T-cell Infusion Research Articles

Cancer cachexia and weight loss prior to CAR T-cell therapy for lymphoma are independently associated with poor outcomes

CAR T-cell therapy has transformed the care of lymphoma, yet many patients relapse. Several prognostic markers have been associated with CAR T cell outcomes, such as tumor burden, response to bridging chemotherapy, and laboratory parameters at the time of lymphodepletion or infusion. The effect of cancer cachexia and weight loss prior to CAR T cells on toxicity and outcomes is not well understood. Here, we present a retrospective single institution cohort study of 259 patients with lymphoma treated with CAR T-cells between 2017 and 2023. We observed that patients with a >5% decrease in their body mass index (BMI) in the 3 months preceding CAR T treatment (weight loss group; all meeting one of the commonly accepted definitions of cancer cachexia) had higher disease burden and inflammatory parameters (CRP, ferritin, IL6, TNFa) at time of lymphodepletion and CAR T-cell infusion. Patients with weight loss experienced higher rates of grade 3+ neurotoxicity and early hematotoxicity but those effects were not seen upon multivariable adjustment. However, in both univariate and multivariable analysis, patients with weight loss had worse response rates, overall survival, and event-free survival, indicating that weight loss is an independent poor prognostic factor. Our data suggest that weight loss in the 3 months preceding CAR T-cell therapy represents a worrisome "alarm signal" and potentially modifiable factor alongside tumor burden and inflammation and warrants further investigation in patients treated with CAR T therapy.

A matter of inflammation: CAR T-cell therapy and atrial fibrillation

Abstract Background Chimeric antigen receptor (CAR) T-cell therapy has been revolutionary in the treatment of blood cancers, but has been associated with arrhythmias such as atrial fibrillation (AF). Whether the incidence of AF has changed over time and if contributing risk factors are present remains to be defined. Methods Leveraging the Mayo Electronic Medical Record, we extracted a cohort of patients who underwent CAR T-cell therapy between 2016 and 2022. From this cohort, we identified those who had a diagnosis of AF at any point. We then defined the endpoint of interest as the first episode of new or recurrent AF during or after CAR T-cell infusion. Fine and Gray subdistribution hazard modeling was used to calculate the association of patient characteristics to the endpoint of interest. Variables with P<0.20 in univariate modeling were chosen for the multivariate model. Significance was defined as P<0.05. Results There were 328 patients who underwent CAR T-cell therapy between 2016 and 2022. Of this cohort, 27 (8.2%) patients had a pre-existing diagnosis of AF, of which 6 had recurrence of AF after CAR T (22.2%), while 21 (77.8%) did not. Of the 301 patients without a prior history of AF, 8 (2.7%) patients developed new-onset AF after CAR T. The majority of the 14 new or recurrent AF events (4.3% overall incidence) occurred within 30 days of receiving CAR T (N=10, 71.4%), the remainder after 180 days (Figure 1). No trend in declining incidence over time was noted. Prior AF, neurotoxicity, and inflammation (cytokine release syndrome and macrophage activating syndrome-like (MAS-L)) were strongly associated with the risk of developing new or recurrent AF (Table 1). Only presence of MAS-L remained an independent predictor in the multivariate model (HR 15.4, 95% CI 3.9-61.2, P<0.001). Conclusion AF is mainly seen early following CAR T-cell therapy, and mainly in association with severe inflammatory responses. Early and aggressive treatment of CRS and MAS-L may be recommendable for patients undergoing CAR-T therapy, especially for those with a prior history of AF.

Incidence of pre-existing B-cell aplasia in B-ALL: Implications for post-CAR T-cell monitoring

Ongoing B-cell aplasia (BCA) post-CAR T-cell infusion is increasingly utilized as a surrogate for functional CAR T-cell persistence in patients with relapsed/refractory B-ALL. We sought to evaluate the incidence of pre-treatment BCA—which may impact post-infusion BCA monitoring.

EASIX-guided risk stratification for complications and outcome after CAR T-cell therapy with ide-cel in relapsed/refractory multiple myeloma

BackgroundChimeric antigen receptor (CAR) T-cell therapy has demonstrated significant benefits in the treatment of relapsed/refractory multiple myeloma (RRMM). However, these outcomes can be compromised by severe complications, including cytokine release...

Prognostic significance of fludeoxyglucose positron emission tomography delta radiomics following bridging therapy in patients with large B-cell lymphoma undergoing CAR T-cell therapy.

Bridging radiation therapy (bRT) is increasingly being utilized prior to chimeric antigen receptor (CAR) T-cell therapy for large B-cell lymphoma (LBCL). It is unknown how the extent of cytoreduction during bRT impacts outcomes. We retrospectively reviewed patients with LBCL treated with bRT followed by CAR T-cell therapy. Metabolic tumor volume (MTV), maximum standardized uptake value (SUVmax), SUVmean, and total lesion glycolysis (TLG) were extracted from F18-fluorodeoxyglucose positron emission tomography (PET) scans acquired prior to bRT and between completion of bRT and CAR T-cell infusion. Delta radiomics based on changes of these values were then calculated. The association between delta radiomics and oncologic outcomes [progression-free survival (PFS), freedom from distant progression (FFDP), and local control (LC)] were then examined. Thirty-three sites across 23 patients with LBCL were irradiated. All metabolically active disease was treated in 10 patients. Following bRT, median overall decreases (including unirradiated sites) in MTV, SUVmax, SUVmean, and TLG were 22.2 cc (63.1%), 8.9 (36.8%), 3.4 (31.1%), and 297.9 cc (75.8%), respectively. Median decreases in MTV, SUVmax, SUVmean, and TLG in irradiated sites were 15.6 cc (91.1%), 17.0 (74.6%), 6.8 (55.3%), and 157.0 cc (94.6%), respectively. Median follow-up was 15.2 months. A decrease in SUVmax of at least 54% was associated with improved PFS (24-month PFS: 83.3% vs. 28.1%; p = 0.037) and FFDP (24-month FFDP: 100% vs. 62.4%; p < 0.001). A decrease in MTV of at least 90% was associated with improved FFDP (24-month FFDP: 100% vs. 62.4%; p < 0.001). LC was improved in sites with decreases in SUVmax of at least 71% (24-month LC: 100% vs. 72.7%; p < 0.001). Decreases of MTV by at least 90% (100% vs. 53.3%; p = 0.038) and TLG by at least 95% (100% vs. 56.3%; p = 0.067) were associated with an improved complete response rate. bRT led to substantial reductions in MTV, SUVmax, SUVmean, and TLG. The relative extent of these decreases correlated with improved outcomes after CAR T-cell infusion. Prospective cohorts should validate the value of interim PET following bRT for quantifying changes in disease burden and associated prognosis.

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.

CD19-Directed CAR T-Cells in a Patient With Refractory MOGAD: Clinical and Immunologic Follow-Up for 1 Year.

In MOG antibody-associated disease (MOGAD), relapse prevention and the treatment approach to refractory symptoms are unknown. We report a patient with refractory MOGAD treated with CD19-directed CAR T-cells. CD19-directed CAR T-cells (ARI-0001) were produced in-house by lentiviral transduction of autologous fresh leukapheresis and infused after a conventional lymphodepleting regimen. A 18-year-old man developed 2 episodes of myelitis associated with serum MOG-IgG, which were followed by 6 episodes of left optic neuritis (ON) and sustained the presence of MOG-IgG over 6 years despite multiple immunotherapies. After the sixth episode of ON, accompanied by severe residual visual deficits, CAR T-cell treatment was provided without complications. Follow-up of cell counts showed complete depletion of CD19+ B cells at day +7; reconstituted B cells at day +141 showing a naïve B-cell phenotype, and low or absent memory B cells and plasmablasts for 1 year. MOG-IgG titers have remained undetectable since CAR T-cell infusion. The patient had an early episode of left ON at day +29, when MOG-IgG was already negative, and since then he has remained free of relapses without immunotherapy for 1 year. This clinical case shows that CD19-directed CAR T-cell therapy is well-tolerated and is a potential treatment for patients with refractory MOGAD. This provides Class IV evidence. It is a single observational study without controls.

Outcome of patients with large B-cell lymphoma treated with tafasitamab plus lenalidomide either before or after CAR T-cell therapy

AbstractTafasitamab plus lenalidomide (TAFA-LEN) treatment relevance pre- or post-anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is debated. We analyzed patients with large B-cell lymphoma in the DESCAR-T registry treated with axi[1]cel or tisa-cel in ≥3rd line and TAFA-LEN before (n = 15, “TL-pre-CAR-T” set) or directly after (n = 52, “TL-post-CAR-T” set) CAR T-cell therapy. We compared TAFA-LEN v. other treatments using inverse probability weighting in the TL-post-CAR[1]T set. In the TL-post-CAR-T set, the median progression-free survival (mPFS), overall survival (mOS), and duration of response (mDOR) since the first treatment for progression (mPFS2/mOS2/mDOR2) were 3, 4.7, and 8.1 months, respectively. The best overall response rate (bORR) and best complete response rate (bCRR) after TAFA-LEN were 13.5% and 7.7%, respectively. Outcomes were better for patients who relapsed >6 months after CAR T-cell therapy (mPFS2: 5.6 vs 2 months, P = .0138; mOS2: not reached vs 3.8 months, P = .0034). The bORR and bCRR between TAFA-LEN and other treatments were 20.6% vs 24.9% and 11.6% vs 15.6%, respectively. Outcomes were similar between TAFA-LEN and other treatments (mPFS2: 2.9 vs 2.4 months, P = .91; mOS2: 3.3 vs 5.5 months, P = .06). In an exploratory analysis of the TL-pre-CAR-T set, the median TAFA-LEN treatment duration before CAR-T was 3.7 months with no patient becoming CD19 negative. The bORR, bCRR, 6- month PFS, and OS rates after CAR T-cell infusion were 45.5%, 36.4%, 20.1%, and 58.2%, respectively. Neither TAFA-LEN nor comparative salvage treatment improved outcomes for patients relapsing after CAR T-cell therapy.

Persistent cytopenias after anti-BCMA CAR T-cell therapy are associated with reduced hematopoietic activity in posttreatment bone marrows.

We attempt to analyze bone marrow findings and correlation with cytopenia(s) after anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell infusion in this study. Relevant clinicopathologic data, including complete blood counts, neutrophil counts, relevant therapy history, and pre- and posttherapy bone marrow evaluations, were studied in 12 patients who received anti-BCMA CAR T-cell therapy. Bone marrow findings after CAR T-cell therapy were available in 6 of 12 cases, 3 of which showed markedly hypocellular marrow with either markedly reduced or essentially absent hematopoiesis. One case showed a hypocellular marrow with trilineage hematopoiesis, while the remaining 2 cases showed persistent involvement by plasma cell myeloma. Reticulin stains did not reveal significant fibrosis. Ten patients had anemia, and 8 patients had leukopenia and thrombocytopenia at day 90 posttherapy. Long-term follow-up showed persistent disease in 10 of 12 cases. Prolonged cytopenias occur in most patients after BCMA CAR T-cell therapy with bone marrow evaluations demonstrating associated marked hypocellularity with minimal or no hematopoiesis without an increase in fibrosis.

Rapid identification of early infections in febrile patients after CD19 target CAR-T cell therapy for B-cell malignancies

BackgroundCD19-targeted chimeric antigen receptor T (CAR-T) cell therapy stands out as a revolutionary intervention, exhibiting remarkable remission rates in patients with refractory/relapsed (R/R) B-cell malignancies. However, the potential side effects of therapy, particularly cytokine release syndrome (CRS) and infections, pose significant challenges due to their overlapping clinical features. Promptly distinguishing between CRS and infection post CD19 target CAR-T cell infusion (CTI) remains a clinical dilemma. Our study aimed to analyze the incidence of infections and identify key indicators for early infection detection in febrile patients within 30 days post-CTI for B-cell malignancies.MethodsIn this retrospective cohort study, a cohort of 104 consecutive patients with R/R B-cell malignancies who underwent CAR-T therapy was reviewed. Clinical data including age, gender, CRS, ICANS, treatment history, infection incidence, and treatment responses were collected. Serum biomarkers procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP) levels were analyzed using chemiluminescent assays. Statistical analyses employed Pearson’s Chi-square test, t-test, Mann–Whitney U-test, Kaplan–Meier survival analysis, Cox proportional hazards regression model, Spearman rank correlation, and receiver operating characteristic (ROC) curve analysis to evaluate diagnostic accuracy and develop predictive models through multivariate logistic regression.ResultsIn this study, 38 patients (36.5%) experienced infections (30 bacterial, 5 fungal, and 3 viral) within the first 30 days of CAR T-cell infusion. In general, bacterial, fungal, and viral infections were detected at a median of 7, 8, and 9 days, respectively, after CAR T-cell infusion. Prior allogeneic hematopoietic cell transplantation (HCT) was an independent risk factor for infection (Hazard Ratio [HR]: 4.432 [1.262–15.565], P = 0.020). Furthermore, CRS was an independent risk factor for both infection ((HR: 2.903 [1.577–5.345], P < 0.001) and severe infection (9.040 [2.256–36.232], P < 0.001). Serum PCT, IL-6, and CRP were valuable in early infection prediction post-CAR-T therapy, particularly PCT with the highest area under the ROC curve (AUC) of 0.897. A diagnostic model incorporating PCT and CRP demonstrated an AUC of 0.903 with sensitivity and specificity above 83%. For severe infections, a model including CRS severity and PCT showed an exceptional AUC of 0.991 with perfect sensitivity and high specificity. Based on the aforementioned analysis, we proposed a workflow for the rapid identification of early infection during CAR-T cell therapy.ConclusionsCRS and prior allogeneic HCT are independent infection risk factors post-CTI in febrile B-cell malignancy patients. Our identification of novel models using PCT and CRP for predicting infection, and PCT and CRS for predicting severe infection, offers potential to guide therapeutic decisions and enhance the efficacy of CAR-T cell therapy in the future.

Chimeric Antigen Receptor T-Cell Postinfusion Fever: Infection Profile, Clinical Parameters, and Biomarkers Trends to Assist Antibiotic Stewardship.

This study aimed to describe documented infections associated with postinfusion fever after CAR T-cell therapy and to evaluate daily changes in vital signs, laboratory results, and the National Early Warning Score (NEWS) in patients with and without confirmed bacterial infections following fever onset, with the objective of assisting in antibiotic stewardship. This was a retrospective, observational study including all consecutive adult patients who received CAR T-cell therapy. Documented infection in the first fever episode after infusion, and clinical and analytic trend comparison of patients with bacterial documented infections and those without documented infections, are described. Among 152 patients treated with CAR T-cell therapy, 87 (57.2%) had fever within 30 days of infusion, with a median time from infusion to fever of 3 (interquartile range, 2-5) days. Of these 87 patients, 82 (94.3%) received broad-spectrum antibiotics. Infection was documented in 9 (10.3%) patients and only 4 (4.6%) had bacterial infections. Clinical signs and biomarkers were similar in patients with bacterial documented infection and in those without documented infection at fever onset. Fever, tachycardia, and high C-reactive protein levels remained high during the first 3 days after CAR T-cell infusion, even when no infection was documented. Fever is a common symptom following CAR T-cell infusion and is largely treated with broad-spectrum antibiotics. However, confirmed bacterial documented infections after the first fever post-CAR T-cell infusion are very unusual. Because clinical parameters and biomarkers are not useful for identifying infectious fever, other methods should be assessed to ensure the proper use of antibiotics.

Molecular Disease Monitoring in Patients With Relapsed/refractory B-Cell Lymphoma Receiving Anti-CD19 CAR T-Cell Therapy

BackgroundChimeric antigen receptor (CAR) T-cell therapy has improved the historically poor outcomes for relapsed and refractory (R/R) large B-cell non-Hodgkin's lymphoma (LBCL). However, nearly 60% of patients will either fail to respond or relapse after CAR T-cell therapy. Currently, PET/CT scans are used to assess response. Cell-free circulating tumor DNA (ctDNA) is released by tumor cells into the peripheral blood and can be measured for minimal residual disease (MRD) assessment. MethodsIn this retrospective, IRB approved pilot study, archived lymphoma tissue and ctDNA from peripheral blood samples on day 0, 14, 28, 56, 90, 180, and 365 after CAR T-cell infusion from 10 patients with R/R NHL were collected for next-generation sequencing (NGS) of clonal variable-diversity-joining (VDJ) rearrangements (Adaptive biotechnologies [Seattle, WA]). Response was assessed by PET/CT on days 90 and 365 and graded according to the Lugano 2014 criteria. The primary endpoint was to determine the feasibility of detecting ctDNA to monitor disease response after anti-CD19 CAR T-cell therapy. The secondary endpoint was to compare the sensitivity/specificity of MRD assessment from ctDNA to PET/CT imaging. ResultsNine out of 10 patients with a trackable sequence [median age 69 (range: 56-76); 55.6% male; median LDH 224], were included in this study. Each received tisagenlecleucel (tisa-cel) CAR T-cell therapy after median 2 prior treatments (range: 2-4). 7/9 patients had R/R diffuse large B-cell lymphoma (DLBCL), and 2/9 had transformed follicular lymphoma. At a median follow up of 12.7 months (range: 1.5-30 months), 4 patients were alive. By day 90, 3 patients (33.3%) achieved a radiographic complete response (CR) whilst 6 patients (66.6%) had progressive disease (PD). Detectable MRD on day 14 or day 28 had 83% sensitivity and 100% specificity for radiographic progression at any time before 1 year. For patients with PD, the median (interquartile range) MRD at day 0, 14, and 28 were 17.31 (1.01, 96.84), 9.12 (0.30, 18.8), and 23.77 (8.01, 137.53) copies per milliliter (mL), respectively. For patients with detectable MRD at day 28, mOS and mPFS were 6.7 and 1.3 months, respectively. ConclusionMonitoring MRD was a sensitive and specific method to detect poor response to tisa-cel. Additional studies evaluating MRD more frequently and with different products are warranted.

Outpatient administration of CAR T-cell therapies using a strategy of no remote monitoring and early CRS intervention

AbstractRecent studies demonstrating the feasibility of outpatient chimeric antigen receptor (CAR)–modified T-cell therapy administration are either restricted to CARs with 41BB costimulatory domains or use intensive at-home monitoring. We report outcomes of outpatient administration of all commercially available CD19- and B-cell maturation antigen (BCMA)–directed CAR T-cell therapy using a strategy of no remote at-home monitoring and an early cytokine release syndrome (CRS) intervention strategy. Patients with hematologic malignancies who received CAR T-cell therapy in the outpatient setting during 2022 to 2023 were included. Patients were seen daily in the cancer center day hospital for the first 7 to 10 days and then twice weekly through day 30. The primary end point was to determine 3-, 7-, and 30-day post–CAR T-cell infusion hospitalizations. Early CRS intervention involved administering tocilizumab as an outpatient for grade ≥1 CRS. Fifty-eight patients received outpatient CAR T-cell infusion (33 myeloma, 24 lymphoma, and 1 acute lymphoblastic leukemia). Of these, 17 (41%), 16 (38%), and 9 patients (21%) were admitted between days 0 to 3, 4 to 7, and 8 to 30 after CAR T-cell infusion, respectively. The most common reason for admission was CAR T-cell–related toxicities (33/42). Hospitalization was prevented in 15 of 35 patients who received tocilizumab for CRS as an outpatient. The nonrelapse mortality rates were 1.7% at 1 month and 3.4% at 6 months. In conclusion, we demonstrate that the administration of commercial CAR T-cell therapies in an outpatient setting is safe and feasible without intensive remote monitoring using an early CRS intervention strategy.

Analysis of polyfunctionality for enhanced BAFF-R CAR T-cell therapy for hematologic malignancies

AbstractChimeric antigen receptor (CAR) T-cell therapy has emerged as a promising immunotherapeutic strategy for eradicating human cancers. Their therapeutic success and durability of clinical responses hinges, in large part, on their functional capacity, including the ability of these engineered cells to simultaneously expand and persist after infusion into patients. CD19 CAR T-cell polyfunctionality, assessing the simultaneous functions of cytokine production, proliferation, and cytotoxicity has been reported to correlate with clinical outcomes. Assay optimization is potentially limited by the heterogeneous nature of CAR T-cell infusion products and target specificity. We optimized a single-cell platform for polyfunctionality using CAR T-cell products manufactured from healthy donors, engineered against a novel target, B-cell–activating factor receptor (BAFF-R) and validated the protocol using CD19 CAR T cells. We observed distinct qualitative differences between BAFF-R and CD19 CAR T cells relative to the proportions of stimulatory vs effector cytokines, based on target antigen density, and, generally, CD19 CAR T cells exhibited lower indices of polyfunctionality. Finally, we applied our assay to the autologous BAFF-R CAR T-cell product generated from the first patient with non-Hodgkin lymphoma treated in an ongoing clinical trial who had progressed after prior CD19 CAR T-cell therapy. We observed robust indicators of polyfunctionality, which correlated with successful CAR T-cell expansion after infusion and achievement of durable complete remission ongoing after 18 months. The precise identification of factors determining the role of BAFF-R CAR T-cell fitness in toxicity and clinical outcome will require the application of this robust assay in the analysis of additional treated patients. This trial was registered at www.ClinicalTrials.gov as #NCT05370430.

DIPG-47. SEQUENTIAL INTRAVENOUS AND INTRACEREBROVENTRICULAR GD2-CAR T-CELL THERAPY FOR H3K27M-MUTATED DIFFUSE MIDLINE GLIOMAS

Abstract BACKGROUND H3K27M-mutant diffuse midline gliomas (DMGs) express uniformly high levels of the GD2 disialoganglioside. In preclinical models, chimeric antigen receptor modified T-cells (CAR T-cells) targeting GD2 robustly regressed orthotopically xenografted DMGs. METHODS This Phase I trial (NCT04196413) administered one IV dose of autologous T-cells transduced with a GD2-CAR retroviral vector to patients with H3K27M-mutant pontine (DIPG) or spinal (sDMG) diffuse midline gliomas at two dose levels (DL1=1e6 GD2-CAR T-cells/kg; DL2=3e6 GD2-CAR T-cells/kg) following standard lymphodepleting (LD) chemotherapy. Patients with clinical or imaging benefit following IV infusion were eligible for subsequent intracerebroventricular (ICV) GD2-CAR T-cell infusions (10-30e6 GD2-CAR T-cells). Primary objectives were to determine feasibility of manufacturing, assess tolerability of IV GD2-CAR T-cells in patients with DIPG and sDMG, and identify a maximally tolerated dose of IV GD2-CAR T-cells following lymphodepleting chemotherapy. Secondary objectives included preliminary assessments of benefit. Here we report the final results of Arm A. RESULTS Thirteen patients enrolled and 11 received one IV GD2-CAR T infusion on study [n=3 DL1(3 DIPG); n=8 DL2(6 DIPG/2 sDMG). GD2-CAR T-cells were successfully manufactured for each patient. After IV infusion, no dose-limiting toxicities (DLTs) occurred on DL1, but three patients experienced DLT on DL2 due to grade 4 cytokine release syndrome (CRS). Nine patients received ICV infusions, which were not associated with DLTs. All patients exhibited tumor inflammation-associated neurotoxicity (TIAN). Four patients demonstrated major volumetric reductions of 52%, 54%, 91% and 100%. One patient exhibited a complete response durable for &amp;gt;30 months since therapy began. Eight patients demonstrated neurological benefit based upon a protocol-directed Clinical Improvement Score. CONCLUSIONS Sequential IV followed by ICV GD2-CAR T-cells infusions induced tumor regressions and neurological improvements. DL1 was established as the maximally tolerated IV GD2-CAR T-cell dose. Neurotoxicity was safely managed with intensive monitoring and close adherence to a management algorithm.

Knocking Out CD70 Rescues CD70-Specific NanoCAR T Cells from Antigen-Induced Exhaustion.

CD70 is an attractive target for chimeric antigen receptor (CAR) T-cell therapy for the treatment of both solid and liquid malignancies. However, the functionality of CD70-specific CAR T cells is modest. We optimized a CD70-specific VHH-based CAR (nanoCAR). We evaluated the nanoCARs in clinically relevant models in vitro, using co-cultures of CD70-specific nanoCAR T cells with malignant rhabdoid tumor organoids, and in vivo, using a diffuse large B-cell lymphoma patient-derived xenograft (PDX) model. Although the nanoCAR T cells were highly efficient in organoid co-cultures, they showed only modest efficacy in the PDX model. We determined that fratricide was not causing this loss in efficacy but rather CD70 interaction in cis with the nanoCAR-induced exhaustion. Knocking out CD70 in nanoCAR T cells using CRISPR/Cas9 resulted in dramatically enhanced functionality in the diffuse large B-cell lymphoma PDX model. Through single-cell transcriptomics, we obtained evidence that CD70 knockout CD70-specific nanoCAR T cells were protected from antigen-induced exhaustion. In addition, we demonstrated that wild-type CD70-specific nanoCAR T cells already exhibited signs of exhaustion shortly after production. Their gene signature strongly overlapped with gene signatures of exhausted CAR T cells. Conversely, the gene signature of knockout CD70-specific nanoCAR T cells overlapped with the gene signature of CAR T-cell infusion products leading to complete responses in chronic lymphatic leukemia patients. Our data show that CARs targeting endogenous T-cell antigens negatively affect CAR T-cell functionality by inducing an exhausted state, which can be overcome by knocking out the specific target.

Incidence and outcomes of cytomegalovirus reactivation after chimeric antigen receptor T-cell therapy

AbstractCytomegalovirus (CMV) reactivation is a major complication among seropositive allogeneic hematopoietic cell transplantation recipients; however, data on CMV reactivation after chimeric antigen receptor (CAR) T-cell therapy are limited. We report the incidence and outcomes of 95 adult CMV-seropositive patients who received CAR T-cell therapy between February 2018 and February 2023. CMV outcomes were CMV reactivation (any viremia) and clinically significant CMV infection (cs-CMV). Thirty-one patients (33%) had evidence of CMV reactivation (any viremia), and 10 patients (11%) had cs-CMV. The median time from CAR T-cell infusion to CMV reactivation was 19 days (interquartile range [IQR], 9-31). The cumulative incidence of CMV (any viremia) was significantly higher among patients with grade 3 to 4 cytokine release syndrome (67 vs 28%; P = .01), and those who received corticosteroids (39 vs 21%; P = .03), anakinra (56 vs 28%; P = .02), or ≥2 immunosuppressants (41 vs 21%; P = .02). Receipt of corticosteroids (18 vs 0%; P = .004), tocilizumab (14 vs 0%; P = .04), anakinra (33 vs 7%; P = .008), and ≥2 immunosuppressants (20 vs 0%; P = .001) were all associated with cs-CMV. Receiving ≥2 immunosuppressants was associated with a twofold increase in CMV reactivation in multivariate analyses (adjusted odds ratio [aOR], 2.27; 95% confidence interval, 1.1-4.8; P = .03). Overall, the 1-year mortality was significantly higher in those with CMV reactivation (57% vs 23%; P = .001). Immunosuppression, particularly with corticosteroids, for the management of CAR T-cell toxicities, is a major risk factor for CMV reactivation.

Chimeric antigen receptor T-cell therapy for T-cell acute lymphoblastic leukemia.

Chimeric antigen receptor (CAR) T-cell therapy is a new and effective treatment for patients with hematologic malignancies. Clinical responses to CAR T cells in leukemia, lymphoma, and multiple myeloma have provided strong evidence of the antitumor activity of these cells. In patients with refractory or relapsed B-cell acute lymphoblastic leukemia (ALL), the infusion of autologous anti-CD19 CAR T cells is rapidly gaining standard-of-care status and might eventually be incorporated into frontline treatment. In T-ALL, however, leukemic cells generally lack surface molecules recognized by established CAR, such as CD19 and CD22. Such deficiency is particularly important, as outcome is dismal for patients with T-ALL that is refractory to standard chemotherapy and/or hematopoietic stem cell transplant. Recently, CAR T-cell technologies directed against T-cell malignancies have been developed and are beginning to be tested clinically. The main technical obstacles stem from the fact that malignant and normal T cells share most surface antigens. Therefore, CAR T cells directed against T-ALL targets might be susceptible to self-elimination during manufacturing and/or have suboptimal activity after infusion. Moreover, removing leukemic cells that might be present in the cell source used for CAR T-cell manufacturing might be problematic. Finally, reconstitution of T cells and natural killer cells after CAR T-cell infusion might be impaired. In this article, we discuss potential targets for CAR T-cell therapy of T-ALL with an emphasis on CD7, and review CAR configurations as well as early clinical results.

Predictors of severe hematotoxicity after CAR T-cell therapy.

7024 Background: The EHA/EBMT immune effector cell-associated hematotoxicity (ICAHT) grading system characterizes hematotoxicity after CAR T-cell therapy based on depth and duration of neutropenia (Rejeski et al, Blood, 2023). We evaluated pre- and post-infusion factors associated with grade 3-4 ICAHT and developed a predictive model in 602 patients with hematologic malignancies undergoing CAR T-cell therapy at Fred Hutch Cancer Center. Methods: Grading of early hematotoxicity (day-0-30 after CAR T-cell cell infusion) was automated using the heatwaveR package. Associations with 50 patient, disease-related, and laboratory factors, and grade 3-4 ICAHT were modeled using univariate and multivariable logistic regression. Results: The most common disease types were aggressive non-Hodgkin lymphoma (NHL; n = 293; 49%), indolent NHL (n = 150; 25%), and acute lymphoblastic leukemia (ALL; n = 94; 16%). The most common CAR T-cell products were the investigational CD19 CAR T-cell product JCAR014 (n = 197; 33%), axicabtagene ciloleucel (n = 129; 21%), and lisocabtagene maraleucel (n = 73; 12%). Incidences of early ICAHT grades 1, 2, 3, and 4 were 319 (53%), 96 (16%), 60 (10%), and 35 (6%) patients, respectively. Baseline patient factors associated with grade 3-4 ICAHT included ALL (reference: aggressive NHL, OR = 4.18, 95% CI, 2.41-7.26, p &lt; 0.001) , Hispanic or Latino ethnicity (OR = 2.17, 95% CI, 1.07-4.20, p = 0.025), and lower age (OR = 1.03, 95% CI, 1.02-1.05, p &lt; 0.001). Pre-lymphodepletion (LD) laboratory factors associated with grade 3-4 ICAHT in univariate analyses included lower ANC (OR = 6.67 per log10 cells/μL, 95% CI, 4.0-11.1, p &lt; 0.001), LDH (OR = 8.70per log10U/L, 95% CI, 4.03-19.4, p &lt; 0.001), CRP (OR = 3.18 per log10mg/L, 95% CI, 2.06-5.07, p &lt; 0.001), and ferritin (OR = 6.07 per log10mg/L, 95% CI, 3.65-10.6, p &lt; 0.001). Peak CRP (OR = 15.6, 95% CI, 7.27-36.4, p &lt; 0.001), peak ferritin (OR = 7.41, 95% CI, 5.02-11.3, p &lt; 0.001), peak CRS grade (OR = 2.01, 95% CI, 1.59-2.56, p &lt; 0.001), and peak ICANS grade (OR = 1.51, 95% CI, 1.29-1.77, p &lt; 0.001) after CAR T-cell infusion were also strongly associated with grade 3-4 ICAHT. A multivariable model using restricted cubic splines and including disease type, pre-LD ANC, pre-LD LDH, peak CRP, peak ferritin, and CRS grade demonstrated high discrimination to predict grade 3-4 ICAHT (C-index = 0.89). Internal validation using bootstrapping showed near-perfect calibration without overfitting. Sensitivity and specificity based on the Youden criteria was 74% and 90%, respectively. The sensitivity and specificity of the CAR-HEMATOTOX score in predicting grade 3-4 ICAHT was 93% and 30%, respectively. Conclusions: We identified pre- and post-infusion predictors of grade 3-4 ICAHT and internally validated a multivariable logistic regression model including disease-type, pre-LD ANC, pre-LD LDH, peak CRP, peak ferritin, and CRS grade. We plan to further evaluate our model in an external cohort.

Chimeric antigen receptor T-cell infusion for large B-cell lymphoma in complete remission: a center for international blood and marrow transplant research analysis.

CD19 CAR T-cell (CAR-T) therapy is commonly administered to patients with relapsed or refractory large B-cell lymphomas (LBCL), but salvage or bridging therapy can sometimes lead to a complete response (CR) prior to infusion. Limited studies have assessed the outcomes of patients infused in CR. A total of 134 patients with LBCL in CR prior to CAR-T infusion were identified from the CIBMTR registry, with median prior lines of therapy of 3 (range 2-9). At two years post-infusion, the probability of progression-free survival was 43.5% (95% CI 34.4-52.8) and the probability of overall survival was 63.8% (95% CI 54.4-72.6). The cumulative incidence rates of non-relapse mortality and relapse/progression at two years were 9.2% (95% CI 4.5-15.4) and 47.3% (95% CI 38.2-56.6), respectively. The rate of grade 3 or higher cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were 2.2% and 8.2%, respectively. In summary, CAR-T in heavily pretreated patients with LBCL who are in CR following two or more lines of prior therapy demonstrate that a subset of patients may remain free of progression at two years. Additionally, the toxicity profile was impressive with very low rates of grade 3 CRS and ICANS.