Safety Of Chimeric Antigen Receptor Research Articles

Chimeric antigen receptor T cell therapy for autoimmune disease.

Infusion of T cells engineered to express chimeric antigen receptors (CARs) that target B cells has proven to be a successful treatment for Bcell malignancies. This success inspired the development of CAR T cells to selectively deplete or modulate the aberrant immune responses that underlie autoimmune disease. Promising results are emerging from clinical trials of CAR T cells targeting the B cell protein CD19 in patients with B cell-driven autoimmune diseases. Further approaches are being designed to extend the application and improve safety of CAR T cell therapy in the setting of autoimmunity, including the use of chimeric autoantibody receptors to selectively deplete autoantigen-specific B cells and the use of regulatory T cells engineered to express antigen-specific CARs for targeted immune modulation. Here, we highlight important considerations, such as optimal target cell populations, CAR construct design, acceptable toxicities and potential for lasting immune reset, that will inform the eventual safe adoption of CAR T cell therapy for the treatment of autoimmune diseases.

Impact of scFv on functionality and safety of third generation CD123 CAR T cells.

Chimeric antigen receptor (CAR) T cells express an extracellular domain consisting of a single-chain fragment variable (scFv) targeting a surface tumor-associated antigen. scFv selection should involve safety profiling with evaluation of the efficacy/toxicity balance, especially when the target antigen also is expressed on healthy cells. Here, to assess differences in terms of efficacy and on-target/off-tumor effects, we five different CARs targeting CD123 by substituting only the scFv. In in vitro models, T cells engineered to express three of these five CD123 CARs were effectively cytotoxic on leukemic cells without increasing lysis of monocytes or endothelial cells. Using the IncuCyte® system, we confirmed the low cytotoxicity of CD123 CAR T cells on endothelial cells. Hematotoxicity evaluation using progenitor culture and CD34 cell lysis showed that two of the five CD123 CAR T cells were less cytotoxic on hematopoietic stem cells. Using a humanized mouse model, we confirmed that CD123- cells were not eliminated by the CD123 CAR T cells. Two CD123 CAR T cells reduced tumor infiltration and increased overall survival of mice in three in vivo models of blastic plasmacytoid dendritic cell neoplasm. In an aggressive version of this model, bulk RNA sequencing analysis showed that these CD123 CAR T cells upregulated genes associated with cytotoxicity and activation/exhaustion a few days after the injection. Together, these results emphasize the importance of screening different scFvs for the development of CAR constructs to support selection of cells with the optimal risk-benefit ratio for clinical development.

CAR T cells vs bispecific antibody as third- or later-line large B-cell lymphoma therapy: a meta-analysis

AbstractThis meta-analysis evaluates the efficacy and safety of chimeric antigen receptor (CAR) T-cell therapy and bispecific antibodies for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). We searched MEDLINE, Embase, and Cochrane databases until July 2023 for trials assessing CAR T-cell therapies and CD20×CD3 bispecific antibodies as third or subsequent lines in R/R DLBCL. Random-effects models estimated the complete response (CR) rate and secondary outcomes, with meta-regressions adjusting for relevant covariates. Sixteen studies comprising 1347 patients were included in the pooled analysis. The pooled CR rate for bispecific antibodies was 0.36 (95% confidence interval [CI], 0.29-0.43), compared with 0.51 (95% CI, 0.46-0.56) for CAR T-cell therapy (P < .01). This superiority persisted when comparing the CAR T-cell–naive patients within the bispecific antibody group, with a CR rate of 0.37 (95% CI, 0.32-0.43). Multivariable meta-regression also revealed better efficacy of CAR T cells with adjustment for the proportion of double-hit lymphoma. The pooled 1-year progression-free survival rate mirrored these findings (0.32 [95% CI, 0.26-0.38] vs 0.44 [95% CI, 0.41-0.48]; P < .01). For adverse events of grade ≥3, the bispecific antibody had incidences of 0.02 (95% CI, 0.01-0.04) for cytokine release syndrome, 0.01 (95% CI, 0.00-0.01) for neurotoxicity, and 0.10 (95% CI, 0.03-0.16) for infections. The CAR T cell had rates of 0.08 (95% CI, 0.03-0.12), 0.11 (95% CI, 0.06-0.17), and 0.17 (95% CI, 0.11-0.22), respectively, with significant differences observed in the first 2 categories. In summary, CAR T-cell therapy outperformed bispecific antibody in achieving higher CR rates, although with an increase in severe adverse events.

Impact of tocilizumab on anti-CD19 chimeric antigen receptor T-cell therapy in B-cell acute lymphoblastic leukemia.

Tocilizumab is commonly used for the management of chimeric antigen receptor (CAR) T-cell therapy-associated cytokine release syndrome (CRS). However, it remains unknown whether tocilizumab or its dosage affects the efficacy and safety of CAR T-cell therapy. The objective of this multicenter retrospective study was to explore the impact of tocilizumab on CAR T-cell therapy. In total, 93 patients with B-cell acute lymphoblastic leukemia (B-ALL) receiving humanized anti-CD19 CAR T cells were recruited from May 2016 to November 2022. Forty-five patients received tocilizumab (tocilizumab group), whereas 48 patients did not (nontocilizumab group). Thirteen patients received >1 dose of tocilizumab. The primary end point was the effect of tocilizumab on the efficacy and safety of CAR T cells. Additionally, proliferation, killing, and cytokine assays of CAR T cells were performed in vitro in the presence of tocilizumab. The median age of the patients was 33 years, with 47 males and 46 females. Patients in the tocilizumab group showed similar complete response (CR) rate, overall survival (OS), and event-free survival (EFS) compared with the nontocilizumab group. Compared with patients who received ≤1 dose of tocilizumab, receiving >1 dose of tocilizumab did not affect their CR rate, OS, or EFS. In the tocilizumab group, all patients experienced CRS and 26.7% experienced immuneeffector cell-associated neurotoxicity syndrome (ICANS). In the nontocilizumab group, 64.6% of patients experienced CRS and 8.3% experienced ICANS. Up to 75% of ICANS and 87.5% of grade ≥3 ICANS occurred in the tocilizumab group. In vitro, tocilizumab did not impair the proliferation and killing effects of CAR T cells. Tocilizumab does not affect the efficacy of CAR T cells but may increase the likelihood of ICANS.

Abstract 1321: In vivo immune cell programming using mRNA-LNP chimeric antigen receptors

Abstract Introduction: The tumor microenvironment (TME) is a dynamic and multifaceted system that comprises largely myeloid lineage immune cells including monocytes, neutrophils, macrophages, and dendritic cells. Reprogramming the myeloid compartment within the context of cancer therapy presents an attractive strategy to overcome current limitations in solid tumor treatment. We have developed a novel approach that harnesses the natural ability of Myeloid cells to take up mRNA loaded lipid nanoparticles, to reprogram these cells with chimeric antigen receptors (CAR’s) that arm these cells to recognize and kill tumor cells. Methods: Current LNPs technology is sufficient to deliver significant mRNA cargo to numerous cell types, including B cells, T cells and myeloid cells. Leveraging this phenomenon we have developed a new class of chimeric antigen receptors (CARs), using protein biology that imparts targeted immune cell expression and functionality, specifically in Myeloid cells. These CARs harness Immunoreceptor Tyrosine-based Activation Motif (ITAM) signaling adaptors expressed exclusively in immune cells, achieving immune cell-type specific CAR-directed tumor lysis and cytokine responses. With a FcaR I (CD89) based CAR design, we have developed a CAR that is dependent on the common Fc receptor gamma chain, primarily restricted to myeloid cells, for stable expression and function. Results: We have demonstrated specific expression of CD89-based CAR in myeloid cells in mouse and monkey following systemic mRNA/LNP delivery, and in human myeloid cells following in vitro treatment with mRNA/LNPs. Systemic mRNA/LNP delivery of CD89-based CAR has demonstrated robust anti-tumor efficacy against multiple tumor antigens in various xenograft mouse models of human breast cancer, hepatocellular carcinoma, and ovarian cancer. Furthermore, in syngeneic mouse tumor models, robust anti-tumor immune responses, characterized by tumoral infiltration of activated CD8+ T cells, diminished tumor-associated Tregs, systemic enhancement of dendritic cells and anti-tumor IgG production, were observed for treated animals. Conclusions: Taken together, we present CAR designs that achieve expression and function in targeted immune cell populations, capable of eliciting anti-tumor efficacy against multiple target antigens by leveraging innate and adaptive immune responses, and demonstrating a class of novel CAR designs to overcome limitations faced by current in vivo mRNA/LNP delivery strategy. A phase I clinical trial is currently on-going to assess the safety and preliminary efficacy of CD89-based CAR against TROP2+ epithelial malignancies. Citation Format: Shannon Argueta, Franciele K. Melber, Michael Gorgievski, Neha Divangi, Edward Cochran, Thach Chu, Yuxiao Wang, Jian Ding, Daniel Getts. In vivo immune cell programming using mRNA-LNP chimeric antigen receptors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1321.

Systemically administered low-affinity HER2 CAR T cells mediate antitumor efficacy without toxicity

BackgroundThe paucity of tumor-specific targets for chimeric antigen receptor (CAR) T-cell therapy of solid tumors necessitates careful preclinical evaluation of the therapeutic window for candidate antigens. Human epidermal growth factor...

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

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

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

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

Efficacy and Safety of BCMA-Specific CAR T Cell-Based Therapy in Relapsed/Refractory Multiple Myeloma Patients with Extramedullary Disease

Background Extramedullary disease (EMD) is an aggressive subentity of multiple myeloma (MM), characterized by the ability of a subclone to grow independent of the bone marrow microenvironment, resulting in a high-risk state associated with increased proliferation, evasion of immune surveillance and treatment resistance. Relapsed/refractory multiple myeloma (R/R MM) patients with EMD have unfavorable prognoses and no effective treatment options. B-cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T-cell therapies have shown promising efficacy in R/R MM; however, data on patients with EMD remain limited. We aimed to assess the efficacy and safety of CAR T-cell therapy in R/R MM patients with EMD. Methods We conducted a retrospective multi-institutional study of 55 R/R MM patients confirmed with EMD at referral. The definition of EMD included (1) soft tissue masses in extraosseous locations resulting from hematogenous spread (EM-E) and (2) bone-related plasmacytomas that extend via disruption of cortical bones into contiguous soft tissues (EM-B). The overall response, long-term outcomes, and safety were assessed. We also characterized differential response between medullary and extramedullary disease, analyzed unique attributes of compartmental toxicity, and explored patterns of relapse in the setting of EMD. Gene expression profiling was performed using nCounter Human CAR-T Characterization Panel (NanoString, #XT-CSO-HCART1-12) on 40 biopsy specimens from patients enrolled in this study, including EMD and bone marrow biopsy specimens at pretreatment or/and at relapse. Results were analyzed based on outcome (no durable response [progression within 6 months, NDR] vs durable response [progression beyond 6 months, DR]). Multiplex immunofluorescence (mIF) was performed for detection of populations and phenotyping of infiltrated CD8 + T cells (Panel A: CD8/PD-1/LAG-3/TIM-3) and macrophages (Panel B: CD68/CD86/CD163) with EMD biopsies. Results The infusion resulted in an overall response rate of 90.9% (95% confidence interval [CI], 80.4-96.1) in medullary disease and 70.9% (95% CI, 57.9-81.2) in EMD ( P = 0.008). Discrepant outcomes between medullary and extramedullary response were observed, with suboptimal and delayed overall response and shortened duration of response achieved in EMD. With a median follow-up of 27.3 months, the median progression-free survival was 8.7 months (95% CI, 3.7-18.8), and the median overall survival was 16.0 months (95% CI, 13.5-20.1). Landmark analysis was conducted to compare OS in patients who progressed versus remained progression-free at the 6-month landmark time point. We demonstrated that progression before 6 months post-infusion is strongly associated with an increased risk of death (HR = 11.15 [95% CI, 3.49 to 35.60]; P &amp;lt; 0.001). Local cytokine release syndrome (CRS) was depicted in 21.8% patients and was moderately associated with the occurrence of systemic CRS (r = 0.322; P = 0.017). 78.2% patients experienced post-infusion progression in EMD, and BCMA + progression constituted the main pattern of EMD progression. At the time of EMD progression, peripheral CAR + cells were detectable, and 50% patients had ongoing documented B cell aplasia. We next interrogated NanoString gene expression data of tumor microenvironment (TME) genes for possible association with clinical response and toxicity. Pretreatment TME enriched for immune checkpoint, and type I interferon signaling were associated negatively with clinical outcomes. We found that the infiltration of type 2 macrophages (CD68 +CD163 +) in pretreatment TME is associated with the density of activated or exhausted CD8 + T cell ( PD-1 +LAG-3 +/-), and is associated with no durable response in EMD. We interrogated TME dynamic changes of patients developing EMD progression between cohorts of DR and NDR. An increase in immune counter-regulatory marker and lower diversity of T-cell receptor (TCR) repertoire, was observed at relapse in cohort of NDR. Discussion Our study shows that anti-BCMA CAR-T therapy has provided apparent therapeutic advantage over the existing drugs in response rate and long-term survival. Compared with medullary disease, BCMA-specific CAR T cell-based therapy showed limited and discrepant efficacy in EMD, perhaps due to the the properties of EMD-specific microenvironment.

Efficacy and Safety of Chimeric Antigen Receptor T Cells Therapy Strategy with Dual Targeting of CD19 and CD70 to Treat Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Background: Chimeric antigen receptor (CAR) T cells therapy is highly effective in the treatment of B-cell lymphoma, providing alternative therapeutic options for patients who failed to respond to conventional treatment or relapse. Despite impressive progress, more than 30-50% of patients treated with CD19 CAR-T cells experienced progressive disease. Antigen escape is one of the common causes of relapse, especially CD19-negative relapse. Absent or decreased cell surface CD19 as a mechanism of resistance after CD19 CAR-T cells treatment. CD70 is a novel and promising therapeutic target due to the restricted expression pattern in normal tissues and over expression in some lymphoma tissues. Our center explored the efficacy and safety of CAR-T cells therapy with dual targeting of CD19 and CD70 in the treatment of r/r lymphoma. Patients and Methods: The study included 8 relapsed/refractory diffuse large B-cell lymphoma patients, all patients have exhausted all available treatment options with progressive or stable disease and life expectancy &amp;gt;2 months were enrolled in the study. All patients expressed strong positivity of CD19 and CD70, all of patient details can be found in the table (Fig.1). Autologous T cells were apheresis collected and transduced with an apoptosis-inducible, safety-engineered lentiviral CAR with the following intracellular signaling domains: CD28/CD27/CD3z-iCasp9. All patients received cyclophosphamide/fludarabine chemotherapy conditioning 1-2 days before infusions of CAR-T cells. The quality of apheresis cells, efficiencies of gene transfer and T cell proliferation, CAR-T infusion dose and blood CAR copies were quantitatively documented. Results: In the first months after CAR-T cells infusion, 75.0% (6/8) of patients achieved complete response (CR), while 12.5% (1/8) of patients evaluated as partial response (PR) and 12.5% (1/8) of patients as progressive disease (PD), overall response rate (ORR) is 87.5% (7/8). In the evaluation of safety, 37.5% (3/8) of patients experienced cytokine release syndrome (CRS), and 25% (2/8) of patients experienced grade 1 CRS and 12.5% (1/8) of patients experienced grade 2 CRS, no case of severe CRS defined as≥grade 3 and no immune effector cell-associated neurotoxicity syndrome (ICANS) occurred. After a median follow-up of 19.9 months, 50% (4/8) of patients maintained CR, while 37.5% (3/8) of patients were relapsed, with a duration of response (DOR) of 50% (4/8), median DFS was 10.5 months and median OS was not reached (Fig.2). Conclusions: In summary, our research data confirms that the efficacy and safety of CD19/CD70 dual targeted CAR-T cells infusion, continued follow-up will determine whether the CD19/CD70 CAR-T cells therapy can obtain long term overall survival in our study. How to further improve the efficacy and safety of dual target CAR-T is still worth exploring. It's needed to optimize multi-specific targeting by CAR-T cells to improve the efficacy both in B cell malignancies and other hematological malignancies.

Efficacy and Safety of TLR2 Co-Stimulated CAR T Cells in CD19-Positive Lymphoid Malignancies with Central Nervous System Involvement

Background CD19 chimeric antigen receptor (CAR) T cell therapy showed remarkable remission rates in patients with refractory or relapsed (R/R) non-Hodgkin's lymphoma (NHL) and acute lymphoblastic leukemia (ALL). However, data on outcomes of CAR T cell therapy for patients with central nervous system (CNS) involvement are limited, as most of them have been excluded from most pivotal CAR-T studies because of concerns about treatment-related neurotoxicity. Here, we show results of a third generation of CD19 CAR T cells for patients with R/R B cell cancers with CNS involvement in a single-center cohort study. Methods A total of 21 patients with R/R B cell malignancies (including ALL and NHL) with CNS involvement were included in this study. Patients derived peripheral lymphocytes were collected through apheresis and lentivirally transduced with a 3 rd generation CAR containing CD28 and TLR2 co-stimulatory domains. The cells were expanded ex vivo and administered in a single infusion (1×10 6 or 2×10 6 CAR T cells per kilogram of body weight) after a conditioning regimen of cyclophosphamide and fludarabine. Results Of the 21 patients with CNS involvement, 11 patients with ALL and 10 with NHL were included in this study, with a data cutoff of July 2023. All 11 patients with ALL had both bone marrow (BM) and cerebrospinal fluid (CSF) involvement. Of the 10 patients with NHL, 5 of the 10 lymphoma patients had parenchyma involvement, 6 patients (6/10) had CSF infiltration and 1 had oculus sinister involvement; the majority of patients (8/10) were diagnosed with secondary CNS lymphoma, whereas 2 patient was primary CNS lymphoma. Of the 21 patients who were treated, the overall response rate (ORR) was 71% (15/21), with 73% (8/11) in ALL and 70% (7/10) in NHL. 67% of patients with ALL (7/11) had a complete remission in both BM and CSF, while 40% of NHL patients (4/10) had a complete response and 30% (3/10) received a partial response. The median overall survival (OS) of ALL was 14.3 months, with a median follow-up of 20.3 months, while the median OS of NHL was not reached with a median follow-up of 14.2 months. Median progression-free survival (PFS) of ALL and NHL were 11.1 months (95% CI, 0.7-29.9 months) and 4.8 months (95% CI, 1.0-15.3 months), respectively (P = 0.84). In the total CNS cohort, cytokine release syndrome (CRS) of any grade was seen in 20 patients (95%), grade 3 in 3 patients (14%). ICANS occurred in 9 patients (42.8%, including 5 ALL and 4 NHL patients), grade 3 in 5 patients (23.8%), and there was no grade 4 event. Median time to ICANS was 5 days (range, 2-10 days) after CAR-T infusion. All the CRS or ICANS were manageable. No significant difference in occurrence of and time to ICANS was seen between ALL and NHL patients (P = 0.22 and 0.96). CAR T cells were identified in CSF of patients following infusion, and the median time to peak CAR T cells in CSF of ALL and NHL were 6.5 days and 10 days post-infusion, respectively (P = 0.141). Median time to last documented follow-up of all patients (alive or dead) was 18.1 months (range 1.0-31.2 months). At the end point of observation, 5 of the 11 ALL patients and 5 of 10 NHL patients were still alive with sustained CR of CNS disease and systemic disease (Figure 1). Conclusion TLR2-costimulated CAR T cell therapy for patients with R/R B cell malignancies with CNS involvement is safe, feasible, and results in high response rates and durable remission in both ALL and NHL patients with CNS disease. The clinical trial was registered at www.clinicaltrials.gov as # NCT04605666.

3-Year Analysis of ZUMA-12: A Phase 2 Study of Axicabtagene Ciloleucel (Axi-Cel) As First-Line Therapy in Patients with High-Risk Large B-Cell Lymphoma (LBCL)

Background: Axi-cel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for the treatment of relapsed/refractory (R/R) LBCL. ZUMA-12 (NCT03761056) is a Phase 2, multicenter, single-arm study of axi-cel as part of first-line treatment in patients with high-risk LBCL. In the primary efficacy analysis (n=37; median follow-up of 15.9 months), axi-cel demonstrated a high rate of investigator-assessed complete response (CR; 78%; 95% CI, 62-90) and an 89% objective response rate (ORR; 95% CI, 75-97). Axi-cel also had a manageable safety profile, with no new safety signals observed in the first-line setting (Neelapu et al. Nat Med. 2022). Here, we report updated efficacy and safety outcomes from ZUMA-12 in all patients treated with axi-cel after a median follow-up of ≥40 months. Methods: Eligible adults had high-risk LBCL, with MYC and BCL2 and/or BCL6 rearrangements (double- or triple-hit histology) per investigator or an International Prognostic Index (IPI) score ≥3, plus a positive interim PET per Lugano classification (Deauville score 4/5) after 2 cycles of an anti-CD20 monoclonal antibody and anthracycline-containing regimen. Patients underwent leukapheresis, followed by lymphodepleting chemotherapy (cyclophosphamide and fludarabine) on Days -5, -4, and -3, and a single axi-cel infusion of 2×10 6 CAR T cells/kg on Day 0. Per investigator discretion, non-chemotherapy bridging could be administered. The primary endpoint was investigator-assessed CR rate per Lugano classification (Cheson et al. J Clin Oncol. 2014). Secondary endpoints included ORR, duration of response (DOR), event-free survival (EFS), progression-free survival (PFS), overall survival (OS), safety, and levels of CAR T cells in blood and cytokines in serum. Results: As of May 3, 2023, 42 patients were enrolled and 40 were treated with axi-cel, with a median follow-up of 40.9 months (range, 29.5-50.2). In total, 37 patients were evaluable for response (centrally confirmed double- or triple-hit histology or IPI score ≥3). The CR rate was 86% (95% CI, 71-95), and 92% (95% CI, 78-98) of patients had an objective response. Patients with centrally confirmed double- or triple-hit histology (n=10) had a CR rate of 90%. Responses were ongoing in 73% of response-evaluable patients at data cutoff. Medians for DOR, EFS, PFS, and OS were not reached. The 36-month estimates for DOR, EFS (Figure 1), PFS, and OS (Figure 2) were 82%, 73%, 75%, and 81%, respectively. All treated patients (n=40) experienced adverse events (AEs) of any grade and 88% of patients had grade ≥3 AEs. Similar to the primary analysis, the most common any-grade AEs were pyrexia (100%), headache (70%), and neutrophil count decreased (55%). No new cases of cytokine release syndrome (CRS) or neurologic events of any grade occurred since the prior data cut and all cases of CRS and neurologic events reported were resolved by data cutoff. Prolonged cytopenias of any grade (present Day ≥30 post-infusion) occurred in 9 patients (n=7 neutrophil count decreased) and were resolved by data cutoff. There were 8 deaths due to progressive disease (n=5) and other causes not related to axi-cel (1 COVID-19, 1 esophageal adenocarcinoma, 1 septic shock on Days 350, 535, and 287 post axi-cel infusion, respectively). Two of the 8 deaths (1 progressive disease and 1 esophageal adenocarcinoma) occurred after the primary analysis. Among treated patients, post-infusion CAR T-cell expansion by peak and area under the curve was 36.9 cells/µL and 368.0 cells/µL×days, respectively, in those with ongoing responses at data cutoff (n=17), 45.1 cells/µL and 413.4 cells/µL×days in those who relapsed (n=6), and 34.7 cells/µL and 566.8 cells/µL×days in non-responders (n=3). Conclusion: In this updated analysis of ZUMA-12 with a median follow-up of ≥40 months, axi-cel demonstrated a high rate of durable responses and no new safety signals. Axi-cel may benefit patients exposed to fewer prior therapies and those with high-risk LBCL, a population with high unmet need and poor outcomes after standard first-line chemoimmunotherapy.

Safety and Efficacy of GPRC5D CAR T Cell Therapy in Relapsed/Refractory Multiple Myeloma Patients

B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapies have shown breakthrough therapeutic effects in treating relapsed/refractory (R/R) multiple myeloma patients. However, relapses, including some that are BCMA negative, remain a challenge. Here we have developed a second-generation GPRC5D CAR-T, composed of a GPRC5D-binding scFv (derived from a humanized rabbit monoclonal antibody), a 4-1BB costimulatory domain, and a CD3ζ signaling domain. Following pre-clinical studies, we initiated a phase 1 dose-escalation clinical trial. Lymphodepletion with fludarabine and cyclophosphamide was performed before administering 3E6, 6E6, or 1E7/kg anti-GPRC5D CAR T cells. To date, we have enrolled a total of 7 R/R MM patients, including 3 patients with prior BCMA CAR-T treatment. All patients received autologous CAR T-cell infusions and were clinically evaluated between February 7th, 2023, and June 26th, 2023. No dose-limiting toxicities (DLT) were observed, even at the highest dose of 1E7/kg. Grade 3 or higher adverse events (AEs) were mainly hematological toxicities, such as neutropenia (6 [85.7%]), anemia (3 [43%]), and thrombocytopenia (3 [43%]). Cytokine release syndrome occurred in 6 (85.7%) of 7 patients, with all cases classified as grade 1 or 2. Notably, no neuro-toxicities were observed in any of the seven patients. The overall response rate was 85.7% (6/7 patients), comprising 3 complete responses or better, 3 partial responses, and one no-response (NR). The NR patient had previously shown no response to BCMA CAR-T therapy, with FACS analysis confirming the absence of both BCMA and GPRC5D on their tumor cells. Interestingly, the other two patients previously treated with BCMA CAR T-cell therapy, one reached complete response (CR), and the other reached partial response (PR). Remarkably, one patient diagnosed as COVID-19 positive two days before CAR-T infusion still received the CAR-T cell product, which led to a dramatic in vivo expansion of CAR-T cells, resulting in CR within one month after cell infusion. In conclusion, GPRC5D CAR T-cell therapy demonstrated promising clinical efficacy and tolerable safety in patients with R/R MM. For those who relapsed after anti-BCMA CAR T-cell therapy, GPRC5D CAR T-cell therapy offered an effective option (NCT05739188).“

Assessment of Activities of Daily Living (ADL)Scale Can be Used to Predict Overall Survival after CAR-T Cell Therapy in Elderly Patient(over 70 years of age) with Refractory/Relapsed B-Cell Lymphoma

Background:The advent of chimeric antigen receptor (CAR) T-cell therapy has changed the treatment landscape for refractory/relapsed B-cell lymphoma (r/r B-NHL). However, there are limited data on outcomes in older patients (age≥65 years) treated with CAR -T-cell therapy, particularly in patients older than 70 years. Objectives:Our objective was to evaluate the efficacy of CAR -T-cell therapy in elderly patients with r/r B-NHL, including response rates, progression-free survival (PFS), and overall survival (OS), as well as factors affecting survival. Methods:As of April 1, 2023, a total of 80 patients with r/r B-NHL in the age group 65-70 years (n=57) or older than 70 years (n=23) were included. Diagnoses included DLBCL NOS (n=58) ,HGBCL(n=6) ,TFL(n=6), Richter(n=4) and Other(n=6). Baseline characteristics are described in Table 1.All patients were heavily pretreated. 71/80 (88.75%) patients were at stage III-IV. The median IPI score was 3 (range 1-5). 8/96 (10%) patients failure of prior autologous hematopoietic stem cell transplantation (HSCT). The median assessment score of ADL scale was 95 for both the 65-70 and &amp;gt; 70 age groups, and 47.5% of patients received bridging therapy(BT) prior to CAR -T cell therapy. There were no significant differences in baseline data between age groups. Prior to the study, CD19/CD22 antigen expression in tumor tissue was confirmed by pathology, and the target was selected according to antigen expression. The kinetics and function of CAR -T cells were monitored by quantitative PCR and flow cytometry. Efficacy was assessed by PET-CT every 3 months after CAR -T therapy. All p-values were two-sided values. Survival curves were calculated by the Kaplan-Meier method. Results: The number of patients who chose a CD19 target or a CD19/CD22 dual target for CAR -T therapy was 67/80 (%) and 13/80 (%), respectively. The median CAR -T cells infused dose in the 65-70 and &amp;gt; 70 age groups was 1.3 (range, 0.0485-9.5) and 1.6 (range, 0.088-3.91) (×106/Kg), respectively (P=0.9618).(Table 2).There were no differences between the 2 age groups in the occurrence of cytokine release syndrome (CRS) grade 3 or higher(P=0.6221). The proportion of patients using glucocorticoid therapy for CRS was higher in the age group &amp;gt; 70 years than in the age group 65-70 years, but there was no statistically significant difference (P=0.0957). A response occurred in 35/57 (61.4%) of patients in the 65-70 years age group and in 14/23 (60.7%) of patients in the &amp;gt; 70 years age group (P=0.9646), with a complete response in 21/57 (36.8%) and 8/23 (34.8%), respectively (P=0.8623). At a median follow-up of 8.05 months (95% CI: 10.27-15.20), 12-month overall survival(OS) was 54.6% (95%CI: 39.3%-67.6%) vs 72.1% (95%CI:43.9%-87.8%) at ages 65-70 vs &amp;gt; 70,12-month progression-free survival (PFS) was 32.8% (95%CI: 19.8%-46.5%) vs 32.9% (95%CI: 13.5%-54%), and there was no significant difference in OS (p=0.0623) and PFS(p=0.6327) by age group. In contrast, patients aged &amp;gt; 70 with ADL &amp;lt; 95 showed significantly shorter 12-m OS (0) compared to patients aged 65-70 with ADL≥95(55.2%,95%CI:35.5%-71.1%) or ADL &amp;lt; 95(40.5%, 95%CI: 14.2%-59.9%), or &amp;gt; 70 with ADL≥95(85.6%, 95%CI:52.5%-96.3%), respectively (Figure 1: P= 0.0069). The three negative factors comprising the prognostic tool OS: low ADL scores (P=0.0124), high IPI scores (P=0.0029), and presence of extranodal lesions (P=0.0143). Conclusions: Our data suggest that the safety and efficacy of CAR -T-cell therapy in &amp;gt; 70-year-old patients is not significantly different from that in 65-70-year-olds. Elderly patients with ADL scores below 95 have poor survival after CAR -T therapy, especially those over 70 years of age. However, studies on curative approaches and long-term follow-up are needed.

Conditional Control of Universal CAR T Cells by Cleavable OFF-Switch Adaptors.

As living drugs, engineered T cell therapies are revolutionizing disease treatment with their unique functional capabilities. However, they suffer from limitations of potentially unpredictable behavior, toxicities, and nontraditional pharmacokinetics. Engineering conditional control mechanisms responsive to tractable stimuli such as small molecules or light is thus highly desirable. We and others previously developed "universal" chimeric antigen receptors (CARs) that interact with coadministered antibody adaptors to direct target cell killing and T cell activation. Universal CARs are of high therapeutic interest due to their ability to simultaneously target multiple antigens on the same disease or different diseases by combining with adaptors to different antigens. Here, we further enhance the programmability and potential safety of universal CAR T cells by engineering OFF-switch adaptors that can conditionally control CAR activity, including T cell activation, target cell lysis, and transgene expression, in response to a small molecule or light stimulus. Moreover, in adaptor combination assays, OFF-switch adaptors were capable of orthogonal conditional targeting of multiple antigens simultaneously, following Boolean logic. OFF-switch adaptors represent a robust new approach for the precision targeting of universal CAR T cells with potential for enhanced safety.

Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting

Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumors. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies. Here, we describe CAR T cells targeting tumor-associated glycoprotein-72 (TAG72), utilizing the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFNγ secretion. CAR T cell-mediated IFNγ production facilitated by IL-12 signaling is required for tumor cell killing, which is recapitulated by engineering an optimized membrane-bound IL-12 (mbIL12) molecule in CAR T cells. These T cells show improved antigen-dependent T cell proliferation and recursive tumor cell killing in vitro, with robust in vivo efficacy in human ovarian cancer xenograft models. Locoregional administration of mbIL12-engineered CAR T cells promotes durable anti-tumor responses against both regional and systemic disease in mice. Safety and efficacy of mbIL12-engineered CAR T cells is demonstrated using an immunocompetent mouse model, with beneficial effects on the immunosuppressive tumor microenvironment. Collectively, our study features a clinically-applicable strategy to improve the efficacy of locoregionally-delivered CAR T cells engineered with antigen-dependent immune-modulating cytokines in targeting regional and systemic disease.

Systematic single amino acid affinity tuning of CD229 CAR T cells retains efficacy against multiple myeloma and eliminates on-target off-tumor toxicity.

T cells expressing chimeric antigen receptors (CARs) have shown remarkable therapeutic activity against different types of cancer. However, the wider use of CAR T cells has been hindered by the potential for life-threatening toxicities due to on-target off-tumor killing of cells expressing low amounts of the target antigen. CD229, a signaling lymphocyte-activation molecule (SLAM) family member, has previously been identified as a target for CAR T cell-mediated treatment of multiple myeloma (MM) due to its high expression on the surfaces of MM cells. CD229 CAR T cells have shown effective clearance of MM cells in vitro and in vivo. However, healthy lymphocytes also express CD229, albeit at lower amounts than MM cells, causing their unintended targeting by CD229 CAR T cells. To increase the selectivity of CD229 CAR T cells for MM cells, we used a single amino acid substitution approach of the CAR binding domain to reduce CAR affinity. To identify CARs with increased selectivity, we screened variant binding domains using solid-phase binding assays and biolayer interferometry and determined the cytotoxic activity of variant CAR T cells against MM cells and healthy lymphocytes. We identified a CD229 CAR binding domain with micromolar affinity that, when combined with overexpression of c-Jun, confers antitumor activity comparable to parental CD229 CAR T cells but lacks the parental cells' cytotoxic activity toward healthy lymphocytes in vitro and in vivo. The results represent a promising strategy to improve the efficacy and safety of CAR T cell therapy that requires clinical validation.

CD19-Targeting CAR T Cells for Myositis and Interstitial Lung Disease Associated With Antisynthetase Syndrome

Autoimmune disorders can affect various organs and if refractory, can be life threatening. Recently, CD19-targeting-chimeric antigen receptor (CAR) T cells were efficacious as an immune suppressive agent in 6 patients with refractory systemic lupus erythematosus and in 1 patient with antisynthetase syndrome. To test the safety and efficacy of CD19-targeting CAR T cells in a patient with severe antisynthetase syndrome, a complex autoimmune disorder with evidence for B- and T-cell involvement. This case report describes a patient with antisynthetase syndrome with progressive myositis and interstitial lung disease refractory to available therapies (including rituximab and azathioprine), who was treated with CD19-targeting CAR T cells in June 2022 at University Hospital Tübingen in Tübingen, Germany, with the last follow-up in February 2023. Mycophenolate mofetil was added to the treatment to cotarget CD8+ T cells, hypothesized to contribute to disease activity. Prior to treatment with CD19-targeting CAR T cells, the patient received conditioning therapy with fludarabine (25 mg/m2 [5 days before until 3 days before]) and cyclophosphamide (1000 mg/m2 [3 days before]) followed by infusion of CAR T cells (1.23×106/kg [manufactured by transduction of autologous T cells with a CD19 lentiviral vector and amplification in the CliniMACS Prodigy system]) and mycophenolate mofetil (2 g/d) 35 days after CD19-targeting CAR T-cell infusion. The patient's response to therapy was followed by magnetic resonance imaging of the thigh muscle, Physician Global Assessment, functional muscle and pulmonary tests, and peripheral blood quantification of anti-Jo-1 antibody levels, lymphocyte subsets, immunoglobulins, and serological muscle enzymes. Rapid clinical improvement was observed after CD19-targeting CAR T-cell infusion. Eight months after treatment, the patient's scores on the Physician Global Assessment and muscle and pulmonary function tests improved, and there were no detectable signs of myositis on magnetic resonance imaging. Serological muscle enzymes (alanine aminotransferase, aspartate aminotransferase, creatinine kinase, and lactate dehydrogenase), CD8+ T-cell subsets, and inflammatory cytokine secretion in the peripheral blood mononuclear cells (interferon gamma, interleukin 1 [IL-1], IL-6, and IL-13) were all normalized. Further, there was a reduction in anti-Jo-1 antibody levels and a partial recovery of IgA (to 67% of normal value), IgG (to 87%), and IgM (to 58%). CD19-targeting CAR T cells directed against B cells and plasmablasts deeply reset B-cell immunity. Together with mycophenolate mofetil, CD19-targeting CAR T cells may break pathologic B-cell, as well as T-cell responses, inducing remission in refractory antisynthetase syndrome.

Embracing Myeloma Chimeric Antigen Receptor-T: From Scientific Design to Clinical Impact.

Despite recent advancement of treatment strategies in multiple myeloma (MM), patients with relapsed/refractory MM disease, particularly after triple-class refractoriness, continue to have poor prognosis. Chimeric antigen receptor (CAR-T) cells were developed and applied to improve outcomes in this setting, and two products, idecabtagene vicleucel and ciltacabtagene autoleucel, both targeting B-cell maturation antigen, have been approved by the Food and Drug Administration in the United States and European Medicines Agency in Europe. Both have shown unprecedented clinical outcomes with high response rate and prolonged progression-free survival and overall survival in this patient population with grim prognosis. Currently, further investigations are ongoing for CAR-T targeting different tumor antigens such as G protein-coupled receptor, class C, group 5, member D or with different combinations of intracellular signaling domains, as well as fourth-generation CAR-T with antigen-unrestricted inducible cytokines. Although CAR-T therapies hold hopes and enthusiasm from the myeloma community, several hurdles remain before these treatments become available for all patients in need. These barriers include CAR-T-cell manufacturing availability, access to administering centers, financial cost, caregivers' availability, and socioeconomic and racial disparities. Expanding clinical trial eligibility criteria and real-world data collection and analysis is crucial to understand the efficacy and safety of CAR-T in the patient cohort who tends to be excluded from current trials.

Efficacy and safety of chimeric antigen receptor T cell therapy in relapsed/refractory diffuse large B-cell lymphoma with different HBV status: a retrospective study from a single center.

Chimeric antigen receptor T cell (CAR-T) therapy is an effective salvage treatment in relapsed or refractory(r/r) diffuse large B-cell lymphoma (DLBCL), but the impact of hepatitis B virus (HBV) infection has not been studied. Here, 51 patients with r/r DLBCL receiving CAR-T therapy were enrolled and analyzed at the First Affiliated Hospital of Soochow University. The overall response rate and the complete remission rate (CR) of CAR-T therapy were 74.5% and 39.2%, respectively. With a median follow-up of 21.1 months after CAR-T, the probabilities of overall survival (OS) and progression-free survival (PFS) at 36 months were 43.4% and 28.7%, respectively. These patients were divided into three cohorts including chronic HBV infection group (n=6), resolved HBV infection group (n=25) and non-HBV infection group (n=20). Bone marrow involvement was significantly higher in the HBV infection group(P<0.001), other basic characteristics before CAR-T therapy were comparable. Subgroup analysis showed that HBV infection status did not affect the efficacy of CAR-T therapy in CR rate, OS or PFS, and there was no significant difference in CAR-T related toxicities between three cohorts. Only one cirrhosis patient with chronic HBV infection experienced HBV reactivation. CAR-T therapy was effective and can be used safely in r/r DLBCL with HBV infection under proper monitoring and antiviral prophylaxis.