T-cell Recipients Research Articles

Cardiovascular Events After Chimeric Antigen Receptor T-Cell Therapy for Advanced Hematologic Malignant Neoplasms

The frequency and clinical phenotypes of cardiotoxic events in chimeric antigen receptor (CAR) T-cell recipients remain poorly understood given that landmark approval trials typically exclude patients with high-risk cardiovascular profiles and data from nontrial settings are scarce. To summarize the prevalence of adverse cardiovascular events among adults receiving CAR T-cell therapies for advanced hematologic malignant neoplasms. MEDLINE, Embase, Cochrane Library, and Google Scholar were systematically searched from database inception until February 26, 2024. Observational studies were included if they comprised adult CAR T-cell recipients with advanced hematologic malignant neoplasms and if they systematically evaluated cardiovascular complications. Extraction of prespecified parameters related to the patient population, study design, and clinical events was performed at the study level by 2 independent reviewers in accordance with the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline. Meta-analysis of single proportions was conducted using random-effect models with Freeman-Tukey double arcsine transformations to calculate pooled prevalence estimates. Sensitivity analysis was performed using generalized linear mixed models with logit transformations. Ventricular and supraventricular arrhythmias, heart failure events, reduction in left ventricular ejection fraction, myocardial infarction, and cardiovascular and all-cause mortality. Thirteen studies comprising 1528 CAR T-cell recipients (median [IQR] age, 61 [58.7-63.0] years; 1016 males [66%]; 80% patients with lymphoma) were included. The median (IQR) duration of follow-up was 487 (294-530) days. On random-effects meta-analysis, we observed a pooled prevalence of 0.66% (95% CI, 0.00%-2.28%) for ventricular arrhythmia, 7.79% (95% CI, 4.87%-11.27%) for supraventricular arrhythmia, 8.68% (95% CI, 2.26%-17.97%) for left ventricular dysfunction, 3.87% (95% CI, 1.77%-6.62%) for heart failure events, 0.62% (95% CI, 0.02%-1.74%) for myocardial infarction, and 0.63% (95% CI, 0.13%-1.38%) for cardiovascular death. The pooled prevalence of all-cause mortality was 30.01% (95% CI, 19.49%-41.68%). Sensitivity analyses generated similar findings. This meta-analysis found a low prevalence of ventricular arrhythmia, myocardial infarction, and cardiovascular death among CAR T-cell recipients over a short-term to midterm follow-up. Left ventricular dysfunction and supraventricular arrhythmia were the most commonly reported cardiovascular complications, suggesting that cardiovascular surveillance strategies should focus on decreases in ejection fraction and supraventricular arrhythmia.

EASIX and m-EASIX predict CRS and ICANS in pediatric and AYA patients after CD19-CAR T-cell therapy

AbstractCytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS) are complications of CD19-directed chimeric antigen receptor (CD19-CAR) T-cell therapy. The Endothelial Activation and Stress Index (EASIX) and modified EASIX (m-EASIX) scores have been retrospectively proven to be predictive of CRS and ICANS in adult CAR T-cell recipients. However, these scores have not been evaluated in pediatric cohorts. We retrospectively report on 76 pediatric and adolescent and young adult (AYA) patients with relapsed/refractory B-cell acute lymphoblastic leukemia treated with CD19-CAR T cells at St. Jude Children’s Research Hospital or John’s Hopkins Hospital. Data included patient, disease, and treatment characteristics. EASIX and m-EASIX scores were calculated at days –5 before, 0, and +3 after CAR T-cell infusion. CRS and ICANS occurred in 47 and 17 patients, respectively. At all evaluated time points, the median EASIX scores were higher for patients who developed severe CRS and any grade ICANS, and the median m-EASIX scores were higher in patients who developed severe CRS and severe ICANS than those with no/mild CRS/ICANS. Receiver operating characteristic curve analysis showed that both scores were strong predictors of CRS, especially severe CRS, at all time points. Any grade and severe ICANS were best predicted by both scores at day +3. m-EASIX uniformly outperformed EASIX, except for predicting any grade ICANS. Our results validate the potential utility of EASIX and m-EASIX scores for predicting CAR T-cell–related complications for pediatric and AYA patients.

Hypophosphatemia correction reduces ICANS incidence and duration in CAR T-cell therapy: a pooled clinical trial analysis.

A common complication of chimeric antigen receptor (CAR)-T cell therapy is immune effector cell associated neurotoxicity syndrome (ICANS), which presents with encephalopathy, aphasia, inattention, somnolence, seizures, weakness, or cerebral edema. Despite its significant morbidity, there are currently no effective targeted treatments. Given the clinical similarities between ICANS and the neurological manifestations of acute hypophosphatemia, we retrospectively reviewed 499 patients treated with CD19-targeted CAR-T cell therapy across multiple clinical trials between 2015 and 2020. In addition to clinical toxicities experienced by the patients, we also interrogated the impact of serum electrolyte data and repletion of corresponding electrolyte deficiencies with ICANS incidence, severity, and duration. Hypophosphatemia was a common occurrence in CAR T-cell recipients, and the only electrolyte derangement associated with a significantly higher cumulative incidence of ICANS. Moreover, phosphorus repletion in hypophosphatemic patients was associated with significantly decreased ICANS incidence and duration. Hypophosphatemia was uniquely associated with encephalopathy neurological adverse events, which also showed the strongest positive correlation with both ICANS and CRS severity. These findings suggest that serum phosphorus could be a reliable biomarker for ICANS, and expeditious, goal-directed phosphorus repletion in response to serum hypophosphatemia could be a safe, inexpensive, and widely available intervention for such patients.

COVID-19 Outcomes Among Hematopoietic Cell Transplant and Chimeric Antigen Receptor T-Cell Recipients in the Era of SARS-CoV-2 Omicron Variants and COVID-19 Therapeutics

Recipients of cellular therapies, including hematopoietic cell transplant (HCT) and chimeric antigen receptor T-cell (CART) therapy, are at risk for poor outcomes from coronavirus disease 2019 (COVID-19). There are limited data describing outcomes among patients in the pre- and early post-cellular therapy period during the Omicron era when multiple antiviral therapeutics were widely available. The objective of this study is to describe COVID-19 treatment and outcomes in patients diagnosed with COVID-19 during the pre- or early post-cellular therapy period. This is a single-center retrospective cohort study of adult HCT and CART recipients diagnosed with COVID-19 in the pre- and early post-cellular therapy period who tested positive for COVID-19 at our cancer center between January 1, 2022 and March 1, 2023. Primary outcomes were 30-day COVID-19-related hospitalization and death. A secondary outcome was development of persistent COVID-19, defined by a positive SARS-CoV-2 polymerase chain reaction (PCR) 31 to 90 days after COVID-19 diagnosis. Among 65 patients included, 52 (80%) received at least one COVID-19 therapeutic. The most common treatment after initial COVID-19 diagnosis was nirmatrelvir/ritonavir (29%), followed by monoclonal antibody therapy (26%) and remdesivir (11%). Of the 64 patients with at least 30 days of follow-up, 8 (12%) had at least one COVID-19-related hospitalization and one patient died, though cause of death was not due to COVID-19. Of the 8 patients hospitalized for COVID-19, one had severe disease and 7 had mild or moderate infection. Persistent COVID-19 was observed in 13/65 (20%) patients, with 4 patients requiring additional antiviral therapy. Three pre-cellular therapy patients had delays in receiving cellular therapy due to persistent COVID-19. During the Omicron era, rates of 30-day COVID-19-related hospitalization and death were relatively low in this cohort of pre- and early post-HCT and CART recipients, the majority of whom received treatment with at least one antiviral agent. Persistent COVID-19 occurred in 1 in 5 patients in the peri-cellular therapy period and led to cellular therapy treatment delays in several patients, highlighting the need for new COVID-19 treatment strategies.

Improved outcome of COVID-19 over time in patients treated with CAR T-cell therapy: Update of the European COVID-19 multicenter study on behalf of the European Society for Blood and Marrow Transplantation (EBMT) Infectious Diseases Working Party (IDWP) and the European Hematology Association (EHA) Lymphoma Group

COVID-19 has been associated with high mortality in patients treated with Chimeric Antigen Receptor (CAR) T-cell therapy for hematologic malignancies. Here, we investigated whether the outcome has improved over time with the primary objective of assessing COVID-19-attributable mortality in the Omicron period of 2022 compared to previous years. Data for this multicenter study were collected using the MED-A and COVID-19 report forms developed by the EBMT. One-hundred-eighty patients were included in the analysis, 39 diagnosed in 2020, 35 in 2021 and 106 in 2022. The median age was 58.9 years (min-max: 5.2–78.4). There was a successive decrease in COVID-19-related mortality over time (2020: 43.6%, 2021: 22.9%, 2022: 7.5%) and in multivariate analysis year of infection was the strongest predictor of survival (p = 0.0001). Comparing 2022 with 2020–2021, significantly fewer patients had lower respiratory symptoms (21.7% vs 37.8%, p = 0.01), needed oxygen support (25.5% vs 43.2%, p = 0.01), or were admitted to ICU (5.7% vs 33.8%, p = 0.0001). Although COVID-19-related mortality has decreased over time, CAR T-cell recipients remain at higher risk for complications than the general population. Consequently, vigilant monitoring for COVID-19 in patients undergoing B-cell-targeting CAR T-cell treatment is continuously recommended ensuring optimal prevention of infection and advanced state-of-the art treatment when needed.

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.

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

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

Primary vs. pre-emptive anti-seizure medication prophylaxis in anti-CD19 CAR T-cell therapy

IntroductionSeizures may occur in up to 30% of non-Hodgkin lymphoma patients who received anti-CD19 CAR T-cell therapy, yet the optimal anti-seizure medication (ASM) prevention strategy has not been thoroughly investigated.MethodsConsecutive patients affected by refractory non-Hodgkin lymphoma who received anti-CD19 CAR T-cells were included. Patients were selected and assessed using similar internal protocols. ASM was started either as a primary prophylaxis (PP-group) before CAR T-cells infusion or as a pre-emptive therapy (PET-group) only upon the onset of neurotoxicity development.ResultsOne hundred fifty-six patients were included (PP-group = 88, PET-group = 66). Overall, neurotoxicity and severe neurotoxicity occurred in 45 (29%) and 20 (13%) patients, respectively, equally distributed between the two groups. Five patients experienced epileptic events (PET-group = 3 [4%]; PP-group = 2 [2%]). For all the PET-group patients, seizure/status epilepticus occurred in the absence of overt CAR-T-related neurotoxicity, whereas patients in the PP-group experienced brief seizures only in the context of critical neurotoxicity with progressive severe encephalopathy. ASMs were well-tolerated by all patients, even without titration. No patients developed epilepsy or required long-term ASMs.ConclusionOur data suggest that both primary and pre-emptive anti-seizure prophylaxis are safe and effective in anti-CD19 CAR T-cell recipients. Clinical rationale suggests a possible more favourable profile of primary prophylaxis, yet no definitive conclusion of superiority between the two ASM strategies can be drawn from our study.

Incidence of Laboratory Tumor Lysis Syndrome in CAR T-Cell Recipients

Incidence of Laboratory Tumor Lysis Syndrome in CAR T-Cell Recipients

The Mechanisms of Altered Blood-Brain Barrier Permeability in CD19 CAR T-Cell Recipients.

Cluster of differentiation 19 (CD19) chimeric antigen receptor (CAR) T cells are a highly effective immunotherapy for relapsed and refractory B-cell malignancies, but their utility can be limited by the development of immune effector cell-associated neurotoxicity syndrome (ICANS). The recent discovery of CD19 expression on the pericytes in the blood-brain barrier (BBB) suggests an important off-target mechanism for ICANS development. In addition, the release of systemic cytokines stimulated by the engagement of CD19 with the CAR T cells can cause endothelial activation and decreased expression of tight junction molecules, further damaging the integrity of the BBB. Once within the brain microenvironment, cytokines trigger a cytokine-specific cascade of neuroinflammatory responses, which manifest clinically as a spectrum of neurological changes. Brain imaging is frequently negative or nonspecific, and treatment involves close neurologic monitoring, supportive care, interleukin antagonists, and steroids. The goal of this review is to inform readers about the normal development and microstructure of the BBB, its unique susceptibility to CD19 CAR T cells, the role of individual cytokines on specific elements of the brain's microstructural environment, and the clinical and imaging manifestations of ICANS. Our review will link cellular pathophysiology with the clinical and radiological manifestations of a complex clinical entity.

Experiences and perspectives on chimeric antigen receptor (CAR) T-cell therapy among recipients, carers and referrers (RE-TELL): a qualitative study to inform CAR T-cell service design

ObjectivesRE-TELL is a qualitative study, which aims to understand patient, support person, clinician and coordinator experiences and perspectives of chimeric antigen receptor (CAR) T-cell therapy, to inform design of a...

2708. Infectious Complications Among CD19 Chimeric Antigen Receptor T-cell Recipients

Abstract Background Current data on infectious complications of chimeric antigen receptor (CAR) T-cell therapy are limited to single center retrospective cohort studies. Presented here is a subset of patients from a multicenter retrospective cohort study including recipients of CAR T-cell therapy at Duke University, University of North Carolina at Chapel Hill, and Stanford University. Methods In a retrospective cohort of 66 patients who received CD19 CAR T-cell therapy Duke University between January 1, 2018 and August 31, 2021 rates and characteristics of bacterial, viral, and fungal infections within the first year after CAR T-cell infusion are described. Demographic, baseline clinical, and outcome variables are compared between patients who developed infection and those who did not. Results Forty-nine total infections occurred in 29 (43.9%) patients within 1 year of CAR T-cell infusion. Patients who developed infection were more likely to have an underlying malignancy other than diffuse large B-cell lymphoma (34% vs 8%, p = 0.031), and to have developed immune effector cell-associated neurotoxicity syndrome (62% vs. 32%, p = 0.016). Viral (23/49, 46.9%) and bacterial (20/49, 40.8%) pathogens predominated and infections most often involved the bloodstream (19/49, 38.8%) and lung (18/49, 36.7%).There were no statistically significant differences between rates of bacterial and viral infection based on time since CAR T-cell infusion (≤30 days vs 30 – 90 days vs >90 days), though fungal infections only occurred after 90 days in patients with relapse of their underlying disease. Conclusion Infectious complications after CAR T-cell therapy are common within the first year of infusion. Bacterial and viral infections predominate while fungal infections are rare and occurred only in patients with relapsed disease. Disclosures Melody Smith, MD, MS, BMS: Advisor/Consultant Krista Rowe-Nichols, RN, MSN, AOCNS, Bristol Myers Squibb: Advisor/Consultant|Kite Pharmaceuticals: Advisor/Consultant|Kite Pharmaceuticals: Speaker Bureau Christopher Kelsey, MD, Colgate-Palmolive: Expert Testimony|Johnson and Johnson: Expert Testimony Taewoong Choi, MD, Janssen biotech: Honoraria Matthew McKinney, MD, ADC Therapeutics: Advisor/Consultant|ADC Therapeutics: Honoraria|Beigene: Grant/Research Support|Beigene: Honoraria|Epizyme: Advisor/Consultant|Genentech: Advisor/Consultant|Genentech: Grant/Research Support|Genentech: Honoraria|Gilead/Kite: Advisor/Consultant|Gilead/Kite: Honoraria|Incyte: Grant/Research Support|Novartis: Advisor/Consultant|Seagen, Inc.: Advisor/Consultant|Takeda: Advisor/Consultant|TG therapeutics: Advisor/Consultant

Efficacy of Chimeric Antigen Receptor T-Cell Therapy Is Not Impaired By Previous Bispecific Antibody Treatment in Patients with Large B-Cell Lymphoma

Introduction: Potential T-cell exhaustion after bispecific antibody (BsAb) treatment remains an open question, raising the theoretical concern that prior BsAb exposure could affect subsequent chimeric antigen receptor (CAR) T-cell efficacy. Clinical data on CAR T-cell outcomes after prior BsAb treatment in the setting of large B-cell lymphoma (LBCL) are scarce and highly awaited to better define treatment sequencing in relapsed/refractory (R/R) patients. Methods: We conducted a retrospective, international study including R/R LBCL patients treated with CD19-targeted CAR T-cells at 15 centers between July 2018 and January 2023 who had been exposed to BsAbs prior to apheresis. Then, we identified a control cohort from patients included in the DESCAR-T Registry (n=764). We carried out a 1:1 propensity score matching (PSM) to achieve balance between cohorts; 13 baseline covariates were included in the PSM. We compared response rates, survival outcomes and toxicity after CAR T-cell therapy, according to previous BsAb exposure. Results: We identified 47 LBCL patients who received BsAb therapy prior to CAR T-cell apheresis. Median age was 65 years (range 31-82), with a male predominance (66%), and median prior lines of therapy before BsAb were 2 (IQR 2-3) (Table). The BsAbs targeted CD20/CD3 (91%) or CD22/CD3 (9%), either in monotherapy (n=41, 87%) or in combination with other agents (n=6, 13%) (lenalidomide [n=2], polatuzumab [n=1], chemotherapy [n=2], missing [n=1]). The median time on BsAb treatment was 98 days (IQR 56-160) with a best overall (complete) response rate (ORR [CRR]) of 47% (19%). Median progression-free survival (PFS) and duration of response (DOR) were 3.1 months (95% CI 2.7-4.4 months) and 8.8 months (95% CI 2.2-NR), respectively. Cytokine release syndrome (CRS) occurred in 59% of patients (grade 3 in 4%). No neurologic toxicity (NT) was reported. In 26 (55%) patients, bispecific antibody was the last line before CAR T-cell therapy. Median washout between the last BsAb dose and lymphocyte apheresis for CAR T-cell manufacturing was 43 days (range 34-103 days). In terms of the subsequent CAR T-cell therapy, patients received axi-cel (n=22, 47%), tisa-cel (n=20, 43%) or liso-cel (n=5, 11%). Most patients developed CRS after infusion (79%, 6% grade >2), with a low rate of NT (23%, 2% grade >2). Neutropenia and thrombocytopenia grade >2 were reported in 66% and 45% of patients, respectively. Regarding efficacy, ORR after infusion was 83% (CR 43%). Median PFS and overall survival (OS) were 6.6 months (95% CI 2.6-not reached [NR]) and NR (95% CI 9.0-NR), respectively. The rate of overall (complete) response was similar between patients who had previously responded (CR or PR) or not (SD or PD) to BsAb therapy (82% [41%] vs 84% [44%], respectively, p=0.64). However, all 9 patients achieving CR after BsAb achieved subsequent response to CAR T-cells. Given the wide variability in the washout between last BsAb dose and lymphocyte apheresis, we evaluated the impact of this interval on CAR T-cell efficacy. The 6-month PFS and OS of patients previously exposed to BsAb within 45 days of lymphocyte apheresis was similar to patients who had a longer washout (59% vs 47% [p=0.25] and 83% vs 67% [p=0.21], respectively). In the second part of the analysis, we matched our cohort with a control group of CAR T-cell recipients not previously exposed to BsAbs. The final analysis included 2 sets of 42 patients with comparable characteristics. Median follow-up from CAR T-cell infusion was 11.5 months for the BsAb cohort (CI 95% 6.4-19.0 months) and 18.8 months for the control cohort (CI 95% 10.9-23.0 months). Patients with previous BsAb exposure showed a similar PFS (p=0.10, Figure) and OS (p=0.08) after CAR T-cell infusion in comparison to the control group. In terms of toxicity, there were no differences in the incidence of CRS (p=0.41) or NT (p=1.0) after infusion. Conclusions: Previous exposure to bispecific antibody treatment targeting different antigens does not have a negative impact on survival outcomes after CAR T-cell therapy. Lack of response to a previous BsAb does not predict for lower response rates after CAR T-cell infusion.

Risk of Bleeding and Thrombosis with CAR T-Cell Therapy: A Scoping Review

Introduction: Chimeric antigen receptor (CAR) T-cell therapy is emerging as a novel and revolutionary therapy in the treatment of relapsed or refractory lymphoma and other hematological malignancies. Patients with hematological malignancies are at risk of bleeding and thrombosis due to multiple risks factors. As there is an ongoing exploration of the incidence and characteristics of bleeding and thrombosis after CAR T-cell therapy, there is no existing published data that incorporates both peer-reviewed and non-peer-reviewed literature. Aim: Assess the risk of bleeding and thrombosis in CAR T-cell recipients for hematological malignancies. Method: We conducted a systematic literature search in MEDLINE, EMBASE, and CENTRAL electronic databases from inception to October 2022 using a combination of subject headings and text words. We included studies that assessed thrombotic and bleeding complications in patients eighteen or older who underwent CAR T-cell therapy for a hematologic malignancy. Our search strategy yielded 14 studies in the form of abstracts and full-text articles. The review process consisted of two levels of screening: (1) a title and abstract review and (2) a full-text review. Result: Of 3354 records, we included 14 studies based on our inclusion criteria [figure 1]. Majorities of the studies were retrospective. Most of the patients in these studies received CAR T-cell therapy for refractory diffuse large B-cell lymphoma. Patients received at least 2 lines of therapy or more before CAR T-cell treatment. Different types of CAR T-cell therapy were used. Based on the included studies, the risk of bleeding was higher than thrombosis [figure 2]. Bleeding sites were variable, but gastrointestinal (GI) bleeding was predominant. In Ma et al, GI bleeding occurred in 11 (42.3%) patients. In Qi et al and Johnsrud et al, bleeding occurred in 44 (11%) and 12 (9.4%) patients respectively. Variable sites of thrombosis were noticed. In Hashmi et al incidence of thrombosis was 10.8%. Although there are some risk factors associated with bleeding and thrombosis in this population, the exact mechanism is still unknown. We think future studies to determine the exact mechanism of this toxicity and to assess the underlying risk factors would be crucial to decrease morbidity and mortality in this population and to develop risk assessment tools.

Recent Bendamustine Treatment Before Apheresis Has a Negative Impact on Outcomes in Patients With Large B-Cell Lymphoma Receiving Chimeric Antigen Receptor T-Cell Therapy.

Approximately 30%-40% of patients with relapsed/refractory (R/R) large B-cell lymphoma (LBCL) infused with CD19-targeted chimeric antigen receptor (CAR) T cells achieve durable responses. Consensus guidelines suggest avoiding bendamustine before apheresis, but specific data in this setting are lacking. We report distinct outcomes after CAR T-cell therapy according to previous bendamustine exposure. The study included CAR T-cell recipients from seven European sites. Safety, efficacy, and CAR T-cell expansion kinetics were analyzed according to preapheresis bendamustine exposure. Additional studies on the impact of the washout period and bendamustine dose were performed. Inverse probability treatment weighting (IPTW) and propensity score matching (PSM) analyses were carried out for all efficacy comparisons between bendamustine-exposed and bendamustine-naïve patients. The study included 439 patients with R/R LBCL infused with CD19-targeted commercial CAR T cells, of whom 80 had received bendamustine before apheresis. Exposed patients had significantly lower CD3+ cells and platelets at apheresis. These patients had a lower overall response rate (ORR, 53% v 72%; P < .01), a shorter progression-free survival (PFS, 3.1 v 6.2 months; P = .04), and overall survival (OS, 10.3 v 23.5 months; P = .01) in comparison with the bendamustine-naïve group. Following adjustment methods for baseline variables, these differences were mitigated. Focusing on the impact of bendamustine washout before apheresis, those with recent (<9 months) exposure (N = 42) displayed a lower ORR (40% v 72%; P < .01), shorter PFS (1.3 v 6.2 months; P < .01), and OS (4.6 v 23.5 months; P < .01) in comparison with bendamustine-naïve patients. These differences remained significant after IPTW and PSM analysis. Conversely, the cumulative dose of bendamustine before apheresis did not affect CAR-T efficacy outcomes. Recent bendamustine exposure before apheresis was associated with negative treatment outcomes after CD19-targeted CAR T-cell therapy and should be therefore avoided in CAR T-cell candidates.

1488-P: Reduced iPLA2b Expression in T-Lymphocytes Decreases Proinflammatory Eicosanoid Production and Cytokine Secretion Delaying Type 1 Diabetes Development in NOD Mice

Type 1 diabetes (T1D) is characterized by the destruction of insulin-producing pancreatic islet β-cells, but the causes of this process remain unclear. We find that Ca2+-independent phospholipase A2β (iPLA2β), which hydrolyzes membrane phospholipids at the sn-2 substituent to yield iPLA2β-derived lipids (iDLs), is induced under a diabetic milieu and mitigation of iPLA2β activity attenuates β-cell death. Several iDLs are pro-inflammatory and have been studied in different diseases but are not understood in diabetes. We investigated the role of immune-cell iDLs by utilizing T-cell adoptive transfer. Isolated CD4+/8+ T-cells from splenocytes prepared from donor female NOD and NOD. iPLA2β+/− (HET) mice, were transferred i.p. to NOD.scid recipient mice. We observed T1D onset for all T-cell recipient groups between 10-12 weeks of age. However, reduction of iPLA2β in CD4/8 T-cells delayed 50% incidence by 10 weeks in NOD4/HET8-recipient mice and HET4/NOD8 T-cell recipients compared to “matched” T-cell recipients. Furthermore, reduced insulitis and increased β-cell preservation was detected in HET4/NOD8-recipients compared to NOD4/8 recipients. The immune cell composition between our genotypes revealed no difference suggesting iDL signaling contributes to the observed incidence. Lipidomic analyses revealed a decrease in pro-inflammatory eicosanoids (PGs, DHETs and HETEs) in nondiabetic recipient mice, compared to diabetic counterparts. In addition, by targeting select eicosanoid signaling (PGE2 and DHET) utilizing chemical inhibitors (i.e., Grapiprant (EP4 receptor antagonist) and EC5026 (soluble epoxide hydrolase inhibitor)), we observed decreased IFN-γ production by Th1 helper cells in HET donors compared to NOD. These findings suggest that iPLA2β in T-cells is a critical contributor to the production of pro-inflammatory iDLs and could be a potential target in reducing T1D development. Disclosure T. White: None. S. Ramanadham: None. T.P. DiLorenzo: None. C.E. Chalfant: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (R01DK069455); National Institute of Allergy and Infectious Diseases (R21AI146743, R21AI169214); JDRF (2-SRA-2022-1210-S-B); University of Alabama at Birmingham (5T32GM8111-34)

Procalcitonin as a biomarker for predicting bacterial infection in chimeric antigen receptor T-cell therapy recipients.

It is unknown whether serum procalcitonin (PCT) concentration monitoring can differentiate between bacterial infection or cytokine release syndrome (CRS) when chimeric antigen receptor T-cell (CAR-T) recipients present with a constellation of signs and symptoms that may represent both complications. The objective of the study was to assess the utility of serum PCT concentrations as a biomarker of bacterial infection in CAR-T recipients. This single-center, retrospective, medical record review evaluated patients prescribed CAR-T therapy until death or 30 days after infusion. Logistic regression modeling determined the association between elevated serum PCT concentrations within 48 h of fever onset and microbiologically confirmed infection. Secondary outcomes included clinically suspected infection, CAR-T toxicity rates, and broad-spectrum antibiotic usage. Predictive performance of PCT was assessed by area under the receiver operating characteristic curve (AUC). The 98 included patients were a median age of 63 (IQR: 55-69) years old, 47 (48%) were male, and 87 (89%) were Caucasian. Baseline demographics and clinical characteristics were similar between patients with and without a bacterial infection. Serum PCT >0.4 ng/mL within 48 h of fever was significantly associated with a microbiologically confirmed bacterial infection (OR: 2.75 [95% CI: 1.02-7.39], p= 0.045). Median PCT values in patients with and without confirmed infections were 0.40 ng/mL (IQR: 0.26, 0.74) and 0.26 ng/mL (IQR: 0.13, 0.47), respectively. The AUC for PCT to predict bacterial infection was 0.62 (95% CI 0.48-0.76). All patients experienced CRS of some grade, with no difference in CRS severity based on elevated PCT. Broad-spectrum antibiotics were used for a median of 45% and 23% of days in those with and without confirmed infection, respectively (p= 0.075). Elevated serum PCT concentrations above 0.4ng/mL at time of first fever after CAR-T infusion was significantly associated with confirmed bacterial infection. Furthermore, rigorous, prospective studies should validate our findings and evaluate serial PCT measurements to optimize antimicrobial use after CAR-T therapy.

574 - Increasing Access to Survivorship Care for Chimeric Antigen Receptor T-Cell (CAR-T) Recipients

574 - Increasing Access to Survivorship Care for Chimeric Antigen Receptor T-Cell (CAR-T) Recipients

100 - Utilizing Remote Patient Monitoring to Safely Manage Chimeric Antigen Receptor T-Cell Recipients in the Outpatient Setting

100 - Utilizing Remote Patient Monitoring to Safely Manage Chimeric Antigen Receptor T-Cell Recipients in the Outpatient Setting

Infectious complications of chimeric antigen receptor (CAR) T-cell therapies

CAR T-cells have revolutionized the treatment of many hematological malignancies. Thousands of patients with lymphoma, acute lymphoblastic leukemia, and multiple myeloma have received this “living medicine” and achieved durable remissions. Their place in therapy continues to evolve, and there is ongoing development of new generation CAR constructs, CAR T-cells against solid tumors and CAR T-cells against chronic infections like human immunodeficiency virus and hepatitis B. A significant fraction of CAR T-cell recipients, unfortunately, develop infections. This is in part due to factors intrinsic to the patient, but also to the treatment, which requires lymphodepletion (LD), causes neutropenia and hypogammaglobulinemia and necessarily increases the state of immunosuppression of the patient. The goal of this review is to present the infectious complications of CAR T-cell therapy, explain their temporal course and risk factors, and provide recommendations for their prevention, diagnosis, and management.