CD19 CAR Research Articles

CAR T cell therapy represents an emerging, promising approach in the field of autoimmune diseases. Unlike monoclonal antibodies, CAR T cells offer a deeper B cell depletion than monoclonal antibodies through their ability to infiltrate tissues and their independence from effector mechanisms. Early data from case reports and phase I/II studies demonstrate encouraging clinical responses in patients with severely refractory autoimmune disorders. CD19, BCMA and dual-targeting CAR constructs were generally well tolerated with limited safety concerns. This promising data encourages further research investigating CAR T cell therapy in a broader range of autoimmune indications and to advance CAR T constructs to improve efficacy, safety, and clinical application. In this review, we explore the rationale of using CAR T cell therapy in autoimmune diseases, summarize relevant clinical data, and highlight future perspectives within the field.

ABSTRACTRichter transformation (RT) is a serious complication of chronic lymphocytic leukaemia (CLL), with poor outcomes. While CAR T‐cells have shown promise in large B‐cell lymphoma, their efficacy in RT remains unclear, and the role of allogeneic stem cell transplant (alloSCT) post‐CAR T‐cells has not been established. This study aimed to assess the clinical response and survival of patients with RT treated with anti‐CD19 CAR T‐cells. This retrospective multicentre study, conducted by the European Research Initiative on CLL (ERIC), included patients with RT who received anti‐CD19 CAR T‐cells between 06/2018 and 01/2024. Progression‐free survival (PFS) and overall survival (OS) were evaluated from CAR T‐cell infusion. Fifty‐four patients with RT were treated with anti‐CD19 CAR T‐cells (academic products, n = 29; commercial products, n = 25). The median age was 63 years, with 72% having an ECOG performance status (PS) of 0 to 1. Seven patients (13%) underwent alloSCT following CAR T‐cell infusion, with the indications being consolidation therapy (n = 4) and relapse/progression (n = 3). The overall response rate was 65%, with 46% achieving complete response (CR) at 1 month and 50% at 3 months. The median PFS was 8.0 months (95% CI: 2.1–13.8) and the median OS was 14.4 months (95% CI: 8.8–19.2). The median PFS was 31.6 months for patients achieving CR at 1 or 3 months post CAR T‐cells. Significant factors associated with mortality included high ECOG PS (p < 0.001), high LDH at CAR T infusion (p = 0.005), ICANS (p = 0.046) and no response at 1 month (p = 0.02). Multivariable Cox regression analysis identified treatment response at 1 month (p = 0.001) and increasing age (p = 0.5) as significant predictors of mortality. This study shows encouraging response rates and manageable toxicity for patients with RT treated with both academic and commercially available CAR T‐cell products.

Preliminary evaluation of a whole blood dual-platform flow cytometry protocol for CAR-T cell quantitation: Toward accreditation and clinical routine application.

CAR-T treatment for B-cell acute lymphoblastic leukemia (ALL) induces high initial response rates, but most patients relapse. Low disease burden (often defined as < 5% blasts in the bone marrow) is associated with better outcomes. CAR-HEMATOTOX (HT) is a score using pre-lymphodepletion hematologic and inflammatory parameters to predict outcomes in lymphoma. Here, we assess its prognostic utility in a large multicenter adult B-ALL cohort. Patients who received brexucabtagene autoleucel across 33 centers in North America were included as part of the ROCCA consortium. An independent cohort of 61 ALL patients treated with an investigational CD19 CAR-T at one center was also described. Among 199 ROCCA patients, the 43 (22%) HTlow patients had lower rates of delayed neutrophil recovery than HThigh (26% vs. 52%, p = 0.002) and fewer severe infections (2.5% vs. 18.8%, p = 0.011). They had higher response rates, overall survival (OS) and event free survival (EFS), as well as lower non-relapse mortality and cumulative incidence of relapse (CIR). The survival differences remained significant after multivariable adjustment for disease burden and other covariates. In the investigational cohort of 61 patients, HTlow patients had improved OS and EFS, as well as higher peak CAR-T expansion. In summary, CAR HT is a prognostic factor independent of disease burden in adult ALL. HTlow score is associated with superior outcomes post CD19 CAR and higher CAR expansion in a single-center cohort. NCT01044069 and NCT01860937.

FDA-approved CD19 CAR T cell therapy for treating B-cell lineage malignancies gave impetus to the adoptive immune/cell and gene therapy field. Although tested to a considerable extent, side effects such as immune effector cell-associated neurotoxicity syndrome (ICANS), immune effector cell-associated hematotoxicity (ICAHTs), the high cost of the therapy, and often complicated logistics make the accessibility of this CAR therapy far from the reach of many eligible patients. Therefore, the development of a safe, cost-effective, streamlined indigenous workflow for T-cell expansion, transduction, and CAR T-cell characterization is essential in a preclinical as well as clinical setting. We have optimized a method to develop CD19 CAR T cells from peripheral blood T cells from healthy donors. In this chapter, we describe an indigenous protocol for the generation and characterization of CD19 CAR T cells via lentiviral transduction to understand the immunology or possible downstream applications.

Dermatologic Adverse Events Following CD19-Directed CAR T-Cell Therapy in Hematologic Malignancies.

MTV-guided radiotherapy bridging in large B-cell lymphoma patients receiving CD19 CAR T-cell therapy.

Chimeric antigen receptor T-cells (CAR T-cells) are an effective therapeutic approach in the treatment of B-cell driven malignancies. In addition to malignant B-cells, autoreactive B-cells are important targets for CD19 CAR T-cells, as they are a source of autoantibody production and support both the onset and progression of systemic lupus erythematosus (SLE). We and others have shown that their use in severe and therapy-refractory cases of SLE is effective and, moreover, safe. The current status and an interim analysis of the efficacy and safety of CD19-CAR T‑cell therapy in SLE. Patients with severe, treatment-refractory, and active SLE received autologous CD19-CAR T‑cell therapy (MB19.1, Miltenyi Biotec, Bergisch Gladbach, Germany) as part of an individual compassionate treatment attempt and are regularly followed up at our center. 11 patients with progressive, therapy-refractory SLE received an autologous CD19 CAR T-cell therapy as part of an individual treatment attempt. The median follow-up time is 2.5 years [0.5 - 4 years]. All patients achieved a DORIS remission within 6 months. Immunosuppressive therapy was completely discontinued in all patients. Five out of the 11 patients experienced grade 1 cytokine release syndrome (CRS). Grade 2 CRS was observed only once. No higher-grade CRS occurred in this cohort. So far, no neurotoxicity (immune effector cell-associated neurotoxicity syndrome, ICANS) has been observed in our SLE patients. All patients remain in a sustained and drug-free remission to date. One patient experienced an SLE flare. Initial data, despite similar CD19 CAR T-cell expansion and kinetics, suggest a better safety profile of CD19 CAR T-cell therapy in SLE compared to lymphoma cohorts. Additionally, adaptive immunity in SLE patients recovers rapidly after CD19 CAR T-cell therapy. The use of CD19-CAR T‑cells in patients with severe SLE proved to be safe and effective.

We retrospectively evaluated the treatment outcomes of 47 adult patients with TP53-mutated acute lymphoblastic leukaemia (ALL) treated with either blinatumomab, inotuzumab or/and CD19 CAR T-cell therapy. The complete remission with or without count recovery (CR/CRi) (negative minimal residual disease (MRD-) rate) following treatment with blinatumomab (n = 46), inotuzumab (n = 26) and CD19 CAR T cells (n = 6) was 58.7% (96.3%), 61.5% (60%) and 66.7% (75%) respectively. The median OS was 13.6 months (95% CI: 9.6-17.2) for all patients, and it was not significantly different based on the individual novel salvage therapy (p = 0.40). The 12-month leukaemia-free survival (LFS) for responders to blinatumomab, InO and CAR T cells was 20%, 11% and 0% (p = 0.743) respectively. Patients who had undergone allogeneic haematopoietic stem cell transplantation (HSCT) post-response had improved 12-month LFS compared to those who did not (35% vs. 9%, p = 0.014). Among relapsed patients following blinatumomab, 11 (61%) presented with CD19-negative disease. Hence, targeted and immune-based therapies are effective in inducing high MRD-negative remission rates in adults with B-cell ALL harbouring TP53 mutations. Nonetheless, the durability of remission is short in the absence of allogeneic HCT consolidation and relapse frequently manifested as CD19-negative disease following blinatumomab.

IBCL-783: High CR and MRD Negativity Rates With GLPG5101, a Fresh, Stem-Like, Early Memory CD19 CAR T With 7-Day Vein-to-Vein Time: Full Results From ATALANTA-1 Cohort 3 (iNHL)

Proteasome subunit beta type-9 (PSMB9), a member of the proteasome beta subunit family, encodes the pivotal β1i component of the immunoproteasome. PSMB9 plays a crucial role in antigen processing and presentation; however, its comprehensive role in orchestrating a tumor-immune landscape and regulating the anti-tumor immune responses remains unexplored. Here we investigated the context-dependent functions of PSMB9 by integrating multi-omics data from The Cancer Genome Atlas, Genotype-Tissue Expression database, Human Protein Atlas, Tumor Immunotherapy Gene Expression Resource, and multiple other databases. Moreover, we explored the predictive value of PSMB9 in multiple immunotherapy cohorts and investigated its functional relevance in CAR-T therapy using genome-scale CRISPR/Cas9 screening, gene knockout cell line in vitro, and clinical cohort validation. We found widespread dysregulation in PSMB9 across cancers, predominantly upregulated in most malignancies and associated with advanced pathological stages in specific contexts. PSMB9 was also broadly and negatively correlated with tumor stemness indices. Crucially, PSMB9 expression was robustly linked to anti-tumor immunity by being significantly correlated with immune-pathway activation (e.g., IFN response, cytokine signaling), immune regulatory and immune checkpoint gene expression, and enhanced infiltration of T cells across nearly all tumor types. Consequently, elevated PSMB9 predicted superior response to immune checkpoint inhibitors in multiple cohorts, showing comparable predictive power to established predictive signatures. Furthermore, CRISPR/Cas9 screening identified PSMB9 loss as a novel mechanism of resistance to CD19 CAR T cell therapy, with PSMB9-deficient tumor cells exhibiting a survival advantage under CAR-T pressure, supported by trends in clinical CAR-T outcomes. Our study uncovers PSMB9 as a previously unrecognized critical regulator of the tumor immune landscape in a pan-cancer scope, whose expression orchestrates key immune processes within the tumor microenvironment and serves as a potent biomarker for patient prognosis. Critically, we first established PSMB9 as a novel prognostic indicator for both checkpoint blockade and CAR-T cell therapies, highlighting its dual role as a crucial immune modulator and a promising biomarker for guiding T cell-based immunotherapy strategies across diverse human cancers.

Over the past decade, CAR-T cell therapy has achieved remarkable success in treating hematological malignancies. However, traditional CAR-T cell engineering employs viral vectors, which has several limitations. Additionally, the immunosuppressive tumor microenvironment, particularly mediated by the PD-1/PD-L1 pathway, significantly restricts CAR-T cell efficacy. CRISPR/Cas9-mediated PD-1 knockout can enhance CAR-T cell anti-tumor activity, but traditional electroporation (EP) method often damages T cells. Herein, a novel lipid nanoparticles (LNPs)-mediated delivery technology are introduced to engineer CAR-T cells. The LNPs platform enables the simultaneous expression of CAR cassette and CRISPR/Cas9 gene editor in T cells via co-delivery of multiplex RNAs (CD19 CAR mRNA+Cas9 mRNA+sgRNA targeting PD-1). Importantly, LNPs exhibit higher transfection efficiency and superior cell viability compared to traditional electroporation method. The engineered CAR-T cells with PD-1 knockout, which express anti-CD19 CAR, can specifically kill CD19+ Nalm-6 tumor cells in vitro and display enhanced anti-tumor activity in vivo. Furthermore, LNPs-mediated co-delivery of Cas9 mRNA and sgRNAs targeting PD-1, TRAC, and B2M enables triple-knockout of T cells with high editing efficiencies (76% for PD-1, 86% for TRAC, and 80% for B2M), highlighting the ability for multiplex gene editing. This LNP-mediated delivery strategy has great potentials for the development of safer and more efficacious CAR-T cells.

T cells engineered with CD19-directed chimeric antigen receptors (CD19 CAR) T cells have become standard treatment for patients with high risk, relapsed or refractory (R/R) large B-cell lymphomas (LBCL). However, outcomes in patients with rare subsets of LBCL, such as primary mediastinal large B-cell lymphoma (PBMCL), have not been well characterized. The impact of prior immune checkpoint inhibitor (ICI) treatment, commonly used to treat R/R PMBCL, is also unknown. To address these gaps, we retrospectively analyzed CIBMTR registry data including PMBCL patients undergoing CD19 CAR T-cell therapy per standard-of-care. A total of 135 PMBCL adults from 66 centers were included. Median age at the time of CAR T-cell therapy was 32. Thirty-nine patients (28.9%) had received an ICI prior to CAR T-cell therapy. The best overall and complete response (CR) rates after CD19 CAR T-cell therapy were 79% and 67.7%, respectively. The 2-year progression-free (PFS) and overall survival (OS) were 58.6% (95% CI, 49.7-67.3) and 80.8% (95% CI, 72.6-87.8), respectively. The 2-year cumulative incidence (CI) of relapse and non-relapse mortality (NRM) were 36% (95% CI, 27.8-44.7) and 5.4% (95% CI, 1.9-10.5), respectively. We observed grade ≥ 3 CRS and ICANS in 6.1% and 14.7%, respectively. Prior ICI exposure was associated with lower 2-year CI of relapse (ICI-exposed, 21.7%; ICI-naïve, 41.6%; p = 0.03) and higher 2-year NRM (ICI-exposed, 11.7%; ICI-naïve, 2.8%; p = 0.03). We could not confirm statistically different PFS (p = 0.19) or OS (p = 0.26) between ICI-exposed and ICI-naïve patients. CD19 CAR T-cell therapy led to high rates of durable responses in PMBCL patients with low rates of severe toxicities.

Transformed follicular lymphoma (tFL) is typically associated with chemotherapy resistance and a poor prognosis. There are limited data regarding outcomes after CD19-directed chimeric antigen receptor T-cell (CAR T) therapy in relapsed/refractory (R/R) tFL. A total of 923 adult patients with R/R tFL who received commercial CD19 CAR T therapy between 2017 and 2023 were identified in the Center for International Blood and Marrow Transplant Research registry. Median age was 64 years (range: 30-86) and median prior lines of therapy was 4 (range: 1-18). Most patients (78%) received axicabtagene ciloleucel, with 67% of patients having resistant disease at the time of CAR T infusion. At a median follow-up of 25 months (range: 1-72) from CAR T infusion, the 2-year overall survival (OS) was 57% (95% CI: 53-60) and progression-free survival (PFS) was 43% (95% CI: 40-47). The 2-year cumulative incidences of relapse or progression (rel/prog) and non-relapse mortality (NRM) were 47% (95% CI: 44-51) and 9% (95% CI: 7-11), respectively. The overall response rate to CAR T was 76%, with a complete response rate of 63%. Grade ≥ 3 cytokine release syndrome (CRS) was observed in 7.1% and grade ≥ 3 immune effector cell-associated neurologic syndrome (ICANS) in 21.6% of patients. Multivariable analysis suggested that resistant disease status at the time of CAR T, use of bridging therapy, and high comorbidity index ≥ 3 were associated with inferior PFS and OS. Older age ≥ 60 significantly increased the risk of NRM. Our study suggests that CD19 CAR T is effective and safe for tFL.

Anti CD19 CAR transduced T cells

BackgroundCD19-targeted chimeric antigen receptor T (CAR T) cell therapy has revolutionized the treatment of refractory/relapsed B-cell malignancies. However, this therapy introduces significant safety concerns, including cytokine release syndrome (CRS) and infections, both of which can lead to life-threatening complications. These two complications often require conflicting treatment approaches, making it challenging to balance patient safety and therapeutic effectiveness. The optimal approach to managing infections complicated by CRS remains unclear.Case presentationA 54-year-old man with primary refractory high-grade B-cell lymphoma, who had failed multiple prior therapies, received CD19 CAR T-cell therapy after bridging therapy and intensive lymphodepletion. He developed a severe diffuse alveolar hemorrhage induced by CRS complicated with virus infection following CAR T-cell infusion. Despite aggressive therapeutic approaches including anti-infection measures, immune modulation, and anticytokine agents, no significant clinical improvement was initially observed. The patient’s toxicity was effectively managed, ultimately leading to a complete response (CR), only after the introduction of glucocorticoids following the median time to peak CAR T-cell expansion. The patient sustained this CR for over 36 months, until January 2025.ConclusionThis case highlights the importance of early diagnosis and management of CRS and infection after CAR T-cell therapy, offering critical insights into managing adverse reactions and optimizing patient outcomes.

Bridging radiation therapy (BRT) is increasingly utilized prior to CART19 in NHL patients. However, its impact on CART19 outcomes is not established. We conducted a systematic review and meta-analysis to estimate the safety and efficacy of BRT prior to CART19 therapy. A comprehensive search was performed in databases from inception to October 2024. We identified 18 studies encompassed 538 adult NHL patients who received BRT prior to commercial CART19. Random-effect models were applied to explore meta-analysis outcomes. DLBCL was the most common diagnosis (73%), and axicabtagene ciloleucel was the most utilized product (67%). Bulky disease was present in 37%. Median BRT dose was 30 Gy delivered comprehensively to all sites of PET avid disease in 76% of cases. ORR to CART19 was 78.9%. At 1 year, PFS was 54.6% while OS was 71.2%. All-grade CRS was 80% while all-grade ICANS was 39.4%. Grade 3/4 CRS was 3.6% and grade 3/4 ICANS was 10.6%. Sensitivity analyses including studies with bulky disease and excluding studies with patients who also received systemic bridging therapy, demonstrated consistent results compared to the main study findings. Sub-group meta-regression showed similar results in studies that utilized BRT only compared to studies that utilized combined-modality treatment. In conclusion, this metaanalysis found that BRT use prior to CART19, whether as a standalone approach or in combination with systemic therapy, does not increase toxicity or compromise the efficacy of CART19 therapy in NHL. Furthermore, use of BRT is associated with low rate of CRS, even in patients with bulky disease.

This single-center, retrospective study analyzed vaccine responses in patients who received post-Chimeric Antigen Receptor (CAR) T-cell therapy vaccination between 2018 and 2024. Vaccinations were administered according to EBMT/CIBMTR recommendations and pathogen-specific IgG responses to 12 vaccine-preventable infections were assessed. Seroprotection was defined by established cut-offs or a significant fold increase in titers. A total of 73 patients that had not received intravenous immunoglobulins within the eight weeks prior to pre- or post titer were included. The median time to vaccination initiation was 13 months (range 6–66) post-CAR T. Pre and post-vaccination titers were available for 49 patients. Pre-vaccination seroprotection was high (> 85%) for tetanus and poliovirus. Among patients not seroprotected prior to vaccination, vaccine response rates were high for tetanus and polio (100%), moderate for diphtheria (75%) and haemophilus influenzae type b (62%), and lower for pertussis (48%), hepatitis A (43%), hepatitis B (44%), and pneumococcal disease (33%). CD19 CAR T recipients had higher pre-vaccination seroprotection rates than BCMA recipients, but vaccine responses did not differ significantly between groups. Pre-vaccination IgA levels were significantly associated with vaccine response, and absolute B-cell counts trended higher among responders (p = 0.054). Our findings highlight the importance of immune reconstitution in vaccine responses post-CAR T.

We demonstrate that DLBCL cells surviving CD19 CAR T-cell treatment develop a resistance phenotype with a "resistance signature" predictive of clinical CAR T-cell response, mediating cross-resistance between CAR T cells targeting different antigens. Our findings suggest that up-front dual-antigen targeting and combination therapies could improve clinical outcomes.

2020 Background: Refractory CNS lymphoma (CNSL) has a poor prognosis, with 5-year survival of ~30%. We conducted a trial of axi-cel for CNSL, where we achieved a CR of 67%. To deeply interrogate the immune mediators of response, we collected daily paired CSF and peripheral blood (PB) samples post-CAR T infusion. This enabled single-cell transcriptional profiling at an unprecedented depth, identifying key drivers of CD19 CAR T responses and compartment-specific mechanisms of CAR T function. Methods: CNSL patients were enrolled in the ‘Axi-cel in CNS Lymphoma’ Trial, NCT04608487. PB and CSF samples were collected daily from Day 0–14 post-infusion, and 5’10x scRNA /TCR-Seq was performed. This analysis focused on peak CAR T expansion (Day 5-10) and included 1,224,178 T cells from 17 patients. Samples were tested for compartment (CSF vs PB) and response-specific (CR vs PD) transcriptomic differences using a mixed-effects model and GSEA. Functional assays were conducted with CD19 CAR Ts and CD19 CAR+ Jurkat-NFAT reporter cells. Results: Transcriptomic analysis identified distinct compartmental differences in CAR Ts, with PB CAR Ts displaying a robust proliferation signature, while CSF CAR Ts were enriched for type I interferon and T-cell dysfunction signatures, including upregulation of inhibitory genes PD-1, TIGIT, TIM3, LAG3. In vitro , CSF-exposed CD19-CAR Ts showed increased expression vs culture-media controls for TIGIT (up 40.1%, SEM 7.4), PD-1 (18.9%, SEM 3.8), and Tim3 (60.6%, SEM 7.5). CAR T NFAT expression was reduced from 18.4, 0.1 SEM (media) to 7.2, 0.2 SEM (CSF) relative to unstimulated controls. Differential expression analysis comparing CSF CD8+ CAR Ts from patients achieving CR (n = 11) or PD (n = 4) showed upregulation of Type I interferon signaling (IFIT1, IFIT3) in PD patients. In contrast, CR patients exhibited increased expression of counter-inhibitory genes (TCF7, CD226) in CSF CAR Ts, suggesting a functional advantage of these CAR Ts in the inhibitory CNS environment. Functional assays of CD19-CAR Ts overexpressing the costimulatory molecule CD226, demonstrated higher lymphoma-cell killing vs WT-CAR Ts (48.6%, SEM 4.1 vs 24%, SEM 2.2, p = 0.01) and greater IFNγ production (63.2%, SEM 1.6 vs 49.4%, SEM 1.7, P = 0.006). CD226 acts as a costimulatory receptor and counteracts TIGIT signaling by competing for its shared ligands, CD112 and CD155. Notably, scRNA-Seq receptor-ligand analysis identified CD112 exclusively expressed in myeloid cells, highlighting a critical myeloid-CAR T interaction that enhances CD226 high CAR T efficacy. Conclusions: ScRNA-Seq suggests tissue-specific CAR T dysfunction in the CNS microenvironment, with CR patients demonstrating upregulation of counter-inhibitory genes, including CD226. This study offers novel insights into axi-cel's mechanism of efficacy and identifies targets to improve CNSL CAR T therapy.