, blunted cytokine production, and/or facilitated leukemia relapse, which was abrogated by time-sequenced/delayed ruxolitinib co-exposure. Importantly, ruxolitinib co-administration prevented fatal TSLPRCART cytokine-associated toxicity in ALL PDX mice. Upon ruxolitinib withdrawal, TSLPRCART functionality recovered in vivo with clearance of subsequent ALL rechallenge. These translational studies demonstrate an effective two-pronged therapeutic strategy that mitigates acute CART-induced hyperinflammation and provides potential anti-leukemia 'maintenance' relapse prevention for CRLF2-rearranged Ph-like and DS-ALL.

Simple and early prediction of severe CAR-T-related adverse events after Axi-cel infusion by initial high fever

Chimeric antigen receptor T-cell (CAR-T)-related adverse events (CAR-AEs), such as immune effector cell-associated neurotoxicity syndrome (ICANS) and cytokine release syndrome (CRS), can be life-threatening and may require high-dose steroids. Identifying patients at high risk for severe CAR-AEs in a simplified way is crucial for early therapeutic intervention. This retrospective study analyzed 44 patients treated with axicabtagene ciloleucel (Axi-cel) to identify predictive factors for severe CAR-AEs. We found that grade ≥ 3 ICANS, hemophagocytic syndrome, and ICU admission were associated with a greater need for high-dose steroids, which we defined as events associated with high-dose steroids (EHS). The incidence of EHS was significantly higher in patients who developed an initial fever (≥ 38.6 °C) within 24 h of CAR-T infusion (p < 0.001). Progression-free survival (PFS) was significantly shorter in patients with EHS compared to those without EHS (p < 0.001). Additionally, patients who developed a fever within 24 h and those with a peak fever of ≥ 38.6 °C both tended to have higher peak CAR-T counts compared to other patients. Our findings suggest that an initial fever (≥ 38.6 °C) within 24 h of Axi-cel infusion may predict severe CAR-AEs requiring high-dose steroids, and that EHS is associated with worse PFS.

Influence of CAR T-cell therapy associated complications

Since the introduction of chimeric antigen receptor (CAR) T-cell therapy, it has elicited an immense response in both targeted and residual cancers. Its clinical efficacy is often accompanied by a group of side effects that may become serious because of factors such as tumor burden, the extent of lymphodepletion, and the type of co-stimulus. It is also crucial to know the common toxicities associated with CAR T-cell therapy, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), cardiotoxicity, metabolic disorders, pulmonary toxicity, macrophage activation syndrome (MAS), prolonged cytopenia, coagulation disorders, and potential off-target effects on various organs. If not well managed, these can be fatal. However, knowledge about molecular pathways, calcineurin inhibitors, IL-6 receptor antagonists, steroids, suppression of nitric oxide synthase, various therapeutic approaches, and other recent advances have been developed to mitigate the fatal results of various short-term and chronic adverse events related to CAR T-cell therapy. This study provides a comprehensive perspective on contemporary management strategies and presumed causative processes of CAR T-cell-related adverse effects, albeit with several limitations. When CAR T-cell complications, costs, and challenges of toxicity management are properly considered, the CAR T-cell therapy of the future will include a number of toxicity-escaping options.

Monitoring the neurological complications of chimeric antigen receptor (CAR) T-cell therapy in patients with sensory and physical impairments and non-native-speaking backgrounds using modified immune effector cell-associated encephalopathy (ICE) scores: a case series

Background

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a common complication of chimeric antigen receptor (CAR) T-cell therapy. Current practice guidelines recommend the immune effector cell-associated encephalopathy (ICE) score for the assessment and monitoring of ICANS.

Objective

To demonstrate modifications to ICE score to patients with vision and hearing impairments or who are who are from non-native-speaking backgrounds.

Methods

We discuss five cases and the modifications made to adapt the ICE score to meet patients' needs.

Results

Modifications to ICE score was feasible and it assisted with CAR T cell therapy outcome monitoring.

Discussion

These cases highlight the need for flexible and patient-tailored strategies and the importance of collaboration between multidisciplinary teams and patients' families/caregivers when monitoring patients for ICANS after CAR T-cell therapy.

Real-world outcomes with tisagenlecleucel in aggressive B-cell lymphoma: subgroup analyses from the CIBMTR registry

BACKGROUND

Tisagenlecleucel, a CD19 chimeric antigen receptor T-cell therapy, is approved for adults with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) or high-grade B-cell lymphoma (HGBCL) after ≥2 lines of therapy. When used in real-world settings, tisagenlecleucel has shown similar efficacy and improved safety compared with previous clinical trials. However, long-term data on real-world outcomes are lacking.

METHODS

Clinical data from a cohort of patients treated with tisagenlecleucel in a real-world setting were captured in the Center for International Blood and Marrow Transplant Research registry. The main clinical outcomes analysed included response rate, duration of response, survival, adverse events and clinicopathologic and treatment characteristics that may affect those outcomes.

RESULTS

As of May 2022, 1159 patients with R/R DLBCL/HGBCL received tisagenlecleucel. The overall response rate was 59.5%, and the complete response rate was 44.5%. With a median follow-up of 23.2 months in the efficacy set (n=968), the 24 month rates of progression-free survival, ongoing response and overall survival were 28.4%, 52.6% and 43.6%, respectively. Grade ≥3 cytokine release syndrome and neurotoxicity were reported in 6% and 7.4% of patients, respectively. Patients with DLBCL (vs HGBCL), complete response before infusion, prior autologous or allogeneic haematopoietic stem cell transplant and lactate dehydrogenase (LDH) within normal limits experienced more favourable efficacy outcomes, and those with Eastern Cooperative Oncology Group performance status of ≥2, ≥3 prior lines of therapy, elevated LDH and fludarabine-based lymphodepleting chemotherapy experienced less favourable safety outcomes.

CONCLUSIONS

This real-world study of tisagenlecleucel for patients with R/R DLBCL/HGBCL shows consistent efficacy and better safety outcomes than the pivotal trial. This study also identifies baseline disease characteristics and prior or concurrent treatments that may affect clinical outcomes.Tisagenlecleucel, a CD19 chimeric antigen receptor T-cell therapy, is approved for adults with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) or high-grade B-cell lymphoma (HGBCL) after ≥2 lines of therapy. When used in real-world settings, tisagenlecleucel has shown similar efficacy and improved safety compared with previous clinical trials. However, long-term data on real-world outcomes are lacking.Clinical data from a cohort of patients treated with tisagenlecleucel in a real-world setting were captured in the Center for International Blood and Marrow Transplant Research registry. The main clinical outcomes analysed included response rate, duration of response, survival, adverse events, and clinicopathologic and treatment characteristics that may affect those outcomes.As of May 2022, 1159 patients with R/R DLBCL/HGBCL received tisagenlecleucel. The overall response rate was 59.5%, and the complete response rate was 44.5%. With a median follow-up of 23.2 months in the efficacy set (n=968), the 24 month rates of progression-free survival, ongoing response, and overall survival were 28.4%, 52.6%, and 43.6%, respectively. Grade ≥3 cytokine release syndrome and neurotoxicity were reported in 6% and 7.4% of patients, respectively. Patients with DLBCL (vs HGBCL), complete response before infusion, prior autologous or allogeneic haematopoietic stem cell transplant, and lactate dehydrogenase (LDH) within normal limits experienced more favourable efficacy outcomes, and those with Eastern Cooperative Oncology Group performance status ≥2, ≥3 prior lines of therapy, elevated LDH, and fludarabine-based lymphodepleting chemotherapy experienced less favourable safety outcomes.In conclusion, this real-world study of tisagenlecleucel for patients with R/R DLBCL/HGBCL shows consistent efficacy and better safety outcomes than the pivotal trial. This study also identifies baseline disease characteristics and prior or concurrent treatments that may affect clinical outcomes.

Novel strategies to manage CAR-T cell toxicity

The immune-related adverse events associated with chimeric antigen receptor (CAR)-T cell therapy result in substantial morbidity as well as considerable cost to the health-care system, and can limit the use of these treatments. Current therapeutic strategies to manage immune-related adverse events include interleukin-6 receptor (IL-6R) blockade and corticosteroids. However, because these interventions do not always address the side effects, nor prevent progression to higher grades of adverse events, new approaches are needed. A deeper understanding of the cell types involved, and their associated signalling pathways, cellular metabolism and differentiation states, should provide the basis for alternative strategies. To preserve treatment efficacy, cytokine-mediated toxicity needs to be uncoupled from CAR-T cell function, expansion, long-term persistence and memory formation. This may be achieved by targeting CAR or independent cytokine signalling axes transiently, and through novel T cell engineering strategies, such as low-affinity CAR-T cells, reversible on-off switches and versatile adaptor systems. We summarize the current management of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome, and review T cell- and myeloid cell-intrinsic druggable targets and cellular engineering strategies to develop safer CAR-T cells.

Practical management of adverse events in patients receiving tarlatamab, a delta-like ligand 3-targeted bispecific T-cell engager immunotherapy, for previously treated small cell lung cancer

Tarlatamab is a bispecific T-cell engager immunotherapy targeting delta-like ligand 3 (DLL3) and the cluster of differentiation 3 (CD3) molecule. In the phase 2 DeLLphi-301 trial of tarlatamab for patients with previously treated small cell lung cancer, tarlatamab 10 mg every 2 weeks achieved durable responses and encouraging survival outcomes. Analyses of updated safety data from the DeLLphi-301 trial demonstrated that the most common treatment-emergent adverse events were cytokine release syndrome (53%), pyrexia (38%), decreased appetite (36%), dysgeusia (32%), and an emia (30%). Cytokine release syndrome was mostly grade 1 or 2 in severity, occurred primarily after the first or second tarlatamab dose, and was managed with supportive care, which included the administration of antipyretics (e.g., acetaminophen), intravenous hydration, and/or glucocorticoids. Other treatment-emergent adverse effects of interest included neutropenia (16%) and immune effector cell-associated neurotoxicity syndrome and associated neurologic events (10%). Given that tarlatamab is the first T-cell engager approved for the treatment of small cell lung cancer, raising awareness with regard to the monitoring and management of tarlatamab-associated adverse events is essential. Here, the authors describe the timing, occurrence, and duration of these adverse events and review the management and risk-mitigation strategies used by clinical investigators during the DeLLphi-301 trial.

Novel treatment strategy targeting interleukin-6 induced by cancer associated fibroblasts for peritoneal metastasis of gastric cancer

Cancer-associated fibroblasts (CAFs) are a crucial component in the tumor microenvironment (TME) of peritoneal metastasis (PM), where they contribute to tumor progression and metastasis via secretion of interleukin-6 (IL-6). Here, we investigated the role of IL-6 in PM of gastric cancer (GC) and assessed whether anti-IL-6 receptor antibody (anti-IL-6R Ab) could inhibit PM of GC. We conducted immunohistochemical analysis of IL-6 and α-smooth muscle (α-SMA) expressions in clinical samples of GC and PM, and investigated the interactions between CAFs and GC cells in vitro. Anti-tumor effects of anti-IL-6R Ab on PM of GC were investigated in an orthotopic murine PM model. IL-6 expression was significantly correlated with α-SMA expression in clinical samples of GC, and higher IL-6 expression in the primary tumor was associated with poor prognosis of GC. Higher IL-6 and α-SMA expressions were also observed in PM of GC. In vitro, differentiation of fibroblasts into CAFs and chemoresistance were observed in GC cells cocultured with fibroblasts. Anti-IL-6R Ab inhibited the progression of PM in GC cells cocultured with fibroblasts in the orthotopic mouse model but could not inhibit the progression of PM consisting of GC cells alone. IL-6 expression in the TME was associated with poor prognosis of GC, and CAFs were associated with establishment and progression of PM via IL-6. Anti-IL-6R Ab could inhibit PM of GC by the blockade of IL-6 secreted by CAFs, which suggests its therapeutic potential for PM of GC.

CD19-directed chimeric antigen receptor T-cell therapy: what can we learn from the haematologist?

CD19-directed chimeric antigen receptor (CAR) T-cell therapy, originally developed for haematological malignancies, has recently emerged as a promising therapy for patients with autoimmune diseases. By selectively depleting CD19-positive B-cells, this therapy brings a new approach in resetting immune dysregulation and potentially providing long-term remission for patients with a refractory disease. Recent reports have highlighted its effectiveness in conditions such as SLE, systemic sclerosis and myositis. However, while these early results are encouraging, questions remain regarding strategies for optimal patient selection and minimising toxicity on the short and long term. The experiences with CD19 CAR T-cell therapy in haematology may offer valuable insights for immunologists and rheumatologists. This article reviews the key principles learnt in haematology, the results and the mechanisms behind its efficacy, toxicities, and the challenges that need to be addressed for its broader application in clinical practice.

Prognostic significance of immune reconstitution following CD19 CAR T-cell therapy for relapsed/refractory B-cell lymphoma

Immune deficits after CD19 chimeric antigen receptor (CAR) T-cell therapy can be long-lasting, predisposing patients to infections and non-relapse mortality. In B-cell non-Hodgkin lymphoma (B-NHL), the prognostic impact of immune reconstitution (IR) remains ill-defined, and detailed cross-product comparisons have not been performed to date. In this retrospective observational study, we longitudinally characterized lymphocyte subsets and immunoglobulin levels in 105 B-NHL patients to assess patterns of immune recovery arising after CD19 CAR-T. Three key IR criteria were defined as CD4+ T helper (TH) cells > 200/µL, any detectable B cells, and serum immunoglobulin G (IgG) levels >4 g/L. After a median follow-up of 24.6 months, 38% of patients displayed TH cells, 11% showed any B cells, and 41% had IgG recovery. Notable product-specific differences emerged, including deeper TH cell aplasia with CD28z- versus longer B-cell aplasia with 41BBz-based products. Patients with any IR recovery experienced extended progression-free survival (PFS) (median 20.8 vs. 1.7 months, p < 0.0001) and overall survival (OS) (34.9 vs. 4.0 months, p < 0.0001). While landmark analysis at 90 days confirmed improved PFS in patients with any recovery (34.9 vs. 8.6 months, p = 0.005), no significant OS difference was noted. Notably, 72% of patients with refractory disease never displayed recovery of any IR criteria. Early progressors showed diminished IR at the time of progression/relapse compared to patients with late progression/recurrence (after Day 90). Our results highlight the profound immune deficits observed after CD19 CAR-T and shed light on the intersection of IR and efficacy in B-NHL. Importantly, IR was impaired considerably postprogression, carrying significant implications for subsequent T-cell-engaging therapies and treatment sequencing.

Idecabtagene vicleucel (ide-cel) for the treatment of triple-class exposed relapsed and refractory multiple myeloma

INTRODUCTION

Modern anti-myeloma therapies have broken new ground in the treatment of the disease, and the incorporation of ide-cel in the treatment landscape represents one of the major scientific and clinical advances.

AREAS COVERED

Ide-cel was the first cell-based gene therapy approved for the treatment of triple-class exposed relapsed/refractory myeloma patients, showing impressive results, and demonstrating superiority over standard regimens in terms of efficacy, potential treatment-free intervals, and improved quality of life in heavily pretreated patients and in high-risk disease. This review summarizes the state-of-the-art of the most recent updates deriving from the use of ide-cel within ongoing, or upcoming, clinical trials, and from real-life experiences.

EXPERT OPINION

As the use of chimeric antigen receptor (CAR)-T therapy is likely to progressively increase over time and current indications expand to earlier treatment lines, efforts should be directed toward ameliorating overall management to facilitate proactive planning for treatment sequencing and provide adequate time for logistical planning. Importantly, the potential limited availability of CAR-T therapy highlights the importance of careful patient selection and coordination among centers. Meanwhile, attempts are underway to improve tolerance and reduce toxicity while enhancing anti-myeloma activity.

Evolving strategies for addressing CAR T-cell toxicities

The field of chimeric antigen receptor (CAR) T-cell therapy has grown from a fully experimental concept to now boasting a multitude of treatments including six FDA-approved products targeting various hematologic malignancies. Yet, along with their efficacy, these therapies come with side effects requiring timely and thoughtful interventions. In this review, we discuss the most common toxicities associated with CAR T-cells to date, highlighting risk factors, prognostication, implications for critical care management, patient experience optimization, and ongoing work in the field of toxicity mitigation. Understanding the current state of the field and standards of practice is critical in order to improve and manage potential toxicities of both current and novel CAR T-cell therapies as they are applied in the clinic.

Emergencies in Hematology: Why, When and How I Treat?

Hematological emergencies are critical medical conditions that require immediate attention due to their rapid progression and life-threatening nature. As various examples, hypercalcemia, often associated with cancers such as multiple myeloma, can lead to severe neurological and cardiac dysfunction. Hyperleukocytosis, common in acute myeloid leukemias, increases the risk of leukostasis and multiorgan failure. Sickle cell crisis, a common complication in sickle cell disease, results from vaso-occlusion, leading to acute pain and tissue ischemia. Tumor lysis syndrome, reported in cases of rapid destruction of cancer cells, causes electrolyte imbalances and acute kidney injury. Acute transfusion reactions, fundamental in hematological conditions, can range from mild allergic responses to severe hemolysis and shock, requiring prompt management. Disseminated intravascular coagulation, involving excessive coagulation and bleeding, is commonly triggered by hematological malignancies, common in the first phases of acute promyelocytic leukemia. Recently, in the era of bispecific antibodies and chimeric antigen receptor T cells, cytokine release syndrome is a manifestation that must be recognized and promptly treated. Understanding the pathophysiology, recognizing the clinical manifestations, and ensuring adequate diagnostic strategies and management approaches for each condition are central to early intervention in improving patient outcomes and reducing mortality.

The role of chemokines and interleukins in acute lymphoblastic leukemia: a systematic review

Acute lymphoblastic leukemia (ALL) is the most common childhood hematological malignancy, but it also affects adult patients with worse prognosis and outcomes. Leukemic cells benefit from protective mechanisms, which are mediated by intercellular signaling molecules - cytokines. Through these signals, cytokines modulate the biology of leukemic cells and their surroundings, enhancing the proliferation, survival, and chemoresistance of the disease. This ultimately leads to disease progression, refractoriness, and relapse, decreasing the chances of curability and overall survival of the patients. Targeting and modulating these pathological processes without affecting the healthy physiology is desirable, offering more possibilities for the treatment of ALL patients, which still remains unsatisfactory in certain cases. In this review, we comprehensively analyze the existing literature and ongoing trials regarding the role of chemokines and interleukins in the biology of ALL. Focusing on the functional pathways, genetic background, and critical checkpoints, we constructed a summary of molecules that are promising for prognostic stratification and mainly therapeutic use. Targeted therapy, including chemokine and interleukin pathways, is a new and promising approach to the treatment of cancer. With the expansion of our knowledge, we are able to uncover a spectrum of new potential checkpoints in order to modulate the disease biology. Several cytokine-related targets are advancing toward clinical application, offering the hope of higher disease response rates to treatment.

CAR-T Cells for the Treatment of Central Nervous System Tumours: Known and Emerging Neurotoxicities

The advent of chimeric antigen receptor (CAR)-T cells has recently changed the prognosis of relapsing/refractory diffuse large B-cell lymphomas, showing response rates as high as 60 to 80%. Common toxicities reported in the pivotal clinical trials include the cytokine release syndrome (CRS) and the Immune effector Cell-Associated Neurotoxicity Syndrome (ICANS), a stereotyped encephalopathy related to myeloid cell activation and blood-brain barrier dysfunction, presenting with a distinctive cascade of dysgraphia, aphasia, disorientation, attention deficits, vigilance impairment, motor symptoms, seizures, and diffuse brain oedema. The tremendous oncological efficacy of CAR-T cells observed in systemic B-cell malignancies is leading to their growing use in patients with primary or secondary central nervous system (CNS) lymphomas and in patients with solid tumours, including several CNS cancers. Early studies conducted in adult and paediatric patients with solid CNS tumours reported a distinct profile of neurotoxicity referred to as Tumour inflammation-associated neurotoxicity (TIAN), corresponding to local inflammation at the tumour site manifesting with focal neurological deficits or mechanical complications (e.g., obstructive hydrocephalus). The present review summarises available data on the efficacy and safety of CAR-T cells for solid and haematological CNS malignancies, emphasising known and emerging phenotypes, ongoing challenges, and future perspectives.

Comparison of CAR T-cell and bispecific antibody as third-line or later-line treatments for multiple myeloma: a meta-analysis

BACKGROUND

CAR-T-cell therapy and bispecific antibody have revolutionized the treatment landscape for multiple myeloma. However, there is currently a lack of studies comparing the efficacy and safety of these two approaches. This meta-analysis assesses the efficacy and safety of B-cell maturation antigen (BCMA)-directed CAR-T-cell therapies and BCMA×CD3 bispecific antibodies as third-line or later interventions for relapsed/refractory multiple myeloma (RRMM).

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane databases up to May 31, 2024, identifying 11 eligible studies encompassing 1269 participants. Random-effects models evaluated the primary (complete response (CR) rate) and secondary (overall response rate (ORR)) outcomes, while meta-regression analyses adjusted for relevant covariates.

RESULTS

CAR-T-cell therapy achieved significantly higher pooled CR rate (0.54 (95% CI 0.42-0.69) vs bispecific antibodies 0.35 (0.30-0.41), p<0.01) and pooled ORR (0.83 (0.76-0.90) vs 0.65 (0.59-0.71), p<0.01). However, CAR-T therapy had a higher incidence of adverse events, particularly cytokine release syndrome (CRS 0.83 (0.70-0.97) vs bispecific antibodies 0.59 (0.43-0.74), p<0.05). Severe CRS (grade ≥3) occurred at a rate of 0.07 (0.03-0.14) in the CAR-T cell group, contrasting with a negligible rate of 0.01 (0.00-0.02) in the bispecific antibody group (p<0.01). Hematologic adverse events, including neutropenia (grade ≥3; 0.88 (0.81-0.95) vs 0.48 (0.30-0.67), p<0.01) and anemia (grade≥3; 0.55 (0.47-0.62) vs 0.34 (0.28 to 0.40), p<0.01), were also more frequent in the CAR-T-cell group. Furthermore, differences in efficacy were observed among various CAR-T products, with ciltacabtagene autoleucel showing greater efficacy in CR rate (0.77 (0.71-0.84) vs 0.37 (0.32-0.41), p<0.01) and ORR (0.91 (0.83-0.99) vs 0.73 (0.68-0.77), p<0.01) compared with idecabtagene vicleucel.

CONCLUSION

CAR-T-cell therapy demonstrated superior CR rates compared with bispecific antibodies, although with an increase in severe adverse events.

Bispecific antibody targets and therapies in multiple myeloma

Recently, several bispecific antibodies (BsAbs) have been approved for the treatment of relapsed multiple myeloma (MM) after early phase trials in heavily pre-treated patients demonstrated high response rates and impressive progression-free survival with monotherapy. These BsAbs provide crucial treatment options for relapsed patients and challenging decisions for clinicians. Evidence on the optimal patient population, treatment sequence, and duration of these therapeutics is unknown and subject to active investigation. While rates of cytokine release syndrome and neurotoxicity appear to be lower with BsAbs than with CAR T-cells, morbidity from infection is high and novel pathways of treatment resistance arise from the longitudinal selection pressure of chronic BsAb therapy. Lastly, a wealth of novel T-cell engagers with unique antibody-structures and antigenic targets are under active investigation with promising early outcome data. In this review, we examine the mechanism of action, therapeutic targets, combinational approaches, sequencing and mechanisms of disease relapse for BsAbs in MM.

CAR-T-Cell Therapy for Systemic Lupus Erythematosus: A Comprehensive Overview

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder characterized by the production of autoreactive B and T cells and cytokines, leading to chronic inflammation affecting multiple organs. SLE is associated with significant complications that substantially increase morbidity and mortality. Given its complex pathogenesis, conventional treatments for SLE often have significant side effects and limited efficacy, necessitating the exploration of novel therapeutic strategies. One promising approach is the use of chimeric antigen receptor (CAR)-T-cell therapy, which has shown remarkable success in treating refractory hematological malignancies. This review provides a comprehensive analysis of the current use of CAR-T-cell therapy in SLE.

Into the storm: the imbalance in the yin-yang immune response as the commonality of cytokine storm syndromes

There is a continuous cycle of activation and contraction in the immune response against pathogens and other threats to human health in life. This intrinsic yin-yang of the immune response ensures that inflammatory processes can be appropriately controlled once that threat has been resolved, preventing unnecessary tissue and organ damage. Various factors may contribute to a state of perpetual immune activation, leading to a failure to undergo immune contraction and development of cytokine storm syndromes. A literature review was performed to consider how the trajectory of the immune response in certain individuals leads to cytokine storm, hyperinflammation, and multiorgan damage seen in cytokine storm syndromes. The goal of this review is to evaluate how underlying factors contribute to cytokine storm syndromes, as well as the symptomatology, pathology, and long-term implications of these conditions. Although the recognition of cytokine storm syndromes allows for universal treatment with steroids, this therapy shows limitations for symptom resolution and survival. By identifying cytokine storm syndromes as a continuum of disease, this will allow for a thorough evaluation of disease pathogenesis, consideration of targeted therapies, and eventual restoration of the balance in the yin-yang immune response.

Transformed follicular lymphoma with laryngeal edema requiring tracheal intubation after tisagenlecleucel treatment: A case report

RATIONALE

Cytokine release syndrome (CRS) is a common adverse event of chimeric antigen receptor T (CAR-T) cell therapy. CRS is generally a systemic inflammatory reaction, but in rare cases, it can occur in specific body areas and is referred to as "local CRS (L-CRS)." A case of laryngeal edema due to L-CRS that required tracheal intubation because of the lack of response to tocilizumab (TCZ) and dexamethasone (DEX) is reported.

PATIENT CONCERNS

A 67-year-old woman with relapsed transformed follicular lymphoma was treated with CAR-T cell therapy. Although she had been given TCZ and DEX for CRS, neck swelling appeared on day 4 after infusion.

DIAGNOSES

Laryngoscopy showed severe laryngeal edema, which was presumed to be due to L-CRS, since there were no other apparent triggers based on history, physical examination, and computed tomography.

INTERVENTIONS

Tracheal intubation was performed because of the risk of upper airway obstruction. Ultimately, 4 doses of tocilizumab (8 mg/kg) and 6 doses of dexamethasone (10 mg/body) were required to improve the L-CRS.

OUTCOMES

On day 7, laryngeal edema improved, and the patient could be extubated.

LESSONS

The lessons from this case are, first, that CAR-T cell therapy may induce laryngeal edema in L-CRS. Second, TCZ alone may be ineffective in cervical L-CRS. Third, TCZ, as well as DEX, may be inadequate. In such cases, we should recognize L-CRS and manage it early because it may eventually progress to laryngeal edema that requires securing the airway.

Management of chimeric antigen receptor T (CAR-T) cell-associated toxicities

The use of chimeric antigen receptor T (CAR-T) cells is a significant therapeutic improvement increasing the prognosis for patients with a variety of hematological malignancies. However, this therapy has also sometimes life-threatening, complications. Therefore, knowledge of the treatment and management of these complications, especially in treatment centers and intensive care units, respectively, is of outstanding importance. This review provides recommendations for the diagnosis, management, and treatment of CAR-T cell-associated complications such as cytokine release syndrome, immune effector cell associated neurotoxicity syndrome, hematotoxicity, hypogammaglobulinemia, and CAR-T cell-induced pseudo-progression amongst others for physicians treating patients with CAR-T cell-associated complications and intensivists.

Exploring the potential of the convergence between extracellular vesicles and CAR technology as a novel immunotherapy approach

Cancer therapy is a dynamically evolving field, witnessing the emergence of innovative approaches that offer a promising outlook for patients grappling with persistent disease. Within the realm of therapeutic exploration, chimeric antigen receptor (CAR) T cells as well as CAR NK cells, have surfaced as novel approaches, each possessing unique attributes and transformative potential. Immune cells engineered to express CARs recognizing tumour-specific antigens, have shown remarkable promise in treating terminal cancers by combining the precision of antibody specificity with the potent cytotoxic function of T cells. However, their application in solid tumours is still in its nascent stages, presenting unique major challenges. On the same note, CAR NK cells offer a distinct immunotherapeutic approach, utilizing CARs on NK cells, providing advantages in safety, manufacturing simplicity, and a broader scope for cancer treatment. Extracellular vesicles (EVs) have emerged as promising therapeutic agents due to their ability to carry crucial biomarkers and biologically active molecules, serving as vital messengers in the intercellular communication network. In the context of cancer, the therapeutic potential of EVs lies in delivering tumour-suppressing proteins, nucleic acid components, or targeting drugs with precision, thereby redefining the paradigm of precision medicine. The fusion of CAR technology with the capabilities of EVs has given rise to a new therapeutic frontier. CAR T EVs and CAR NK EVs, leveraging the power of EVs, have the potential to alleviate challenges associated with live-cell therapies. EVs are suggested to reduce the side effects linked to CAR T cell therapy and hold the potential to revolutionize the penetrance in solid tumours. EVs act as carriers of pro-apoptotic molecules and RNA components, enhancing immune responses and thereby expanding their therapeutic potential. In this review article, we navigate dynamic landscapes, with our objective being to evaluate comparative efficacy, safety profiles, manufacturing complexities, and clinical applicability.

A Systematic Review on the Dual Role of Interleukin-1 in CAR T-Cell Therapy: Enhancer and Mitigator

Chimeric antigen receptor T-cell therapy is a groundbreaking approach for treating certain hematologic malignancies and solid tumors. However, its application is limited by severe toxicities, particularly CRS and ICANS, dramatically limit its broader application. IL-1 plays a crucial role in both enhancing CAR T-cell efficacy and driving these toxic effects. This review systematically examines the dual functions of IL-1, highlighting its role in promoting CAR T-cell activation and persistence while contributing to CRS and ICANS pathogenesis. Strategies to mitigate IL-1-driven toxicities, including IL-1 receptor antagonists, monoclonal antibodies, IL-1 trapping, and interference with IL-1 production, show promise in reducing adverse effects without compromising therapeutic efficacy. Understanding the complex role of IL-1 in CAR T-cell therapy may lead to optimized treatment strategies, improving safety and expanding clinical applicability. Further research is essential to refine IL-1-targeted interventions and enhance the therapeutic potential of CAR T-cell therapy.

Chimeric antigen receptor (CAR) T-cell therapy is a groundbreaking approach for treating certain hematologic malignancies and solid tumors. However, its application is limited by severe toxicities, particularly cytokine release syndrome (CRS) and cell-associated neurotoxicity syndrome (ICANS), dramatically limit its broader application. IL-1 plays a crucial role in both enhancing CAR T-cell efficacy and driving these toxic effects. This review systematically examines the dual functions of IL-1, highlighting its role in promoting CAR T-cell activation and persistence while contributing to CRS and ICANS pathogenesis. Strategies to mitigate IL-1-driven toxicities, including IL-1 receptor antagonists, monoclonal antibodies, IL-1 trapping, and interference with IL-1 production, show promise in reducing adverse effects without compromising therapeutic efficacy. Understanding the complex role of IL-1 in CAR T-cell therapy may lead to optimized treatment strategies, improving safety and expanding clinical applicability. Further research is essential to refine IL-1-targeted interventions and enhance the therapeutic potential of CAR T-cell therapy.

Tocilizumab administration in cytokine release syndrome is associated with hypofibrinogenemia after chimeric antigen receptor T-cell therapy for hematologic malignancies

Chimeric antigen receptor (CAR) T-cell therapy causes serious side effects including cytokine release syndrome (CRS). CRS-related coagulopathy is associated with hypofibrinogenemia that has up to now been considered the result of disseminated intravascular coagulation (DIC) and liver dysfunction. We investigated the incidence and risk factors for hypofibrinogenemia in 41 consecutive adult patients with hematologic malignancies (median age 69 years, range 38-83 years) receiving CAR T-cell therapy between January 2020 and May 2023 at the University Medical Center Regensburg. CRS occurred in 93% of patients and was accompanied by hypofibrinogenemia already from CRS grade 1. Yet DIC and liver dysfunction mainly occurred in severe CRS (≥ grade 3). After an initial increase during CRS, fibrinogen levels dropped after administration of tocilizumab in a dose-dependent manner (r = -0.44, P=0.004). In contrast, patients who did not receive tocilizumab had increased fibrinogen levels. Logistic regression analysis identified tocilizumab as an independent risk factor for hypofibrinogenemia (odds ratio = 486, P<0.001). We thus hypothesize that fibrinogen synthesis in CRS is up-regulated in an interleukin-6-dependent acute phase reaction compensating for CRS-induced consumption of coagulation factors. Tocilizumab inhibits fibrinogen upregulation resulting in prolonged hypofibrinogenemia. These observations provide novel insights into the pathophysiology of hypofibrinogenemia following CAR T-cell therapy, and emphasize the need for close fibrinogen monitoring after tocilizumab treatment of CRS.

CAR-T cell therapy in relapsed or refractory multiple myeloma and access in Turkey

The past decade has seen the development of immunotherapy for the treatment of multiple myeloma (MM), beginning with monoclonal antibodies (mAbs) in the relapsed and refractory setting and culminating in the market approval of chimeric antigen receptor T cells (CAR-T) and bispecific antibodies (BsAbs). The medical community is evaluating the efficacy and safety of these targeted immunotherapies, most of which currently target B-cell maturation antigen (BCMA) on the surface of plasma cells. Two anti-BCMA CAR-T products are available for treating relapsed or refractory MM: idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel). Ide-cel and cilta-cel demonstrate the ability to induce deep responses in heavily pretreated diseases, including patients with triple-class-refractory and penta-refractory diseases. However, there are key similarities and differences regarding these agents, unknowns regarding their comparative efficacy and toxicity, and mechanisms underlying resistance to these new immunotherapies. This review discusses CAR-T cell therapy in relapsed refractory MM, with a focus on efficacy, toxicities, and the evolving trajectories of these therapies in the USA, as well as access in Turkey.

Looking ahead to CD3, T-cell engager bispecific antibodies for hematological malignancies

INTRODUCTION

Since the approval of the bispecific antibody blinatumomab in 2017 for the treatment of acute lymphoblastic leukemia in relapse, the development of numerous bispecific antibody constructs has dramatically expanded in hematologic malignancies. Many have recently received Food Drug Administration and European Medicines Agency approvals in various stages of treatment for lymphomas, leukemias, and multiple myeloma.

AREAS COVERED

The purpose of this review is to provide an overview of bispecific antibody treatment including the mechanisms leading to effector T cells targeting tumor-associated antigens, the treatment indications, efficacies, toxicities, and challenges of the different constructs. A literature search was performed through access to PubMed and clinicaltrials.gov.

EXPERT OPINION

While there has been substantial success in the treatment of NHL, MM, and ALL, there are still hematologic malignancies such as AML where there has been limited progress. It is important to continue to investigate new designs, tumor antigen targets, and further refine where current approved bispecific antibodies fit in terms of sequencing of therapy. Hopefully, with the knowledge gained in recent years and the explosion of these therapies, patients with blood cancers will continue to benefit from these treatments for years to come.

Riding the storm: managing cytokine-related toxicities in CAR-T cell therapy

The advent of chimeric antigen receptor T cells (CAR-T) has been a paradigm shift in cancer immunotherapeutics, with remarkable outcomes reported for a growing catalog of malignancies. While CAR-T are highly effective in multiple diseases, salvaging patients who were considered incurable, they have unique toxicities which can be life-threatening. Understanding the biology and risk factors for these toxicities has led to targeted treatment approaches which can mitigate them successfully. The three toxicities of particular interest are cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and immune effector cell-associated hemophagocytic lymphohistiocytosis (HLH)-like syndrome (IEC-HS). Each of these is characterized by cytokine storm and hyperinflammation; however, they differ mechanistically with regard to the cytokines and immune cells that drive the pathophysiology. We summarize the current state of the field of CAR-T-associated toxicities, focusing on underlying biology and how this informs toxicity management and prevention. We also highlight several emerging agents showing promise in preclinical models and the clinic. Many of these established and emerging agents do not appear to impact the anti-tumor function of CAR-T, opening the door to additional and wider CAR-T applications.

Emerging roles of CAR-NK cell therapies in tumor immunotherapy: current status and future directions

Cancer immunotherapy harnesses the body's immune system to combat malignancies, building upon an understanding of tumor immunosurveillance and immune evasion mechanisms. This therapeutic approach reactivates anti-tumor immune responses and can be categorized into active, passive, and combined immunization strategies. Active immunotherapy engages the immune system to recognize and attack tumor cells by leveraging host immunity with cytokine supplementation or vaccination. Conversely, passive immunotherapy employs exogenous agents, such as monoclonal antibodies (anti-CTLA4, anti-PD1, anti-PD-L1) or adoptive cell transfers (ACT) with genetically engineered chimeric antigen receptor (CAR) T or NK cells, to exert anti-tumor effects. Over the past decades, CAR-T cell therapies have gained significant traction in oncological treatment, offering hope through their targeted approach. However, the potential adverse effects associated with CAR-T cells, including cytokine release syndrome (CRS), off-tumor toxicity, and neurotoxicity, warrant careful consideration. Recently, CAR-NK cell therapy has emerged as a promising alternative in the landscape of tumor immunotherapy, distinguished by its innate advantages over CAR-T cell modalities. In this review, we will synthesize the latest research and clinical advancements in CAR-NK cell therapies. We will elucidate the therapeutic benefits of employing CAR-NK cells in oncology and critically examine the developmental bottlenecks impeding their broader application. Our discussion aims to provide a comprehensive overview of the current status and future potential of CAR-NK cells in cancer immunotherapy.

Overview of infectious complications among CAR T- cell therapy recipients

Chimeric antigen receptor-modified T cell (CAR T-cell) therapy has revolutionized the management of hematological malignancies. In addition to impressive malignancy-related outcomes, CAR T-cell therapy has significant toxicity-related adverse events, including cytokine release syndrome (CRS), immune effector cell associated neurotoxicity syndrome (ICANS), immune effector cell-associated hematotoxicity (ICAHT), and opportunistic infections. Different CAR T-cell targets have different epidemiology and risk factors for infection, and these targets result in different long-term immunodeficiency states due to their distinct on-target and off- tumor effects. These effects are exacerbated by the use of multimodal immunosuppression in the management of CRS and ICANS. The most effective course of action for managing infectious complications involves determining screening, prophylactic, and monitoring strategies and understanding the role of immunoglobulin replacement and re-vaccination strategies. This involves considering the nature of prior immunomodulating therapies, underlying malignancy, the CAR T-cell target, and the development and management of related adverse events. In conclusion, we now have an increasing understanding of infection management for CAR T-cell recipients. As additional effector cells and CAR T-cell targets become available, infection management strategies will continue to evolve.

Universal CAR 2.0 to overcome current limitations in CAR therapy

Chimeric antigen receptor (CAR) T cell therapy has effectively complemented the treatment of advanced relapsed and refractory hematological cancers. The remarkable achievements of CD19- and BCMA-CAR T therapies have raised high expectations within the fields of hematology and oncology. These groundbreaking successes are propelling a collective aspiration to extend the reach of CAR therapies beyond B-lineage malignancies. Advanced CAR technologies have created a momentum to surmount the limitations of conventional CAR concepts. Most importantly, innovations that enable combinatorial targeting to address target antigen heterogeneity, using versatile adapter CAR concepts in conjunction with recent transformative next-generation CAR design, offer the promise to overcome both the bottleneck associated with CAR manufacturing and patient-individualized treatment regimens. In this comprehensive review, we delineate the fundamental prerequisites, navigate through pivotal challenges, and elucidate strategic approaches, all aimed at paving the way for the future establishment of multitargeted immunotherapies using universal CAR technologies.

Challenges and innovations in CAR-T cell therapy: a comprehensive analysis

Recent years have seen a marked increase in research on chimeric antigen receptor T (CAR-T) cells, with specific relevance to the treatment of hematological malignancies. Here, the structural principles, iterative processes, and target selection of CAR-T cells for therapeutic applications are described in detail, as well as the challenges faced in the treatment of solid tumors and hematological malignancies. These challenges include insufficient infiltration of cells, off-target effects, cytokine release syndrome, and tumor lysis syndrome. In addition, directions in the iterative development of CAR-T cell therapy are discussed, including modifications of CAR-T cell structures, improvements in specificity using multi-targets and novel targets, the use of Boolean logic gates to minimize off-target effects and control toxicity, and the adoption of additional protection mechanisms to improve the durability of CAR-T cell treatment. This review provides ideas and strategies for the development of CAR-T cell therapy through an in-depth exploration of the underlying mechanisms of action of CAR-T cells and their potential for innovative modification.

The Burden of Invasive Fungal Disease Following Chimeric Antigen Receptor T-Cell Therapy and Strategies for Prevention

Chimeric antigen receptor (CAR) T-cell therapy is a novel immunotherapy approved for the treatment of hematologic malignancies. This therapy leads to a variety of immunologic deficits that could place patients at risk for invasive fungal disease (IFD). Studies assessing IFD in this setting are limited by inconsistent definitions and heterogeneity in prophylaxis use, although the incidence of IFD after CAR T-cell therapy, particularly for lymphoma and myeloma, appears to be low. This review evaluates the incidence of IFD after CAR T-cell therapy, and discusses optimal approaches to prevention, highlighting areas that require further study as well as future applications of cellular therapy that may impact IFD risk. As the use of CAR T-cell therapy continues to expand for hematologic malignancies, solid tumors, and most recently to include non-oncologic diseases, understanding the risk for IFD in this uniquely immunosuppressed population is imperative to prevent morbidity and mortality.

Prognostic impact of corticosteroid and tocilizumab use following chimeric antigen receptor T-cell therapy for multiple myeloma

Despite being the mainstay of management for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), there is limited data regarding the impact of tocilizumab (TCZ) and corticosteroids (CCS) on chimeric antigen receptor (CAR) T-cell efficacy in multiple myeloma (MM). The present study aims to evaluate the prognostic impact of these immunosuppressants in recipients of BCMA- or GPRC5D-directed CAR T cells for relapsed/refractory MM. Our retrospective cohort involved patients treated with commercial or investigational autologous CAR T-cell products at a single institution from March 2017-March 2023. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall response rate (ORR), complete response rate (CRR), and overall survival (OS). In total, 101 patients (91% treated with anti-BCMA CAR T cells and 9% treated with anti-GPRC5D CAR T cells) were analyzed. Within 30 days post-infusion, 34% received CCS and 49% received TCZ for CRS/ICANS management. At a median follow-up of 27.4 months, no significant difference in PFS was observed between CCS and non-CCS groups (log-rank p = 0.35) or between TCZ and non-TCZ groups (log-rank p = 0.69). ORR, CRR, and OS were also comparable between evaluated groups. In our multivariable model, administering CCS with/without TCZ for CRS/ICANS management did not independently influence PFS (HR, 0.74; 95% CI, 0.36-1.51). These findings suggest that, among patients with relapsed/refractory MM, the timely and appropriate use of CCS or TCZ for mitigating immune-mediated toxicities does not appear to impact the antitumor activity and long-term outcomes of CAR T-cell therapy.

Mechanisms and management of CAR T toxicity

Chimeric antigen receptor (CAR) T cell therapies have dramatically improved treatment outcomes for patients with relapsed or refractory B-cell acute lymphoblastic leukemia, large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma. Despite unprecedented efficacy, treatment with CAR T cell therapies can cause a multitude of adverse effects which require monitoring and management at specialized centers and contribute to morbidity and non-relapse mortality. Such toxicities include cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, neurotoxicity distinct from ICANS, immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome, and immune effector cell-associated hematotoxicity that can lead to prolonged cytopenias and infectious complications. This review will discuss the current understanding of the underlying pathophysiologic mechanisms and provide guidelines for the grading and management of such toxicities.

Case report: Rapid resolution of grade IV ICANS after first line intrathecal chemotherapy with methotrexate, cytarabine and dexamethasone

Corticosteroid therapy is the mainstay of immune effector cell-associated neurotoxicity syndrome (ICANS) management, although its use has been associated with worse overall survival (OS) and progression-free survival (PFS) after chimeric antigen receptor T-cell (CAR-T cell) therapy. Many options are being investigated for prophylaxis and management. Accumulating evidence supports the use of intrathecal (IT) chemotherapy for the management of high-grade ICANS. Here, we describe a case of a patient with stage IV Primary mediastinal B-cell lymphoma (PMBCL) successfully treated with IT methotrexate, cytarabine, and dexamethasone as first-line therapy for CD19 CAR-T cell-associated grade IV ICANS. The stable and rapid resolution of ICANS to grade 0 allowed us to discontinue systemic corticosteroid use, avoiding CAR-T cells ablation and ensuring preservation of CAR-T cell function. The described patient achieved a complete radiologic and clinical response to CD19 CAR-T cell therapy and remains disease-free after 9 months. This case demonstrates a promising example of how IT chemotherapy could be used as first-line treatment for the management of high-grade ICANS.

Charting new paradigms for CAR-T cell therapy beyond current Achilles heels

Chimeric antigen receptor-T (CAR-T) cell therapy has made remarkable strides in treating hematological malignancies. However, the widespread adoption of CAR-T cell therapy is hindered by several challenges. These include concerns about the long-term and complex manufacturing process, as well as efficacy factors such as tumor antigen escape, CAR-T cell exhaustion, and the immunosuppressive tumor microenvironment. Additionally, safety issues like the risk of secondary cancers post-treatment, on-target off-tumor toxicity, and immune effector responses triggered by CAR-T cells are significant considerations. To address these obstacles, researchers have explored various strategies, including allogeneic universal CAR-T cell development, infusion of non-activated quiescent T cells within a 24-hour period, and in vivo induction of CAR-T cells. This review comprehensively examines the clinical challenges of CAR-T cell therapy and outlines strategies to overcome them, aiming to chart pathways beyond its current Achilles heels.

Glofitamab-Associated Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) Presenting as Serial Seizures and Responding Positively to Antiseizure Drugs and Anakinra: A Case Report

Immune effector cell-associated neurotoxicity syndrome (ICANS) is a well-known side effect of chimeric antigen receptor (CAR) T-cell therapy but has occasionally been described with immune checkpoint inhibitors as well. Glofitamab-associated ICANS with a bispecific monoclonal antibody has rarely been reported. The patient is a 63-year-old male with a history of mantle cell lymphoma, diagnosed at age 37, and aggressive large-cell B-cell lymphoma, diagnosed at age 50. Despite adequate chemotherapy, immunotherapy, autologous stem cell transplantation, and CAR T-cell therapy, there were several relapses, including meningeal carcinomatosis at age 61 and intracerebral lymphoma at age 62. For this reason, glofitamab was started. One week after the ninth cycle, the patient developed drowsiness, behavioral changes, word-finding difficulties, aphasia, focal to bilateral tonic-clonic seizures, and focal onset seizures, which resolved after 16 days with levetiracetam, valproic acid, lorazepam, and midazolam. Since there was no infectious disease, electrolyte disturbance, metabolic disorder, cardiovascular disease, or relapse of lymphoma, glofitamab-associated ICANS was suspected, and anakinra was administered. The case shows that ICANS with drowsiness, behavioral changes, aphasia, and seizures can develop with glofitamab and that patients with structural brain abnormalities may be prone to this.

Improving cell reinfusion to enhance the efficacy of chimeric antigen receptor T-cell therapy and alleviate complications

Adoptive cell therapy (ACT) is a rapidly expanding area within the realm of transfusion medicine, focusing on the delivery of lymphocytes to trigger responses against tumors, viruses, or inflammation. This area has quickly evolved from its initial promise in immuno-oncology during preclinical trials to commercial approval of chimeric antigen receptor (CAR) T-cell therapies for leukemia and lymphoma (Jun and et al., 2018) [1]. CAR T-cell therapy has demonstrated success in treating hematological malignancies, particularly relapsed/refractory B-cell acute lymphoblastic leukemia and non-Hodgkin's lymphoma (Qi and et al., 2022) [2]. However, its success in treating solid tumors faces challenges due to the short-lived presence of CAR-T cells in the body and diminished T cell functionality (Majzner and Mackall, 2019) [3]. CAR T-cell therapy functions by activating immune effector cells, yet significant side effects and short response durations remain considerable obstacles to its advancement. A prior study demonstrated that the therapeutic regimen can induce systemic inflammatory reactions, such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), tumor lysis syndrome (TLS), off-target effects, and other severe complications. This study aims to explore current research frontiers in this area.

Outpatient CAR T-Cell Therapy as Standard of Care: Current Perspectives and Considerations

Chimeric antigen receptor T-cell therapy (CAR-T) has altered the treatment landscape of several hematologic malignancies. Until recently, most CAR-T infusions have been administered in the inpatient setting, due to their toxicity profile. However, the advent of new product constructs, as well as improved detection and management of adverse effects, have greatly increased the safety in administering these therapies. CAR-T indications continue to expand, and inpatient administration is associated with increased healthcare resource utilization and overall cost. Therefore, transitioning CAR-T administration to the outpatient setting has been of great interest in an effort to improve access, reduce financial burden, and improve patient satisfaction. Establishment of a successful outpatient CAR-T requires several components, including a multidisciplinary cellular therapy team and an outpatient center with appropriate clinical space and personnel. Additionally, clear criteria for outpatient administration eligibility and for inpatient admission with pathways for prompt toxicity evaluation and admission, and toxicity management guidelines should be implemented. Education about CAR-T therapy and its associated toxicities is imperative for all clinical staff, as well as patients and their caregivers. Finally, rigorous financial planning and close collaboration with payers to ensure equitable access, while effectively managing cost, are essential to program success and sustainability. This review provides a summary of currently published experiences, as well as expert opinion regarding implementation of an outpatient CAR-T program.