A review of cancer immunotherapy toxicity.

Cancer immunotherapies, including checkpoint inhibitors and adoptive cell therapy, manipulate the immune system to recognize and attack cancer cells. These therapies have the potential to induce durable responses in multiple solid and hematologic malignancies and thus have transformed treatment algorithms for numerous tumor types. Cancer immunotherapies lead to unique toxicity profiles distinct from the toxicities of other cancer therapies, depending on their mechanism of action. These toxicities often require specific management, which can include steroids and immune-modulating therapy and for which consensus guidelines have been published. This review will focus on the toxicities of checkpoint inhibitors and chimeric antigen receptor T cells, including pathophysiology, diagnosis, and management.

Impact of tocilizumab on anti-CD19 chimeric antigen receptor T-cell therapy in B-cell acute lymphoblastic leukemia.

BACKGROUND: Tocilizumab is commonly used for the management of chimeric antigen receptor (CAR) T-cell therapy-associated cytokine release syndrome (CRS). However, it remains unknown whether tocilizumab or its dosage affects the efficacy and safety of CAR T-cell therapy. The objective of this multicenter retrospective study was to explore the impact of tocilizumab on CAR T-cell therapy. METHODS: In total, 93 patients with B-cell acute lymphoblastic leukemia (B-ALL) receiving humanized anti-CD19 CAR T cells were recruited from May 2016 to November 2022. Forty-five patients received tocilizumab (tocilizumab group), whereas 48 patients did not (nontocilizumab group). Thirteen patients received >1 dose of tocilizumab. The primary end point was the effect of tocilizumab on the efficacy and safety of CAR T cells. Additionally, proliferation, killing, and cytokine assays of CAR T cells were performed in vitro in the presence of tocilizumab. RESULTS: The median age of the patients was 33 years, with 47 males and 46 females. Patients in the tocilizumab group showed similar complete response (CR) rate, overall survival (OS), and event-free survival (EFS) compared with the nontocilizumab group. Compared with patients who received ≤1 dose of tocilizumab, receiving >1 dose of tocilizumab did not affect their CR rate, OS, or EFS. In the tocilizumab group, all patients experienced CRS and 26.7% experienced immune effector cell-associated neurotoxicity syndrome (ICANS). In the nontocilizumab group, 64.6% of patients experienced CRS and 8.3% experienced ICANS. Up to 75% of ICANS and 87.5% of grade ≥3 ICANS occurred in the tocilizumab group. In vitro, tocilizumab did not impair the proliferation and killing effects of CAR T cells. CONCLUSIONS: Tocilizumab does not affect the efficacy of CAR T cells but may increase the likelihood of ICANS.

Safety outcomes of teclistamab accelerated dose escalation.

INTRODUCTION: Teclistamab, a bispecific T-cell engaging antibody targeting B-cell maturation antigen (BCMA), is indicated for the treatment of relapsed or refractory multiple myeloma after at least four lines of therapy. It has boxed warnings for life threatening cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). To mitigate these risks, teclistamab is initiated using step-up doses. This article examines safety event rates following the implementation of a 2-day separation between step-up doses at one institution to streamline patient care. METHODS: This was a retrospective, single-center study encompassing all patients who received teclistamab within a 1-year period. The primary endpoint was the overall incidence of CRS and ICANS. Secondary endpoints included hospital length of stay, hematological toxicities, infection rates, among other adverse events. RESULTS: A total of 27 patients were included in the analysis and stratified into accelerated (days 1,3,5) or standard (days 1,4,7) dosing groups. CRS occurred in 48% (11) of patients for the accelerated dosing and 50% (2) for the standard dosing group. ICANS was seen in 17% (4) of patients in the accelerated dosing group and none in the standard dosing group. Average length of stay in the accelerated dose was 7.6 days versus 9.2 days in the standard dose group. CONCLUSION: Accelerated dose escalation of teclistamab yielded safety event rates comparable to those in the literature. These findings may support outpatient administration for teclistamab. Accelerated dose escalation strategy allowed for the optimization of hospitalization and resources.

How I treat refractory/relapsed diffuse large B-cell lymphomas with CD19-directed chimeric antigen receptor T cells.

Chimeric antigen receptor (CAR) T cells targeting CD19 represent a promising salvage immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), offering ~40% of long-term responses. In everyday clinical practice, haematologists involved in CAR T cell treatment of patients with R/R DLBCL have to deal with diagnostically complex cases and difficult therapeutic choices. The availability of novel immunotherapeutic agents for R/R DLBCL and recent advances in understanding CAR T-cell failure mechanisms demand a rational approach to identify the best choice for bridging therapy and managing post-CAR T-cell therapy relapses. Moreover, positron emission tomography/computerised tomography may result in false-positive interpretation, highlighting the importance of post-treatment biopsy. In this review, we discuss all above issues, presenting four instructive cases, with the aim to provide criteria and new perspectives for CAR T-cell treatment of DLBCL.

Pre-existing frontal lobe dysfunction signs as predictors of subsequent neurotoxicity in CAR T cell therapy: insights from a case series.

BACKGROUND: Chimeric Antigen Receptor (CAR) T cell therapies are innovative treatments against hematological malignancies, with increasing therapeutic indications. Despite their great efficacy, these therapies are hampered by high rates of neurotoxicity (immune effector cell-associated neurotoxicity (ICANS)). In the past few years, several risk factors have been associated with ICANS and grouped together in the attempt to build validated models able to predict neurologic complications. However, little is known about pre-existing neurologic conditions possibly related to the development of neurotoxicity. METHODS AND RESULTS: In our case series, including sixteen consecutive patients treated with CAR T cells, we observed that (i) neurotoxicity only occurred in the two patients who presented subtle clinical signs of frontal lobe impairment at baseline and (ii) neurologic manifestations of ICANS consisted of language disturbances and cortical frontal myoclonus, which were both manifestations of a frontal predominant dysfunction. DISCUSSION: Based on our experience, we suggest that a pre-existing frontal lobe impairment, even if at a subclinical level, may eventually drive to ICANS, which in turn shows symptoms compatible with a frontal encephalopathy. It is remarkable that this focal neurotoxicity involved the same CNS regions that were responsible of subtle neurological signs at baseline. Future studies on larger numbers of patients are needed to confirm the possible role of baseline frontal lobe dysfunction as a predictor of ICANS, in order to enhance efforts to safely deliver CAR T cell therapy.

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.

Management of adults and children receiving CAR T-cell therapy: 2021 best practice recommendations of the European Society for Blood and Marrow Transplantation (EBMT) and the Joint Accreditation Committee of ISCT and EBMT (JACIE) and the European Haematology Association (EHA).

BACKGROUND: Several commercial and academic autologous chimeric antigen receptor T-cell (CAR-T) products targeting CD19 have been approved in Europe for relapsed/refractory B-cell acute lymphoblastic leukemia, high-grade B-cell lymphoma and mantle cell lymphoma. Products for other diseases such as multiple myeloma and follicular lymphoma are likely to be approved by the European Medicines Agency in the near future. DESIGN: The European Society for Blood and Marrow Transplantation (EBMT)-Joint Accreditation Committee of ISCT and EBMT (JACIE) and the European Haematology Association collaborated to draft best practice recommendations based on the current literature to support health care professionals in delivering consistent, high-quality care in this rapidly moving field. RESULTS: Thirty-six CAR-T experts (medical, nursing, pharmacy/laboratory) assembled to draft recommendations to cover all aspects of CAR-T patient care and supply chain management, from patient selection to long-term follow-up, post-authorisation safety surveillance and regulatory issues. CONCLUSIONS: We provide practical, clinically relevant recommendations on the use of these high-cost, logistically complex therapies for haematologists/oncologists, nurses and other stakeholders including pharmacists and health sector administrators involved in the delivery of CAR-T in the clinic.

Side-effect management of chimeric antigen receptor (CAR) T-cell therapy.

Chimeric antigen receptor (CAR) T cells directed against the B-cell marker CD19 are currently changing the landscape for treatment of patients with refractory and/or relapsed B-cell malignancies. Due to the nature of CAR T cells as living drugs, they display a unique toxicity profile. As CAR T-cell therapy is extending towards other diseases and being more broadly employed in hematology and oncology, optimal management strategies of side-effects associated with CAR T-cell therapy are of high relevance. Cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and cytopenias constitute challenges in the treatment of patients with CAR T cells. This review summarizes the current understanding of CAR T-cell toxicity and its management.

Neurologic Complications of Cancer Therapies.

PURPOSE OF REVIEW: To review the neurologic complications of systemic anti-cancer therapies and radiation therapy. RECENT FINDINGS: Although many of the newer systemic therapies have more favorable side effect profiles than traditional cytotoxic chemotherapy, neurotoxicity has been seen with some of newer targeted therapies, immunotherapy, and T cell engaging therapies, including CAR-T therapy. The most recent advances in radiation-induced neurotoxicity have focused on the prevention and the management of cognitive dysfunction, a known long-term complication of brain irradiation. Cancer therapies can damage both the central and the peripheral nervous systems, and the damage may not always be reversible. Neurologists and oncologists must be aware of the neurotoxicities associated with newer treatments, particularly CAR-T therapy and immunotherapy. Early recognition and appropriate management can help minimize neurologic injury.

Chimeric Antigen Receptor T-Cell Therapy in the Outpatient Setting: An Expert Panel Opinion from the American Society for Transplantation and Cellular Therapy.

The first series of chimeric antigen receptor T (CAR-T) cell therapy products were approved in 2017 to 2019 and have shown remarkable efficacy in both clinical trials and the real-world setting, but at the cost of prolonged patient hospitalization. As the toxicity management protocols were refined, the concept of cellular therapy administered in the outpatient setting gained steam, and single institutions began to perform certain aspects of CAR-T monitoring in the outpatient setting for select patients. However, there are many considerations for a successful outpatient program. In anticipation of increasing use of CAR-T-cell therapy in the outpatient setting as a mechanism to overcome frequent hospital bed shortages and high cost of inpatient care, the American Society for Transplantation and Cellular Therapy convened a group of experts in hematology, oncology, and cellular therapy to provide a comprehensive review of the existing publications on outpatient CAR-T cell therapy, discuss selected ongoing clinical trials of outpatient CAR-T, and describe strategies to optimize safety without compromising efficacy for patients treated and monitored in the outpatient setting.

An Early Neurological Indicator of Immune Effector Cell-Associated Neurotoxicity Syndrome.

We herein report a 58-year-old female patient undergoing chimeric antigen receptor T-cell (CAR-T) therapy for refractory diffuse large B-cell lymphoma (DLBCL). Following the CAR-T infusion, the patient experienced Cytokine Release Syndrome (CRS), which was subsequently remitted. However, aphasia was observed five days post-infusion, and a loss of consciousness occurred on the sixth day. Brain MRI revealed a possibly high signal intensity in the mesial temporal region. The patient was diagnosed with immune effector cell-associated neurotoxicity syndrome (ICANS) secondary to CRS and received treatment with dexamethasone, which promptly improved her consciousness. As the diagnosis of ICANS was confirmed following the emergence of aphasia, vigilant cognitive monitoring of cognitive function is crucial in patients following CAR-T therapy.

The preclinical discovery and clinical development of ciltacabtagene autoleucel (Cilta-cel) for the treatment of multiple myeloma.

INTRODUCTION: Despite remarkable therapeutic advances over the last two decades, which have resulted in dramatic improvements in patient survival, multiple myeloma (MM) is still considered an incurable disease. Therefore, there is a high need for new treatment strategies. Genetically engineered/redirected chimeric antigen receptor (CAR) T cells may represent the most compelling modality of immunotherapy for cancer treatment in general, and MM in particular. Indeed, unprecedented response rates have led to the recent approvals of the first two BCMA-targeted CAR T cell products idecabtagene-vicleucel ('Ide-cel') and ciltacabtagene-autoleucel ('Cilta-Cel') for the treatment of heavily pretreated MM patients. In addition, both are emerging as a new standard-of-care also in earlier lines of therapy. AREAS COVERED: This article briefly reviews the history of the preclinical development of CAR T cells, with a particular focus on Cilta-cel. Moreover, it summarizes the newest clinical data on Cilta-cel and discusses strategies to further improve its activity and reduce its toxicity. EXPERT OPINION: Modern next-generation immunotherapy is continuously transforming the MM treatment landscape. Despite several caveats of CAR T cell therapy, including its toxicity, costs, and limited access, prolonged disease-free survival and potential cure of MM are finally within reach.

Reactions and adverse events induced by T-cell engagers as anti-cancer immunotherapies, a comprehensive review.

T-cell engagers (TCE) are cancer immunotherapies that have recently demonstrated meaningful benefit for patients with hematological malignancies and solid tumors. The anticipated widespread use of T cell engagers poses implementation challenges and highlights the need for guidance to anticipate, mitigate, and manage adverse events. By mobilizing T-cells directly at the contact of tumor cells, TCE mount an obligatory and immediate anti-tumor immune response that could result in diverse reactions and adverse events. Cytokine release syndrome (CRS) is the most common reaction and is largely confined to the first drug administrations during step-up dosage. Cytokine release syndrome should be distinguished from infusion related reaction by clinical symptoms, timing to occurrence, pathophysiological aspects, and clinical management. Other common reactions and adverse events with TCE are immune effector Cell-Associated Neurotoxicity Syndrome (ICANS), infections, tumor flare reaction and cytopenias. The toxicity profiles of TCE and CAR-T cells have commonalities and distinctions that we sum-up in this review. As compared with CAR-T cells, TCE are responsible for less frequently severe CRS or ICANS. This review recapitulates terminology, pathophysiology, severity grading system and management of reactions and adverse events related to TCE.

Efficacy and safety of bendamustine for lymphodepletion before lisocabtagene maraleucel.

Bendamustine has been retrospectively shown to be an effective and safe lymphodepletion regimen prior to the anti-CD19 chimeric antigen receptor T cell (CART) products tisagenlecleucel and axicabtagene ciloleucel, as well as the anti-BCMA CART products idecabtagene vicleucel and ciltacabtagene autoleucel. However, bendamustine as lymphodepletion prior to lisocabtagene maraleucel (liso-cel), a 4-1BB co-stimulated, fixed CD4:CD8 ratio anti-CD19 CART product, has not been described yet. Thus, we studied a cohort of sequentially-treated patients with large B-cell lymphomas who received bendamustine lymphodepletion before liso-cel at the University of Pennsylvania between 5/2021 and 12/2023 (n = 31). Patients were evaluated for toxicities and responses. Of note, 7 patients (22.6%) would have dnot met the inclusion criteria for the registrational liso-cel clinical trials, mostly due to older age. Overall and complete response rates were 76.9% and 73.1%, respectively. At a median follow-up of 6.3 months, the 6-month progression-free and overall survival were 59.9% and 91.1%, respectively. Rates of cytokine-release syndrome (CRS) and neurotoxicity (ICANS) of any grade were 9.7% and 9.7%, respectively, with no grade ≥ 3 events. No infections were reported during the first 30 days following liso-cel infusion. Neutropenia ≥ grade 3 was observed in 29.0% of patients; thrombocytopenia ≥ grade 3 occurred in 9.7%. In conclusion, bendamustine lymphodepletion before liso-cel appears to be a strategy that can drive tumor responses while ensuring a mild toxicity profile.

Advancing autoimmune Rheumatic disease treatment: CAR-T Cell Therapies - Evidence, Safety, and future directions.

INTRODUCTION: Despite advancements in managing autoimmune rheumatic diseases (ARDs) with existing treatments, many patients still encounter challenges such as inadequate responses, difficulty in maintaining remission, and side effects. Chimeric Antigen Receptor (CAR) T-cell therapy, originally developed for cancer, has now emerged as a promising option for cases of refractory ARDs. METHODS: A search of the literature was conducted to compose a narrative review exploring the current evidence, potential safety, limitations, potential modifications, and future directions of CAR-T cells in ARDs. RESULTS: CAR-T cell therapy has been administered to patients with refractory ARDs, including systemic lupus erythematosus, antisynthetase syndrome, and systemic sclerosis, demonstrating significant improvement. Notable responses include enhanced clinical symptoms, reduced serum autoantibody titers, and sustained remissions in disease activity. Preclinical and in vitro studies using both animal and human samples also support the efficacy and elaborate on potential mechanisms of CAR-T cells against antineutrophil cytoplasmic antibody-associated vasculitis and rheumatoid arthritis. While cautious monitoring of adverse events, such as cytokine release syndrome, is crucial, the therapy appears to be highly tolerable. Nevertheless, challenges persist, including cost, durability due to potential CAR-T cell exhaustion, and manufacturing complexities, urging the development of innovative solutions to further enhance CAR-T cell therapy accessibility in ARDs. CONCLUSIONS: CAR-T cell therapy for refractory ARDs has demonstrated high effectiveness. While no significant warning signs are currently reported, achieving a balance between therapeutic efficacy and safety is vital in adapting CAR-T cell therapy for ARDs. Moreover, there is significant potential for technological advancements to enhance the delivery of this treatment to patients, thereby ensuring safer and more effective disease control for patients.

CAR-T cells neurotoxicity from consolidated practice in hematological malignancies to fledgling experience in CNS tumors: fill the gap.

Chimeric antigen receptor (CAR-T) therapy has marked a paradigm shift in the treatment of hematological malignancies and represent a promising growing field also in solid tumors. Neurotoxicity is a well-recognized common complication of CAR-T therapy and is at the forefront of concerns for CAR-based immunotherapy widespread adoption, as it necessitates a cautious approach. The non-specific targeting of the CAR-T cells against normal tissues (on-target off-tumor toxicities) can be life-threatening; likewise, immune-mediate neurological symptoms related to CAR-T cell induced inflammation in central nervous system (CNS) must be precociously identified and recognized and possibly distinguished from non-specific symptoms deriving from the tumor itself. The mechanisms leading to ICANS (Immune effector Cell-Associated Neurotoxicity Syndrome) remain largely unknown, even if blood-brain barrier (BBB) impairment, increased levels of cytokines, as well as endothelial activation are supposed to be involved in neurotoxicity development. Glucocorticoids, anti-IL-6, anti-IL-1 agents and supportive care are frequently used to manage patients with neurotoxicity, but clear therapeutic indications, supported by high-quality evidence do not yet exist. Since CAR-T cells are under investigation in CNS tumors, including glioblastoma (GBM), understanding of the full neurotoxicity profile in brain tumors and expanding strategies aimed at limiting adverse events become imperative. Education of physicians for assessing individualized risk and providing optimal management of neurotoxicity is crucial to make CAR-T therapies safer and adoptable in clinical practice also in brain tumors.

Novel pathophysiological insights into CAR-T cell associated neurotoxicity.

Chimeric antigen receptor (CAR) T cell therapy represents a scientific breakthrough in the treatment of advanced hematological malignancies. It relies on cell engineering to direct the powerful cytotoxic T-cell activity toward tumor cells. Nevertheless, these highly powerful cell therapies can trigger substantial toxicities such as cytokine release syndrome (CRS) and immune cell-associated neurological syndrome (ICANS). These potentially fatal side effects are now better understood and managed in the clinic but still require intensive patient follow-up and management. Some specific mechanisms seem associated with the development of ICANS, such as cytokine surge caused by activated CAR-T cells, off-tumor targeting of CD19, and vascular leak. Therapeutic tools are being developed aiming at obtaining better control of toxicity. In this review, we focus on the current understanding of ICANS, novel findings, and current gaps.

Molecular and Clinical Characteristics of Different Toxicity Rates in Anti-CD19 Chimeric Antigen Receptor T Cells: Real-World Experience.

Commercially available anti-CD19 chimeric antigen receptor T cells (CARΤ cells) have offered long-term survival to a constantly expanding patient population. Given that novel toxicities including cytokine release syndrome (CRS) and neurotoxicity (ICANS) have been observed, we aimed to document the safety and toxicity of this treatment in a real-world study. We enrolled 31 adult patients referred to our center for CAR T therapy. Tisagenlecleucel was infused in 12 patients, axicabtagene ciloleucel in 14, and brexucabtagene autoleucel in 5. Cytokine release syndrome was noted in 26 patients while neurotoxicity was observed in 7. Tocilizumab was administered for CRS in 18 patients, along with short-term, low-dose steroid administration in one patient who developed grade III CRS and, subsequently, grade I ICANS. High-dose steroids, along with anakinra and siltuximab, were administered in only two MCL patients. With a median follow-up time of 13.4 months, nine patients were then in CR. The progression-free (PFS) and overall survival (OS) rates were 41.2% and 88.1% at one year, respectively. MCL diagnosis, which coincides with the administration of brexucabtagene autoleucel, was the only factor to be independently associated with poor OS (p < 0.001); meanwhile, increased LDH independently predicted PFS (p = 0.027).In addition, CRP at day 14 was associated with a poor OS (p = 0.001). Therefore, our real-world experience confirmed that commercial CAR T therapy can be administered with minimal toxicity.

Exploring the High-Grade and Refractory Neurotoxicity of Teclistamab: An Underreported Entity.

T-cell re-directing bispecific antibodies targeting B-cell maturation antigens have recently entered real-world use in relapsed/refractory multiple myeloma. While no head-to-head comparison has been done, they have generally been observed to have lower-grade toxicities compared with their chimeric antigen receptor T-cell (CAR-T) counterparts. However, in our real-world, single-institution experience, we have encountered two patients receiving teclistamab who experienced high-grade and refractory immune effector cell-associated neurotoxicity syndrome (ICANS) that did not respond to traditional toxicity mitigation strategies of high-dose corticosteroids or other immunosuppressive therapies. As we increase our use of these novel and vital agents, caution must be warranted.

Treatment of adult ALL patients with third-generation CD19-directed CAR T cells: results of a pivotal trial.

BACKGROUND: Third-generation chimeric antigen receptor (CAR)-engineered T cells (CARTs) might improve clinical outcome of patients with B cell malignancies. This is the first report on a third-generation CART dose-escalating, phase-1/2 investigator-initiated trial treating adult patients with refractory and/or relapsed (r/r) acute lymphoblastic leukemia (ALL). METHODS: Thirteen patients were treated with escalating doses of CD19-directed CARTs between 1 × 106 and 50 × 106 CARTs/m2. Leukapheresis, manufacturing and administration of CARTs were performed in-house. RESULTS: For all patients, CART manufacturing was feasible. None of the patients developed any grade of Immune effector cell-associated neurotoxicity syndrome (ICANS) or a higher-grade (≥ grade III) catokine release syndrome (CRS). CART expansion and long-term CART persistence were evident in the peripheral blood (PB) of evaluable patients. At end of study on day 90 after CARTs, ten patients were evaluable for response: Eight patients (80%) achieved a complete remission (CR), including five patients (50%) with minimal residual disease (MRD)-negative CR. Response and outcome were associated with the administered CART dose. At 1-year follow-up, median overall survival was not reached and progression-free survival (PFS) was 38%. Median PFS was reached on day 120. Lack of CD39-expression on memory-like T cells was more frequent in CART products of responders when compared to CART products of non-responders. After CART administration, higher CD8 + and γδ-T cell frequencies, a physiological pattern of immune cells and lower monocyte counts in the PB were associated with response. CONCLUSION: In conclusion, third-generation CARTs were associated with promising clinical efficacy and remarkably low procedure-specific toxicity, thereby opening new therapeutic perspectives for patients with r/r ALL. Trial registration This trial was registered at www. CLINICALTRIALS: gov as NCT03676504.