Use Of Chimeric Antigen Receptor Research Articles

Adverse events associated with chimeric antigen receptor T-Cell therapy in ophthalmology: a narrative review

Chimeric antigen receptors are synthetically produced receptors engineered to engage with target cells with high specificity. These cells are created by inserting an artificial T-cell receptor into an immunoglobulin’s antigen-binding region, allowing the cells to combine and target specific antigens. The use of chimeric antigen receptor (CAR) T-cell therapy has been a remarkable achievement in the field of immunotherapy, particularly in the treatment of ophthalmic tumors like retinoblastoma and uveal melanoma. However, there are some documented side effects, such as cytokine release syndrome (CRS) and immunological effector cell-associated neurotoxicity syndrome (ICANS). Additionally, ocular side effects such as blurred vision, vision impairment, and intraocular infections are also concerning and require further evaluation. This review highlights the advances made in chimeric antigen receptor (CAR) immunotherapy, including its structure and manufacture, as well as relevant clinical discoveries and associated adverse effects. By identifying the gaps in current research, this analysis provides insights into potential strategies and solutions for addressing some of the most severe side effects.

CAR-T CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA

The treatment outcomes of patients with chronic lymphocytic leukemia (CLL) have considerably improved with the introduction of targeted therapies based on Bruton kinase inhibitors (BTKIs), venetoclax, and anti-CD20 monoclonal antibodies. However, despite these consistent improvements, patients who become resistant to these agents have poor outcomes and need new and more productive therapeutic strategies. Among these new treatments, a potentially curative approach consists of the use of chimeric antigen receptor T (CAR-T) cell therapy, which achieved remarkable success in various B-cell malignancies, including B-cell Non-Hodgkin Lymphomas (NHLs) and B-acute lymphoblastic Leukemia (ALL). However, although CAR-T cells were initially used for the treatment of CLL, their efficacy in CLL patients was lower than in other B-cell malignancies. This review analyses the possible mechanisms of these failures. It highlights some recent developments that could offer the perspective of the incorporation of CAR-T cells in treatment protocols for relapsed/refractory CLL patients. Keywords: Chronic Lymphoid Leukemia; CLL; CAR-T Cells; Relapsed/resistant CLL:

InsT-ALLing CD7 chimeric antigen receptors before transplantation.

In their paper, the authors present their experience with the use of chimeric antigen receptor T cells targeting CD7 as a bridge to allogeneic haematopoietic cell transplantation in patients with relapsed/refractory T-cell acute lymphoblastic leukaemia/lymphoblastic lymphoma. Commentary on: Cao etal. A safety and efficacy study of allogeneic haematopoietic stem cell transplantation for refractory and relapsed T-cell acute lymphoblastic leukaemia/lymphoblastic lymphoma patients who achieved complete remission after autologous CD7 chimeric antigen receptor T-cell therapy. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19445.

Abstract 6313: Enhancing CAR T cell-based immunotherapy outcomes in PDAC: Evaluating iC9.B7-H3 CAR T cells in adjuvant, neoadjuvant, and monotherapy settings

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive and lethal cancers worldwide. Despite negative margin resections and subsequent systemic therapy, PDAC often recurs. Additionally, most patients present with locally advanced and unresectable tumors at the time of diagnosis. Cancer-associated fibroblasts (CAFs) contribute to the highly desmoplastic tumor microenvironment (TME) and form a biophysical barrier, limiting immune cell infiltration. Moreover, CAF-secreted factors suppress the anti-tumor activity of T cells and shift cancer cells toward invasive proliferative and mesenchymal phenotypes. Therefore, targeting CAFs can enhance T-cell infiltration and improve the efficacy of T-cell based immunotherapeutic strategies. B7-H3 is an immune checkpoint molecule highly expressed on PDAC cells and CAFs. In this study, we investigate the use of Chimeric Antigen Receptor (CAR) T cells targeting B7-H3 to eliminate metastatic PDAC in a preclinical mouse model in three different settings: I. Adjuvant II. Neoadjuvant III. CAR T cell monotherapy. Our CART-B7-H3 construct includes an inducible caspase 9 (iC9) suicide gene, which allows for the controlled elimination of the CAR T cells in the event of overwhelming cytokine release syndrome. Methods: To validate the therapeutic potential of iC9.B7-H3 CAR T cells in vivo, NSG mice were orthotopically engrafted with 1x105 patient-derived PDAC6 cells and 9x105 hCAF1 cells at a ratio of 1:9, reflecting a clinically relevant model. In the adjuvant group, mice underwent surgical resection of the primary tumor (distal pancreatectomy and splenectomy) after 25 days. On days 30 and 60, they received systemic iC9.B7-H3 CAR T cell treatment (5x106). In the neoadjuvant group, mice were systemically treated with iC9.B7-H3 CAR T cells on day 19 and underwent surgical resection of the primary tumor on day 25, following another systemic CAR T cell dose on day 60. In the CAR T monotherapy group, mice received systemic iC9.B7-H3 CAR T cells on days 19 and 60. Results: In vivo, iC9.B7-H3 CAR T cells in the neoadjuvant group effectively eradicated both local and distant PDAC metastases for the length of the experiment (180 days) and significantly increased the survival (P <0.0001), indicating long-term efficacy in the treatment of PDAC metastases with no adverse side effects. In the adjuvant and CAR T monotherapy groups, iC9.B7-H3 CAR T cells effectively control tumor growth, eliminate metastases, and significantly increase survival (P=0.0018 and P=0.0007, respectively). Conclusion: These data suggest that the neoadjuvant application of iC9.B7-H3 CAR T cells may demonstrate persistent efficacy in eradicating both local and distant PDAC metastases. iC9.B7-H3 CAR T cells adjuvantly and as monotherapy achieved significant tumor control. Citation Format: Shahrzad Arya, Seyed Amir Sanatkar, Marco Ventin, Giulia Cattaneo, Cristina Martin, Gabriella Lionetto, Jingyu Jia, Feng Chen, David T. Ting, Xinhui Wang, Sandra Ryeom, Cristina R. Ferrone, Soldano Ferrone. Enhancing CAR T cell-based immunotherapy outcomes in PDAC: Evaluating iC9.B7-H3 CAR T cells in adjuvant, neoadjuvant, and monotherapy settings [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 6313.

Abstract 2699: Application of whole genome loss of function CRISPR screen in primary natural killer cells

Abstract Natural killer cells (NKs) are cytotoxic lymphocytes of the innate immune system, operating against infections and cancer. NKs act in an antigen independent manner, preventing graft versus host disease in allogeneic settings. NKs can be isolated from healthy donors, activated, expanded and safely administered to cancer patients. Although NKs are highly cytotoxic against cancer cells in vitro, they lose viability and functionality in the suppressive tumor microenvironment (TME). Until recently, viral transduction of primary NKs was considered a technical hurdle. The latest progress using Baboon Lentiviral (BaLV) pseudotyping substantially increased transduction rates and facilitated the use of chimeric antigen receptor (CAR) NKs for cancer immunotherapies. Due to this challenge, most genetic manipulations were performed in single genes with limited capabilities. Large-scale functional manipulation of NKs using CRISPR-cas9 editing was not implemented, leaving a gap in our understanding of NK suppression. We generated a whole genome library of 55,548 guide RNAs (gdRNAs, 4 per gene), targeting 13,749 genes that were determined to be expressed in NKs and 138 (10%) olfactory receptor genes that are not expressed in NKs as control gdRNAs. The gdRNA plasmid was optimized based on our CAR-NK backbone, to express the gdRNA scaffold under U6 promotor and GFP under EF1α promotor. The library plasmids were sequenced and their gaussian distribution was verified, with high representation of all the different gdRNAs. Primary NKs were isolated from 3 healthy donors and transduced at 25% transduction rates using our optimized BaLV system. After a week expansion in vitro, NKs were electroporated with protein cas9-RFP using the maxCyte electroporator. RFP levels at 6 hours after electroporation were at least 80%. The cells were profiled after electroporation for cytotoxicity and for functionality against the K562 target cell line. IFNγ production and degranulation (CD107a) were similar before and after electroporation. Genomic DNA was extracted from the transduced NKs and the gdRNA barcodes were amplified by PCR and sequenced. The distribution of the gdRNA barcodes after sequencing exhibited high representation of almost all gdRNAs, with minimal loss of gdRNAs. Several gene knockouts were identified as important for survival/proliferation of NKs and are being validated using single gdRNAs in vitro and in vivo. NK cell immunotherapy is a promising approach for cancer treatment. Although recent clinical trials with CAR-NK present exciting results, many solid tumors do not benefit from NK immunotherapies due to the inactivation of NKs in the immune-suppressive TME. Here, we successfully implemented an unbiased genome wide loss-of-function CRISPR screen as an effective and informative method to identify novel candidates for NK cell suppression. Citation Format: Michal Sheffer, Isabel E. Kaplan, Eden Bobilev, Yasmin Z. Abdulhamid, Rizwan Romee. Application of whole genome loss of function CRISPR screen in primary natural killer cells [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 2699.

Abstract 6311: From bench to bedside: GMP manufacturing and testing of an LGR5-targeting CAR-T against colorectal cancer

Abstract Colorectal cancer is the third most diagnosed cancer worldwide, and is responsible for the second largest number of cancer related deaths, warranting the need for new treatments. The successful use of chimeric antigen receptor T (CAR-T) cells against B-cell malignancies has inspired the search for CAR-T cell therapies against solid tumours such as colorectal cancer. Cancer stem cells (CSC) are a small population of cells within a tumour with the capacity to self-renew, differentiate, and initiate new tumours. CSC are resistant to chemotherapy and radiotherapy and are enriched in residual disease. Targeting CSC is a strategy to reduce the tumours’ ability to generate new cells. Leucine-rich G protein-coupled receptor 5 (LGR5) is a marker of CSC and LGR5+ cancer cells are implicated in tumour progression and metastasis in colorectal cancer. We designed and tested a chimeric antigen receptor (CAR) targeting the extracellular domain of LGR5. LGR5-targeting CAR-T cells showed significant antigen-specific cytotoxicity and IFNγ release against colorectal cancer (CRC) cell lines in vitro, and in vivo efficacy in a CRC xenograft mouse model. We confirmed the specificity and safety of the LGR5 targeting CAR-T cells by testing against normal human tissues. A GMP ready protocol for clinical scale manufacture of LGR5-targeting CAR-T cells have been developed using CD3+ T-cells from healthy donors. We have successfully tested this protocol using CRC patient-derived CD3+ T-cells and were able to generate clinically relevant cell numbers (80-fold expansion) with high CAR expression. Cells manufactured using this GMP protocol expressed markers of self-renewing naïve-like and central memory phenotype and showed very low percentage of cells that were triple-positive for PD1, TIM3 and LAG3. This protocol has been successfully tested and validated in a GMP manufacturing facility for the production of LGR5 targeting CAR-T cells, in preparation for an FDA approved first in man clinical trial against metastatic colorectal cancer, starting in 2023 (NCT05759728). Citation Format: Veronika Bandara, Batjargal Gundsambuu, Silvana Napoli, Jade Foeng, Dylan McPeake, Timona Tylis, Emma Thompson, Stuart Mills, Allison Cowin, Claudine Bonder, Timothy Sadlon, Shaun McColl, Simon Barry. From bench to bedside: GMP manufacturing and testing of an LGR5-targeting CAR-T against colorectal cancer [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 6311.

Advancements in γδT cell engineering: paving the way for enhanced cancer immunotherapy.

Comprising only 1-10% of the circulating T cell population, γδT cells play a pivotal role in cancer immunotherapy due to their unique amalgamation of innate and adaptive immune features. These cells can secrete cytokines, including interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), and can directly eliminate tumor cells through mechanisms like Fas/FasL and antibody-dependent cell-mediated cytotoxicity (ADCC). Unlike conventional αβT cells, γδT cells can target a wide variety of cancer cells independently of major histocompatibility complex (MHC) presentation and function as antigen-presenting cells (APCs). Their ability of recognizing antigens in a non-MHC restricted manner makes them an ideal candidate for allogeneic immunotherapy. Additionally, γδT cells exhibit specific tissue tropism, and rapid responsiveness upon reaching cellular targets, indicating a high level of cellular precision and adaptability. Despite these capabilities, the therapeutic potential of γδT cells has been hindered by some limitations, including their restricted abundance, unsatisfactory expansion, limited persistence, and complex biology and plasticity. To address these issues, gene-engineering strategies like the use of chimeric antigen receptor (CAR) T therapy, T cell receptor (TCR) gene transfer, and the combination with γδT cell engagers are being explored. This review will outline the progress in various engineering strategies, discuss their implications and challenges that lie ahead, and the future directions for engineered γδT cells in both monotherapy and combination immunotherapy.

Chimeric Antigen Receptor (CAR)-T Cell Therapy for Non-Hodgkin's Lymphoma.

This review focuses on the use of chimeric antigen receptor (CAR)-T cell therapy to treat non-Hodgkin's lymphoma (NHL), a classification of heterogeneous malignant neoplasms of the lymphoid tissue. Despite various conventional and multidrug chemotherapies, the poor prognosis for NHL patients remains and has prompted the utilization of groundbreaking personalized therapies such as CAR-T cells. CAR-T cells are T cells engineered to express a CAR that enables T cells to specifically lyse tumor cells with extracellular expression of a tumor antigen of choice. A CAR is composed of an extracellular antibody fragment or target protein binding domain that is conjugated to activating intracellular signaling motifs common to T cells. In general, CAR-T cell therapies for NHL are designed to recognize cellular markers ubiquitously expressed on B cells such as CD19+, CD20+, and CD22+. Clinical trials using CAR-T cells such as ZUMA-7 and TRANSFORM demonstrated promising results compared to standard of care and ultimately led to FDA approval for the treatment of relapsed/refractory NHL. Despite the success of CAR-T therapy for NHL, challenges include adverse side effects as well as extrinsic and intrinsic mechanisms of tumor resistance that lead to suboptimal outcomes. Overall, CAR-T cell therapies have improved clinical outcomes in NHL patients and generated optimism around their future applications.

Checkpoint CD24 function on tumor and immunotherapy.

CD24 is a protein found on the surface of cells that plays a crucial role in the proliferation, invasion, and spread of cancer cells. It adheres to cell membranes through glycosylphosphatidylinositol (GPI) and is associated with the prognosis and survival rate of cancer patients. CD24 interacts with the inhibitory receptor Siglec-10 that is present on immune cells like natural killer cells and macrophages, leading to the inhibition of natural killer cell cytotoxicity and macrophage-mediated phagocytosis. This interaction helps tumor cells escape immune detection and attack. Although the use of CD24 as a immune checkpoint receptor target for cancer immunotherapy is still in its early stages, clinical trials have shown promising results. Monoclonal antibodies targeting CD24 have been found to be well-tolerated and safe. Other preclinical studies are exploring the use of chimeric antigen receptor (CAR) T cells, antibody-drug conjugates, and gene therapy to target CD24 and enhance the immune response against tumors. In summary, this review focuses on the role of CD24 in the immune system and provides evidence for CD24 as a promising immune checkpoint for cancer immunotherapy.

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...

CD19-targeting CAR T cells protect from ANCA-induced acute kidney injury

ObjectivesAnti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) are life-threatening systemic autoimmune diseases manifesting in the kidneys as necrotizing crescentic glomerulonephritis (NCGN). ANCA antigens are myeloperoxidase (MPO) or proteinase 3. Current treatments...

Challenges in Global Access to CAR-T cells: an Asian Perspective.

The use of cell therapy for clinical applications has seen a dramatic increase in recent years, primarily in oncology, especially with the use of chimeric antigen receptor (CAR) T-cell therapies. However, there are some barriers to the widespread adoption of CAR-T cell therapies globally, primarily because of the high cost of manufacturing these cells and clinical infrastructure considerations. We reviewed the different strategies adopted across Asia to implement CAR-T cell therapy and found that these included patient assistance programs, close engagement with funders, cost-effectiveness studies, on-site manufacturing of CAR-T cells, and joint ventures between local partners and foreign pharmaceutical companies. Although on-site manufacturing can reduce the cost of genetic engineering and expansion, it does not address many other hidden costs and quality considerations. Future growth in large-scale regional manufacturing, facilitated by cutting-edge science and innovation, could reduce costs through economies of scale and facilitate the eagerly needed global access.

Advances of cell therapy in lung cancer: a narrative review.

Lung cancer is the second most prevalent malignancy and has the highest death rate. The main approaches for lung cancer treatment include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, the treatments of the disease need to be further improved. An increasing number of scientific investigations indicated cell therapy to be a successful new treatment for lung cancer. Cell therapy can improve the host's immunity to disease and can compensate for the shortcomings in the therapeutic effects of traditional treatments, particularly in the case of cancer treatment. However, due to its recent development, its clinical efficacy still needs to be further examined. In order to provide an updated source on cell therapy for lung cancer, this paper summarizes the clinical use of chimeric antigen receptor T cells (CAR-Ts), stem cells, cytokine-induced killer cells (CIKs), and tumor-infiltrating lymphocytes (TILs) and discusses recent clinical advancements. We performed a search of the PubMed database on March 28, 2023, and again on June 10, 2023. A review of retrieved literature related to cell therapy and treatments for lung cancer was completed. Cell therapy has been applied in clinical studies on the treatment of disorders of the hematologic system, digestive system, respiratory system, and other systems. CAR-T therapy has been successfully used in the treatment of B-cell malignancies, which suggests that cell therapy has broad prospects in the treatment of malignant tumors. CAR-T, stem cells, CIKs, and TILs exert antitumor activity and can recognize and could be used to treat lung cancer. Cell therapy represents a novel solution in the treatment of lung cancer. Cell therapy, when combined with traditional therapies, can compensate for the shortcomings of these methods. Further research is needed to reduce the occurrence of adverse reactions and provide a more effective approach in treating lung cancer.

Abstract A042: Quantitative multiplex immunoprecipitation reveals distinct protein interaction networks responsible for discrepant in vivo activity exhibited by two second generation CD22-targeted chimeric antigen receptors

Abstract The Pediatric Leukemia Adoptive Therapy (PLAT) trials at Seattle Children’s Hospital have pioneered the use of chimeric antigen receptor (CAR) T cell (CAR-T) therapies in pediatric patients with B cell Acute Lymphoblastic Leukemia. The landmark PLAT-02 trial (n=45), utilizing a second-generation CD19-directed CAR, observed a 93% remission rate following CAR-T infusion. However, approximately half of these subjects relapsed within one year and nearly a third of those tumors no longer expressed the CD19 target. The PLAT-04 trial (n=4) was subsequently conceived with a second-generation CAR (SCRI-C22v1) engineered to target CD22, an alternative antigen expressed on the B cell surface. Despite promising preclinical data, SCRI-C22v1 failed to generate anti-leukemic activity in all four subjects and the trial was halted. In response, a different second-generation CD22-directed CAR (SCRI-C22v2) was engineered, replacing the CD28 transmembrane domain and IgG4 hinge domain in SCRI-C22v1 with a continuous CD8 hinge and transmembrane domain while retaining identical 4-1BB and CD3ζ intracellular signaling domains. The modified SCRI-C22v2 displayed improved anti-tumor activity in preclinical models and was ultimately tested in patients in the PLAT-07 trial (n=4), where it exhibited strong in vivo expansion and persistence while inducing complete remission after 1 month in all four subjects. To investigate the molecular signaling responsible for clinical differences observed between SCRI-C22v1 and SCRI-C22v2, we applied an emerging proteomic technology, Quantitative Multiplex Immunoprecipitation (QMI), that captures medium-throughput quantitative data about fold changes in protein interaction networks downstream of the CAR. CAR-T products from healthy donors expressing either SCRI-C22v1 or SCRI-C22v2 were stimulated with fixed K562 cells expressing CD22 and protein interaction networks were profiled with QMI, revealing distinct differences in signal transduction downstream of the CAR. Contrary to expectation, it was the ineffective SCRI-C22v1 that exhibited significantly enhanced signalosome formation, engaging more strongly than SCRI-C22v2 with both the classical CD3ζ-ZAP70-LAT-SLP76 pathway as well as the non-classical TRAF pathway. Interestingly, the clinically successful SCRI-C22v2 demonstrated stronger baseline engagement with inhibitory molecules that attenuate canonical TCR signaling such as SHP2 and UBASH3A, suggesting regulatory control of CAR signaling is crucial for optimal clinical responses. Since the CAR is a synthetic receptor, it should be possible to bioengineer optimized signal transduction to some extent, and our group continues to work towards identifying an optimized QMI signature that can be used as a CAR-tune network for the rational design of more effective CAR-T therapies. Citation Format: Eric Bueter, Corinne Summers, Isabella Draper, Joshua Gustafson, Stephen EP Smith, Kamila Gwiazda, Julie Park, Colleen Annesley, Rebecca Gardner, Michael Jensen. Quantitative multiplex immunoprecipitation reveals distinct protein interaction networks responsible for discrepant in vivo activity exhibited by two second generation CD22-targeted chimeric antigen receptors [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A042.

CAR-modified Cellular Therapies in Chronic Lymphocytic Leukemia: Is the Uphill Road Getting Less Steep?

The clinical development of chimeric antigen receptor (CAR) T-cell therapy has been more challenging for chronic lymphocytic leukemia (CLL) compared to other settings. One of the main reasons is the CLL-associated state of immune dysfunction that specifically involves patient-derived T cells. Here, we provide an overview of the clinical results obtained with CAR T-cell therapy in CLL, describing the identified immunologic reasons for the inferior efficacy. Novel CAR T-cell formulations, such as lisocabtagene maraleucel, administered alone or in combination with the Bruton tyrosine kinase inhibitor ibrutinib, are currently under investigation. These approaches are based on the rationale that improving the quality of the T-cell source and of the CAR T-cell product may deliver a more functional therapeutic weapon. Further strategies to boost the efficacy of CAR T cells should rely not only on the production of CAR T cells with an improved cellular composition but also on additional changes. Such alterations could include (1) the coadministration of immunomodulatory agents capable of counteracting CLL-related immunological alterations, (2) the design of improved CAR constructs (such as third- and fourth-generation CARs), (3) the incorporation into the manufacturing process of immunomodulatory compounds overcoming the T-cell defects, and (4) the use of allogeneic CAR T cells or alternative CAR-modified cellular vectors. These strategies may allow to develop more effective CAR-modified cellular therapies capable of counteracting the more aggressive and still incurable forms of CLL.

Impact of Social Determinants of Health and Novel Therapies on the Outcomes of Relapsed and Refractory Diffuse Large B Cell Lymphoma

Introduction: Outcomes for patients with relapsed and refractory diffuse large B cell lymphoma (R/R DLBCL) have improved dramatically with the recent approvals of chimeric antigen receptor (CAR) T cell therapies and novel immunotherapies. Unfortunately, studies show persistent disparities in DLBCL that impact survival, including patient race, income, and rural residence. The U.S. Veterans Health Administration (VA) is a single-payer healthcare system that provides coverage for cancer therapies and travel support, which could address barriers to treatment. This national VA study examines the influence of social determinants of health (SDoH) and treatment patterns on the outcomes of veterans with R/R DLBCL in the era of novel therapies. Methods: Patients who received frontline anthracycline at any time and any systemic therapy for R/R DLBCL between 2019-2022 were identified through the VA Corporate Data Warehouse and retrospective chart review. The Social Deprivation Index (SDI) was estimated at the zip code level using the 2019 American Community Survey (Butler et al, 2013). Median household income was estimated from federal census tract data. Logistic regression was used to evaluate binary outcomes, and Cox regression for survival analyses. Results: 225 patients across 70 VA medical centers met eligibility (Table 1). The median age was 69, and most (96%) were male, reflecting the VA population. The median follow-up was 32.7 months (range, 2.3-217.5). Patients received a median of 3 lines of therapy (range, 2-8). Novel immunotherapies were administered to 98 patients (44%): 10 (4%) received loncastuximab, 23 (10%) tafasitamab, and 83 (37%) polatuzumab. 52 (23%) and 26 (12%) patients received CAR T and autologous stem cell transplant (auto-SCT), respectively. The estimated 2-year overall survival (OS) was 65.8% (95% CI, 59.1-71.7). In univariate analyses, age < 70 (HR 0.58, 95% CI 0.41-0.82), use of CAR T (HR 0.64, 95% CI 0.40-0.99), and auto-SCT (HR 0.39, 95% CI 0.19-0.73) were associated with improved OS. Interestingly, the use of novel immunotherapies was associated with worse OS (HR 1.43, 95% CI 1.01-2.01), but among those who received it, using it in earlier lines had better survival (HR 0.71, 95% CI 0.54-0.94). Notably, Hispanic white had worse survival than non-Hispanic white patients (HR 1.97, 95% CI 1.13-3.23), while African Americans had similar survival to non-Hispanic white patients. Higher stage showed worse survival, but this did not reach significance (HR 1.12, 95% CI 0.93-1.40). Other SDoH (sex, income, rural residence, SDI), disease traits (transformed, LDH, cell of origin, double-hit), and medical comorbidities did not impact survival. In multivariate analysis, the impacts of CAR T, auto-SCT, and Hispanic ethnicity persisted (Figure 1). Among patients receiving at least 3 lines of therapy ( n = 143), the only significant covariate in multivariate regression for OS was CAR T (HR 0.57, 95% CI 0.32-0.96). Referrals for SCT and CAR T were sent for 65 (29%) and 81 (36%) patients, respectively. The most advantaged SDI quartile had higher odds of getting an SCT referral than the least advantaged quartile (OR 5.00, p = 0.0015). Similarly, household income ≥ $75,000 had higher odds of SCT referral vs. lower incomes (OR 2.88, p = 0.004). Race did not affect SCT referral rates, and SDoH in general did not impact CAR T referrals. SDoH was not associated with whether patients actually received novel immunotherapies, CAR T, or SCT (only affecting referral rates in the latter). The most common reasons for not pursuing auto-SCT after referral were comorbidities ( n = 23, 33%), pursuance of other cell therapies ( n = 17, 25%), and patient decision ( n = 12, 17%). The most common reasons for deferring CAR T were comorbidities ( n = 15, 28%), death ( n = 15, 28%), and patient decision ( n = 6, 11%). At last follow-up, of the 47 patients in remission for > 1 year, 27 (57%) had CAR T or SCT as their last therapy. Conclusion: Cellular approaches were the most impactful factors in improving OS. Hispanic ethnicity remained an independent poor prognostic factor, but other SDoH did not impact survival in this cohort. Broad drug coverage by a single-payer system, front-line anthracycline, and equal receipt of cell therapies may have mitigated some of the impact of SDoH on DLBCL survival. Nonetheless, cell therapies had a high referral but low administration rate, highlighting the challenge of getting patients to definitive treatment.

Bendamustine Bridging Versus Standard of Care Chemotherapy on Toxicity Profile for Multiple Myeloma Patients Undergoing CAR T Cell Therapy

Introduction Multiple myeloma (MM) remains an incurable malignancy arising from plasma cells, however great promise has been seen with the use of Chimeric Antigen Receptor (CAR) T cells. Autologous CAR-T products require bridging therapy, however little is known about different agents used in this manner. Some studies indicate decrease in disease burden is crucial, while others note an association with higher rates of toxicity and negative effect on survival. As commercial CAR T cell therapy is indicated after failure of at least 4 prior treatments, careful consideration of bridging therapy is crucial, particularly in patients with aggressive and high-risk disease. This study aims to compare the impact of bendamustine to standard of care (SOC) bridging therapy in MM patients undergoing CAR T cell therapy. Methods A single-center retrospective chart review of 19 adult patients with relapsed/refractory multiple myeloma treated with CAR T cells, who also received bridging therapy with either bendamustine (n=9) or SOC/Other (n=10) was conducted at Mount Sinai Hospital. Patient demographic information (gender, race, MM subtype, history of prior transplant) was collected and toxicity profiles (infection, pancytopenia, cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS)) were compared. Descriptive statistics were used to analyze demographic characteristics and toxicity profiles between the two cohorts. Results Comparative analysis of demographics showed that both cohorts were predominantly males with IgG MM subtype, and varied in terms of race ( Figure 1a). The Other cohort had a higher proportion of patients with a history of autologous stem cell transplant (ASCT) (70%) compared to the bendamustine group. In the SOC group, two patients developed infections, whereas none were observed in the bendamustine cohort ( Figure 1b). Pancytopenia was observed in both groups, but interestingly, 100% of patients experienced it in the SOC cohort. CRS and ICANS were comparable between the two groups ( Figure 1b). Comparative statistics demonstrated no significant difference between the two groups ( Figure 1c). Conclusion Our study findings indicate that there was no significant difference in toxicity profiles between the two pre-conditioning therapy groups. Given our limited sample size, future studies with a larger are indicated to validate these results.

High Response Rates Following Point-of-Care Anti-CD19 CAR T-Cell Therapy in Adults with Relapsed/Refractory Acute B Lymphoblastic Leukemia

Background Tisagenlecleucel and brexucabtagene autoleucel have demonstrated remarkable efficacy and safety results in adult patients with relapsed/ refractory acute B lymphoblastic leukemia (R/R B-ALL). Long term follow-up of the ZUMA-3 trial recently reported a median duration of response (DOR) of 14.6 months and an overall response rate of 71% (Hadjivassileva, EBMT 2023). Methods and patients We report results of a phase 1b/2 single center clinical trial (NCT02772198) involving point-of-care (POC) anti-CD19/CD28 costimulatory domain chimeric antigen receptor (CAR) T-cell therapy in adults with R/R B-ALL. Inclusion criteria were age ≥18 years, failure of at least 2 prior therapies, and a preserved organ function. Patients underwent a single leukapheresis procedure. Fresh CAR T products were delivered for immediate infusion. Lymphodepletion included fludarabine and cyclophosphamide. Cell dose was 1x10 6 CAR T cells/kg. Primary endpoints were 1-month disease response and safety. Secondary endpoints were the minimal residual disease (MRD) negativity rate, overall survival, progression-free survival (PFS), and production feasibility. Last follow-up was July 2023. Results Between 03/2017-05/2023, 28 patients enrolled. CAR T-cells were successfully produced in 27 patients (96%) who were included in the analysis. The median age was 33 years (range 19-77), and 7 (25%) patients had Karnofsky Performance Status <90%. Six patients (22%) had positive Philadelphia chromosome, and 14 patients (52%) had an extramedullary disease at leukapheresis. Nineteen patients (70%) had ≥3 prior lines of therapy, 18 patients (67%) underwent prior allogeneic hematopoietic stem-cell transplantation (allo-HCT), and 20 patients (74%) had prior exposure to inotuzumab-ozogamicin or blinatumomab. At leukapheresis, 16 patients (60%) had an active disease, while 11 patients (40%) were in complete morphological response (CR; MRD positive, n=7 [26%], MRD negative or not evaluated, n=4 [15%]). The median time between leukapheresis and cell infusion was 11 days (IQR 10-11). Only 3 patients (11%) received bridging chemotherapy. Grade 3-4 cytokine release syndrome and immune effector cell-associated neurotoxicity syndromes were observed in 30% of the patients, each. Six (22%) and 16 (59%) patients were treated with tocilizumab or corticosteroids, respectively. Severe neutropenia (<0.5k/μl) and thrombocytopenia (≤50 K/μl) occurred in 81% and 70% of the patients, respectively, and anemia requiring blood transfusion occurred in 71%. Three patients (11%) had grade 3 cardiovascular events, and 1 patient (4%) had grade 3 pleural effusion. Bloodstream bacterial infection occurred in 3 (11%) patients. Cellular therapy-related mortality was observed in 2 (7%) patients (both due to septic shock). The 1-month overall response rate was 88% (81% CR; MRD negative CR, 63%). MRD was evaluated by RT-PCR in most of the patients. The median follow-up was 19.7 months (IQR 4.7-43.2). Two-year overall survival and PFS were 62% (95% CI: 42-91), and 56% (95% CI: 38-84), respectively. The median DOR was not reached (95% CI: 6.1 months-not reached). PFS was not affected by prior exposure to inotuzumab-ozogamicin or blinatumomab (hazard ratio (HR) 0.7, 95% CI: 0.17-2.68, p=0.6). All eligible patients who achieved a response were offered consolidation with allo-HCT. Eight patients (30%) underwent allo-HCT (2 nd allo-HCT in 3 of them). The DOR was not affected by consolidation of CR with allo-HCT (HR 0.9, 95% CI: 0.2-4.1, p>0.9). Nevertheless, 2 patients (7%) died due to allo-HCT related complications while in CR. Conclusion Treatment with POC CAR T-cells, produced in an academic center, achieved high response and survival rates in adults with R/R B-ALL. These results are also comparable to the FDA approved CAR T-cells. The use of POC CAR T abrogates the need for cryopreservation and shipment of the cells, thus allowing a short vein-to-vein time without the need of bridging therapy in most patients.

Advances in CAR T Cell Therapy for Non-Small Cell Lung Cancer.

Since its first approval by the FDA in 2017, tremendous progress has been made in chimeric antigen receptor (CAR) T cell therapy, the adoptive transfer of engineered, CAR-expressing T lymphocyte. CAR T cells are all composed of three main elements: an extracellular antigen-binding domain, an intracellular signaling domain responsible for T cell activation, and a hinge that joins these two domains. Continuous improvement has been made in CARs, now in their fifth generation, particularly in the intracellular signaling domain responsible for T cell activation. CAR T cell therapy has revolutionized the treatment of hematologic malignancies. Nonetheless, the use of CAR T cell therapy for solid tumors has not attained comparable levels of success. Here we review the challenges in achieving effective CAR T cell therapy in solid tumors, and emerging CAR T cells that have shown great promise for non-small cell lung cancer (NSCLC). A growing number of clinical trials have been conducted to study the effect of CAR T cell therapy on NSCLC, targeting different types of surface antigens. They include epidermal growth factor receptor (EGFR), mesothelin (MSLN), prostate stem cell antigen (PSCA), and mucin 1 (MUC1). Potential new targets such as erythropoietin-producing hepatocellular carcinoma A2 (EphA2), tissue factor (TF), and protein tyrosine kinase 7 (PTK7) are currently under investigation in clinical trials. The challenges in developing CAR T for NSCLC therapy and other approaches for enhancing CAR T efficacy are discussed. Finally, we provide our perspective on imaging CAR T cell action by reviewing the two main radionuclide-based CAR T cell imaging techniques, the direct labeling of CAR T cells or indirect labeling via a reporter gene.

Humanized single-domain antibody targeting HER2 enhances function of chimeric antigen receptor T cells.

Chimeric antigen receptors (CARs) can redirect T cells against antigen-expressing tumors, and each component plays an important role in the function and anti-tumor efficacy. It has been reported that using human sequences or a low affinity of CAR single-chain variable fragments (scFvs) in the CAR binding domains is a potential way to enhance the function of CAR-T cells. However, it remains largely unknown how a lower affinity of CARs using humanized scFvs affects the function of CAR-T cells until recently. We used different humanized anti-HER2 antibodies as the extracellular domain of CARs and further constructed a series of the CAR-T cells with different affinity. We have observed that moderately reducing the affinity of CARs (light chain variable domain (VL)-based CAR-T) could maintain the anti-tumor efficacy, and improved the safety of CAR therapy both in vitro and in vivo compared with high-affinity CAR-T cells. Moreover, T cells expressing the VL domain only antibody exhibited long-lasting tumor elimination capability after multiple challenges in vitro, longer persistence and lower cytokine levels in vivo. Our findings provide an alternative option for CAR-T optimization with the potential to widen the use of CAR T cells.