Comparison of FACS and PCR for Detection of BCMA-CAR-T Cells

Chimeric-antigen-receptor (CAR)-T-cell therapy is already widely used to treat patients who are relapsed or refractory to chemotherapy, antibodies, or stem-cell transplantation. Multiple myeloma still constitutes an incurable disease. CAR-T-cell therapy that targets BCMA (B-cell maturation antigen) is currently revolutionizing the treatment of those patients. To monitor and improve treatment outcomes, methods to detect CAR-T cells in human peripheral blood are highly desirable. In this study, three different detection reagents for staining BCMA-CAR-T cells by flow cytometry were compared. Moreover, a quantitative polymerase chain reaction (qPCR) to detect BCMA-CAR-T cells was established. By applying a cell-titration experiment of BCMA-CAR-T cells, both methods were compared head-to-head. In flow-cytometric analysis, the detection reagents used in this study could all detect BCMA-CAR-T cells at a similar level. The results of false-positive background staining differed as follows (standard deviation): the BCMA-detection reagent used on the control revealed a background staining of 0.04% (±0.02%), for the PE-labeled human BCMA peptide it was 0.25% (±0.06%) and for the polyclonal anti-human IgG antibody it was 7.2% (±9.2%). The ability to detect BCMA-CAR-T cells down to a concentration of 0.4% was similar for qPCR and flow cytometry. The qPCR could detect even lower concentrations (0.02–0.01%). In summary, BCMA-CAR-T-cell monitoring can be reliably performed by both flow cytometry and qPCR. In flow cytometry, reagents with low background staining should be preferred.

Overview of the pre-clinical and clinical studies about the use of CAR-T cell therapy of cancer combined with oncolytic viruses

Background Cancer is one of the critical issues of the global health system with a high mortality rate even with the available therapies, so using novel therapeutic approaches to reduce the mortality rate and increase the quality of life is sensed more than ever. Main body CAR-T cell therapy and oncolytic viruses are innovative cancer therapeutic approaches with fewer complications than common treatments such as chemotherapy and radiotherapy and significantly improve the quality of life. Oncolytic viruses can selectively proliferate in the cancer cells and destroy them. The specificity of oncolytic viruses potentially maintains the normal cells and tissues intact. T-cells are genetically manipulated and armed against the specific antigens of the tumor cells in CAR-T cell therapy. Eventually, they are returned to the body and act against the tumor cells. Nowadays, virology and oncology researchers intend to improve the efficacy of immunotherapy by utilizing CAR-T cells in combination with oncolytic viruses. Conclusion Using CAR-T cells along with oncolytic viruses can enhance the efficacy of CAR-T cell therapy in destroying the solid tumors, increasing the permeability of the tumor cells for T-cells, reducing the disturbing effects of the immune system, and increasing the success chance in the treatment of this hazardous disease. In recent years, significant progress has been achieved in using oncolytic viruses alone and in combination with other therapeutic approaches such as CAR-T cell therapy in pre-clinical and clinical investigations. This principle necessitates a deeper consideration of these treatment strategies. This review intends to curtly investigate each of these therapeutic methods, lonely and in combination form. We will also point to the pre-clinical and clinical studies about the use of CAR-T cell therapy combined with oncolytic viruses.

Day 30 SUVmax Predicts Progression in Lymphoma Patients Achieving PR/SD After CAR T-cell Therapy

About 70% of patients with large B-cell lymphoma (LBCL) treated with axicabtagene ciloleucel (axi-cel) who achieve a partial response (PR) or a stable disease (SD) on day 30 (D30) PET-CT scan progress, but predictive factors of progression are unknown. This a retrospective study of patients with LBCL treated with axi-cel at MD Anderson Cancer Center between 01/2018 and 02/2021. Among 50 patients with D30 PR/SD, 13 (26%) converted to complete response (CR). Among 95 patients with D30 CR, 72 (76%) remained in CR. On univariate analysis, the only day -5 characteristic associated with conversion from D30 PR/SD to subsequent CR was a higher platelet count (p=0.05). The only D30 factor associated with conversion from D30 PR/SD to subsequent CR was lower D30 SUVmax (p<0.001), and all patients with and D30 SUVmax ≥10 progressed. After a median follow-up of 12 months, no significant difference in median progression-free survival was observed when comparing patients who converted from D30 PR/SD to subsequent CR to those who had been in CR since D30 (p=0.19). Novel predictive and prognostic markers based on tissue biopsy and non-invasive diagnostic assays are needed to more effectively identify these patients and characterize the biology of their residual disease.

CARving the Path to Allogeneic CAR T Cell Therapy in Acute Myeloid Leukemia

Despite advances in the understanding of the genetic landscape of acute myeloid leukemia (AML) and the addition of targeted biological and epigenetic therapies to the available armamentarium, achieving long-term disease-free survival remains an unmet need. Building on growing knowledge of the interactions between leukemic cells and their bone marrow microenvironment, strategies to battle AML by immunotherapy are under investigation. In the current review we describe the advances in immunotherapy for AML, with a focus on chimeric antigen receptor (CAR) T cell therapy. CARs constitute powerful immunologic modalities, with proven clinical success in B-Cell malignancies. We discuss the challenges and possible solutions for CAR T cell therapy development in AML, and examine the path currently being paved by preclinical and clinical efforts, from autologous to allogeneic products.

Prevalence and variation of CHIP in patients with aggressive lymphomas undergoing CD19-directed CAR-T-cell treatment

Inflammation plays an important role in CAR-T-cell therapy, especially in the pathophysiology of cytokine-release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Clonal hematopoiesis of indetermined potential (CHIP) has also been associated with chronic inflammation. The relevance of CHIP in the context of CAR-T-cell treatment is currently widely unknown. We longitudinally evaluated the prevalence of CHIP, using a targeted deep sequencing approach in a cohort of patients with r/r B-NHL before and after CAR-T-cell treatment. The aim was to define the prevalence and variation of CHIP over time and to assess the influence on clinical inflammation syndromes (CRS/ICANS), cytopenia and outcome. Overall, 32 patients were included. CHIP was found in 11 of 32 patients (34 %) before CAR-T-cell therapy. CHIP progression was commonly detected in the later course. Patients with CHIP showed a comparable response rate to CAR-T-cell treatment but had an improved OS (not reached vs. 265 days, p=0.003). No significant difference was observed in terms of the occurrence and severity of CRS/ICANS, therapeutic usage of tocilizumab and glucocorticosteroids, paraclinical markers of inflammation (except ferritin) or dynamics of hematopoietic recovery. CHIP is commonly observed in patients undergoing CD19-directed CAR-T-cell therapy and is not associated with an inferior outcome.

The Implementation of TNFRSF Co-Stimulatory Domains in CAR-T Cells for Optimal Functional Activity

The Tumor Necrosis Factor Receptor Superfamily (TNFRSF) is a large and important immunoregulatory family that provides crucial co-stimulatory signals to many if not all immune effector cells. Each co-stimulatory TNFRSF member has a distinct expression profile and a unique functional impact on various types of cells and at different stages of the immune response. Correspondingly, exploiting TNFRSF-mediated signaling for cancer immunotherapy has been a major field of interest, with various therapeutic TNFRSF-exploiting anti-cancer approaches such as 4-1BB and CD27 agonistic antibodies being evaluated (pre)clinically. A further application of TNFRSF signaling is the incorporation of the intracellular co-stimulatory domain of a TNFRSF into so-called Chimeric Antigen Receptor (CAR) constructs for CAR-T cell therapy, the most prominent example of which is the 4-1BB co-stimulatory domain included in the clinically approved product Kymriah. In fact, CAR-T cell function can be clearly influenced by the unique co-stimulatory features of members of the TNFRSF. Here, we review a select group of TNFRSF members (4-1BB, OX40, CD27, CD40, HVEM, and GITR) that have gained prominence as co-stimulatory domains in CAR-T cell therapy and illustrate the unique features that each confers to CAR-T cells.

Use of a maturity model for facilitating the introduction of CAR T-cell therapy—Results of the START CAR-T project

Introduction: Chimeric antigen receptor (CAR) T-cell therapies are novel immunotherapies for the treatment of hematologic malignancies. They are administered in specialized centers by a multidisciplinary team and require the careful coordination of all steps involved in manufacturing and using cellular therapies. The Maturity Model (MM) is a tool developed and used for assessing the effectiveness of a variety of activities. In healthcare, it may assist clinicians in the gradual improvement of patient management with CAR T-cell therapy and other complex treatments. Methods: The START CAR-T project was initiated to investigate the potential of a MM in the setting of CAR T-cell therapy. Four Italian clinics participated in the creation of a dedicated MM. Following the development and test of this MM, its validity and generalizability were further tested with a questionnaire submitted to 18 Italian centers. Results: The START CAR-T MM assessed the maturity level of clinical sites, with a focus on organization, process, and digital support. For each area, the model defined four maturity steps, and indicated the actions required to evolve from a basic to an advanced status. The application of the MM to 18 clinical sites provided a description of the maturity level of Italian centers with regard to the introduction of CAR T-cell therapy. Conclusion: The START CAR-T MM appears to be a useful and widely applicable tool. It may help centers optimize many aspects of CAR T-cell therapy and improve patient access to this novel treatment option.