CD19 Chimeric Antigen Receptor Research Articles

We retrospectively analyzed outcomes for nine children and young adults who were treated with inotuzumab ozogamicin (InO) for relapsed/refractory (R/R) B-acute lymphoblastic leukemia (ALL) after CD19-chimeric antigen receptor T-cell therapy (CART). After InO cycle 1, overall response rate was 77.8%; 66.7% achieved measurable residual disease (MRD)-negative remission. One-year event-free survival (EFS) was 37.5%; 1-year overall survival (OS) was 50%; 2-year EFS was 37.5%; 2-year OS was 37.5%. Median survivor follow-up is 2.9 years (0.5-4.7). Significant adverse events included prolonged cytopenias, hepatotoxicity, and post-transplant sinusoidal obstructive sydrome. InO showed promising efficacy as treatment for children and young adults with R/R B-ALL after CD19-CART. Extramedullary diseaseprior to InO and positive MRD after InO cycle 1 were associated with poor outcomes.

Immune-based cell therapy offers a promising approach to cancer treatment. While autologous chimeric antigen receptor (CAR) T cells have shown success, production is time-consuming, costly and patient specific. Gamma-delta (γδ) T cells are promising for 'off-the-shelf' CAR T cell therapy. However, clinical translation of γδ CAR T cells is hampered by low frequency, resistance to genetic manipulation and advanced differentiation after expansion, limiting therapeutic feasibility. Here we demonstrate a method for in vitro activation and expansion of peripheral blood γδ T cells, facilitating high rates of gene editing and efficient CAR integration. Using artificial antigen-presenting cells, we produce minimally differentiated, highly functional γδ CAR T cells. By targeting a US Food and Drug Administration-approved CD19 CAR to the CCR5 locus, we generate CCR5-deficient γδ CD19 CAR T cells (γδ CCR5KI-CAR19), which demonstrated resistance to HIV-mediated depletion and robust antitumour responses against B cell lymphoma and leukaemia. γδ CCR5KI-CAR19 T cells enable the immunotherapy of HIV-associated B cell malignancies. These studies provide preclinical evidence supporting large-scale development of potent allogeneic γδ CAR T cells for diverse immunotherapies.

A CD22-Specific T-Cell Receptor Enables Effective Adoptive T-Cell Therapy for B-cell malignancies.

Invasive Fungal Infections after CD19 CAR T-cell Therapy for B-Cell Lymphoma: a LYSA study from the DESCAR-T Registry.

IntroductionChronic lymphocytic leukemia (CLL) has proven difficult to treat with chimeric antigen receptor (CAR) T cell therapy. CLL cells can negatively alter T cell fitness and induce a pseudohypoxic state. We hypothesized that production of CAR T cells under restricted oxygen conditions resembling physiological oxygen levels that can be encountered in tissues (i.e. 2% O2) could promote outgrowth of hypoxia-tolerant CAR T cells.MethodsWe performed in vitro phenotypic and functional assessments of CD19-directed CAR T cells produced in either 21% (NorCAR) or 2% (HypCAR) O2 derived from healthy donors (HDs) or patients with CLL. ResultsProduction of HD-derived CAR T cells in 2% O2 promoted the enrichment of a naïve-like subset. HypCAR and NorCAR cells were functionally distinct; CD4+ HypCAR cells produced more IL-2 and tumor necrosis factor than CD4+ NorCAR cells. Production in 2% O2 was not detrimental to viability or proliferation upon cognate antigen-stimulation and led to increased activation. After chronic stimulation in hypoxia, HypCAR-product remained enriched in naïve-like cells, and demonstrated cytotoxic and cytokine production capacity. In CAR T cells derived from patients with CLL, NorCAR and HypCAR subsets were functionally and phenotypically comparable, but displayed different mitochondrial metabolism. DiscussionWe demonstrated that production in 2% O2 is not detrimental, confers subtle but lasting functional and phenotypic changes in CAR T cells warranting further research on the impact of hypoxic production on CAR T cell functionality in hypoxic tumor microenvironments.

Neuroimaging findings in immune effector cell-associated neurotoxicity syndrome (ICANS) have not been systematically described. We created the chimeric antigen receptor (CAR) T-cell Neurotoxicity Imaging Virtual Archive Library (CARNIVAL), a centralized imaging database for children and young adults receiving CAR T-cell therapy. Objectives of this study were to (1) characterize neuroimaging findings associated with ICANS and (2) determine whether specific ICANS-related neuroimaging findings are associated with individual neurologic symptoms. We performed a multicenter retrospective cohort study of patients ≤30 years who experienced ICANS following CAR T-cell therapy for B-cell malignancies between January 1, 12, and January 31, 23, and had a brain MRI in the first 30 days after CAR T-cell infusion. Deidentified MRIs were reviewed by a central study team of pediatric neuroradiologists with experience in ICANS neuroimaging. Imaging features were categorized and correlated with CAR product and clinical characteristics including preinfusion neurologic history, and postinfusion neurologic symptoms alongside CAR T-cell toxicities using logistic regression. Of 864 patients treated with CD19 and/or CD22-directed CAR T-cells, 343 developed ICANS. 96 of the patients with ICANS (median age 12, 43% female) had an acute brain MRI. Of these, 36% (95% CI 27%-47%) had ICANS-related MRI abnormalities, most commonly affecting the white matter (24/35, 69%), brainstem (14/35, 40%), leptomeninges (10/35, 29%), and thalami (9/35, 26%). ICANS-related white matter abnormalities were generally bilateral, symmetric, and involved the supratentorial deep white structures, including the external and extreme capsules, corticospinal tracts, centrum semiovale, and periatrial white matter. There were no significant associations between ICANS-related MRI abnormalities and baseline clinical/demographic characteristic or specific ICANS symptoms, but higher ICANS grade was positively associated with MRI abnormalities (adjusted odds ratio 3.7, p < 0.001). Among 12 patients with ICANS-related MRI abnormalities who had follow-up imaging, 10 of 12 (83%) improved and 3 of 12 fully resolved. ICANS-related brain MRI abnormalities demonstrate unique patterns in the cerebral white matter, brainstem and thalami; their prevalence increases with ICANS clinical grade. Because our cohort is enriched for patients with severe ICANS, it likely overestimates the incidence of ICANS-related imaging abnormalities. A better understanding of neuroimaging findings is valuable for parsing pathophysiologic mechanisms of ICANS and optimizing patient outcomes.

In the current Canadian treatment landscape for relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL), eligibility for autologous stem cell transplantation (ASCT) guides the choice of salvage treatment. CD19 chimeric antigen receptor T-cell (CAR-T) therapies have improved outcomes in patients with chemorefractory DLBCL, but access is limited to eligible patients. This subanalysis of the RE-MIND2 observational retrospective cohort study investigated treatment patterns for R/R DLBCL in Canada. Data from patients enrolled in RE-MIND2 treated between 2010 and 2020 at 2 Canadian centers were retrospectively collected from health records. Descriptive statistics were used to analyze baseline characteristics, treatment initiated, and duration of treatment by line of therapy. One hundred and nine patients were included; 74.2% of patients were eligible for ASCT as 2 L therapy and 45.4% received transplants. ASCT eligibility for third- (3 L) and fourth-line (4 L) therapy declined to 17.1% and 5.9%, respectively. Patients received a wide variety of treatments in 3 L and 4 L. CAR-T therapy became available in 3 L and 4 L by the end of 2019. Median durations of treatment were <2.6 months in all lines of therapy; median time to next treatment ranged from 3.4 months in 4 L to 5.3 months in 2 L. Results of our study support that ASCT-ineligible patients have a poor prognosis with conventional salvage chemotherapy. Prior to the availability of novel immunotherapies, no apparent standard of care was observed for Canadian patients with R/R DLBCL who were ineligible for or did not receive ASCT, especially after 2 L treatment.

CAR T cells for multiple sclerosis: Engineering T cells to disrupt chronic B cell-driven neuroinflammation.

Patients with systemic lupus erythematosus (SLE) require long-term treatment and experience reduced quality of life (QoL). CD19 chimeric antigen receptor (CAR) T-cell therapy can achieve sustained drug-free remission in patients with SLE. The impact of CAR T-cell therapy on QoL and direct health care costs has not been evaluated. Here, we analyzed longitudinal QoL before and after CAR T-cell therapy and performed an assessment of direct health care costs. Physical and mental health was assessed using the standardized Short Form (SF)-36 before and one year after treatment. Annual direct health care costs were analyzed based on inpatient admissions, emergency department visits, outpatient visits and prescription drug costs in the German health care service. A preliminary analysis was conducted on 8 patients with SLE (7 women, 1 man; age range 19-38 years) who received CAR T-cell therapy and were followed for over two years. CAR T-cell therapy resulted in improvement in the QoL in all patients. The most notable improvement was observed in physical health (from 22.4% to 75.5%), while mental health also improved (from 24.7% to 63.0%). QoL values rose to the level of a healthy comparison cohort. Additionally, CAR T-cell therapy led to a substantial decrease in annual direct health care costs from 29.672 €/year to 3.094 €/year after treatment. In addition to clinical efficacy, in this preliminary cohort CD19 CAR T-cell treatment improves Qol in SLE patients and may substantially reduces the direct socioeconomic burden associated with active disease by over 90%.

BackgroundDespite the curative potential for chimeric antigen receptor (CAR) T-cells in B-cell acute lymphoblastic leukemia (B-ALL), efficacy can be limited by life-threatening adverse events such as severe infections. As immune effector cell-associated hematotoxicity and secondary immunodeficiency may be particularly profound in B-ALL, understanding pre-infusion risk of severe infection is imperative. The ALL-HEMATOTOX (ALL-HT) score is a recently validated tool designed to predict CAR-associated hematotoxicity in B-ALL, but the relationship between ALL-HT and severe infections post-infusion has not yet been comprehensively assessed.MethodsIn this multicenter, retrospective analysis, we evaluated ALL-HT and other pre-infusion variables for an association with severe infection through day+60 (D+60) in patients with B-ALL treated with CD19 and CD22-based CAR T-cell constructs across three institutions. Infections were identified by microbiology, histopathology, or as a clinical syndrome and graded by CTCAE (Common Terminology Criteria for Adverse Events) V.5.0. Severe infections were defined as grade≥3. Multivariable logistic regression and Cox proportional hazard models were constructed to identify independent risk factors for infection.ResultsAcross 350 patients receiving CAR T-cells, 79 (23%) developed a severe infection within day+60 post-CAR, including 8 patients with grade 4 (life-threatening) infection and 5 patients with grade 5 (fatal) infections. Bloodstream infections were the most common, comprising 67% of those with severe infections. In multivariable analysis, pre-infusion factors associated with severe infection included older age (OR 1.35 (1.1–1.6), p=0.002), prior severe infection (OR 2.1 (1.2–3.7), p=0.009), and a higher ALL-HT score (OR 1.15 (1.01–1.31), p=0.04). Patients classified as high-risk (HR) by ALL-HT had a greater risk of infection compared with low-risk patients (HR 1.4 (1.1–2.7), p=0.014).Multiple severe infections occurred in 24 patients (7%). In a subanalysis, ALL-HT risk of infection was primarily driven by baseline thrombocytopenia, with a cut-off of≤50 000 platelets/µL strongly predicting risk of infection (HR 2.2 (1.3–3.6), p=0.002). Post-infusion infection risk was driven by a longer duration of neutropenia (OR 1.26 (1.1–1.4), p<0.001).ConclusionsOlder age, prior infection history, baseline thrombocytopenia, and higher ALL-HT scores are strong independent risk factors for severe infection among patients with B-ALL receiving CAR T-cells. These factors may guide individualized risk mitigation to prevent severe infections in this high-risk patient population.Trial registration numberNCT03827343.

Impact of Granulocyte Colony Stimulating Factor Use Following CD-19 Chimeric Antigen Receptor T-Cell Therapy.

CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy has transformed outcomes for relapsed/refractory large B-cell lymphoma (LBCL), yet nearly half of treated patients relapse, and toxicities remain frequent. A deeper understanding of response predictors is urgently needed to guide patient selection, treatment optimization, and development of rational combination strategies. Emerging data reveal that response to CAR-T therapy is shaped by patient-specific, tumor-intrinsic, and treatment-related factors. Clinical variables such as age, performance status, inflammation, and microbiome composition influence efficacy. Tumor burden, disease distribution, histologic subtype, and genomic alterations correlate with resistance. Treatment factors, including bridging strategies, lymphodepletion regimen, and CAR-T product design, affect expansion, persistence, and clinical outcomes. Novel insights from immune profiling, radiomics, and single-cell transcriptomics offer further granularity and predictive potential. Predictors of CAR-T response span diverse biological and clinical domains and are increasingly actionable. Integrating multimodal biomarkers into routine workflows can personalize care and improve outcomes. Prospective validation, real-time monitoring, and adaptive trial designs are essential next steps toward precision CAR-T therapy.

Inferior survival in double refractory large B-cell lymphoma eligible for third-line CD19 CAR T-cell therapy

Chimeric antigen receptor (CAR) T cell therapy targeting CD19 elicits remarkable clinical efficacy in B cell malignancies, but many patients relapse owing to failed expansion and/or progressive loss of CAR-T cells. We recently reported a strategy to potently restimulate CAR-T cells in vivo, enhancing their functionality by administration of a vaccine-like stimulus comprised of surrogate peptide ligands for a CAR linked to a lymph node-targeting amphiphilic PEG-lipid (amph-vax). Here we demonstrate a general strategy to discover and optimize peptide mimotopes enabling amph-vax generation for any CAR. We use yeast surface display to identify peptide binders to FMC63 (the scFv used in clinical CD19 CARs), which are then subsequently affinity matured by directed evolution. CAR-T vaccines using these optimized mimotopes triggered marked expansion and memory development of CD19 CAR-T cells in both syngeneic and humanized mouse models of B-acute lymphoblastic leukaemia/lymphoma, and enhanced control of disease progression compared with CD19 CAR-T-only-treated mice. This approach enables amph-vax boosting to be applied to any clinically relevant CAR-T cell product.

Abstract Background Chimeric antigen receptor (CAR)-T cell therapy has shown effectiveness in advanced hematological malignancies. As well, evidence is growing on potential cardiotoxic implications of CAR-T cell exposure. However, effects of this therapy on vascular inflammation are unknown. Methods Patients treated with CAR-T cells infusion for relapsed or refractory B- cell aggressive lymphoma with available baseline and 30-day post CAR-T 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) were retrospectively analysed. Maximum standardized uptake values (SUVmax) of arterial and venous walls were calculated. Routine blood analysis results were collected and overtime changes in inflammatory markers were expressed as a Delta (Δ) during the first 14 days after infusion. The population enrolled was stratified according to the complete response to cellular therapy. Results Among the 35 patients finally included, segment-by-segment comparisons between baseline and 30-day PET/CT did not differ significantly. Veins exhibited lower mean SUV values compared to arteries (β = -0.18, 95% CI [-0.27, -0.08], p &amp;lt; 0.001). The interaction effect between time and response was statistically significant (β = -0.15, 95% CI [-0.27, -0.03], p = 0.015); in particular, responders showed an overall increase in SUV values over time, while non-responders exhibited a decrease. As well, imaging modifications observed through PET/CT between these groups were accompanied by consensual changes in inflammatory and endothelial damage biomarkers (e.g., C reactive protein and mEASIX score). Conclusions Our results highlight higher vascular inflammation in patients considered as disease-responders after CAR-T cell therapy. These preliminary observations require confirmation in large-scale, prospective studies and call for patient-tailored cardiovascular surveillance.

Sequential CD19-20 CAR T-cell therapy for refractory/relapsed diffuse large B-cell lymphoma.

Sézary syndrome (SS) is a leukemic form of cutaneous T cell lymphoma (CTCL), distinguished from mycosis fungoides by the presence of cancerous lymphocytes in the blood and often bears very poor prognoses. SS treatment is palliative, and thus novel therapies are needed. The CD7 surface antigen is highly expressed and confined to the surface of T cells, therefore when present, serves as a promising target for immunotherapy. Herein we describe the preclinical validation and clinical application of our non-gene editing CD7 targeted chimeric antigen receptor (CAR) T therapy to treat relapsed/refractory (r/r) CD7 expressing SS. The CD7 CAR construct possesses a "safety switch" (RTX) to enable rapid depletion of the CAR T treatment with administration of rituximab. Preclinical evaluation of the CD7-RTX CAR T cells demonstrated >99% depletion of target cells in both co-cultures, at 1:1 and 2:1 effector: target (E:T) ratios, and mouse models. In a mouse model, "safety switch" testing resulted in rapid elimination of CAR T cells with rituximab infusion. RTX, in our CD7 therapy, has not yet been clinically validated. A 53-year-old male diagnosed with r/r SS, expressing CD7, was treated with 2×106 CD7-RTX CAR T cells/kg of body weight, as compassionate use. The patient achieved medication and symptom free complete remission (CR) within 28 days post-CAR. The patient remained in CR at 18-month follow-up. The treatment was well tolerated and without severe adverse events (SAEs). Our CD7-RTX CAR T therapy demonstrates exceptional safety and efficacy in one patient with CD7+ r/r SS. This was the first recorded use of CD7 targeted CAR T therapy to treat SS. SS is prototypically CD7-, thus despite its efficacy in this patient, this treatment approach is likely not generalizable to most SS patients. However, this study supports the importance of thorough tumor characterization and the potential use of CD7-RTX CAR T cells to treat a variety of malignancies expressing CD7. Future clinical trials are required to characterize the safety and efficacy of CD7-RTX CAR T cells.

CD19 CAR-T cell therapy in a pediatric patient with MDA5+ dermatomyositis and rapidly progressive interstitial lung disease.

Low Peripheral Blood Counts and Elevated Proinflammatory Cytokines Signal a Poor CD19 Chimeric Antigen Receptor T-cell Response in Acute Lymphoblastic Leukemia.

We aimed to develop an actionable and feasible prospective clinical model to estimate toxicity risk to assist chimeric antigen receptor (CAR) T-cell therapy providers with the management of patients with relapsed and/or refractory large B-cell lymphoma. We conducted an observational, retrospective cohort study using secondary data from 390 patients treated with the CD19 CAR T-cell therapy axicabtagene ciloleucel under two prospective clinical trials, ZUMA-1 and ZUMA-7; these clinical trials enrolled patients with relapsed/refractory large B-cell lymphoma between 2015 and 2019. Using machine learning and statistical methods, we developed a classification model for identifying patients unlikely to experience early cytokine release syndrome (CRS) and neurological events (NE) of any grade. We found the use of prophylactic corticosteroids to be an important factor in remaining CRS-free and NE-free within the first 3 days post-treatment (p<0.001). We identified a top model for no early CRS/NE using a set of six pre-lymphodepletion clinicopathologic features: number of lines of prior systemic therapy, age, baseline tumor burden (as measured by sum of the product of the diameters), C-reactive protein, aspartate transaminase, and hemoglobin, which achieves a positive predictive value of 0.71 in the holdout validation cohort. Additionally, we find that predicted probabilities generated from the model are strongly associated with incidence of Grade 2 or higher NE. We illustrated that routine clinicopathologic variables can be used to identify patients at low risk of developing early post-treatment CRS and/or NE. Such knowledge can be used to help treating centers prospectively manage patient care, including consideration of outpatient treatment.