post-CAR T-cell Therapy Research Articles

Outcomes of Salvage Radiotherapy in Refractory or Relapsed High-Grade B-Cell Lymphoma Patients Treated with Commercial CAR T-Cell Therapy

<h3>Purpose/Objective(s)</h3> We sought to describe our early experience of using salvage RT (SRT) in patients with high-grade B-cell lymphoma (HGBCL) who relapsed after CD19 targeted chimeric antigen receptor (CAR) T cell therapy. <h3>Materials/Methods</h3> A multi-institutional retrospective study was conducted for consecutive HGBCL patients who received axi-cel or tisa-cel CAR T-cell therapy between 2018 and 2021. Patients who relapsed following CAR T-cell therapy and received SRT were identified and analyzed using descriptive and statistical analysis. Only the first RT course was included for patients receiving >1 SRT course. Post-CAR T day 30 response, and post-CAR T best overall response, defined as the lowest disease burden measured at any time between post-CAR T-cell therapy and additional salvage therapies, were analyzed. Time to in-field progression was defined as the time from the start date of SRT until the time of in-field progression. <h3>Results</h3> 52 patients with HGBCL who received SRT post-CAR T were identified. The median age at diagnosis was 62 years (33-81 years). 32 patients received axi-cel, while 20 received tisa-cel. The median follow-up from the date of CAR T infusion was 12.5 months (range, 24 days-41.5 months) and the median follow-up from the start date of SRT was 5.7 months (range, 2 days-32.4 months). The post-CAR T day 30 and post-CAR T best response rates were 69.2% and 71.1%, respectively. The median time from CAR T-cell therapy infusion to SRT start was 4.0 months (range, 8 days-23.8 months). The median dose/fractionation were 35 Gy (range, 4-60.4 Gy) and 12.5 fractions (range, 1-33 fractions). Radiation details were incomplete for 13 patients who received SRT at outside institutions. The median time to in-field progression was 1.4 months (range, 20 days-2.3 months). Of the 46 evaluable patients, the complete response, partial response, stable disease, and in-field progression rates were 52% (n=24), 35% (n=16), 4% (n=2), and 9% (n=4), respectively. 2 of 12 patients (17%) with bulky disease (≥5 cm) had in-field recurrence versus 2 of 34 (6%), (p= 0.28) with non-bulky disease. The median OS from the start of CAR T-cell therapy was 19.6 months (95% CI: 12.7 months-not reached) and 12 months (95% CI: 7.27 months-not reached) from the start of SRT. <h3>Conclusion</h3> Our findings suggest that SRT may be a feasible and promising salvage therapeutic avenue that can provide local control post-CAR T failure. The trend toward a higher in-field progression in patients with bulky disease at relapse suggests that these patients may benefit from higher radiation doses.

ABCL-043 Prognostic Factors for High-Grade B Cell Lymphoma Patients Treated With Commercial CD19-Targeted CAR T-Cell Therapy

We hypothesized that specific clinicopathologic characteristics are correlated with survival outcomes among high-grade B cell lymphomas (HGBCL) patients treated with CD19-targeted chimeric antigen receptor (CAR) T-cell therapy. To identify the prognostic factors for survival outcomes among patients with relapsed/refractory HGBCL undergoing CAR T-cell therapy. A retrospective study was conducted for consecutive HGBCL patients who received either tisagenlecleucel (tisa-cel) or axicabtagene ciloleucel (axi-cel) CAR T-cell therapy between 2017 and 2021 at a single institution. Post-CAR T best overall response was defined as the lowest disease burden measured at any time between post-CAR T-cell therapy and additional salvage therapies. A total of 101 HGBCL patients were identified with a median follow-up of 8.3 months (range, 0.13-49.5 months) from the date of CAR T infusion. The median OS and PFS for the entire cohort were 15 months (95% CI: 8.6 months-not reached) and 4.4 months (95% CI: 3.03 months-7.23 months), respectively. The best overall response (complete response-CR and partial response) and CR rates post-CAR T were 75% (n=71) and 48% (n=46), respectively. In univariate analysis, absence of CNS involvement (OR=6.8, p=0.001), IPI score <3 at the time of apheresis (OR=3.4, p=0.003), limited-stage disease at the time of apheresis (OR=3.2, p=0.005), low LDH level at the time of apheresis (OR=5.4, p<0.001), undergoing HSCT pre-CAR T (OR=3.1, p=0.01), and not receiving salvage radiotherapy pre-CAR T (OR=4.2, p=0.03) were predictive of achieving CR post-CAR T. Sixteen patients (22%) had bulky disease (≥5 cm) as per PET/CT post-CAR T, 81% (n=13) of which were bulky pre-CAR T-bulky data was missing for 4 patients. In multivariate analysis, presence of bulky disease (≥5 cm) post-CAR T infusion was a significant prognostic factor for worse OS (HR=6.3, 95% CI: 2.9-13.6, p<0.001). Regarding PFS, high LDH at the time of apheresis, age (≥60) at the time of apheresis, and bulky disease (≥5 cm) post-CAR T infusion were significant prognostic factors for inferior PFS (HR=1.9, 95% CI: 1.02-3.8, p=0.04, HR=2.6, 95% CI: 1.2-5.6, p=0.01, HR=3.4, 95% CI: 1.6-7.5, p=0.002, respectively). Bulky disease post-CAR T is the most significant prognostic factor that can independently predict survival outcomes among HGBCL patients treated with CAR T-cell therapy.

ABCL-044 Clinical Outcomes of Commercial CD19-Targeted CAR T-Cell Therapy in Patients With Secondary Central Nervous System Lymphoma

We hypothesized that CD19-targeted chimeric antigen receptor (CAR) T-cell therapy is safe and feasible among high-grade B cell lymphoma (HGBCL) patients with secondary central nervous system (CNS) lymphoma. To evaluate the safety and efficacy of CD19-targeted CAR T-cell therapy in patients with relapsed/refractory HGBCL with secondary CNS lymphoma involvement. Patients who had active CNS involvement at the time of CAR T-cell therapy were identified retrospectively in a single-institution database of 101 consecutive HGBCL patients who received either tisagenlecleucel (tisa-cel) or axicabtagene ciloleucel (axi-cel) between 2017 and 2021. The best overall post-CAR T-cell therapy response was defined as the lowest disease burden measured at any time between post-CAR T-cell therapy and additional salvage therapies. Survival analysis was conducted using the Kaplan-Meier method. Overall, 19 HGBCL patients with active secondary CNS lymphoma (5 parenchymal, 9 leptomeningeal/CSF, 5 parenchymal and leptomeningeal) were identified, with a median age of 59 years (16-79 years) at the time of apheresis. All patients in the cohort received tisa-cel with a pre-conditioning regimen of fludarabine and cyclophosphamide. The median follow-up was 5.2 months (range, 0.8-36.8 months) from the date of CAR T-cell infusion. Ten patients had concurrent systemic involvement at the time of infusion. Seventeen patients received bridging therapy, of whom four received radiation therapy (patients/radiation field: 2/craniospinal, 1/whole brain, 1/skull base). Cytokine release syndrome occurred in 16 patients, among whom no grade 3 or higher event was reported. Neurotoxicity syndrome occurred in 9 patients, one of whom reported a grade 4 event. The best objective CNS response (complete response and partial response) rate post-CAR T infusion as per MRI was 58% (n=11): parenchymal (n=3, 60%), leptomeningeal/CSF (n=5, 56%), parenchymal and leptomeningeal (n=3, 60%). The median overall survival and progression-free survival from the start of CAR T-cell therapy were 12.7 months (95% CI: 5.4 months-not reached) and 3.9 months (95% CI: 0.93 months-not reached), respectively. Our data demonstrate that CD19-targeted CAR T-cell therapy is safe and feasible among HGBCL patients with secondary CNS lymphoma. Prospective cohort studies are required for validation.

B cell deficiency promotes the initiation and progression of lung cancer.

Currently commercialized CAR-T cell therapies targeting CD19 and BCMA show great efficacy to cure B cell malignancies. However, intravenous infusion of these CAR-T cells severely destroys both transformed and normal B cells in most tissues and organs, in particular lung, leading to a critical question that what the impact of normal B cell depletion on pulmonary diseases and lung cancer is. Herein, we find that B cell frequency is remarkably reduced in both smoking carcinogen-treated lung tissues and lung tumors, which is associated with advanced cancer progression and worse patient survival. B cell depletion by anti-CD20 antibody significantly accelerates the initiation and progression of lung tumors, which is mediated by repressed tumor infiltration of T cells and macrophage elimination of tumor cells. These findings unveil the overall antitumor activity of B cells in lung cancer, providing novel insights into both mechanisms underlying lung cancer pathogenesis and clinical prevention post CAR-T cell therapy.

Role of anakinra in the management of icans after CAR T-cell therapy for lymphoma.

e19506 Background: Chimeric antigen receptor (CAR) T-cell immunotherapy is a revolutionary treatment modality which has gained attention for its potential in treating multiple refractory hematological malignancies. Significant toxicities associated with CAR T- cell therapy remain a major concern. Cytokine release syndrome (CRS) and Immune Effector Cell Associated Neurotoxicity Syndrome (ICANS) are seen early on post CAR-T cell therapy. To date, the treatment of ICANS has largely been limited to supportive care and corticosteroids. More recently, some early clinical data investigated the use of Anakinra as a promising agent in prevention and treatment of severe ICANS. Methods: We analyze three cases in which Anakinra was used to treat high-grade ICANS concurrently with high dose steroids. Results: A 51-year-old woman with high grade DLBCL and secondary CNS involvement was treated with Tisagenlecleucel CAR-T therapy. On day 2, patient became altered and was diagnosed with ICANS Grade II. High dose steroids were started leading to resolution of ICANS. However, patient’s mentation worsened by day 7, progressing to ICANS Grade IV by day 8, and Anakinra 100 mg IV was added to the steroid regimen. By day 11, after 4 doses of Anakinra, patient’s neurotoxicity completely resolved. Patient achieved a PR by day 30 after CAR-T cell infusion. In the second case, a 65-year-old man with DLBCL and leptomeningeal involvement developed ICANS Grade II on day 1 after Tisagenlecleucel CAR-T therapy and was started on high dose steroids. By day 4, neurotoxicity worsened and progressed to ICANS Grade IV. On day 5 patient was transferred to ICU for a mechanical ventilation, and Anakinra 100 mg IV was added and continued daily for 7 days. By day 12, neurotoxicity improved to ICANS grade II and patient was extubated. Meanwhile, high dose steroids were tapered. His condition acutely worsened by day 19, prompting transfer to the ICU and re-initiation of Anakinra concurrently with steroids. His family decided against further escalation of care on day 22. Patient was transitioned to comfort care and died 23 days post CAR-T cell infusion. In the third case, a 65-year-old man with mantle cell lymphoma was treated with Brexucabtagene autoleucel CAR-T therapy. On day 8, patient developed ICANS Grade I which rapidly progressed to Grade IV. High dose steroids were started and ICANS improved to Grade II on Day 9. However, on Day 10 patient’s mentation again worsened and one dose of Anakinra 100mg IV was added to the steroid regimen. By day 11, ICANS completely resolved, and patient was ultimately discharged home on day 15. Patient was able to achieve interval CR by day 30 after CAR-T cell infusion. Conclusions: In the reported cases, ICANS improved following administration of Anakinra, adding support to the idea that Anakinra may be beneficial in treatment of high-grade ICANS. Future studies are needed to better understand the overall efficacy and the ideal timeline for administration.

Immune Reconstitution Post CAR-T - A Role for the Immunologist in Unlocking the CAR-Key?

CAR-T cell therapy utilizes a synthetic chimeric antigen receptor on T-cells to target CD19+ B-cell lineage neoplasms. A critical arm of post CAR-T cell therapy is monitoring for immune reconstitution. We hypothesized that laboratory and clinical immunologic evaluation are underutilized after CAR-T cell therapy.

Understanding the Etiology of Pancytopenias in the CAR T-Cell Therapy Setting: What We Know and What We Don't?

Chimeric antigen receptor T-cell (CAR T-cell) therapy represents an innovative and transformative therapy for patients with relapsed and/or refractory (R/R) hematological malignancies. CAR T-cell therapy was first approved in R/R diffuse large B-cell lymphoma (DLBCL) and acute lymphoblastic leukemia, today the use of CAR T-cell therapy has expanded to multiple myeloma and other lymphoma subtypes such as follicular and mantle cell lymphoma. It is also being explored in earlier lines of therapy in DLBCL. CAR T-cell therapy is associated with a unique toxicity profile and development of cytopenias post CAR T-cell therapy has been reported in all pivotal clinical trials and is now considered a related side effect. Here, we provide an in-depth evaluation of etiologies, consequences, and current management strategies for cytopenias following CAR T-cell therapy.

1163. HIV-1 NAAT Pitfalls in B-cell Lymphoblastic Leukemia Patients Following CAR-T Cell Therapy

BackgroundCAR-T Cell Therapy is approved for the treatment of pediatric patients with relapsed/refractory B-ALL. Lentiviral vector technology, highly modified from HIV-1, is used to induce stable, long-term transgene expression by integration into the host genome. This integration may interfere with HIV-1 NAAT producing false-positive results. MethodsA retrospective chart review of Pre-B ALL patients who underwent to CAR T cell therapy with KYMRIAH(tisagenlecleucel) at a single institution between January 2019 and May 2021 to assess for patients whose CAR-T infusion interfered with post-infusion HIV-1 testing. All patients had HIV NAAT pre and post CAR T-cell therapy (using platform, Roche COBAS AmpliPrep/Quantitative TaqMan HIV-1 T). Reactive HIV NAAT by Roche test were subsequently tested using different HIV-1 assay platforms to rule out or confirm HIV infection.ResultsWe report three cases in which interpretation of HIV-1 NAAT testing was complicated by CAR T cell therapy. Case 1: 1-year-old male with refractory infantile leukemia was found to have a reactive HIV NAAT post CAR-T in routine infectious screening prior to SCT. Case 2: 3-year-old refractory ALL planned for SCT who had a reactive HIV NAAT 9 months post CART. Fourth-generation HIV-1 testing (targeting the p24 antigen and anti-HIV-1 antibodies) was negative pre and post CART. Viral loads were also undetectable indicating false-positive post-CAR-T HIV-1 NAT test results. Case 3: 21-year-old sexually active female with relapsed B cell ALL. Post CAR-T HIV NAAT was reactive, and a quantitative viral load was positive at 176 copies/mm3 one day prior to start of stem cell transplant conditioning regimen. Aptima HIV testing is typically used as confirmatory test for CAR-T associated false positive HIV NAT cases, but surprisingly, the Aptima test was also reactive. Additional testing with Abbott m2000 Realtime HIV-1 assay and 4th generation p24 antigen-based testing were both negative. Table 1 Summary of reported patients with false-positive HIV-1 NAAT test results following CAR T cell therapy and Table 2, HIV platforms used for screening and diagnosis with interpretations following CAR T cell therapy.ConclusionClinicians need to be aware of potential false-positive HIV testing after CAR-T therapy. HIV testing platforms with targets not used in lentiviral vectors (4th generation test/P24, or Abbott test/integrase region) are highly recommended to avoid delays in subsequent therapy and unwanted stress for the patients, families, and cliniciansDisclosures All Authors: No reported disclosures

Triple MAPK Inhibition Salvaged a Relapsed Post BCMA CAR-T Cell Therapy in Multiple Myeloma Patient with BRAF V600E Dominant Clone

Background:Multiple Myeloma (MM) is a progressive plasma cell neoplasm characterized by heterogeneous clonal expansion. Despite numerous targeted therapy options, failing anti-BCMA CAR-T cell therapy represents a challenging treatment course with dismal prognosis. 53% of relapsed/refractory (rr) MM patients have shown emerging clones harboring mutations within the MAPK signaling pathway including the targetable BRAF V600E in 7% of cases. Allosteric kinase inhibition of MAPK pathway with BRAF monomer selective inhibitors +/- MEK inhibitor have been frequently attempted with rrMM patients with equivocal outcome on both disease progression and survival. This could be ascribed to the feedback activation of the pathway via BRAF dimers induction. In solid tumor contexts, a recent study has revealed that the multi-kinase inhibitor regorafenib is a potent and selective inhibitor of dimeric BRAF. Moreover, the study demonstrated overcoming of this negative feedback by combining two inhibitors targeting BRAF in its monomeric and its dimeric form, respectively, with MEK inhibition leading to more efficacious and tolerable treatment (Adamopoulos C. et al. Cancer Discov. 2021). Here, we show the applicability, effectiveness, and tolerability of the aforementioned triple therapy strategy in hematological malignancy context to salvage post BCMA CAR-T cell therapy in a BRAF V600E rrMM patient.Material and Methods:CD138 + selected cells were collected from bone marrow (BM) and patient's plasmacytoma before and after CAR-T cell therapy relapse, respectively. Samples were processed using the standard GATK 4 workflows and a consensus mutation calling approach was used to call somatic mutations using a matched normal obtained from peripheral blood. PhyloWGS (Deshwar et al, Genome Biol 2015) was then used to perform intra-tumor heterogeneity modeling and phylogeny estimation.CD138 + selected cells from BM of rrMM patient were treated with encorafenib (50nM) and binimetinib (250 nM) +/- regorafinib (1mM) for 48 hours, cells were harvested, lysed and immunoblotted with BRAF V600E and pERK antibodies.In parallel, rrMM patient BM selected CD138 + cells' sensitivity to MAPK inhibitors were assessed by Travera. Cells are incubated with different inhibitors at varying concentrations and combinations for 15 hours before having their single-cell mass distributions measured. Sensitivity is then characterized by the relative statistical difference (Hellinger distance) between conditions and untreated controls.A rrMM patient was started on targeted triple therapy using the following combination: BRAF monomer-inhibitor, dabrafenib (100mg, orally twice daily), a MEK-inhibitor, trametinib (1.5mg, orally for 21/28 days daily), and a BRAF dimer inhibitor, regorafenib (40mg, orally once daily).Results:Whole Exome Sequencing (WES) showed a BRAF V600E mutation was present prior to CAR-T cell therapy and persisted through subsequent treatments. The variant allele frequency of the mutation was 41% post CAR-T cell therapy (Figure 1A).Western blot of CD138 + cells confirmed BRAF V600E mutation with a specific antibody, and showed ERK phosphorylation, which was inhibited with trametinib. Longer exposure to trametinib confirmed a feedback loop activating MAPK which was abrogated with the BRAF dimer inhibitor regorafenib (Figure 1B).Travera analysis showed CD138 + cells' sensitivity to the combination of trametinib at 5mM, and dabrafenib at 1µM. Adding regorafenib at 1µM could slightly improve the response compared to the double combination. (Figure 1C).Clinically, three months of the triple therapy administration has led to prompt reduction in subcutaneous skin lesions as well as 80% reduction in free lambda chain (Figure 1D). Furthermore, the patient exhibited good tolerance to all three medications with minimal side effects (grade 1 fatigue). The treatment regimen allowed the patient to carry out activities of daily living and resume work.Conclusion:We have shown the applicability, effectiveness, and tolerability of the triple MAPK inhibition in a hematological malignancy context to salvage post BCMA CAR-T cell therapy in a rrMM patient with BRAF V600E mutation. Also, we have revealed the power of routine WES in tracking clonal evolution, and identifying targetable mutations which allows tailoring of therapeutics for MM patients. [Display omitted] DisclosuresStevens: Travera: Current Employment. Parekh: Foundation Medicine Inc: Consultancy; Amgen: Research Funding; PFIZER: Research Funding; CELGENE: Research Funding; Karyopharm Inv: Research Funding.

Dynamics and Management of CAR-T Cells Associated Cytopenias: A Single-Center Experience

* Martín-Rojas RM and Bailén R equally contributed to this work.INTRODUCTIONCAR-T cell therapy is approved by the European Medicines Agency (EMA) and the Federal Drugs Administration (FDA) for the treatment of adult patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) after two or more lines of systemic therapy and for children and adults up to age 25 with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). Prolonged cytopenias have been reported in up to 30-60% of patients undergoing CAR-T cell therapy, but information about its pathophysiology, dynamics and clinical impact is scarce.METHODSWe conducted a retrospective study of consecutive patients undergoing commercial CAR-T cell therapy in our center between June 2019 and March 2021. We analyzed peripheral blood cell counts pre-lymphodepletion, at admission and during the first year of follow-up. This information was correlated with clinical data and analytical parameters. This study was approved by our institutional Ethics Committee and it was performed in compliance with the Declaration of Helsinki. Data were analyzed using IBM SPSS Statistics version 24 and GraphPad Prism version 8.4.3.RESULTSA total of 40 patients were included, 37 with diagnosis of R/R DLBCL and 3 with B-ALL (Table 1). 6-month overall survival was 71% for patients with lymphoma and 33.3% for patients with B-ALL.The dynamics of neutrophil and platelet counts is shown in Figure 1. Median hospitalization duration was 25 days (range: 11-241) and, during this period, 10 patients (25%) required transfusion of 5 or more red cell concentrates (18.9% lymphoma vs. 100% B-ALL; p=0.002), 11 patients (27.5%) required 5 or more platelet transfusions (21.6% lymphoma vs. 100% B-ALL; p=0.003) and 6 patients needed 5 or more doses of G-CSF (13.5% lymphoma vs. 33.3% B-ALL; p=0.3).On day +28 post CAR-T cell therapy, 26 patients (65%) showed persistent profound cytopenias not related with marrow infiltration (absolute neutrophil counts ≤500/μL and/or platelets ≤50000/ μL): a total of 4 patients (15.4%) had neutropenia, 8 patients (31%) thrombopenia and 14 patients (54%) both. 100% of patients with B-ALL maintained aplasia at day +28, with no evidence of disease.Due to persistent cytopenias at discharge, 22 patients (64.7%) received outpatient treatment with G-CSF (20 lymphoma vs. 2 B-ALL; p=0.41), 13 patients (38.2%) received erythropoietin (11 lymphoma vs. 2 B-ALL; p=0.16) and 12 patients (35.3%) were treated with thrombopoietin analogues (10 lymphoma vs. 2 B-ALL; p=0.13). One patient with B-ALL received a boost of selected CD34+ cells from her donor (Table 1).On day +90 post CAR-T cell therapy, 7 patients (26.9%) showed profound cytopenias and, on day +180 it increased to 9 patients (47.4%). None of the 9 patients who were alive at one year follow-up, presented profound cytopenias at this point (Figure 2).Profound cytopenias on day +28 were related to bridging therapy (p=0.04), bone marrow infiltration at diagnosis (p=0.05), higher lymphodepletion doses (p=0.05), evidence of a bulky mass pre-lymphodepletion (p=0.007), development of cytokine release syndrome (CRS) (p=0.012), ICU admission (p=0.07), infectious complications (p=0.008) and having less than 2000/ μL neutrophils pre-lymphodepletion (p=0.04). A multivariate analysis using logistic regression identified higher doses of lymphodepletion (OR 7.57; 95% CI 1.14-50.4; p=0.03) and bone marrow infiltration at diagnosis (OR 7.31; 95% CI 0.97-54.95; p=0.05) as the only independent predictors factors of these cytopenias.Profound cytopenias on day +180 were related to bone marrow infiltration at diagnosis (p=0.02), having received bridging therapy (p=0.05) and lower pre-lymphodepletion lymphocyte counts (p=0.04) and folate levels (p=0.05). None of these variables reached statistical significancy on the multivariate analysis.CONCLUSIONSProfound cytopenias not associated with progression or relapse were a frequent complication after commercial CAR-T cell therapy, with 65% of cases on day +28, being the lymphodepletion dose and bone marrow infiltration at diagnosis independent predictors for its development. Beyond day +28, up to 47% patients showed profound cytopenias. A higher number of patients and longer follow-up are needed to confirm our findings and identify other potential prognosis factors for these cytopenias. [Display omitted] DisclosuresMartín-Rojas: Pfizer: Membership on an entity's Board of Directors or advisory committees; Celgene-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees. Bailen: Pfizer, Kite-Gilead, Gilead: Honoraria. Oarbeascoa: Gilead: Honoraria, Speakers Bureau. Kwon: Novartis, Celgene, Gilead, Pfizer: Consultancy, Honoraria.

Cardiovascular Side Effects of Chimeric Antigen Receptor (CAR) T-Cell Products: A Single Center Experience in a Minority Rich, Ethnically Diverse Real-World Cohort

Introduction:Axicabtagene ciloleucel (Axi-Cel), an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy demonstrated efficacy in patients with refractory large B cell lymphoma when conventional treatments failed. Cardiovascular side effects of CAR-T therapy that have been noticed so far include hypotension, left ventricular dysfunction, heart failure and cardiogenic shock in settings of CRS. We aimed to assess the cardiovascular side effects in a racially/ ethnically diverse patient population who underwent CAR-T cell therapy.Methods:This study included thirty-four consecutive adult patients who underwent treatment with CAR-T cell product Axi-Cel at an academic health system between 2018-2021. We performed detailed chart reviews and collected information related to the age, gender, hematological malignancy diagnosis, other medical comorbidities, therapeutic regimens, pretreatment cardiac risk factors, development of CRS with grading , pre and post treatment electrocardiograms ( EKG), transthoracic echocardiograms( TTE) , death, cause of death, and duration between administration of CAR-T products and death of the patients . We collected data pertaining to development of hypotension, EKG changes, arrhythmias, left ventricular systolic dysfunction, heart failure (HF), acute cardiac syndrome (ACS), troponin elevation, echocardiographic changes post CAR-T cell therapy, and follow up visits after 60 days to get information pertaining to development of hypotension, tachycardia or SOB, need for further cardiac work up, and cardiology referral.Results:Mean age of our study participants was 65 years ranging between ages of 30 and 84 years with 38 % (13/34) female and 62% (21/34) male study participants. Study population was predominantly Hispanic, white and African American with percentages of 35% (12/34), 32% (11/34), 26 %(9/34) respectively followed by categories Asian 2.9% (1/34) and other at 2.9 %( 1/34). Sixty seven percent (22/37) patients had primary diffuse large B cell lymphoma (DLBCL) and 32% (11/34) had different primary malignancy with transformation into DLBCL. Thirty eight percent individuals had received autologous stem cell transplant. Sixty one percent (21/34) of our study participants developed cytokine release syndrome, with CRS grades 1-3 in 57% (12/29), 25% (08/21) and 4.7% (1/21) respectively. Thirty four percent (09/34) study participants died after cellular therapy. Septic shock and disease progression each were primary cause of death in 55 % (5/9) of patients, followed by respiratory failure in 22% (2/9) and ventricular fibrillation leading to cardiac arrest in 11% (1/9) of the patients. Mean duration of time between administration of therapy and death was 70 days. The cardiovascular effects noted immediately post CAR-T treatment and observations from follow up oncology visits are listed in Table 1. Troponin elevation was noticed in two study participants in settings of CRS, but one participant exhibited troponin elevation in absence of CRS. Seventeen percent of patients (6/34) developed left ventricular dysfunction after Axi-Cel. Most of them had concurrent CRS but one case of fatal heart failure occurred in absence of CRS. Three patients developed fatal arrhythmias post CAR-T therapy (1- Non sustained ventricular tachycardia in settings of CRS, 2- supraventricular tachycardia in settings of CRS, and 3- ventricular tachycardia needing defibrillation without CRS). Only one patient developed ACS in settings of CRS which lead to patient's demise.Conclusions: In a real world, minority rich cohort, we observed that a significant number of our patients had preexisting cardiovascular findings including abnormal EKG (30% excluding sinus tachycardia) or abnormal echocardiographic findings (46%). Hypotension (68%) and sinus tachycardia (59%) were the most commonly observed cardiovascular toxicities. Although Axi-Cel was in general safe and well tolerated, we observed cardiovascular side effects associated with and independent of CRS. Notably, six patients (17%) developed left ventricular dysfunction including one fatality which was independent of CRS. There was only one fatal coronary syndrome and two cases of troponin elevation in our series. Our study stresses the importance of a thorough cardio-oncology evaluation before proceeding with cellular therapies as well as involved follow up during and after hospitalization. [Display omitted] DisclosuresGritsman: iOnctura: Research Funding. Shastri: Kymera Therapeutics: Research Funding; Onclive: Honoraria; Guidepoint: Consultancy; GLC: Consultancy. Verma: BMS: Research Funding; GSK: Research Funding; Incyte: Research Funding; Medpacto: Research Funding; Curis: Research Funding; Eli Lilly: Research Funding; Stelexis: Consultancy, Current equity holder in publicly-traded company; Novartis: Consultancy; Acceleron: Consultancy; Celgene: Consultancy; Stelexis: Current equity holder in publicly-traded company; Throws Exception: Current equity holder in publicly-traded company.

Iomab with Adoptive Cellular Therapy (Iomab-ACT): A Pilot Study of 131-I Apamistamab Followed By CD19-Targeted CAR T-Cell Therapy for Patients with Relapsed or Refractory B-Cell Acute Lymphoblastic Leukemia or Diffuse Large B-Cell Lymphoma

Background: Autologous CD19-targeted chimeric antigen receptor-modified (CAR) T-cell therapy leads to complete responses (CR) in patients (pts) with (w/) relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL, >80% CR rate) and diffuse large B-cell lymphoma (DLBCL, ~40-55% CR rate). However, following fludarabine/cyclophosphamide (Flu/Cy) conditioning and CAR T-cell therapy w/ a CD28 costimulatory domain (e.g. 19-28z CAR T-cells), rates of grade ≥3 ICANS and grade ≥3 cytokine release syndrome (CRS) in pts w/ R/R DLBCL and morphologic R/R B-ALL exceed 30%. CRS and ICANS are associated w/ considerable morbidity, including increased length of hospitalization, and may be fatal. Host monocytes appear to be the major reservoir of cytokines driving CRS and ICANS post-CAR T-cell therapy (Giavradis et al. and Norelli et al., Nature Medicine, 2018). Circulating monocytic myeloid-derived suppressor cells (MDSCs) may also blunt efficacy of 19-28z CAR T-cells in R/R DLBCL (Jain et al., Blood, 2021).The CD45-targeted antibody radioconjugate (ARC) 131-I apamistamab is being investigated at myeloablative doses as conditioning prior to hematopoietic cell transplantation in pts w/ R/R acute myeloid leukemia. However, even at low doses (4-20 mCi), transient lymphocyte and blast reduction are observed. Preclinical studies in C57BL/6 mice demonstrate low-dose anti CD45 radioimmunotherapy (100 microCi) transiently depletes >90% lymphocytes, including CD4/CD8 T-cells, B-cells, NK cells, and T-regs, as well as splenocytes and MDSCs, w/ negligible effect on bone marrow (BM) hematopoietic stem cells (Dawicki et al., Oncotarget, 2020). We hypothesized a higher, yet nonmyeloablative dose of 131-I apamistamab may achieve more sustained, but reversible depletion of lymphocytes and other CD45 + immune cells, including monocytes thought to drive CRS/ICANS. We additionally hypothesized this approach (vs Flu/Cy) prior to CAR T-cell therapy would promote CAR T-cell expansion while reducing CSF levels of monocyte-derived cytokines (e.g. IL-1, IL-6, and IL-10), thus lowering the risk of severe ICANS (Fig 1A).Study design and methods: We are conducting a single-institution pilot study of 131-I apamistamab in lieu of Flu/Cy prior to 19-28z CAR T-cells in adults w/ R/R BALL or DLBCL (NCT04512716; Iomab-ACT); accrual is ongoing. Pts are eligible for leukapheresis if they are ≥18 years-old w/ R/R DLBCL (de novo or transformed) following ≥2 chemoimmunotherapy regimens w/ ≥1 FDG-avid measurable lesion or B-ALL following ≥1 line of multi-agent chemotherapy (R/R following induction/consolidation; prior 2 nd/3 rd gen TKI required for pts w/ Ph+ ALL) w/ ≥5% BM involvement and/or FDG-avid extramedullary disease, ECOG performance status 0-2, and w/ appropriate organ function. Active or prior CNS disease is not exclusionary. Pts previously treated w/ CD19-targeted CAR T-cell therapy are eligible as long as CD19 expression is retained.See Fig 1B/C: Post-leukapheresis, 19-28z CAR T-cells are manufactured as previously described (Park et al., NEJM, 2018). Bridging therapy is permitted at investigator discretion. Thyroid blocking is started ≥48h pre-ARC. 131-I apamistamab 75 mCi is administered 5-7 days pre-CAR T-cell infusion to achieve total absorbed marrow dose ~200 cGy w/ remaining absorbed dose <25 cGy at time of T-cell infusion. 19-28z CAR T-cells are administered as a single infusion (1x10 6/kg, B-ALL pts; 2x10 6/kg, DLBCL pts).The primary objective is to determine safety/tolerability of 131-I apamistamab 75 mCi given prior to 19-28z CAR T-cells in pts w/ R/R B-ALL/DLBCL. Secondary objectives include determining incidence/severity of ICANS and CRS, anti-tumor efficacy, and 19-28z CAR T-cell expansion/persistence. Key exploratory objectives include describing the cellular microenvironment following ARC and 19-28z CAR T-cell infusion using spectral cytometry, as well as cytokine levels in peripheral blood and CRS.The trial utilizes a 3+3 design in a single cohort. If dose-limiting toxicity (severe infusion-related reactions, treatment-resistant severe CRS/ICANS, persistent regimen-related cytopenias, among others defined in protocol) is seen in 0-1 of the first 3 pts treated, then up to 6 total (up to 3 additional) pts will be treated.We have designed this study to provide preliminary data to support further investigation of CD45-targeted ARCs prior to adoptive cellular therapy. [Display omitted] DisclosuresGeyer: Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals, Inc: Research Funding; Amgen: Research Funding. Geoghegan: Actinium Pharmaceuticals, Inc: Current Employment. Reddy: Actinium Pharmaceuticals: Current Employment, Current holder of stock options in a privately-held company. Berger: Actinium Pharmaceuticals, Inc: Current Employment. Ludwig: Actinium Pharmaceuticals, Inc: Current Employment. Pandit-Taskar: Bristol Myers Squibb: Research Funding; Bayer: Research Funding; Clarity Pharma: Research Funding; Illumina: Consultancy, Honoraria; ImaginAb: Consultancy, Honoraria, Research Funding; Ymabs: Research Funding; Progenics: Consultancy, Honoraria; Medimmune/Astrazeneca: Consultancy, Honoraria; Actinium Pharmaceuticals, Inc: Consultancy, Honoraria; Janssen: Research Funding; Regeneron: Research Funding. Sauter: Genmab: Consultancy; Celgene: Consultancy, Research Funding; Precision Biosciences: Consultancy; Kite/Gilead: Consultancy; Bristol-Myers Squibb: Research Funding; GSK: Consultancy; Gamida Cell: Consultancy; Novartis: Consultancy; Spectrum Pharmaceuticals: Consultancy; Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding. OffLabel Disclosure:131-I apamistamab and 19-28z CAR T-cells are investigational agents in treatment of ALL and DLBCL

Patient-reported efficacy and toxicity in CAR T-cell therapy for multiple myeloma via Internet-based platforms.

e20024 Background: Chimeric antigen receptor (CAR) T-cell therapies are in clinical development for multiple myeloma (MM). Patient-reported outcomes (PRO) can provide valuable insights into how patients perceive the relative risks and benefits of these new therapies. This study aimed to evaluate CAR T-cell therapy in relapsed/refractory MM (RRMM) patients. Methods: We utilized HealthTree Cure Hub for Multiple Myeloma to analyze patient-reported data from 17 patients who participated in CAR T-cell clinical trials. In this study, we examined total prior lines of therapy, time to next treatment (TNT), overall survival (OS), patient-reported toxicity and severity, and patient-reported outcomes (myeloma reduction or no myeloma reduction). The Kaplan-Meier model was used to calculate overall survival. The severity of toxicity was assessed using a 1 to 10 scale (1 = minimal and 10 = severe). Results: Our analysis of the 17 patients found a median of 10 lines of therapy prior to CAR T-cell treatment. Ten patients had no new treatments to report at the time of this study, 5 patients reported new treatment with a median TNT of 15.9 months, and for 2 patients we did not have data. The median OS was 24 months (95% CI 21-30 months). The probability that a patient remained alive at 2 years was 0.48 (95% CI: 0.195, 1). Four of the 17 patients died with a median of 22.5 months post-CAR T-cell therapy. Two of these patients died without reporting a change in treatment. There was a total of 36 different side effects reported by patients as a result of the therapy. Table lists the side effects experienced by 2 or more patients and the corresponding average severity. Finally, 76% of patients treated with CAR T-cell therapy reported a reduction in their myeloma, four of these patients had m-protein levels reported and saw an average decrease of 93%. Of the remaining patients, three (18%) reported little to no reduction in their myeloma, and one patient (6%) did not know their response at the time of this analysis. Conclusions: Our investigation of patient-reported results suggests an emerging and viable immunotherapy treatment option for RRMM, with encouraging outcomes and manageable side effects. Future directions include analysis of genetics and treatment options post CAR T-cell therapy. These data highlight the expedited benefit of using PROs via an online platform, like HealthTree Cure Hub, to assess new therapeutics in the research community.[Table: see text]

Allogeneic Hematopoietic Cell Transplantation Is Critical to Maintain Remissions after CD19-CAR T-Cell Therapy for Pediatric ALL: A Single Center Experience

CD19-CAR T-cell therapy has shown remarkable efficacy in pediatric patients with relapsed and/or refractory B-cell acute lymphoblastic leukemia (r/r ALL). Despite high short-term remission rates, many responses are not durable and the best management of patients who achieve a complete response (CR) post-CAR T-cell therapy remains controversial. In particular, it is unclear if these patients should be observed or proceed to consolidative allogeneic hematopoietic cell transplantation (HCT). To address this question, we reviewed the clinical course of all patients (n=22) who received either an investigational CAR T-cell product (Phase I study: SJCAR19 [NCT03573700]; n=12) or tisagenlecleucel (n=10) at our institution. The investigational CD19-CAR T cells were generated by a standard cGMP-compliant procedure using a lentiviral vector encoding a 2nd generation CD19-CAR with a FMC63-based CD19 binding domain, CD8a stalk and transmembrane domain, and 41BB.ζ signaling domain. Patients received therapy between 8/2018 and 3/2020. All products met manufacturing release specifications. Within the entire cohort, median age at time of infusion was 12.3 years old (range: 1.8-23.5) and median pre-infusion marrow burden using flow-cytometry minimal residual disease (MRD) testing was 6.8% (range: 0.003-100%; 1 patient detectable by next-generation sequencing [NGS] only). All patients received lymphodepleting chemotherapy (fludarabine, 25mg/m2 daily x3, and cyclophosphamide, 900mg/m2 daily x1), followed by a single infusion of CAR T-cells. Phase I product dosing included 1x106 CAR+ T-cells/kg (n=6) or 3x106 CAR+ T-cells/kg (n=6). Therapy was well tolerated, with a low incidence of cytokine release syndrome (any grade: n=10; Grade 3-4: n=4) and neurotoxicity (any grade: n=8; Grade 3-4: n=3). At 4-weeks post-infusion, 15/22 (68.2%) patients achieved a CR in the marrow, of which 13 were MRDneg (MRDneg defined as no detectable leukemia by flow-cytometry, RT-PCR and/or NGS, when available). Among the 2 MRDpos patients, 1 (detectable by NGS only) relapsed 50 days after CAR T-cell infusion and 1 died secondary to invasive fungal infection 35 days after infusion. Within the MRDneg cohort, 6/13 patients proceeded to allogeneic HCT while in MRDneg/CR (time to HCT, range: 1.8-2.9 months post-CAR T-cell infusion). All 6 HCT recipients remain in remission with a median length of follow-up post-HCT of 238.5 days (range 19-441). In contrast, only 1 (14.3%) patient out of 7 MRDneg/CR patients who did not receive allogeneic HCT, remains in remission with a follow up of greater 1 year post-CAR T-cell infusion (HCT vs. no HCT: p&amp;lt;0.01). The remaining 6 patients developed recurrent detectable leukemia within 2 to 9 months post-CAR T-cell infusion (1 patient detectable by NGS only). Notably, recurring leukemia remained CD19+ in 4 of 5 evaluable patients. All 4 patients with CD19+ relapse received a 2nd CAR T-cell infusion (one in combination with pembrolizumab) and 2 achieved MRDneg/CR. There were no significant differences in outcome between SJCAR19 study participants and patients who received tisagenlecleucel. With a median follow up of one year, the 12 month event free survival (EFS) of all 22 patients is 25% (median EFS: 3.5 months) and the 12 month overall survival (OS) 70% (median OS not yet reached). In conclusion, infusion of investigational and FDA-approved autologous CD19-CAR T cells induced high CR rates in pediatric patients with r/r ALL. However, our current experience shows that sustained remission without consolidative allogeneic HCT is not seen in most patients. Our single center experience highlights not only the need to explore maintenance therapies other than HCT for MRDneg/CR patients, but also the need to improve the in vivo persistence of currently available CD19-CAR T-cell products. Disclosures Sharma: Spotlight Therapeutics: Consultancy; Magenta Therapeutics: Other: Research Collaboration; CRISPR Therapeutics, Vertex Pharmaceuticals, Novartis: Other: Clinical Trial PI. Velasquez:St. Jude: Patents &amp; Royalties; Rally! Foundation: Membership on an entity's Board of Directors or advisory committees. Gottschalk:Patents and patent applications in the fields of T-cell &amp; Gene therapy for cancer: Patents &amp; Royalties; TESSA Therapeutics: Other: research collaboration; Inmatics and Tidal: Membership on an entity's Board of Directors or advisory committees; Merck and ViraCyte: Consultancy.

A Characterization of Bridging Therapies Leading up to Commercial CAR T-Cell Therapy

A Characterization of Bridging Therapies Leading up to Commercial CAR T-Cell Therapy

Patient-Reported Neuropsychiatric Outcomes of Long-Term Survivors after Chimeric Antigen Receptor (CAR)-T Cell Therapy

CD19-targeted chimeric antigen receptor (CAR)-T cell therapy is a novel treatment with promising results for patients with relapsed/refractory lymphoid malignancies. CAR-T cell therapy has known early toxicities of cytokine release syndrome (CRS) and neurotoxicity, but little is known about long-term neuropsychiatric adverse effects. We have utilized patient-reported outcomes (PROs), including PROMIS®measures, to assess outcomes of patients with relapse/refractory chronic lymphocytic leukemia (CLL), non-Hodgkin lymphoma (NHL), and acute lymphoblastic leukemia (ALL) who were treated with CD19-targeted CAR-T cells on a clinical trial in our institution (NCT01865617) and survived at least one year after treatment. Between October 2018 to February 2019, 52 patients (at their 1-5 year anniversary after CAR-T cell therapy) were sent a questionnaire. The questionnaire included the PROMIS Scale v1.2-Global Health and the PROMIS-29 Profile v2.1, as well as 30 additional questions, including questions pertaining to cognitive function. As of February 28, 2019, 40 questionnaires were returned (76.9% response rate) and were included in the analysis. Patients' characteristics are summarized in Table 1. Cognitive function was assessed by asking if patients had experienced difficulties with concentration, finding words, memory, or solving problems since their CAR-T cell therapy; answer "yes" to each of the questions received "1" point to determine the total cognitive difficulty score (0-4). PROMIS measures are standardized to a T-score metric, with a score of 50 representing the general US population mean. Clinically meaningful differences were defined as a 5-point difference in scores (1/2 standard deviation). The cohort's self-reported cognitive difficulties and PROMIS mean T scores are shown in Table 2. Mean T scores of PROMIS domains of Global Mental health, Global Physical Health, Social Function, anxiety, depression, fatigue, pain and sleep disturbance were not clinically meaningfully different from the mean in the general US population. However, 19 participants (47.5%) reported at least one cognitive difficulty and/or clinically meaningful depression and/or anxiety (Figure 1), and 7 participants (17.5%) scored ≤ 40 in Global Mental Health, indicating at least one standard deviation worse than the general population mean. On risk factor analysis, younger age was found to be associated with worse Global Mental Health (p=0.02), anxiety (p=0.01) and depression (p=0.01). Anxiety prior to CAR-T cell therapy was associated with increased likelihood of anxiety after CAR-T cell therapy (p=0.001). Multivariate analysis confirmed association between age and PROMIS Global Mental Health score (p=0.03). 15 participants (37.5%) reported cognitive difficulties post CAR-T cell therapy. On multivariate analysis, depression prior to CAR-T cell therapy was statistically significantly associated with higher likelihood of self-reported cognitive difficulties after CAR-T therapy (p=0.02) and there was a trend for association between acute neurotoxicity after CAR-T cell infusion and self-reported long-term cognitive difficulties (p=0.08). Having more cognitive difficulties was associated with worse Global Mental Health (p=0.0001) and worse Global Physical Health (p= 0.01). Similarly, worse scores for pain interference, sleep disturbance, fatigue, depression, anxiety, physical function, and social function were associated with more long-term self-reported cognitive difficulties (p=0.007,p=0.0003, p=0.00006, p=0.01, p=0.0007, p=0.003, p=0.0004 respectively). Our study demonstrates overall good neuropsychiatric outcomes in 40 long-term survivors after CAR-T cell therapy. However, despite good overall mean scores, nearly 50% of patients in the cohort reported at least one negative neuropsychiatric outcome (anxiety, depression or cognitive difficulty), and almost 20% scored at least one standard deviation lower than the general US population mean in Global Mental Health, indicating that there is a significant number of patients who would likely benefit from mental health services following CAR-T cell therapy. Younger age, anxiety and depression pre-CAR-T cell therapy, and acute neurotoxicity after CAR-T cell infusion may be risk factors for long-term neuropsychiatric problems in this patient population. Larger studies are needed to confirm these findings. Disclosures Shaw: Therakos: Other: Speaker Engagement. Lee:AstraZeneca: Research Funding; Incyte: Research Funding; Syndax: Research Funding; Amgen: Research Funding; Novartis: Research Funding; Takeda: Research Funding; Kadmon: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding. Turtle:T-CURX: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Other: Ad hoc advisory board member; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Allogene: Other: Ad hoc advisory board member; Humanigen: Other: Ad hoc advisory board member; Juno Therapeutics: Patents &amp; Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Ad hoc advisory board member. Maloney:Juno Therapeutics: Honoraria, Patents &amp; Royalties: patients pending , Research Funding; A2 Biotherapeutics: Honoraria, Other: Stock options ; Celgene,Kite Pharma: Honoraria, Research Funding; BioLine RX, Gilead,Genentech,Novartis: Honoraria.

CAR22/19 Cocktail Therapy for Patients with Refractory/Relapsed B-Cell Malignancies

▪CD19 CAR T-cell (CAR-19) therapy have elicited great clinical responses in B-cell malignancies. However, CD19-negative relapse has emerged as a major challenge for the long-term disease control post CAR-19 therapy and conferred a dismal outcome to these pts. Recently, co-targeting of CD19/CD20, CD19/CD22 or CD19/CD123 has been proposed as a strategic approach to overcome antigen loss relapse after CAR-19 therapy. However, the infusion scheme has not yet been defined, the efficacy to avoid antigen escape has not been tested, and its toxicity remains to be assessed. Furthermore, the impact of genetic abnormalities on the outcome post CAR T-cell therapy has not been fully elucidated.We conducted an open-label, single-center and single-arm pilot study of sequential infusion of third generation CAR T-cell “cocktail” comprising both anti-CD22 and anti-CD19 CAR T-cells, which was registered with Chinese Clinical Trial Registry (ChiCTR, number ChiCTR-OPN-16008526).Between March 2016 and January 2018, a total of 89 eligibility pts completed CAR-22/19 “cocktail” infusion and were included for analysis. Of 89 pts (median age 36 years; range, 9-71), 51 had refractory/relapsed (R/R) B-cell acute lymphoblastic leukemia (B-ALL) and 38 had R/R B-cell non-Hodgkin lymphoma (B-NHL). The cutoff date for data collection was April 30, 2018, with a median follow-up of 7.6 months (mos) for B-ALL and 5.4 mos for B-NHL.CAR-22 and CAR-19 cells were given separately in 2 divided doses (range, 1 to 4 for CAR-22, and 1 to 5 for CAR-19) with a dose-escalation infusion. Eighty-one pts firstly received CAR-22 infusion, and then CAR-19 infusion, while 8 pts received CAR-19 first and CAR-22 later. B-ALL pts received 2.73±1.19×106/kg CAR-22 and 2.61±1.45×106/kg CAR-19; B-NHL pts received instead higher doses, i.e. 5.28±2.44 ×106/kg CAR-22 and 5.14±2.06 ×106/kg CAR-19.Of the 50 evaluable B-ALL pts, 48 (96.0%) achieved complete remission (CR)/or CR with incomplete count recovery (CRi) at the day 30 assessment. By sensitive multi-parameter flow cytometry (MFC) assay, 47 (94.0%) achieved MRD-negative CR/CRi. At a median follow-up of 7.6 mos (range, 1.3 to 22.2), the progression-free survival (PFS) of all B-ALL pts was 12.0 mos and the overall survival (OS) was not reached. Of the 13 pts with Ph+ B-ALL, 6 of whom had T315I mutation, 11 (84.6%) achieved MRD-negative CR/CRi. The PFS was 15.4 months, and the OS was not reached at a median follow-up of 13.5 months (range, 3 to 22.5). Of the 6 pts with MLL translocations (mainly MLL-AF6), 66.7% were progression-free and the median PFS was not reached. However, among pts with Ph-like ALL, the PFS was only 4.6 months. A total of 23 pts relapsed, however, antigen loss of CD19 and CD22 was not detected by MFC. Forty-Seven pts (92.2%) experienced cytokine release syndrome (CRS) and 11 (21.6%) had severe CRS (≥ grade 3). Except for 1 pt, all the severe cases were reversible. Seven pts (13.7%) developed neurotoxicity.At a minimum follow-up of 3 months, the overall response rate (ORR) and CR rate in 36 evaluable B-NHL pts was 72.2% and 50%, respectively. At the cutoff date for data collection, 50.5% of all pts remained progression-free. A total of 8 pts (26.7%) had relapsed with a median PFS of 2.6 months. Re-biopsy and immunophenotyping was performed in 3 relapsed pts and antigen loss of CD19 or CD22 was not detected. At a median follow-up of 5.4 months (range, 3.0 to 16.2), both PFS and OS of all pts were not reached. Of the 9 pts with MYC translocation, 8 had a response and 7 maintained their responses with a median follow-up of 10.1 months, including all the 4 pts with “double-hit” lymphoma (concurrently carrying MYC and BCL2 or BCL6 translocations). Of the 10 pts with del(17p) or TP53 mutation, 8 (80.0%) had a clinical response. With a median follow-up of 5.3 months, the PFS was 3.3 months, and 45.0% of these pts were progression-free. All the B-NHL pts experienced CRS, but only 21.1% had severe (grade 3 or 4), but reversible CRS and 13.2% developed reversible neurotoxicity.In summary, our results indicated that infusion of third generation CD22/19 CAR T-cell “cocktail” is feasible and safe for pts with B-cell malignancies. Co-targeting to CD19/CD22 is a promising approach for overcoming antigen escape relapse of CAR-19 therapy, but this remain to be fully tested. The treatment response predictive value of distinct genetic subtypes for CAR T-cell therapy should be considered for selection of pts for personalized immunotherapy. DisclosuresNo relevant conflicts of interest to declare.