Severe Cytokine Release Syndrome Research Articles

Azacitidine, Venetoclax and Allogeneic NK Cells in Newly Diagnosed Acute Myeloid Leukemia (ADVENT-AML): An Investigator-Initiated Multicenter Phase Ib Trial

BACKGROUND AND SIGNIFICANCE : Older/unfit patients with acute myeloid leukemia (AML) have limited treatment options. Outcomes in adverse-risk subgroups of AML are modest with CR/CRi rates of 45% to 60% and median overall survival (OS) of 5 to 12 months with current standard frontline therapy of hypomethylating agent with venetoclax (HMA-VEN).While allogeneic stem cell transplantation (allo-SCT) can significantly improve OS in AML, only 10 to 20% of older pts are able to undergo allo-SCT (Pratz et al. Blood 2019, Maiti et al. Blood 2022) Natural killer (NK) cells bridge the innate and adaptive immune system and play a major role in graft-vs-leukemia (GVL) effect responsible for the clinical benefit noted with allo-SCT. NK cell-based adoptive cellular therapies have shown good safety profiles and promising activity in AML with responses noted in 25% to 88% of patients. Furthermore, NK cells are less likely to induce graft-versus-host disease (GVHD), severe cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). We hypothesize that the combination of azacitidine, venetoclax and allogeneic NK cells will be safe and improve cure rates in AML compared to either Aza/Ven or NK cells alone. Improved clinical activity may be mediated through multiple synergistic mechanisms including reduction of disease burden by Aza/Ven, upregulation of epigenetically silenced NKG2D ligands, dual activation of extrinsic and intrinsic apoptotic cascades, mitochondrial priming of leukemia cells by venetoclax, and bypassing significant morbidity and mortality associated allo-SCT. Significance: This will be the first trial to evaluate 1) cellular therapy in the frontline setting in AML; 2) the synergy of venetoclax with adoptive NK cell therapy; and 3) Aza/Ven as a lymphodepletion strategy. The results will have significant impact on the development of cellular therapies for hematological and solid tumors. STUDY DESIGN AND METHODS: This investigator-initiated, multicenter, open-label, phase Ib study will evaluate the combination of azacitidine, venetoclax and ex vivo-expanded, off-the-shelf cryopreserved allogeneic NK cells in patients with AML (NCT05834244). Eligibility criteria: The dose escalation phase will enroll adults with relapsed or refractory AML or MDS/AML, and the dose expansion phase will enroll older/unfit pts with newly diagnosed adverse-risk AML. Eligible Pts will be ≥ 75 years, or ≥ 18 years with at least one protocol-defined comorbidity. Patients with favorable risk AML, poor end-organ function, needing immunosuppression, uncontrolled infection or CNS leukemia will be excluded. Trial design: The dose escalation phase will enroll a maximum of 12 patients at 2 dose levels to establish a recommended phase 2 dose (RP2D) using a BOIN design. The dose expansion will enroll up to 20 patients at the RP2D ( Fig. 1). Study treatment: Patients will receive Aza/Ven as standard. Two dose levels of NK cells including 0.5 x10 9 and 1 x10 9 flat dose on day 8 and 15 of the first 4 cycles will be evaluated. Subsequently, pts will continue Aza/Ven indefinitely. Objectives: The primary objective is to determine the safety of this novel triplet combination in terms of dose-limiting toxicities including acute GVHD, CRS or ICANS. Secondary objectives include overall response rate, CR/CRi by 4 cycles, rate of negative measurable residual disease, OS and relapse-free survival. Exploratory objectives include additional response and survival endpoints, the persistence of NK cells using SNP-NGS chimerism, kinetics of allorejection, remodeling of host immune microenvironment and impact on AML stem/progenitor cell hierarchies using single cell CyTOF to understand response/resistance mechanisms. Status: Trial approved by the FDA and institutional IRB. Activation planned for 2H 2023. Funding: Gateway for Cancer Research, MDACC PRIME Award, Chimeric Therapeutics, NCI Cancer Center Support Grant.

Efficacy and Safety of the Second CAR-T Therapy in Patients with Refractory/Relapsed Acute B-Cell Lymphoblastic Leukemia

Background: Chimeric antigen receptor T (CAR-T) cells therapy has shown significant efficacy in relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL), but a substantial proportion of patients still relapse after a period of remission. The efficacy of a second CAR-T cell infusion is uncertain. The aim of this study was to explore the efficacy and safety of the second CAR-T therapy in R/R B-ALL patients. Methods: Between August 2018 and October 2022, 35 patients with R/R B-ALL successfully received the second CAR-T treatment. Among them, 18 patients received single CD19 or CD22 CAR-T therapy, 14 patients received tandem CD19/CD22 CAR-T therapy, and 3 patients received sequential CD19 and CD22 CAR-T therapy. Results: The complete remission (CR) rates were 55.6% (10/18) in patients who received CD19 or CD22 CAR-T therapy, 85.7% (12/14) in patients who received tandem CD19/CD22 CAR-T therapy, and 33.3% (1/3) in patients who received sequential CD19 and CD22 CAR-T therapy (tandem CD19/CD22 vs. others, P=0.045). Tandem CD19/CD22 CAR-T therapy remained one of the significant favorable factors in multivariate logistic regression analysis of CR rate in all patients (hazard ratio, 0.128; 95% CI, 0.017-0.974). A total of 5 patients with severe cytokine release syndrome (Grade ≥ 3) were observed, including 2 patients in the single CD19 CAR-T group, 2 patients in the tandem CD19/CD22 CAR-T group, and 1 patient in the sequential CD19 and CD22 CAR-T group. Of the 23 patients who achieved CR, 4 patients bridged to allogeneic hematopoietic stem cell transplantation (allo-HSCT) and 3 patients received decitabine (DAC) consolidation.With the median follow-up of 25.5 months (range, 1.1 to 33.5), the 2-year overall survival, leukemia-free survival (LFS) and cumulative incidence of relapse rates were 23.7%, 30.5% and 69.5%, respectively. Multivariate Cox regression analyses showed that a better LFS related to the absence of high-risk cytogenetics and genetic characteristics, DAC combination with fludarabine and cyclophosphamide lymphodepletion regimen, and bridging allo-HSCT or DAC consolidation. Conclusions: Our study showed that the second infusion of tandem CD19/CD22 CAR-T therapy obtains a better response than other infusion strategies. Bridging allo-HSCT or DAC consolidation had a significant survival benefit in patients with CR after the second CAR-T therapy.

Updated Follow-up of a Phase 1 Trial of Bispecific CART19/20 Cells for Relapsed or Refractory Non-Hodgkin Lymphoma

CART19/20 was developed by engineering autologous naïve/memory T (T N/MEM) cells with a bispecific anti-CD19/CD20 chimeric antigen receptor (CAR) with the goal of mitigating antigen escape and lack of CAR T-cell persistence. We report an update of an ongoing first-in-human phase 1 clinical trial of CART19/20 for patients with relapsed/refractory non-Hodgkin lymphoma (R/R NHL) (NCT04007029). Eligible patients were ≥18 years old with R/R diffuse large B-cell lymphoma (DLBCL) or primary mediastinal B-cell lymphoma (PMBCL) after ≥2 prior lines of therapy, or with mantle-cell lymphoma (MCL), follicular lymphoma (FL), or CLL/SLL after ≥3 prior lines of therapy. Autologous leukocytes were obtained by leukapheresis and sorted for CD14-/CD25-/CD62L+ T N/MEM cells, followed by lentiviral transduction of the bispecific CD19/CD20 CAR. Lymphodepletion chemotherapy with fludarabine 30 mg/m 2/day and cyclophosphamide 500 mg/m 2/day was administered on Days −5 to −3 prior to CAR T-cell infusion. The primary endpoint was assessment of safety. Secondary endpoints were overall response rate (ORR), progression free survival (PFS), overall survival (OS), and CART19/20 transgene persistence. As of data cutoff on July 21, 2023, 11 patients had received CART19/20 cells (6 DLBCL, including 4 transformed FL; 3 primary FL; 1 PMBCL; 1 MCL). Patients were treated at two dose levels, either 50 x 10 6 ± 30% CAR+ cells (8 patients) or 200 x 10 6 ± 30% CAR+ cells (3 patients). The median age was 58 (range: 34 to 70). Patients had received a median of 3 prior lines of therapy (range: 2 - 4). None of the treated patients had received prior CAR-T cell therapy; one patient had received a prior CD19-directed therapy. All patients had stage IV disease and 9 of 11 patients received bridging therapy. The engineered CART19/20 cells were enriched with central-memory T cells (T CM: CD45RA-/CD45RO+/CD62L+) which composed a median of 30.8% (range: 5.3 - 80.1%) of the CAR+ T-cells in the infused products. There were no occurrences of CRS grade ≥ 2 or neurotoxicity of any grade. Six patients had grade 1 cytokine release syndrome (CRS) with a median onset of 8 days from infusion (range: 5 - 11 days). One patient met criteria for dose-limiting toxicity with persistent thrombocytopenia after Day+120. Ten of the 11 patients achieved an objective response (91% ORR), with 8 patients (73%) achieving complete response (CR). One patient with FL, who progressed 18 months after receiving CART19/20, received a second infusion of CART19/20 cells and achieved a second CR for 14.9 months. With a median follow-up of 32.3 months (range: 5.1 - 44.0 months), the median PFS (95% CI 2.6 months - not estimable) and median OS (95% CI 5.7 months - not estimable) have not been reached. Overall, CART19/20 demonstrated a favorable safety profile with no severe CRS or neurotoxicity of any grade. Moreover, CART19/20 showed robust activity in patients with R/R NHL with durable responses seen. By utilizing a bispecific CAR and enriching for T N/MEM cells, this phase 1 trial of CART19/20 demonstrates the possibility of improving outcomes through targeting common mechanisms of CAR-T cell resistance.

Risk Factors and Outcomes for Hematotoxicity Following Tisagenlecleucel for Pediatric B-Acute Lymphoblastic Leukemia

Background: Hematotoxicity following chimeric antigen receptor (CAR) T-cell therapy is increasingly recognized as a distinct adverse event. The CAR-HEMATOTOX score has been developed as a prognostic tool for subsequent development of prolonged cytopenias in adults with lymphoma. However, risk factors in children and young adults (CAYA) with B-acute lymphoblastic leukemia (B-ALL) receiving CAR T cell therapy are less well-defined. We sought to describe incidence, outcomes, and risk factors for prolonged severe neutropenia in CAYA treated with tisagenlecleucel. Methods: This was a multi-institutional retrospective study involving CAYA ≤26 years of age with B-ALL treated with tisagenlecleucel who underwent leukapheresis and manufacturing between August 2017 and March 2020, with data collected through the Pediatric Real World CAR Consortium (PRWCC). Of 185 patients infused, 41 patients were excluded from analysis due to missing data (n=10), refractory disease/death from leukemia (n=27) or non-relapse mortality (n=4) prior to day 35 post-CAR T. Severe prolonged neutropenia was defined as absolute neutrophil count (ANC) <500 cells/mm 3 for ≥30 days. For those with severe neutropenia pre-CAR T, day 0 of severe neutropenia was considered the day of CAR T-cell infusion. Statistical analyses included comparisons using Mann-Whitney and Fisher's exact tests, receiver operating characteristic (ROC) curves to determine cut points with optimal sensitivity and specificity, univariate logistic regression, Kaplan-Meier curves for recovery from neutropenia, overall survival (OS) and relapse free survival (RFS). Results: Of 144 patients, 23 (15.9%) met the definition of severe prolonged neutropenia and 121 (84%) did not. For lymphodepleting chemotherapy, 139 (96.5%) received standard fludarabine (30mg/m 2/dose x 4) and cyclophosphamide (500mg/m 2 x 2). Pre- and post-infusion characteristics are shown in Table 1. Pre-infusion, higher pre-infusion C-reactive protein (CRP), ferritin, bone marrow disease burden, and lower ANC and platelet counts were associated with severe prolonged neutropenia. Post-infusion, any grade cytokine release syndrome (CRS), severe CRS, CRS with hemophagocytic lymphohistiocytosis (HLH)-like manifestations, any grade neurotoxicity, peak CRP and ferritin, use of tocilizumab and steroids, and presence of infections within 30 days were associated with severe prolonged neutropenia. With univariate logistic regression, pre-infusion inflammatory markers, cytopenias, and bone marrow disease burden associated with severe prolonged neutropenia and of these, disease burden >15% had the highest odds ratio (Figure 1). Post-infusion infections and inflammatory toxicities, particularly CRS with HLH-like toxicities, as well as peak CRP, and peak ferritin, were associated with severe prolonged neutropenia. Peak ferritin >3800 ng/ml had the highest odds ratio. In patients with severe prolonged neutropenia, OS was inferior (p<0.0001) and RFS trended towards being inferior (p=0.052), compared to those without. Groups with or without severe prolonged neutropenia were also subdivided into >15% or ≤15% pre-infusion bone marrow disease burden subgroups. OS was similar between patients without severe prolonged neutropenia that had >15% or ≤15% pre-infusion disease burden, but patients with severe prolonged neutropenia and >15% disease burden had inferior OS, suggesting prolonged severe neutropenia may have independent prognostic value. Conversely, RFS was inferior in patients in the subgroups with >15% disease burden compared to those with ≤15%, regardless of occurrence of severe prolonged neutropenia. Discussion/Conclusions: We describe incidence, risk factors and outcomes for the development of severe prolonged neutropenia in CAYA with B-ALL following tisagenlecleucel. While there are similarities in risk factors with the CAR-HEMATOTOX score that has been validated in adults, in CAYA with B-ALL high disease burden pre-infusion and severe inflammation post-infusion were identified as the strongest risk factors for prolonged neutropenia. Identification of risk factors unique to the CAYA B-ALL population allows for tailored risk mitigation in higher risk patients and may help improve outcomes in CAYA at increased risk of prolonged severe neutropenia following tisagenlecleucel.

Bendamustine Lymphodepletion (LD) Prior to Idecabtagene Vicleucel (Ide-cel) Is Associated with Inferior Outcomes in Relapsed Refractory Multiple Myeloma (RRMM)

Background Chimeric antigen receptor therapy (CART) has revolutionized the management of RRMM. LD prior to CART cells modulates the immune environment creating optimal conditions for T cell expansion and subsequent efficacy. Fludarabine/cyclophosphamide (FLU/CY) is an effective LD regimen, and its use has been adopted widely prior to CART cells for all indications. Since the safety of FLU/CY is not established in patients with substantial renal impairment and given recent nationwide fludarabine shortage, alternative lymphodepletion strategies have been explored. Bendamustine (BENDA) has been shown to be a safe alternative with equivalent efficacy and reduced toxicity in non-Hodgkin's lymphoma (NHL). While its use has been extrapolated to RRMM, efficacy and long-term outcomes have not been examined. Methods We retrieved and analyzed data on sequential patients (pts) with RRMM treated with commercial Ide-cel at a single institution from its approval in 3/2021 until 5/2023. We captured baseline patient, disease and treatment characteristics. We used IgG (with monoclonal component deducted) and uninvolved FLC as indirect surrogate of CAR-T expansion and on target, off tumor killing of non-malignant plasma cells. We assessed cytokine release syndrome (CRS) and immune effector cell associated neurotoxicity (ICANS) based on the American Society for Transplantation and Cellular Therapy criteria and disease responses using the International Myeloma Working Group response criteria. We graded hematologic toxicity using the Common Terminology Criteria for Adverse Events version 5.0. We compared efficacy between the cohorts using overall response rate (ORR) and progression-free survival (PFS), since overall survival is expected to be affected by choice of subsequent, often experimental therapies. Results We identified 28 pts with RRMM who met the inclusion criteria. Nine pts received alternative LD with BENDA (2 pts - renal dysfunction with creatinine clearance <30ml/min; 7 - fludarabine shortage) and 19 received FLU/CY as LD. Baseline characteristics are summarized in Table. Prior autologous stem cell transplant (ASCT) and prior B cell maturation antigen (BCMA) targeting therapy were more frequent in the FLU/CY cohort. Median absolute lymphocyte count (measured in 10^3/ cmm) prior to LD chemotherapy was similar in both cohorts (0.85 in BENDA vs 0.80 in FLU/CY). Median duration of absolute neutrophil count <1,000/μL was shorter in the BENDA cohort. The incidence of any grade CRS (56% vs. 90%, p=0.06) and tocilizumab use (56% vs. 84%, p=0.16) was lower with BENDA compared to FLU/CY. In the absence of ide-cel expansion data, we used nadir polyclonal IgG and uninvolved free light chain (uFLC) in the initial 90 days post CART cell infusion as surrogate of non-malignant plasma burden and therefore ide-cel expansion. We noted lower median uFLC and median IgG with FLU/CY vs. BENDA. The overall response rate was lower with BENDA (22%) vs. FLU/CY (79%, p=0.01). With median follow up of 4.8 mo., all pts in the BENDA cohort progressed with median PFS of 1.6 months vs 7.8 months for FLU/CY (p<0.001, Figure). The median OS for both cohorts is not yet reached. Conclusion: BENDA LD prior to ide-cel infusion results in suboptimal lymphodepletion and subsequent inferior outcomes including low rate of objective responses and decreased progression free survival. The inferior efficacy of BENDA as LD likely results from inferior ide-cel expansion and persistence resulting in less frequent and severe CRS and cytopenias and less suppression of unaffected immunoglobulins. Future efforts to study alternative lymphodepletion approaches is essential given inability to use fludarabine in patients with severe renal dysfunction and periods of critical drug shortages. While there is a need to develop alternatives for LD prior to ide-cel, BENDA is an inadequate substitute of FLU/CY.

Day +3/Day 0 Ferritin Ratio: A Simple Point-of-Care Index Predictive of Severe Immune Effector Cell-Associated Neurotoxicity Syndrome after CD19 CAR T-Cell Therapy

Introduction: Chimeric antigen receptor (CAR) T-cell therapy is transforming the management of patients with relapsed/refractory (R/R) B- and plasma-cell malignancies. However, a major limitation of CAR T-cell therapy is the development of severe, sometimes life-threatening, toxicities such as immune effector cell-associated neurotoxicity (ICANS) and cytokine release syndrome (CRS). While the management of CRS has dramatically improved with the early use of tocilizumab and corticosteroids, how to best predict and treat ICANS remains poorly understood, with up to 30% of patients developing severe ICANS after CD19 CAR T-cell therapy. Since we had previously observed features overlapping with hemophagocytosis lymphohistiocytosis in patients with severe CRS and ICANS, we hypothesized that the early kinetics of ferritin and soluble IL-2 receptor alpha [sIL-2Rα] post infusion could predict the development of severe ICANS. Methods: We retrospectively analyzed data from 195 patients with R/R B-cell malignancies previously treated on a phase I/II clinical trial (NCT01865617) of an investigational defined 1:1 CD8+:CD4+ composition CD19 CAR-T product (JCAR014; training set). CRS and ICANS severity were graded using Lee 2014 and CTCAE 4.03 criteria, respectively. Logistic regression was used to predict the occurrence of severe ICANS. Ferritin was measured using an enzyme immunoassay. sIL-2Rα was measured using Luminex®. Goodness of fit was assessed using the Akaike information criterion (AIC). Independent test set included 203 patients treated at our center with the standard-of-care CD19 CAR T-cell products axicabtagene or lisocabatagene maraleucel. Discrimination and calibration were assessed in both the training and test set. Results: In the training set (n=195), median age was 55 (range: 20-76). Disease type was as follows: acute lymphoblastic leukemia, n=64 (32.8%); B-cell non-Hodgkin lymphoma, n=82 (42.1%); chronic lymphocytic leukemia, n= 47 (24.1%). We observed any grade and grade ≥3 CRS in 134 (68.7%) and 27 (13.8%), respectively, and any grade and grade ≥3 ICANS in 72 (38.8%) and 37 (19.0%), respectively. Longitudinal analyses of serum ferritin (Figure 1) and sIL-2Rα values using locally estimated scatterplot smoothing suggested that the rate of increase of both analytes was markedly higher in patients with grade ≥3 ICANS compared to grade 0-2 ICANS. We applied univariate logistic regression to estimate the association between serum ferritin levels at early timepoints, select ratios of ferritin and sIL-2Rα values, and the occurrence of severe ICANS. The strongest association was observed between the ferritin day +3/day 0 ratio and severe ICANS (OR per log10 increase, 175; 95% CI, 19.1-2668; p < 0.001). We could further improve our model by modeling the ferritin day +3/day 0 ratio with a restricted cubic spline to allow for non-linear effects (unsplined model, AIC = 129, C-index, 0.74; splined model, AIC = 127, C-index, 0.78). Ferritin day +3/day 0 ratios of 3, 5, and 10 were associated with an 81%, 95%, and 99% probability of grade ≥3 ICANS, respectively (Figure 2). The splined model was associated with near-perfect calibration corrected for optimism using bootstrapping. We next evaluated the predictive ability of the ferritin day +3/day 0 ratio to predict severe ICANS in our independent test set. Predictions in the test set based on our splined model retained good discriminative ability with a C-index of 0.64, although with suboptimal calibration. In a refitted logistic regression model in the test set, the ferritin day +3/day 0 ratio remained strongly associated with the development of severe ICANS (OR = 18.8 per log10 increase, 95%CI, 2.48-142.01, p = 0.004). Conclusion: We validated the ability of a simple point-of-care index (day +3/day 0 ferritin ratio) to predict the development of severe ICANS after CD19 CAR T-cell therapy in our training and test set. Since serum ferritin levels can be quickly measured by most clinical laboratories, the day +3/day 0 ferritin ratio could become a practical and useful tool for practitioners taking care of CAR T-cell patients. The early identification of patients at high risk of developing severe ICANS days prior to symptoms onset could enable the evaluation of targeted prophylactic interventions in future clinical trials. We plan to refine our modeling approach to further improve the calibration in test set.

Retrospective and Observational Study on CAR-T 19 Bridge Therapies in Pediatric, Adolescents and Young Adults <24 Years with B-Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL): Experience of the Spanish Hematopoietic Stem Cell Trasplantation and Cellular Therapy Group (GETH-TC)

INTRODUCTION CAR-T therapy has revolutionized the treatment of B-ALL. The development of CAR-T therapy is a long and delicate process where once apheresis is done, a bridge period that least until CAR-T cells are infused starts. Meanwhile, the objective will be to maintain disease control, decrease tumor burden (TB) and prevent disease progression with no severe comorbidities by the administration of a bridge chemotherapy. That will decrease the risk of severe (grade 3-4 ASTCT) Cytokine Release Syndrome (CRS) and Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) with an improvement of event free survival. Nevertheless, there is no consensus nor standard guidelines about bridge chemotherapy type, especially in pediatric patients. In this way, the main objective of this study is to identify CAR-T outcomes in pediatric, adolescents and young adults (AYA) diagnosed of BCP-ALL based on bridge chemotherapy. MATHERIAL AND METHODS An observational, retrospective and non-interventional study of Spanish pediatric and AYA under 24 years old diagnosed with BCP-ALL treated with tisagenlecleucel that have been registered by the Spanish Hematopoietic Stem Cell Transplantation and Cellular Therapy (GETH-TC) CAR-T clinical database from years 2017 to 2022. Data have been collected from nine centers members of GETH-TC CAR-T workgroup: La Paz University Hospital, Sant Joan de Déu University Hospital, Virgen del Rocío University Hospital, Niño Jesús Pediatric University Hospital, Gregorio Marañón General University Hospital, Vall d'Hebron University Hospital, Salamanca Clinic University Hospital, Germans Trials i Pujol University Hospital and Valencia Clinic Hospital. General, pre-CAR-T, CAR-T-related and post-CAR-T variables have been analysed from GET-TC CAR-T database, highlighting those related to bridge therapy and related outcomes. Bridging chemotherapy was analyzed considering whether the patients had received high (myelosuppression ≥7 days) or low (myelosuppression ≤7 days) intensity schemes, or in contrast, immunotherapy. Fisher's Exact Test for count data and Log Rank test for Overall Survival (OS), Relapse Free Survival (RFS) and Duration of Response (DOR). Variables with p<0.05 value have been considered of statistical significance. RESULTS Baseline characteristics of the 103 patients are summarized in Table 1. CRS after infusion was presented in 86 (83.5%) patients. Grade 3-4 was developed in 4/29 (13.8%) with low pre infusion TB in contrast to 18/55 (32.7%) with high TB (p=0.001). Complete remission (CR) was achieved 87 (85.3%) patients. All patients (100%) with a low TB were in CR VS 78.2% in the high TB arm (p=0.015). Otherwise, 91.9% of those patients that received low intensity bridge chemotherapy or immunotherapy were in CR VS 71% of those where high intensity bridge was administered (p=0.027). With a median of 23.75 months, OS at 12 months was 62.23% (CI95% 51.71-74.89). No statistical significance was found between bridge chemotherapy groups, although it was higher in low intensity and immunotherapy group (68.33% CI95% 55.41-84.27) VS (57.89% CI95% 40.43-82.89) (p=0.11). With a median of 9.26 months, RFS at 12 months was 41.7% (CI95% 31.71-54.85). No statistical significance was found between bridge chemotherapy groups, but was higher in low intensity group and immunotherapy (51.8% CI95% 39.45-68.01) VS (34.69% CI95% 18.59-64.74) (p=0.089). With a median of 8.28 months, DOR at 12 months was 41.7% (CI95% 31.71-54.85). No statistical significance was found between bridge chemotherapy groups, with an increasing tendency in low intensity group and immunotherapy (51.8% CI95% 39.45-68.01) VS (34.69% CI95% 18.59-64.74) (p=0.089). In the multivariate analysis, grade 3-4 CRS HR 8.7 (CI95% 0.82-92) (p = 0.072) and high TB HR 4.7 (CI95% 1.1-20) (p = 0.038) were related with a decreased OS. CONCLUSIONS Receiving low intensity bridge or immunotherapy is related with high rates of CR. In the same way, in this group of patients there is tendency to achieve higher OS, RFS and DOR. This is the reason because its use should be prioritized avoiding those of high intensity bridge chemotherapy. High TB is an important risk factor related with a poor response and high grade CRS development, so it is essential to reduce TB previous CAR-T infusion in order to improve outcomes and reduce toxicities.

Phase 2 Study of Anakinra to Prevent CRS and Neurotoxicity after Treatment with Lisocabtagene Maraleucel: Planned Interim Analysis

BACKGROUND CD19 chimeric antigen receptor (CAR) T-cell therapies have transformed the treatment landscape for patients (pts) with relapsed/refractory B-cell malignancies, but they remain limited by significant toxicities: cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). While a more favorable toxicity profile had been reported with lisocabtagene maraleucel (liso-cel), based on our real-world experience CRS and ICANS are still observed in 70% and 30% of pts, respectively (Portuguese et al., ASH abstract #172978). Data from our group (Gazeau, TCT, 2023) and others (Strati, Blood, 2023; Park, Nat Med, 2023) suggested the recombinant interleukin-1 receptor antagonist anakinra may successfully prevent and treat CRS and ICANS. Thus, we conducted a phase 2 investigator-initiated clinical trial of anakinra to prevent CRS and ICANS after liso-cel (NCT04359784). We report here our planned interim analysis (n = 15). METHODS Adults ≥18 years of age with Karnofsky performance status ≥60% and B-cell non-Hodgkin lymphoma receiving liso-cel per the FDA label were eligible for this study. Anakinra was administered at 200 mg/day SC from day 0 through day +13 after liso-cel infusion, with the first dose administered approximately 2-4 hours prior to liso-cel infusion. CRS and ICANS severity were assessed per 2019 ASTCT criteria. The primary endpoint was the absence of any grade CRS assessed using the Bayesian optimal phase 2 design.The primary endpoint was not met if ≥6 of the first 15 pts developed any grade CRS. RESULTS Nineteen pts were screened for the study and 15 pts were enrolled. All 15 pts received liso-cel and all doses of SC anakinra. All pts were evaluable for toxicity assessment; 12 pts were evaluable for disease response assessment at day +28 (n = 3, no measurable disease prior to lymphodepletion [LD]). Pt and disease characteristics are shown in Table 1. Eleven pts (73%) had diffuse large B-cell lymphoma, 3 (20%) had active CNS involvement, and 5 (33%) had bulky disease (≥5 cm). Median pre-LD serum ferritin and C-reactive protein (CRP) were 153 ng/mL (IQR, 129-231) and 6.8 (IQR, 1.5-17.2), respectively. All 15 pts received anakinra as planned without dose adjustment or interruption. There were no injection-site reactions or AEs attributed to anakinra. Two pts developed infections during anakinra treatment and were both due to mild Clostridium difficile colitis requiring oral antibiotics. Eight pts (53%) developed any grade CRS, including 1 (7%) case of grade 3 CRS. Four pts (27%) developed any grade ICANS, including 3 (20%) with grade 3 (Figure 1). Median CRS onset and duration were 2 and 2.5 days, respectively, and median ICANS onset and duration were 6 and 9 days, respectively. Three pts (20%) required tocilizumab (range, 0-1 doses), 4 (50%) required dexamethasone (median total dose, 5 mg; range, 0-200 mg), and 1 (12%) required high-dose methylprednisolone. The best overall response rate (ORR) by Lugano criteria was 67% (complete response, n = 5 [42%]). Study pts were retrospectively compared to pts who received liso-cel per standard of care off trial without prophylactic anakinra at our center (n = 42). Despite higher median pre-LD CRP and IL-6 levels, the incidence of CRS was lower in anakinra-treated compared to anakinra-untreated pts (53% vs. 69%, respectively) with comparable median duration of CRS (2.5 vs. 3 days, respectively). The incidence and duration of ICANS were similar (27% vs. 28%; median 9 vs. 8 days, respectively), as was the incidence and duration of hospitalization (67% vs. 74%, median 9.5 vs. 10 days, respectively). Based on Locally Estimated Scatterplot Smoothing (LOESS) estimates, time from liso-cel infusion to CRP normalization was faster in patients receiving anakinra (9 days) compared to those receiving liso-cel alone (14 days). CONCLUSION Low-dose SC anakinra prophylaxis during liso-cel treatment was very well tolerated with preserved anti-tumor efficacy. While our primary endpoint was not reached at our planned interim analysis, we observed lower CRS rates and faster resolution of CRS in comparison to a real-world cohort of pts receiving liso-cel without prophylactic anakinra. To further enhance the preventative effects of anakinra, we plan to change the administration route from SC to intravenous, and to allow anakinra dose uptitration for the last 10 participants in the study.

Axicabtagene Ciloleucel in Patients Aged 75 and Older: A Retrospective Cohort Study

Background The treatment of older patients with relapsed/refractory (R/R) aggressive non-Hodgkin B-cell lymphomas (NHL) remains a significant clinical challenge. Chimeric antigen receptor T-cell (CAR-T) therapy represents a potentially curative option, but elderly patients remain underrepresented in relevant clinical trials, and less is known about the safety of CAR-T among patients older than 75 years. Toxicities including cytokine release syndrome (CRS), neurotoxicity (ICANS), arrhythmias, renal failure, and cytopenias may pose higher risk in elderly patients with comorbidities and decreased physiologic reserve compared to younger CAR-T recipients. We sought to characterize outcomes and toxicities of axicabtagene ciloleucel (axi-cel) in a cohort of patients aged ≥ 75 years. Methods This was a retrospective analysis of consecutive patients aged ≥ 75 years with R/R NHL who received axi-cel at New York-Presbyterian/Weill Cornell Medical Center. Data collected included patient characteristics and outcomes including response rates, event-free and overall survival, rates of CRS, ICANS, arrhythmias and severe cytopenias, and length of hospital stay. CRS and ICANS severity were graded following the ASTCT consensus criteria. Cytopenias were graded as per NCI-CTCAE v5.0. Event free survival (EFS) was defined as time to disease progression or death. Results We identified 15 patients with a median age of 78 (range 75-87) years; 6 (40%) were ≥ 80 years of age. 14 patients had a diagnosis of large B-cell lymphoma and 1 had multiply relapsed follicular lymphoma. Ten patients (67%) had received 3 or more prior lines of therapy. Additional baseline characteristics are summarized in Table 1. Among 10 patients (67%) who developed CRS of any grade, only 1 (7%) experienced grade ≥3 CRS; this CRS event was fatal. Five (33%) patients developed ICANS with only 1 patient (7%) developing grade ≥3 ICANS. Two (13%) patients and 10 (67%) patients developed grades 3 and 4 cytopenias within 30 days of infusion, respectively. Four (27%) patients required blood or platelet transfusions within 100 days of infusion. Febrile neutropenia was seen in 8 (53%) patients, and 8 patients had culture or PCR-verified bacterial (33%), viral (40%), or fungal (7%) infections. Only 1 (7%) patient developed a new abnormality on EKG within 30 days of infusion (right ventricular conduction delay). Median length of inpatient stay was 17 days (range 13-35), and 2 (13%) required re-hospitalization within 100 days of infusion. Overall and complete response rates at 100 days post-infusion were 13 (86%) and 11 (73%), respectively. At one year, overall and event-free survival were 72.2% (95% CI: 54.4-99.6%) and 53.3% (95% CI: 33.2%-85.6%), respectively. The median overall survival was 30.8 months with a median follow-up of 21.4 months. One patient experienced treatment-related mortality due to CRS, and 5 (33%) had subsequent disease relapse. Conclusion These results suggest that axi-cel is an effective and well-tolerated treatment for patients age ≥ 75 with R/R NHL. Only 1/15 patients developed grade ≥3 CRS or ICANS which is comparable to reported rates of toxicities in younger patients. Although multiple studies have identified cytopenias and cardiac arrhythmias as major CAR-T toxicities, a minority of our cohort required transfusions, and none developed life-threatening arrhythmias. OS and EFS were also comparable to real-world experience seen in younger patients. This study may be limited by the selection of a relatively fit population of elderly patients; however, the median Karnofsky Performance Score was 80 and ranged as low as 60. Overall, these findings show that axi-cel may be an appropriate strategy for relapsed aggressive NHL in carefully selected patients in their eighth and even ninth decades of life.

Optec: A Phase 2 Study to Evaluate Outpatient Administration of Teclistamab, a BCMA-Targeting Bispecific Antibody, in Patients with Multiple Myeloma

Background: Teclistamab is the only approved BCMA×CD3 bispecific antibody with a personalized, weight-based dosing schedule for the treatment of triple-class exposed relapsed/refractory multiple myeloma (RRMM). It is FDA approved for patients (pts) of therapy (LOTs), including a proteasome inhibitor, immunomodulatory drug, and anti-CD38 antibody. In the pivotal MajesTEC-1 study (Moreau et al NEJM 2022), teclistamab showed deep and durable responses and a manageable safety profile in heavily pretreated pts with RRMM who had limited treatment options. The incidence of all grade cytokine release syndrome (CRS) during the first 2 cycles was 70%. Most pts experienced CRS following step-up doses 1 (42%) or 2 (35%), or the initial treatment dose (24%); 33% of pts experienced recurrent CRS. Most CRS events were grade 1/2 and fully resolved without discontinuation or dose reduction of teclistamab. One (0.6%) case of grade 3 CRS occurred in a pt who pneumonia but resolved in 2 days. No grade 4 or 5 CRS occurred. Tocilizumab is a monoclonal antibody targeting the interleukin-6 receptor (IL-6R) which is used to manage CRS resulting from T-cell redirection therapy. Preclinical data indicate that inhibition of IL-6 signaling prior to teclistamab administration can prevent CRS development without impacting anti-tumor activity (Li et al Ann. Oncol. 2019). In MajesTEC-1, pts who received a single IV dose of tocilizumab before the first teclistamab step-up dose (n=23) showed a reduction in the incidence of all grades of CRS, compared with the overall study population (26% vs 72%). Currently, there are no data on the safety of administering the step-up doses of teclistamab in the outpatient (OP) setting, but OP step-up dosing may make teclistamab more accessible. Therefore, we seek to investigate whether the use of prophylactic tocilizumab can reduce the incidence and severity of CRS associated with teclistamab and allow safe OP administration of the step-up dosing. Methods: This single-arm, non-randomized, multicenter, prospective study (NCT05972135) will evaluate CRS incidence and severity after prophylactic tocilizumab in pts treated with teclistamab in the OP setting. A target of 50 participants will be enrolled with an initial PK/PD safety cohort (n=10). Objectives through end of study include recurrent CRS, grade ≥3 and any grade infections, neurotoxicity including ICANS, neutropenia, febrile neutropenia, and efficacy. Eligible pts are ≥18 years with a documented diagnosis of RRMM who have previously received ≥4 LOTs. Pts with rapidly progressing disease, central nervous system involvement, active infection, or contraindication to tocilizumab will be excluded from the trial. Prior to the treatment phase, pts will participate in a 28-day screening phase to determine study eligibility. During the treatment phase, a single dose of tocilizumab will be administered at 8 mg/kg IV, 2 to 4 hours prior to step-up dose 1 of teclistamab (Cycle 1 Day 1) in an outpatient setting (Figure 1). Teclistamab will then be administered at step-up doses of 0.06 mg/kg subcutaneously (SC) (Cycle 1 Day 1) and 0.3 mg/kg SC (Cycle 1 Days 3-5), followed by 1.5 mg/kg SC (Cycle 1 Day 8), with weekly administration for twelve 28-day cycles or until disease progression or unacceptable toxicity. Teclistamab may be reduced to 1.5 mg/kg SC every two weeks for participants who achieve partial response or better after 6 months of therapy. Safety evaluations will include physical examination, vital sign measurements, neurological examination, assessment of ECOG performance status, and clinical safety laboratory assessments. IVIG is recommended in pts with serum IgG <4 g/L. Follow-up of participants during the study will include monitoring for all adverse events, disease progression, and survival until end of study. By studying the feasibility and safety of administering the step-up dosing schedule in an outpatient setting, teclistamab may become more accessible to pts with RRMM and limited treatment options.

Expression of a Novel Chimeric Inhibitory Receptor Attenuates CD19 CAR T Cells: A Promising Strategy for Toxicity Mitigation

Introduction Chimeric antigen receptor (CAR) T cells targeting CD19 are highly effective in patients with refractory/relapsed acute lymphoblastic leukemia and lymphoma but often trigger severe cytokine release syndrome (sCRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). For r/rALL patients, as many as 77% develop Grade 3-5 CRS and 40% Grade 3-5 ICANS. sCRS occurs when hyperactivated CAR T cells undergo exponential expansion accompanied by the release of excessive amounts of inflammatory cytokines. This leads to a systemic pro-inflammatory state that can cause hypotension, multi-organ failure and even death. Tocilizumab is the only FDA-approved drug for CRS and despite concurrent corticosteroids, often fails to control CRS. Attempts to improve safety have been proposed, but have significant limitations, such as permanent removal of CARs. New and innovative methods to mitigate toxicities are needed. The purpose of this study was to design and test the efficacy of a novel autoregulatory element in the form of a chimeric inhibitory receptor (CIR), that when engaged by a specific CRS-associated pro-inflammatory molecule would trigger inhibitory signaling within CAR T cells. We hypothesize that as cytokine levels increase following activation, these signals can be redirected through responsiveness of the CIR, leading to an attenuation of CAR activity. In this study, we have tested a CIR construct that couples the recognition of IFNγ to the signaling domain of the TIGIT inhibitory receptor. We co-expressed this CIR with a CD19.28ζ CAR to evaluate its ability to attenuate activation and cytokine production and to assess its cytotoxic activity. Methods An anti-IFNγ scFv followed by the transmembrane and intracellular domains of TIGIT were arranged in sequence with the truncated EGFR receptor followed by the CD19.28ζ FMC63 CAR with intervening T2A cleavage domains and cloned into a retroviral backbone. Transduction efficiency was assessed by staining with biotinylated CD19-Fc protein or biotinylated EGFR. Following expansion, memory and effector cell differentiation was evaluated by staining for CD45RO, CD45RA, CCR7, CD127, and CD95. Activation following stimulation with NALM-6 tumor cells was measured by staining for CD69, CD25, CD38, PD-1, and CD107a. Cytotoxicity was evaluated using bioluminescence. To mimic cell types present during CRS, we utilized a coculture assay that consists of CAR T cells, NALM-6 tumor cells, and either macrophages or dendritic cells (DC) differentiated from autologous CD14 + monocytes. Cocultures were incubated for 48 hr. and supernatants were collected for analyses by Luminex. Results CD19 CARs co-expressing a CIR composed of an anti-IFNγ scFv coupled to TIGIT inhibitory signaling expanded during the manufacturing process as well as T cells expressing only CD19 CAR and displayed normal levels of CAR expression. The presence of the CIR did not affect the differentiation profile of memory and effector subsets. CIR-expressing CD19 CARs exhibited robust tumor cell killing of NALM-6 targets equivalent to CD19 CARs. Next, CD19 CAR/CIR cells were pretreated with IFNγ for 24 hr. and then cultured with NALM-6 cells. Exposure to IFNγ resulted in a significant abrogation in cytotoxicity, which was eventually restored with time. Activation profile analysis of CARs equipped with CIR signaling after target stimulation revealed an overall diminution of CARs expressing multiple (4 or 5) activation markers relative to CD19 CARs. Importantly, CIR signaling resulted in significant reductions in the levels of effector, stimulatory, and inflammatory mediators including IFNγ, TNFα, GM-CSF, and IL-17. CARs expressing the CIR exhibited slower killing kinetics when challenged with sequential stimulations by fresh tumor cells. However, in vivo anti-tumor cell activity was not adversely affected as CAR/CIR T cells robustly eliminated disease in leukemia-bearing NSG mice. Lastly, using an in vitro CRS assay, we sought to determine if attenuated CAR T cells would be less potent in activating myeloid cells. We observed that monocyte-derived macrophage and DC activation by CD19 CAR/CIR T cells was reduced as evidenced by decreased secretion of proinflammatory cytokines and chemokines. Conclusion These results provide a compelling proof of concept of a novel self-regulating CAR T cell design with the potential to mitigate severe toxicities in patients.

Efficacy and Safety of Chimeric Antigen Receptor T Cells Therapy Combined with Zanubrutinib in the Treatment of Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Background: While complete response rate of CD19 CAR-T in diffuse large B-cell lymphoma (DLBCL) reached 40-60%, about 30%-50% of patients still face relapse, strategies that can enhance the therapeutic effects of CAR-T cells infusion should be actively explored. Bruton's tyrosine kinase (BTK) is an essential component of multiple signaling pathways including B-cell receptor signaling that regulate B cell proliferation, survival, and functions. These receptor signaling has been implicated in the survival of malignant B-cells making it a promising therapeutic target for various B-cell malignancies and inflammatory diseases. Different types of BTKi regulate T cell and B cell function through different signal pathways. Research has proved that CD19 CAR-T Cells in combination with ibrutinib for the treatment of relapsed/refractory aggressive B-cell lymphomas shows a high response rate and low level of adverse events, while zanubrutinib has not been reported. Therefore, our center explored the efficacy and safety of CD19 CAR-T Cells in combination with zanubrutinib for the strategy of relapsed/refractory DLBCL. Patients and Methods: The study included 6 r/r DLBCL patients, 4 patients have previously received 3-line or above treatment, and 2 patients began CAR-T treatment after 1-line chemotherapy. All patients received fludarabine (FLU) and cyclophosphamide (CTX) conditioning chemotherapy (FLU 30mg/m 2. d1-3; CTX 500mg/m 2, d1-3) before CAR-T infusions. T cells were apheresis collected and transduced with a lentiviral CD19 scFv CAR fused with intracellular signaling domains: CD28/CD27/CD3z-iCasp9. CAR-T cells were infused at dose of 2.0x10 6 cells/kg. The quality of apheresis cells, gene transfer and T cell proliferation efficiencies, and effective CAR-T infusion dose were quantitatively scored and documented. All patients began to combine with zanubrutinib after one month of CAR-T cells infusion. Results: After one month of CAR-T cells infusion, total of 50% (3/6) of patients achieved complete response (CR), while 50%(3/6) of patients were evaluated as partial response (PR), with an overall response rate (ORR) of 100%. Within 6 months after combined with zanubrutinib, all patients of PR achieved CR. In the evaluation of safety, 83% (5/6) of patients occurred grade 2 cytokine release syndrome (CRS), and 33.3% (2/6) patient occurred grade 1 immune effector cell-associated neurotoxicity syndrome (ICANS), no case of severe CRS defined as≥grade 3 occurred, 66.7% (4/6) of patients occurred grade 2 hematotoxicity and 33.3% (2/6) of patients occurred grade 4 hematotoxicity. After a median follow-up of 19.5 months, 6 patients maintained CR, with an duration of response (DOR) of 100%, median DFS and OS were not reached. All patients can be detected CAR-T cells sustain in peripheral blood mononuclear cells continuously until last follow-up date(Fig.2). Continued follow-up will confirm whether the CAR-T cells therapy combined with zanubrutinib can obtain long term overall survival in these study. Conclusions: Our study proved that CD19 CAR-T Cells combined with zanubrutinib for the strategy of relapsed/refractory DLBCL and as maintenance treatment showed strong efficacy with acceptable toxicity, the current results already support that zanubrutinib in the treatment of r/r DLBCL is expected to reduce the risk of relapsed, thereby prolonging the disease-free survival of patients, without increasing the incidence of adverse effects. More follow-up and clinical trials are needed to clarify the efficacy of Chimeric Antigen Receptor T Cells Therapy combined with zanubrutinib in the treatment of r/r DLBCL.

Health Care Resource Utilization (HCRU) and Cost of Management of Cytokine Release Syndrome (CRS) and Neurological Events (NEs) in Patients with R/R CLL/SLL Receiving Lisocabtagene Maraleucel (liso-cel) Treatment in the TRANSCEND CLL 004 Study

Background:Liso-cel is an autologous, CD19-directed, 4-1BB CAR T cell product administered at equal target doses of CD8 + and CD4 + CAR + T cells, which is currently being evaluated for treatment of patients with R/R CLL/SLL in the TRANSCEND CLL 004 study (NCT03331198). Initial study results suggested that a single infusion induced CRs or remission in patients with R/R CLL/SLL and had a manageable safety profile, with low to moderate incidence of severe CRS and NEs (Siddiqi T, et al. Lancet 2023). While the clinical consequences of CRS/NEs associated with CAR T cell therapies are well understood, limited data are available on the cost of management of these AEs. This analysis evaluated HCRU and estimated costs of managing CRS/NEs by grade in patients with R/R CLL/SLL who received liso-cel treatment in TRANSCEND CLL 004. Methods: Case report forms were analyzed from the trial database, capturing patient-level HCRU related to the management of CRS/NEs. Only patients that received liso-cel at a dose level of 100 × 10 6 CAR + T cells (dose level 2 [DL2]) and subsequently experienced treatment-emergent CRS and/or NEs were included in this study. Treatment-emergent AEs were defined as those initiated within a 90-day period of liso-cel administration. Costs for management of CRS/NEs were estimated using microcosting methodology. Relevant HCRU observed from the day of AE onset through resolution that was associated with the management of CRS/NEs per protocol management guidelines was identified; unit costs sourced from public databases were applied to each HCRU. Included HCRU categories were: facility (standard inpatient admission, ICU stay), diagnostics (laboratory, imaging), medications (tocilizumab, corticosteroids, vasopressors), and procedures (dialysis, intubation). Cost analyses were conducted from the United States (US) health care system perspective and adjusted to 2023 US dollars. Unit costs were obtained from the US Centers for Medicare & Medicaid Services Hospital Outpatient Prospective Payment System, laboratory and physician fee schedules, IBM ® Micromedex ® RED BOOK ®, and literature. Descriptive statistical analyses stratified by AE severity grade and type of AE experienced were performed. Results: Ninety-four of 108 (87%) patients who received liso-cel at DL2 experienced CRS and/or NEs; 68 (72%) were grade ≤ 2 and 26 (28%) were grade ≥ 3. Overall, 44 (47%) patients had CRS only, 1 (1%) had NEs only, and 49 (52%) experienced both CRS and NEs. The study sample had a mean (standard deviation) age of 64.5 y (7.9) and were predominantly male (69%), White (84%), and non-Hispanic or Latino (90%). HCRU and total length of stay (LOS; the sum of inpatient and ICU stay days) are shown in the Table. All patients had an inpatient stay. ICU admissions only occurred among patients who experienced both CRS and NEs (10/49 [20%]) and were more common among patients with grade ≥ 3 (29%) compared with grade ≤ 2 (12%) AEs. Among patients who had an ICU admission, the median duration of an ICU stay was 5 days. Median total LOS increased with increasing AE severity for patients who had CRS only (grade 1, 5 days; grade 2, 9 days; grade 3, 15 days) and for patients who experienced both CRS and NEs (grade ≤ 2, 12 days; grade ≥ 3, 15 days). Overall, 68% and 62% of patients received tocilizumab and corticosteroids, respectively. Patients with grade ≥ 3 CRS and/or NEs had higher rates of utilization of medications, diagnostics, and procedures than those with grade ≤ 2 (Table). Additionally, patients who experienced both CRS and NEs had higher rates of utilization across all HCRU categories compared with those who experienced CRS or NEs only (Table). Estimated median management costs for CRS or NEs ranged from $14,638 (CRS only grade 1) to $46,802 (experienced both CRS and NEs with CRS or NEs grade ≥ 3) (Figure). Facility-related costs were the largest contributor to median total costs. Conclusions: While most patients treated with liso-cel at DL2 in TRANSCEND CLL 004 experienced CRS and/or NEs, they were primarily of low severity. HCRU and associated costs for management of CRS and/or NEs after liso-cel infusion increased with AE severity.Although everyone in this study required hospitalization, ICU admissions were rare and only observed among patients who experienced both CRS and NEs. Overall, costs of managing CRS and/or NEs were modest.

Evaluation of the Impact of Tocilizumab Use in Recipients of CAR T Cells for Non-Hodgkin Lymphoma

Introduction: CAR T has revolutionized the treatment of patients with relapsed or refractory (R/R) Non-Hodgkin lymphoma (NHL). Treatment of the major toxicity of cytokine release syndrome (CRS) is tocilizumab (toci) and corticosteroids based on the ASTCT grade. Real-world experiences in the United States and Europe have reported a higher rate of tocilizumab use than in pivotal trials; however, the impact of single or multiple administrations on clinical outcomes is not clear. Methods: Patients diagnosed with diffuse (DLBCL), high grade (HGBCL) and primary mediastinal B cell lymphoma (PMBL) treated at our institution with commercial CAR T were retrospectively identified. The association between the number of doses received with best overall response by day 100, PFS, and OS was investigated through a Cox regression model using a 14-day landmark analysis. Late neutropenia was defined as an ANC <1000/mmc for two consecutive counts beyond day 30 post CAR-T infusion and a 30-day landmark analysis was performed in this case. Results: 230 patients with R/R DLBCL (80%), HGBCL (17%) and PMBL (3%) were included in the analysis. Axicabtagene ciloleucel (Axi-cel), tisagenlecleucel (Tisa-cel), and lisocabtagene maraleucel (Liso-cel) were administered in 62%, 29% and 9% of cases, respectively. Median age at time of CAR-T infusion was 65 years (range 20-86), with a male predominance (63%). The median number of prior treatment lines was 3 (range 1-12), and 21% underwent a prior autologous hematopoietic cell transplant. Disease burden prior to CAR-T infusion can be inferred by the following: bridging therapy was deemed necessary in 77% of patients, pre-lymphodepletion LDH was elevated in 40%, and bulky disease with largest mass diameter was > 10 cm in 10%. CRS and ICANS were grade 2 in 107 patients (46%) and 46 patients (20%), respectively. Median time to first administration of toci was 4 days (range 1-16) with patients receiving 0 (51%), 1 (27%), 2 (14%), or 3-4 (8%) doses. Best response by day 100 for the whole cohort was CR in 138 (60%) and PR in 36 (16%) patients. In univariable analysis, factors associated with a lower likelihood of response were the administration of Tisa-cel (p=0.014), bulky disease (p<0.001), administration of bridging therapy (p=0.009), and being refractory to the last treatment line (p=0.006). Number of doses of tocilizumab did not impact the likelihood of response (p=0.72). In a Cox regression model for survival, number of doses of tocilizumab was not associated with worse PFS (p=0.38, Figure 1) or OS (p=0.64), while other known negative predictors of response had impact on survival, such as bulky and refractory disease. By univariable analysis, tocilizumab administration was significantly associated with prolonged neutropenia (p<0.001). The likelihood to observe an ANC<1000/mmc beyond day 30 increased accordingly to the number of doses received (Figure 2). Other factors associated with late neutropenia were bulky disease (P=0.013), need of bridging therapy (p=0.004), and corticosteroids administration (p<0.001). Conclusion: The number of tocilizumab infusions did not impact CAR T efficacy in terms of overall response and long-term survival, a finding that is concordant with other real-world experiences. The cumulative incidence of late neutropenia events was impacted by the number of doses received. We speculate that a severe CRS driven systemic inflammatory response, requiring several tocilizumab and corticosteroids administrations, may hinder the bone marrow function and recovery.

A Phase I Clinical Trial of CLL-1 CAR-T Cells for the Treatment of Relapsed/Refractory Acute Myeloid Leukemia in Adults

Background: Relapsed/refractory acute myeloid leukemia (r/r AML) has a poor prognosis, and most patients fail standard chemotherapy and hematopoietic stem cell transplantation or relapse after treatment. We previously reported and evaluated CLL-1-targeted chimeric antigen receptor T-cell therapy in adult r/r AML patients, demonstrating for the first time the efficacy and tolerable safety of CLL-1 CAR-T cell therapy in adult r/r AML patients. On this basis, we expanded the data volume and continued to evaluate the safety and efficacy of CLL-1 CAR-T in AML with dose escalation. Methods: This is a single-center, phase I, dose-escalation trial of CLL-1 CAR-T cell in adult patients with r/r AML (ChiCTR2000041054）admitted to Tianjin First Central Hospital from January 2021 to June 2023. All patients received a lymphodepleting chemotherapy with cyclophosphamide (500mg/m2) and fludarabine (30mg/m2) 3 days before CAR-T cell infusion, followed by 4 incremental doses of CAR-T cells: dose level (DL)1 (0.5×10^6/kg），DL2（1×10^6/kg），DL3（1.5×10^6/kg）and DL4（2×10^6/kg）CAR-T cells. The primary objective of the trial was to evaluate safety and tolerability, and to determine the recommended Phase 2 dose. Key secondary objectives included the assessment of overall response rate, complete response rates as well as progression free survival and overall survival. Results: Thirty patients were enrolled and treated in the dose-escalation phase of the study. The median age of the patients was 38 years (range 18-73), and the median number of prior lines of treatment was 4(2-10), 5(16.67%) patients progressed from MDS to AML, 13(43.33%) patients relapsed after treatment, of which 8(26.67%) patients had previously received HSCT. There were 9, 9, 6 and 6 patients receiving DL1, DL2, DL3 and DL4, respectively. All patients experienced cytokine release syndrome (CRS) (100%): grade 0-2(n=18), grade 3(n=11), grade 4(n=1), and only one patient (3.33%) experienced grade 4 neurotoxicity (NTX), which improved after plasma exchange. In addition, all patients experienced hematological toxicity, with 29 patients (96.67%) developing grade 3/4 granulocytopenia, 28 patients (93.33%) developing grade 3/4 anemia, and 30 patients (100%) developing thrombocytopenia. Patients who received haploidentical bridge transplantation after infusion had normal granulocyte, erythrocyte, and platelet transplantation and did not develop serious infection, suggesting that when severe agranulocytosis occurs after CAR-T infusion, bridge transplantation can reverse this toxicity (Table 1). Efficacy evaluation showed that 73% of patients responded to the infusion, with 12(40%) patients achieving MRD-CR/CRi and 10(33.33%) patients achieving MRD+CR/CRi, for an overall response rate (ORR) of 73.33% (Figure 1). All patients who underwent bridging haploidentical HSCT after CAR-T cell infusion achieved MRD-CR/CRi, and the median time to transplantation was 0.7 months (0.3-1.13). The median OS rate of patients after transplantation was higher than that of patients without transplantation after infusion (P=0.015), as was PFS (p=0.044). The maximum tolerated dose was not determined as no dose-limiting toxic effects were observed. Responses were observed at all dose levels, with a median follow-up of 132 days (range 15-914 days). Patients had a median PFS of 300 days (95% CI, 191.320 to 408.680) and a median OS of 348 days (95% CI, 234.011 to 461.989). The expansion of CLL-1CAR-T cells was tracked by flow cytometry, and the median peak of CAR-T expansion occurred at day 11 (range 2-15) after infusion. When comparing the peak CAR-T expression in CR/CRi and NR patients, the proportion of peak CAR-T cells was significantly higher in CR/CRi patients. Conclusion: CLL-1 is a potential therapeutic target in AML. The proportion of patients who developed severe CRS was low and only 1 patient experienced NTX. Although severe agranulocytosis may occur, patients receiving CLL-1CAR-T therapy may have the opportunity to achieve CR/CRi prior to transplantation, which may reduce the risk of relapse and mortality, and prolong patient survival with encouraging results. Due to the small sample size, no relevant dose-response relationship was observed, and the trial is currently enrolling more cases and will be progressively expanded to Phase II clinical trials.

A Phase II Trial of Prophylactic Anakinra to Prevent Neurotoxicity in Patients Receiving Anti-CD19 CAR T-Cell Therapy for Relapsed or Refractory Lymphoma: Final Results from Cohort 2

Background: Whilst tocilizumab is effective in the management of chimeric antigen receptor T-cell (CAR-T) associated cytokine release syndrome (CRS), there are no targeted therapies for immune effector cell-associated neurotoxicity syndrome (ICANS). Rates of severe (≥ grade 3) ICANS remain high with axicabtagene (axi-cel) and brexucabtagene (brexu-cel) at > 30%. Preclinical models have shown that anakinra, an IL-1 receptor antagonist, reduced CAR-mediated immune toxicities without affecting efficacy. Based on these data, we conducted a phase 2 trial of prophylactic anakinra in patients receiving commercial anti-CD19 CAR-T for r/r B-cell lymphoma (NCT04148430). The study had sequential enrollment in 2 independent cohorts. We recently reported results from cohort 1 in which patients received subcutaneous (SC) anakinra from day 2 until at least day 10 post-CAR infusion and showed that prophylactic anakinra reduced the rate of severe ICANS to 9.7% (Park, Nat Med, 2023). Herein, we report results from cohort 2 of the study where we utilized anakinra as a complete prophylactic strategy. Methods: Adult patients with a diagnosis of r/r large B-cell lymphoma (LBCL), high-grade B-cell lymphoma (HGBCL), follicular lymphoma (FL) or mantle cell lymphoma (MCL) receiving commercial anti-CD19 CAR-T were enrolled. Patients received SC anakinra 100 mg daily from day 0 for at least 7 d. The frequency of anakinra could be increased up to 100 mg every 6 h, and the duration beyond 7 d for persistent or progressive CRS and ICANS. Tocilizumab and steroid use were allowed for the management of persistent or progressive CRS and ICANS. A baseline and day 5 lumbar puncture were performed for CSF analysis. The primary endpoint was the rate of severe ICANS, graded per the ASTCT criteria. Secondary endpoints included rates of severe CRS, all grade CRS and ICANS, overall response rate (ORR), survival outcomes, and serum and CSF biomarker levels. Results: 37 patients were screened, 31 enrolled, and 30 treated (LBCL=13, HGBCL=6, FL=6, MCL=5). 1 enrolled patient did not proceed with treatment due to COVID-19 infection. The median age of the cohort was 65yrs (range: 24 - 81yrs) and patients received axi-cel (19 pts; 63%), brexu-cel (5 pts; 17%), lisocabtagene (4 pts; 13%) and tisagenlecleucel (2 pts; 7%). Patients received a median 3 prior lines of therapy (range: 1 - 7); 22 (73%) were refractory to their immediate prior therapy; 17 (57%) received bridging therapy and 3 (10%) had active CNS disease at CAR infusion. Pretherapy tumor burden as measured by the median sum of the products of diameters was 1638mm 2 (range: 0 - 21,570mm 2). All patients started anakinra on day 0. Anakinra administration was increased in 24 patients (80%) during CRS; it was increased to a maximum of 100mg q12h in 1 patient and 100mg q6h in 23 patients. The median duration of anakinra administration was 9.5 d (IQR 8 - 13). No patient stopped anakinra due to an adverse event. A total of 3 patients (10%) experienced severe ICANS, all of which were grade 3 only. 9 patients (30%) experienced any grade ICANS (Fig 1A). The median time to ICANS onset was 6.5 d (range: 4 - 10 d). All-grade CRS occurred in 24 patients (80%). Most CRS events were grade 1 or 2 except for 3 grade 3 events (10%) (Fig 1A). Of the 24 patients who received CD28-containing CARs (axi-cel and brexu-cel), all-grade and severe ICANS rate was 29% and 12.5%, respectively (Fig 1B). In the 3 patients with active CNS disease, there was 1 grade 2, and 1 grade 3 ICANS event. 23 patients (77%) received tocilizumab and 18 (60%) received steroids for CRS and/or ICANS. The median follow-up was 5.8mo. The best ORR by day 100 was 83% (95% CI 65-94%) with a CR rate of 73% (95% CI 54-89%). The estimated progression-free and overall survival at 6mo was 72% (95% CI 50-93%) and 81% (95% CI 66-86%), respectively. Conclusion: Early use of prophylactic anakinra was safe, feasible and reduced the rate of severe ICANS without affecting efficacy in adult patients receiving anti-CD19 CAR-T for r/r B-cell lymphoma. Rates of severe ICANS were very similar between cohorts 1 and 2; at 9.7% and 10% in the entire cohorts, respectively, and 11% and 12.5% in patients treated with CD28-containing CARs, respectively. The risk-adapted dosing of anakinra likely contributed to the low rates of severe ICANS in this study. Detailed comparison of results from cohort 1, analysis of the anakinra dose-relationship on efficacy, and serum and CSF biomarkers will be presented at the meeting.

CNS Radiotherapy As Bridging Prior to CAR T-Cell Therapy for Non-Hodgkin B-Cell Lymphoma

Introduction: Up to 80% of patients who receive CAR T-cell therapy (CAR T) for central nervous system lymphoma (CNSL) require bridging therapy, yet optimal regimens remain undefined. Radiotherapy is an established strategy for extracranial lymphoma that provides beneficial cytoreduction. However, CNS bridging radiotherapy (CNS-BRT) prior to CAR T is controversial due to concerns of potential enhanced neurotoxicity. We explored the safety and response profiles in patients treated with CNS-BRT prior to CAR T. Methods: We identified patients with non-hodgkin B-cell lymphoma who received CNS-BRT at our institution prior to commercial CAR T infusion. CNS-BRT was defined as treatment delivered between apheresis and CAR T infusion or within 30 days prior to apheresis, targeting the CNS parenchyma, leptomeninges, or epidural spine. Patients with epidural spine disease were included since the adjacent spinal cord is part of the treatment field. Safety was evaluated by rate of cytokine release syndrome (CRS) and immune effector associated neurotoxicity syndrome (ICANS) after CAR T. Best CNS response post CAR T was evaluated using the International Primary CNS Lymphoma Collaborative Group (IPCG) or Response Assessment in Neuro-Oncology (RANO) for parenchymal or leptomeningeal lesions, respectively. Cytoreduction from CNS-BRT was estimated by calculating the change in lesion size (sum of product diameter) from before and after CNS-BRT, but before CAR T infusion. Risk of any CNS relapse after CAR T was estimated using the Gray's method with death as a competing risk. Patients with epidural spine disease were not evaluate for CNS response or relapse. Results: 12 patients received CNS-BRT with median follow up of 8.5 months (range: 3.2 - 30.2), median age of 60 (30-76), median Karnofsky Performance Status (KPS) of 80 (range: 50 - 90). Histologies included diffuse large B cell (DLBCL) (n = 9), mantle cell (n = 2), and Burkitt lymphoma (n = 1), with disease localizing to the brain parenchyma (n = 6), leptomeninges (n = 4), and epidural spine (n = 2). 9 patients had secondary CNSL and 1 patient had primary CNSL. Prior to CNS-BRT, 11/12 patients had progressive disease. 5/12 patients had disease outside of the CNS. 5/12 patients received prior autologous hematopoietic stem cell transplantation. 9/12 patients received prior high dose methotrexate with median 46-day interval to CNS-BRT (range: 0 - 393). RT targets included whole brain (n = 3), involved site (partial) brain (n = 4), involved site spine (n = 4), and orbits (n = 1) with median dose 24 Gy (range: 15 - 33). CAR T products included Tisagenlecleucel (n = 4), Lisocabtagene maraleucel (n = 7), and Axicabtagene ciloleucel (n = 1). Among 10 patients with available toxicity grading, 6/10 experienced CRS (n = 1 grade (G) 1, n = 4 G2, and n = 1 G3), and 3/10 experienced ICANS (n = 1 G1, n = 1 G3, n = 1 G4). 6/10 patients required tocilizumab and/or steroids. CNS-BRT achieved a 74.4% (95% CI, 62.9 - 85.9) mean reduction in lesion size prior to CAR T infusion. Best CNS response after CAR T infusion included 3 complete responses (CR), 6 partial responses (PR), and 1 progressive disease (PD). The patients who achieved PR remained in PR at last follow up. The 12-month estimated risk of CNS progression after CNS-BRT and CAR T infusion was 20.0% (95% CI, 3- 49). CNS progression was not observed in patients who received involved site brain RT. Conclusion: Preliminary data suggest CNS-BRT achieves rapid cytoreduction prior to CAR T therapy and is associated with a favorable CNS response profile. While overall numbers are limited to date, the rate of severe CRS and ICANS is similar to that of historical series of CNSL patients treated with CAR T. However, a larger cohort will be required to determine the safety of CNS-BRT. These data support further study of RT, and exploration of involved site brain RT, as an effective bridging modality for CAR T-cell therapy in CNSL.

Clinical Outcomes with Prophylactic Corticosteroid Use for Axicabtagene Ciloleucel (axi-cel) in Patients with Relapsed/Refractory Large B-Cell Lymphoma (R/R LBCL): A Multicenter Analysis

Introduction: In Cohorts 1+2 of the ZUMA-1 Phase 1/2 study of axi-cel in R/R LBCL, 11% and 31% of patients (pts) experienced Grade ≥3 cytokine release syndrome (CRS) or neurologic evenets), respectively. To minimize the toxicities seen with axi-cel, a safety management cohort, Cohort 6 (N=40), was added to evaluate whether prophylactic (ppx) corticosteroids (CS) could decrease grade ≥ 3 CRS or ICANS. The 2-year update of ZUMA-1 Cohort 6 showed no grade ≥3 CRS and 15% grade ≥3 ICANS without any difference in objective response rate (ORR) or complete response rate (CR) when compared to cohorts 1+2 (Oluwole Blood 2022). The FDA had previously approved an update to the prescribing information for axi-cel to include use of ppx CS across all approved indications in January 2022. However, ppx CS is not a mandatory standard treatment and we sought to establish the clinical outcomes in the real-world practice. Methods: To assess the clinical outcomes of pts receiving ppx CS, we conducted a multicenter retrospective analysis of pts with R/R LBCL who were treated with axi-cel since the FDA approval of ppx CS in January 2022. Baseline characteristics, toxicities, and efficacy were compared between the no ppx and ppx CS groups. CRS and ICANS were graded based on ASTCT 2019 guidelines. Event-free survival (EFS) was defined as time from axi-cel infusion to progression, re-treatment, or death. Overall survival (OS) was defined as time from axi-cel infusion to death due to any cause. Results: A total of 66 pts at 5 centers received axi-cel between Jan 31, 2022, and June 20, 2023. Thirty-five (52%) pts received ppx CS, with a median age of 63 years (26-85 years). By histology, 75% (n=50) of the pts had DLBCL, 13.6% (n=9) had high grade B-cell lymphoma (HGBL), 9.1% (n=6) had transformed follicular lymphoma (TFL) and 1.5% (n=1) primary mediastinal LBCL (PMBCL). 59% of the pts (n=37) had IPI >2 and 66% (n=43) had stage III/IV disease. The baseline characteristics at the time of apheresis are shown in Table 1 and were comparable between the 2 groups, except for more HGBL, fewer prior lines of therapy and longer median time from apheresis to axi-cel infusion in the ppx CS group. Among the entire cohort, only 37% (n=25) met ZUMA-1 eligibility criteria at the time of lymphodepletion, and 67% (n=44) needed bridging therapy. Any grade CRS occurred in 88% (n=58) of the pts, with grade ≥2 CRS in 38% (n=25). Any grade ICANS occurred in 55% (n=37) of the pts, with grade ≥2 ICANS in 41% (n=27). Any grade ICANS was significantly lower in the ppx CS group than the no ppx group (45.7% vs 65.5%). The rates of any grade CRS, grade ≥2 CRS, grade ≥2 ICANS, the median time to CRS onset, ICANS onset, CRS duration, and ICANS duration were comparable between the 2 groups. Tocilizumab and steroids use was similar between two groups with a trend towards less ICU admission in patients in the ppx CS group. Overall, 14 (21%) pts developed infectious complications within 30 days of axi-cel infusion. The day 30 ORR was 84% and was comparable between the 2 groups (77% in the ppx group vs 93% in the no ppx group). The CR was 45.7% in ppx CS group compared to 65.5% in no ppx group. At a median follow up of 219 days (27-1178), 37 (56.1%) pts had progressed and 25 (37.9%) pts had died. The number of days to progress was significantly lower in the ppx CS arm. The median EFS and OS were not significant between the 2 groups. Conclusions: This multicenter retrospective study showed that the efficacy of treatment with axi-cel in R/R LBCL did not decrease with the use of ppx CS. No significant differences in efficacy or CAR-T-associated toxicities were noted in the 2 groups, potentially due to selective use with patients at presumed higher risk of severe CRS and ICANS. A larger dataset and longer follow-up is needed for risk-stratified analysis and the study is ongoing.

Efficacy and Safety of Chimeric Antigen Receptor T Cells Therapy Strategy That Dual Targeting CD19 and CD22 to Treat Relapsed/Refractory Acute Lymphoblastic Leukemia in Adults

Background: Chimeric antigen receptor T-cells (CAR-T) targeting CD19 therapy is reported to induce 83-93% response in relapsed/refractory acute lymphoblastic leukemia (r/r-ALL) in adults. However, 30-60% of patients relapse after CAR-T treatment, of which 14-25% CD19-negative relapse. In spite of CAR-T cells persistence, CD19 absent causing tumors that evade CAR-T cells mediated recognition and clearance. For CD19-negative relapse, it is necessary to explore more effective targets. There are some research proved that compared with single-targeted CARs, CD19/CD22 dual-targeted CARs induce more IFN-γ and IL-2 in vitro and eradicate patient-derived xenografts (PDX) produced with CD19-negative relapse of CD19-directing CAR-T treatment. Therefore, our study explored the efficacy and safety of clinical studies on mixture of CD19 CAR-T and CD22 CAR-T cells in the treatment of r/r ALL in adults. Patients and Methods: CD3 + cells were selected from the apheresis PBMC and activated before lentiviral CAR T cells infection. The cells were transduced with a caspase9-inducible, safety-engineered lentivector CAR containing anti-CD19 or -CD22 scFv fused with multiple intracellular signaling domains: CD28/CD27/CD3z-iCasp9. The quality of apheresis cells, gene transfer and T cell proliferation efficiencies, and effective CAR-T infusion dose were quantitatively scored and documented. All enrolled patients expressed CD19 and CD22 positively. All patients received fludarabine (FLU) and cyclophosphamide (CTX) conditioning chemotherapy (FLU 30mg/m 2, d1-3; CTX 500mg/m 2, d1-3) before CAR-T infusions. Results: The study included 16 r/r ALL patients, median age is 26 years, and median of previous theraples is 6, all of patient details can be found in the table (Fig.1). In the first month after CD19/CD22 CAR-T cells infusion, total of 93.8% (15/16) of patients achieved complete response (CR), 1 case (6.25%) was evaluated as non-remission (NR). In the evaluation of safety, 68.75% (11/16) of patients did not experience cytokine release syndrome (CRS), 25% of patients (4/16) occurred grade 1 CRS and 6.25% (1/16) of patients occurred grade 2 CRS, no case of severe CRS defined as≥grade 3 and no any immune effector cell-associated neurotoxicity syndrome (ICANS) occurred. After a median follow-up of 9.9 months, 4 patients maintained CR, while other 11 patients were relapsed, with a duration of response (DOR) of 25% (4/16), median LFS was 6.1 months and median OS were not reached (Fig.2). Conclusions: In summary, CD19/CD22 exhibited a manageable safety but limited antileukemia activity. Our study showed that mixture of CD19 CAR-T and CD22 CAR-T cells infusion is fail to expected to compensate for the treatment of relapsed in r/r ALL and prolonging the leukemia-free survival of patients. The low-efficacy of dual-targeted CAR-T cells may be caused by the CAR19 and CAR22 cells interfere with each other and weaken the CAR-T amplification in vivo. From our data, it seems that the timing of treatment and tumor burden status may play a more important role rather than new targets CAR-T cells infusion for r/r ALL in adults.

Incorporating radiation with anti-CD19 chimeric antigen receptor T-cell therapy for relapsed/refractory non-Hodgkin lymphoma: A multicenter consensus approach.

Anti-CD19 chimeric antigen receptor T-cell therapy (CART) has revolutionized the outcomes of relapsed and/or refractory B-cell non-Hodgkin lymphoma. However, CART is still limited by its availability, toxicity, and response durability. Not all patients make it to the CART infusion phase due to disease progression. Among those who receive CART, a significant number of patients experience life-threatening cytokine release syndrome toxicity, and less than half maintain a durable response with the majority relapsing in pre-existing sites of disease present pre-CART. Radiation therapy stands as a promising peri-CART and salvage treatment that can improve the outcomes of these patients. Evidence suggests that bridging radiotherapy prior to CART controls the disease during the manufacturing period, augments response rates and local control, cytoreduces/debulks the disease and decreases the severity of cytokine release syndrome, and may prolong disease-free intervals and survival especially in patients with bulky disease. Consolidative radiotherapy for residual post-CART disease alters the pattern of relapse and improves local recurrence-free and progression-free survivals. Salvage radiotherapy for relapsed post-CART disease has favorable survival outcomes when delivered comprehensively for patients with limited relapsed disease and palliates symptoms for patients with diffuse relapsed disease. The biology of the disease during the peri-CART period is poorly understood, and further studies investigating the optimal timing and dosing of radiation therapy (RT) are needed. In this review, we tackle the most significant challenges of CART, review and propose how RT can help mitigate these challenges, and provide The Mayo Clinic experts' approach on incorporating RT with CART.