Allogeneic stem cell transplantation and CAR-T in B-cell Non-Hodgkin Lymphoma: a two-center experience and review of the literature

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still a potentially curative option for B-cell Non-Hodgkin Lymphoma (B-NHL) in the modern immunotherapy era. The objective of this study was to analyze long-term outcomes of patients with B-NHL who received allo-HSCT. We analyzed overall survival (OS), progression-free survival (PFS) and graft versus host disease (GVHD) relapse-free survival (GRFS) in 53 patients undergoing allo-HSCT from two institutions. The median follow-up of the study was 72 months (range 29-115 months). The median number of lines of therapy before allo-HSCT was 3 (range 1-6) and twenty-eight patients (53%) had received a previous autologous transplant. The 3-year PFS, OS and GRFS were 55%, 63%, and 55%, respectively. One-year non-relapse mortality was 26%. Karnofsky Performance Scale < 90 was associated with worse OS in multivariable analysis. A non-comparative analysis of a cohort of 44 patients with similar characteristics who received chimeric antigen receptor T-cell therapy was done, showing a 1-year PFS and OS were 60% and 66%, respectively. Our data shows that allo-HSCT is still a useful option for treating selected patients with R/R B-NHL. Our retrospective analysis and review of the literature demonstrate that allo-HSCT can provide durable remissions in a subset of patients with R/R B-NHL.

Magnetic CAR T cell purification using an anti-G4S linker antibody

Chimeric antigen receptor (CAR) redirected T cells are successfully employed in the combat against several hematological malignancies, however, are often compromised by low transduction rates making refinement of the CAR T cell products necessary. Here, we report a broadly applicable enrichment protocol relying on marking CAR T cells with an anti-glycine4-serine (G4S) linker antibody followed by magnetic activated cell sorting (MACS). The protocol is broadly applicable since the G4S peptide is an integral part of the vast majority of CARs as it links the VH and VL recognition domains. We demonstrate the feasibility by using the canonical second generation CARs specific for CEA and Her2, respectively, obtaining highly purified CAR T cell products in a one-step procedure without impairing cell viability. The protocol is also applicable to a dual specific CAR (tandem CAR). Except for CD39, T cell activation/exhaustion markers were not upregulated after separation. Purified CAR T cells retained their functionality with respect to antigen-specific cytokine secretion, cytotoxicity, and the capacity to proliferate and eliminate cognate tumor cells upon repetitive stimulation. Collectively, the one-step protocol for purifying CAR T cells extends the toolbox for preclinical research and specifically for clinical CAR T cell manufacturing.

IL-24 improves efficacy of CAR-T cell therapy by targeting stemness of tumor cells

BACKGROUND

Cancer stem cells (CSCs) induce therapeutic resistance and may be an important barrier to cancer immunotherapy. Chimeric antigen receptor T (CAR-T) cell therapy has demonstrated remarkable efficacy in clinical settings. However, CAR-T cell therapy fails in a large proportion of patients, especially in those with solid tumors. It is unclear how CSCs mediate resistance to CAR-T cells, and whether CAR-T cells can more effectively eradicate CSCs.

METHODS

In this study, the effect of CSCs on CAR-T cell therapy was determined using in vitro and in vivo assays. Subsequently, Interleukin-24 (IL-24) was expressed along with CAR in T cells. Further in vitro and in vivo tests were performed to determine the effects of IL-24 on CSCs and CAR-T cell therapy.

RESULTS

IL-24 induced apoptosis in CSCs and contributed to T cell activation, differentiation, and proliferation. CAR.IL-24-T cells inhibited CSC enrichment and exhibited stronger antitumor activity in vitro and in vivo.

CONCLUSIONS

IL-24 helps eliminate CSCs and endows CAR-T cells with improved antitumor reactivity.

CD7 CAR T bridging to allo-HSCT in R/R T-ALL: A case report

BACKGROUND

Refractory/relapsed T-cell acute lymphoblastic leukemia (R/R T-ALL) is a hematological malignancy with a poor prognosis. The current treatment strategy has not benefited most patients, and the treatment methods are still being explored.

CASE PRESENTATION

An 8-year-old boy with R/R T-ALL achieved CR after multiple chemotherapies, followed by the first allo-HSCT. Unfortunately, 1 year and 3 months later, he relapsed. After recurrence, the patient underwent multiple chemotherapies, but the NOTCH1 gene and MRD were still positive. FCM and immunohistochemistry revealed abnormally high expression of CD7, so we considered bridging the second allo-HSCT after CD7 CAR T-cells treatment. The patient has low toxic and side effects and is still in CR, findings from this case report have more important therapeutic significance for R/R T-ALL.

CONCLUSION

In conclusion, CD7 CAR T-cells bridging to allo-HSCT is a safe and effective approach for R/R T-ALL, resulting in durable CR and longer survival.

Applying the EHA/EBMT grading for ICAHT after CAR-T: comparative incidence and association with infections and mortality

ABSTRACT

Cytopenias represent the most common side effect of CAR T-cell therapy (CAR-T) and can predispose for severe infectious complications. Current grading systems, such as the Common Terminology Criteria for Adverse Events (CTCAE), neither reflect the unique quality of post-CAR-T neutrophil recovery, nor do they reflect the inherent risk of infections due to protracted neutropenia. For this reason, a novel EHA/EBMT consensus grading was recently developed for Immune Effector Cell-Associated HematoToxicity (ICAHT). In this multicenter, observational study, we applied the grading system to a large real-world cohort of 549 patients treated with BCMA- or CD19-directed CAR-T for refractory B-cell malignancies (112 multiple myeloma [MM], 334 large B-cell lymphoma [LBCL], 103 mantle cell lymphoma [MCL]) and examined the clinical sequelae of severe (≥3°) ICAHT. The ICAHT grading was strongly associated with the cumulative duration of severe neutropenia (r = 0.92, P < .0001), the presence of multilineage cytopenias, and the use of platelet and red blood cell transfusions. We noted an increased rate of severe ICAHT in patients with MCL vs those with LBCL and MM (28% vs 23% vs 15%). Severe ICAHT was associated with a higher rate of severe infections (49% vs 13%, P < .0001), increased nonrelapse mortality (14% vs 4%, P < .0001), and inferior survival outcomes (1-year progression-free survival: 35% vs 51%, 1-year overall survival: 52% vs 73%, both P < .0001). Importantly, the ICAHT grading demonstrated superior capacity to predict severe infections compared with the CTCAE grading (c-index 0.73 vs 0.55, P < .0001 vs nonsignificant). Taken together, these data highlight the clinical relevance of the novel grading system and support the reporting of ICAHT severity in clinical trials evaluating CAR-T therapies.

Bispecific CAR T cell therapy targeting BCMA and CD19 in relapsed/refractory multiple myeloma: a phase I/II trial

Despite the high therapeutic response achieved with B-cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T-cell therapy in relapsed and refractory multiple myeloma (R/R MM), primary resistance and relapse exist with single-target immunotherapy. Here, we design bispecific BC19 CAR T cells targeting BCMA/CD19 and evaluate antimyeloma activity in vitro and in vivo. Preclinical results indicate that BC19 CAR specifically recognize target antigens, and BC19 CAR T cells mediate selective killing of BCMA or CD19-positive cancer cells. BC19 CAR T cells also exhibit potent antigen-specific anti-tumor activity in xenograft mouse models. We conduct an open-label, single-arm, phase I/II study of BC19 CAR T cells in 50 patients with R/R MM (ChiCTR2000033567). The primary endpoint was safety. BC19 CAR T cells are well tolerated with grade 3 or higher cytokine release syndrome in 8% of patients and grade 1 neurotoxic events in 4% of patients, which meet the pre-specified primary endpoint. Secondary endpoints include overall response rate (92%), median progression-free survival (19.7 months), median overall survival (19.7 months) and median duration of response (not reached). Our study demonstrates that bispecific BC19 CAR T cells are feasible, safe and effective in treating patients with R/R MM.

The development of chimeric antigen receptor T-cells against CD70 for renal cell carcinoma treatment

In this study, we investigated CD70 as a promising target for renal cell carcinoma (RCC) therapy and developed a potent chimeric antigen receptor T (CAR-T) cells for potential clinical testing. CD70, found to be highly expressed in RCC tumors, was associated with decreased survival. We generated CAR-T cells expressing VHH sequence of various novel nanobodies from immunized alpaca and a single-chain variable fragment (scFv) derived from human antibody (41D12). In our in vitro experiments, anti-CD70 CAR-T cells effectively eliminated CD70-positive tumor cells while sparing CD70-negative cells. The nanobody-based CAR-T cells demonstrated significantly higher production of cytokines such as IL-2, IFN-γ and TNF-ɑ during co-culture, indicating their potential for enhanced functionality. In xenograft mouse model, these CAR-T cells exhibited remarkable anti-tumor activity, leading to the eradication of RCC tumor cells. Importantly, human T cell expansion after infusion was significantly higher in the VHH groups compared to the scFv CAR-T group. Upon re-challenging mice with RCC tumor cells, the VHH CAR-T treated group remained tumor-free, suggesting a robust and long-lasting anti-tumor response. These findings provide strong support for the potential of nanobody-based CD70 CAR-T cells as a promising therapeutic option for RCC. This warrants further development and consideration for future clinical trials and applications.

Associations of granulocyte colony-stimulating factor with toxicities and efficacy of chimeric antigen receptor T-cell therapy in relapsed or refractory B-cell acute lymphoblastic leukemia

Few studies have reported the associations of granulocyte colony-stimulating factor (G-CSF) with cytokine release syndrome (CRS), neurotoxic events (NEs) and efficacy after chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). We present a retrospective study of 67 patients with R/R B-ALL who received anti-CD19 CAR T-cell therapy, 41 (61.2%) patients received G-CSF (G-CSF group), while 26 (38.8%) did not (non-G-CSF group). Patients had similar duration of grade 3-4 neutropenia between the two groups. The incidences of CRS and NEs were higher in G-CSF group, while no differences in severity were found. Further stratified analysis showed that the incidence and severity of CRS were not associated with G-CSF administration in patients with low bone marrow (BM) tumor burden. None of the patients with low BM tumor burden developed NEs. However, there was a significant increase in the incidence of CRS after G-CSF administration in patients with high BM tumor burden. The duration of CRS in patients who used G-CSF was longer. There were no significant differences in response rates at 1 and 3 months after CAR T-cell infusion, as well as overall survival (OS) between the two groups. In conclusion, our results showed that G-CSF administration was not associated with the incidence or severity of CRS in patients with low BM tumor burden, but the incidence of CRS was higher after G-CSF administration in patients with high BM tumor burden. The duration of CRS was prolonged in G-CSF group. G-CSF administration was not associated with the efficacy of CAR T-cell therapy.

Oncotherapy resistance explained by Darwinian and Lamarckian models

Cell and antibody therapies directed against surface molecules on B cells, e.g., CD19-targeting chimeric antigen receptor T cells (CD19 CAR-T), are now standard for patients with chemorefractory B cell acute lymphoblastic leukemias and other B cell malignancies. However, early relapse rates remain high. In this issue of the JCI, Aminov, Giricz, and colleagues revealed that leukemia cells resisting CD19-targeted therapy had reduced CD19 but also low CD22 expression and were sensitive to Bruton's tyrosine kinase and/or MEK inhibition. Overall, their observations support the evolution of resistance following a Lamarckian model: the oncotherapy directly elicits adaptive, resistance-conferring reconfigurations, which are then inherited by daughter cells as epigenetic changes. The findings prompt reflection also on the broader role of epigenetics in decoupling of replication from lineage differentiation activation by the B cell lineage master transcription factor hub. Such oncogenesis and resistance mechanisms, being predictable and epigenetic, offer practical opportunities for intervention, potentially non-cross-resistant and safe vis-à-vis present cytotoxic and CAR-T treatments.

Intention-to-treat outcomes utilising a stringent event definition in children and young people treated with tisagenlecleucel for r/r ALL through a national access scheme

CAR T-cell therapy has transformed relapsed/refractory (r/r) B-cell precursor acute lymphoblastic leukaemia (B-ALL) management and outcomes, but following CAR T infusion, interventions are often needed. In a UK multicentre study, we retrospectively evaluated tisagenlecleucel outcomes in all eligible patients, analysing overall survival (OS) and event-free survival (EFS) with standard and stringent definitions, the latter including measurable residual disease (MRD) emergence and further anti-leukaemic therapy. Both intention-to-treat and infused cohorts were considered. We collected data on feasibility of delivery, manufacture, toxicity, cause of therapy failure and followed patients until death from any cause. Of 142 eligible patients, 125 received tisagenlecleucel, 115/125 (92%) achieved complete remission (CR/CRi). Severe cytokine release syndrome and neurotoxicity occurred in 16/123 (13%) and 10/123 (8.1%), procedural mortality was 3/126 (2.4%). The 2-year intent to treat OS and EFS were 65.2% (95%CI 57.2-74.2%) and 46.5% (95%CI 37.6-57.6%), 2-year intent to treat stringent EFS was 35.6% (95%CI 28.1-44.9%). Median OS was not reached. Sixty-two responding patients experienced CAR T failure by the stringent event definition. Post failure, 1-year OS and standard EFS were 61.2% (95%CI 49.3-75.8) and 55.3% (95%CI 43.6-70.2). Investigation of CAR T-cell therapy for B-ALL delivered on a country-wide basis, including following patients beyond therapy failure, provides clinicians with robust outcome measures. Previously, outcomes post CAR T-cell therapy failure were under-reported. Our data show that patients can be successfully salvaged in this context with good short-term survival.

Development of nanobodies targeting hepatocellular carcinoma and application of nanobody-based CAR-T technology

BACKGROUND

Chimeric antigen receptor T (CAR-T) cell therapy, as an emerging anti-tumor treatment, has garnered extensive attention in the study of targeted therapy of multiple tumor-associated antigens in hepatocellular carcinoma (HCC). However, the suppressive microenvironment and individual heterogeneity results in downregulation of these antigens in certain patients' cancer cells. Therefore, optimizing CAR-T cell therapy for HCC is imperative.

METHODS

In this study, we administered FGFR4-ferritin (FGFR4-HPF) nanoparticles to the alpaca and constructed a phage library of nanobodies (Nbs) derived from alpaca, following which we screened for Nbs targeting FGFR4. Then, we conducted the functional validation of Nbs. Furthermore, we developed Nb-derived CAR-T cells and evaluated their anti-tumor ability against HCC through in vitro and in vivo validation.

RESULTS

Our findings demonstrated that we successfully obtained high specificity and high affinity Nbs targeting FGFR4 after screening. And the specificity of Nbs targeting FGFR4 was markedly superior to their binding to other members of the FGFR family proteins. Furthermore, the Nb-derived CAR-T cells, targeting FGFR4, exhibited significantly enhanced anti-tumor efficacy in both experiments when in vitro and in vivo.

CONCLUSIONS

In summary, the results of this study suggest that the CAR-T cells derived from high specificity and high affinity Nbs, targeting FGFR4, exhibited significantly enhanced anti-tumor efficacy in vitro and in vivo. This is an exploration of FGFR4 in the field of Nb-derived CAR-T cell therapy for HCC, holding promise for enhancing safety and effectiveness in the clinical treatment of HCC in the future.

Cytomegalovirus (CMV) Reactivation and CMV-Specific Cell-Mediated Immunity After Chimeric Antigen Receptor T-Cell Therapy

BACKGROUND

The epidemiology of cytomegalovirus (CMV) after chimeric antigen receptor-modified T-cell immunotherapy (CARTx) is poorly understood owing to a lack of routine surveillance.

METHODS

We prospectively enrolled 72 adult CMV-seropositive CD19-, CD20-, or BCMA-targeted CARTx recipients and tested plasma samples for CMV before and weekly up to 12 weeks after CARTx. We assessed CMV-specific cell-mediated immunity (CMV-CMI) before and 2 and 4 weeks after CARTx, using an interferon γ release assay to quantify T-cell responses to IE-1 and pp65. We tested pre-CARTx samples to calculate a risk score for cytopenias and infection (CAR-HEMATOTOX). We used Cox regression to evaluate CMV risk factors and evaluated the predictive performance of CMV-CMI for CMV reactivation in receiver operator characteristic curves.

RESULTS

CMV was detected in 1 patient (1.4%) before and in 18 (25%) after CARTx, for a cumulative incidence of 27% (95% confidence interval, 16.8-38.2). The median CMV viral load (interquartile range) was 127 (interquartile range, 61-276) IU/mL, with no end-organ disease observed; 5 patients received preemptive therapy based on clinical results. CMV-CMI values reached a nadir 2 weeks after infusion and recovered to baseline levels by week 4. In adjusted models, BCMA-CARTx (vs CD19/CD20) and corticosteroid use for >3 days were significantly associated with CMV reactivation, and possible associations were detected for lower week 2 CMV-CMI and more prior antitumor regimens. The cumulative incidence of CMV reactivation almost doubled when stratified by BCMA-CARTx target and use of corticosteroids for >3 days (46% and 49%, respectively).

CONCLUSIONS

CMV testing could be considered between 2 and 6 weeks in high-risk CARTx recipients.

PD-1 downregulation enhances CAR-T cell antitumor efficiency by preserving a cell memory phenotype and reducing exhaustion

BACKGROUND

Despite the encouraging outcome of chimeric antigen receptor T cell (CAR-T) targeting B cell maturation antigen (BCMA) in managing relapsed or refractory multiple myeloma (RRMM) patients, the therapeutic side effects and dysfunctions of CAR-T cells have limited the efficacy and clinical application of this promising approach.

METHODS

In this study, we incorporated a short hairpin RNA cassette targeting PD-1 into a BCMA-CAR with an OX-40 costimulatory domain. The transduced PD-1KD BCMA CAR-T cells were evaluated for surface CAR expression, T-cell proliferation, cytotoxicity, cytokine production, and subsets when they were exposed to a single or repetitive antigen stimulation. Safety and efficacy were initially observed in a phase I clinical trial for RRMM patients.

RESULTS

Compared with parental BCMA CAR-T cells, PD-1KD BCMA CAR-T cell therapy showed reduced T-cell exhaustion and increased percentage of memory T cells in vitro. Better antitumor activity in vivo was also observed in PD-1KD BCMA CAR-T group. In the phase I clinical trial of the CAR-T cell therapy for seven RRMM patients, safety and efficacy were initially observed in all seven patients, including four patients (4/7, 57.1%) with at least one extramedullary site and four patients (4/7, 57.1%) with high-risk cytogenetics. The overall response rate was 85.7% (6/7). Four patients had a stringent complete response (sCR), one patient had a CR, one patient had a partial response, and one patient had stable disease. Safety profile was also observed in these patients, with an incidence of manageable mild to moderate cytokine release syndrome and without the occurrence of neurological toxicity.

CONCLUSIONS

Our study demonstrates a design concept of CAR-T cells independent of antigen specificity and provides an alternative approach for improving the efficacy of CAR-T cell therapy.

[CAR-T therapy for autoimmune diseases]

Cellular therapy using genetically modified T lymphocytes expressing synthetic receptors, known as CAR (Chimeric Antigen Receptor), has revolutionized the treatment of certain hematologic malignancies. This success has led to exploring the same approach in the treatment of severe autoimmune diseases refractory to conventional therapies. Initial results in systemic lupus erythematosus have shown complete remissions that appear to persist over time. Consequently, there is a growing number of ongoing clinical trials. In this review, we discuss the rationale behind the use of CAR-T therapies, the targeted autoimmune diseases, and the associated risks.

Efficacy and safety of idecabtagene vicleucel in patients with relapsed-refractory multiple myeloma not meeting the KarMMa-1 trial eligibility criteria: A real-world multicentre study

Ide-cel received approval for relapsed-refractory multiple myeloma based on the results of the KarMMa-1 trial. However, patients with significant comorbidities, aggressive disease and prior B-cell maturation antigen-directed therapy (BCMA-DT) were excluded. This retrospective study evaluated real-world outcomes of patients who did not meet the KarMMa-1 eligibility criteria and were treated with standard of care (SOC) ide-cel. A total of 69 patients from three US centres who did not meet the KarMMa-1 criteria underwent ide-cel infusion. The main reasons for trial ineligibility included baseline grade 3-4 cytopenia (39%), prior BCMA-DT (26%), renal impairment (19%) and Eastern Cooperative Oncology Group performance status ≥2 (14.5%). Cytokine-release syndrome occurred in 81% vs. 84%, and immune effector cell-associated neurotoxicity syndrome occurred in 28% vs. 18% of SOC versus KarMMa-1 patients, respectively. Early infection (≤8 weeks post-infusion) and severe infection rates were 42% vs. 49% and 30% vs. 22% for the SOC versus KarMMa-1 cohorts, respectively. Grade 3-4 cytopenias for SOC versus KarMMa-1 cohorts were: neutropenia (87% vs. 89%), anaemia (51% vs. 60%) and thrombocytopenia (65% vs. 52%). Overall response rate was higher for the SOC cohort (93% vs. 73%), as was the complete response or better rate (48% vs. 33%). However, median progression-free survival and overall survival were comparable between the two groups. Our findings support broadening the inclusion criteria of future trials evaluating ide-cel.

Clinical Impact of Cytokine Release Syndrome on Prolonged Hematotoxicity after Chimeric Antigen Receptor T Cell Therapy: KyoTox A-Score, a Novel Prediction Model

Prolonged hematotoxicity is the most common long-term adverse event in chimeric antigen receptor T cell therapy (CAR-T). To evaluate the impact on prolonged cytopenia of inflammatory status after CAR T infusion, we performed a single-center retrospective study and analyzed patients with B cell lymphomas after CAR-T. Among 90 patients analyzed at 90 days after infusion, the cumulative incidence was 57.5% for prolonged neutropenia, 36.7% for anemia, and 49.8% for thrombocytopenia. Patients who experienced cytokine release syndrome (CRS) had significantly higher incidence and longer duration of prolonged cytopenia. In addition, we found that among patients with grade 1 CRS, those with a longer duration of CRS-related symptoms (>5 days; grade 1b in modified CRS grading [m-CRS]) had a significantly higher incidence and longer duration of prolonged cytopenia than those whose CRS-related symptoms resolved within 5 days (grade 1a m-CRS). Multivariate analysis revealed that a higher m-CRS grade (grade 1b or 2; hazard ratio [HR], 2.42), higher peak CRP (≥10 mg/dL; HR, 1.66), longer duration of elevated CRP (≥10 days; HR, 1.83), and a decrease in serum inorganic phosphorus concentration (≥30% from baseline; HR, 1.95) were associated with significantly higher cumulative incidence of prolonged neutropenia, as well as anemia and thrombocytopenia. Using these factors, we developed a new predictive scoring model for prolonged hematotoxicity, the KyoTox a-score, which can successfully stratify the incidence and duration of cytopenia independent of the existing model, CAR-HEMATOTOX, which is based on laboratory data at lymphodepletion. Thus, this newly developed post-CAR-T inflammation-dependent score is accurate and useful for predicting prolonged hematotoxicity.

Chimeric antigen receptor T-cell therapy after COVID-19 in refractory high-grade B-cell lymphoma

Although chimeric antigen receptor T-cell (CAR-T) therapies have dramatically improved the outcomes of relapsed/refractory B-cell malignancies, recipients suffer from severe humoral immunodeficiencies. Furthermore, patients with coronavirus disease 2019 (COVID-19) have a poor prognosis, as noted in several case reports of recipients who had COVID-19 before the infusion. We report the case of a 70-year-old woman who developed COVID-19 immediately before CAR-T therapy for high-grade B-cell lymphoma. She received Tixagevimab-Cilgavimab chemotherapy and radiation therapy but never achieved remission. She was transferred to our hospital for CAR-T therapy, but developed COVID-19. Her symptoms were mild and she was treated with long-term molnupiravir. On day 28 post-infection, lymphodepleting chemotherapy was restarted after a negative polymerase chain reaction (PCR) test was confirmed. The patient did not experience recurrence of COVID-19 symptoms or severe cytokine release syndrome. Based on the analysis and comparison of the previous reports with this case, we believe that CAR-T therapy should be postponed until a negative PCR test is confirmed. In addition, Tixagevimab-Cilgavimab and long term direct-acting antiviral agent treatment can be effective prophylaxis for severe COVID-19 and shortening the duration of infection.

Features and Factors Associated With Myeloid Neoplasms After Chimeric Antigen Receptor T-Cell Therapy

This case-control study examines the incidence and risks of myeloid neoplasms in adults treated for B-cell lymphoproliferative disorders or multiple myeloma.

Discrete Event Simulation to Incorporate Infusion Wait-Time When Assessing Cost-Effectiveness of a Chimeric-Antigen Receptor T Cell Therapy

OBJECTIVES

The main objective was to use discrete event simulation to model the impact of wait-time, defined as the time between leukapheresis and chimeric antigen receptor (CAR-T) infusion, when assessing the cost-effectiveness of tisagenlecleucel in young patients with relapsed/refractory acute lymphoblastic leukemia.

METHODS

The movement of patients through the model was determined by parametric time-to-event distributions, with the competing risk of an event determining the costs and quality-adjusted life-years (QALYs) assigned. Cost-effectiveness was expressed using the incremental cost-effectiveness ratio (ICER) for tisagenlecleucel compared with chemotherapy over the lifetime.

RESULTS

The base case generated a total of 5.79 QALYs and $622 872 for tisagenlecleucel and 1.19 QALYs and $181 219 for blinatumomab, resulting in an ICER of $96 074 per QALY. An increase in mean CAR-T wait-time to 6.20 months reduced the benefit and costs of tisagenlecleucel to 2.78 QALYs and $294 478 because of fewer patients proceeding to infusion, reducing the ICER to $71 112 per QALY. Alternatively, when the cost of tisagenlecleucel was assigned pre-infusion in sensitivity analysis, the ICER increased with increasing wait-time.

CONCLUSIONS

Under a payment arrangement where CAR-T cost is incurred post-infusion, the loss of benefit to patients is not reflected in the ICER. This may be misguiding to decision makers, where cost-effectiveness ratios are used to guide resource allocation. discrete event simulation is an important tool for economic modeling of CAR-T as it is amenable to capturing the impact of wait-time, facilitating better understanding of factors affecting service delivery and consequently informed decision making to deliver faster access to CAR-T for patients.

Adoptive cell therapy for solid tumors beyond CAR-T: Current challenges and emerging therapeutic advances

Adoptive cellular immunotherapy using immune cells expressing chimeric antigen receptors (CARs) is a highly specific anti-tumor immunotherapy that has shown promise in the treatment of hematological malignancies. However, there has been a slow progress toward the treatment of solid tumors owing to the complex tumor microenvironment that affects the localization and killing ability of the CAR cells. Solid tumors with a strong immunosuppressive microenvironment and complex vascular system are unaffected by CAR cell infiltration and attack. To improve their efficacy toward solid tumors, CAR cells have been modified and upgraded by "decorating" and "pruning". This review focuses on the structure and function of CARs, the immune cells that can be engineered by CARs and the transformation strategies to overcome solid tumors, with a view to broadening ideas for the better application of CAR cell therapy for the treatment of solid tumors.

Locoregional delivery of IL-13Rα2-targeting CAR-T cells in recurrent high-grade glioma: a phase 1 trial

Chimeric antigen receptor T cell (CAR-T) therapy is an emerging strategy to improve treatment outcomes for recurrent high-grade glioma, a cancer that responds poorly to current therapies. Here we report a completed phase I trial evaluating IL-13Rα2-targeted CAR-T cells in 65 patients with recurrent high-grade glioma, the majority being recurrent glioblastoma (rGBM). Primary objectives were safety and feasibility, maximum tolerated dose/maximum feasible dose and a recommended phase 2 dose plan. Secondary objectives included overall survival, disease response, cytokine dynamics and tumor immune contexture biomarkers. This trial evolved to evaluate three routes of locoregional T cell administration (intratumoral (ICT), intraventricular (ICV) and dual ICT/ICV) and two manufacturing platforms, culminating in arm 5, which utilized dual ICT/ICV delivery and an optimized manufacturing process. Locoregional CAR-T cell administration was feasible and well tolerated, and as there were no dose-limiting toxicities across all arms, a maximum tolerated dose was not determined. Probable treatment-related grade 3+ toxicities were one grade 3 encephalopathy and one grade 3 ataxia. A clinical maximum feasible dose of 200 × 106 CAR-T cells per infusion cycle was achieved for arm 5; however, other arms either did not test or achieve this dose due to manufacturing feasibility. A recommended phase 2 dose will be refined in future studies based on data from this trial. Stable disease or better was achieved in 50% (29/58) of patients, with two partial responses, one complete response and a second complete response after additional CAR-T cycles off protocol. For rGBM, median overall survival for all patients was 7.7 months and for arm 5 was 10.2 months. Central nervous system increases in inflammatory cytokines, including IFNγ, CXCL9 and CXCL10, were associated with CAR-T cell administration and bioactivity. Pretreatment intratumoral CD3 T cell levels were positively associated with survival. These findings demonstrate that locoregional IL-13Rα2-targeted CAR-T therapy is safe with promising clinical activity in a subset of patients. ClinicalTrials.gov Identifier: NCT02208362 .

Serial Evaluation of Preimmunization Antibody Titers in Lymphoma Patients Receiving Chimeric Antigen Receptor T Cell Therapy

Antibody titers and the potential need for immunization have not been formally studied in recipients of chimeric antigen receptor T cell therapy (CAR-T). Prior studies have shown that CD19-targeted CAR-T can induce persistent B cell aplasia but preserve plasma cells for humoral response. Aiming to assess the immune repertoire and antibody titer status of CAR-T recipients, we conducted a retrospective study of immune cell recovery and antibody titers to vaccines in anti-CD19 CAR-T recipients at Mayo Clinic, Rochester. In our cohort of 95 CAR-T recipients, almost one-half had low CD4 T and B cell counts prior to CAR-T that remained persistently low post-CAR-T. Prior to CAR-T, the seronegative rate was lowest for tetanus and highest for pneumococcus irrespective of prior transplantation status (within 2 years of CAR-T). At 3 months post-CAR-T, overall seronegativity rates were similar to pre-CAR-T rates for the prior transplantation and no prior transplantation groups. For patients who received IVIG, loss of seropositivity was seen for hepatitis A (1 of 7; 14%). No seroconversion was noted for pneumococcus. For patients who did not receive IVIG, loss of seropositivity was seen for pneumococcus (2 of 5; 40%) and hepatitis A (1 of 4; 25%). CAR-T recipients commonly experience T cell and B cell lymphopenia and might not have adequate antibody titers against vaccine-preventable diseases despite IVIG supplementation. Loss of antibody titers post-CAR-T is possible, highlighting the need for revaccination. Additional studies with long-term follow-up are needed to inform the optimal timing of immunization post-CAR-T.

Unselected donor-derived hematopoietic stem cells boost for Chimeric Antigen Receptor T-cell associated hematotoxicity

Hematological toxicity following Chimeric Antigen Receptor-T therapy in a patient with a prior allogeneic stem cell transplantation was resolved by the infusion of unselected donor-derived stem cell boost. Due to the donor's lymphocytes, the patient experienced a well-controlled flare-up of acute graft versus host disease.

Chimeric Antigen Receptor T - Cell Therapy for Large B-Cell Lymphoma Patients with Central Nervous System Involvement, a Systematic Review and Meta-analysis

Chimeric Antigen Receptor T-cell (CAR T-cell) therapy is an effective treatment for relapsed/refractory (R/R) large B cell lymphoma (LBCL). However, patients with central nervous system (CNS) lymphoma were excluded in most of the CAR T-cell therapy trials. This meta-analysis assesses the efficacy with CAR T-cell therapy in LBCL patients with CNS involvement. Two reviewers independently searched PubMed and Cochrane Library to identify all published literature associated with United States Food and Drug Administration approved CAR T-cell therapies for LBCL. Patients with CNS LBCL were included. Meta-analysis of proportion was performed to evaluate the overall response (ORR), complete response (CR) for efficacy, and cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome for safety assessment. Nineteen studies were qualified for inclusion with 141 CNS LBCL patients. The ORR and CR rates were 61% and 55% respectively. The median overall survival (OS) was 8.8 months, and the median progression free survival (PFS) was 4.4 months. Severe immune effector cell-associated neurotoxicity syndrome (grade≥3) were reported in 25% (32/130) patients and severe cytokine release syndrome (grade≥3) were found in 10% (13/124) of the patients. The safety and efficacy of CAR T-cell therapy in CNS LBCL patients appears comparable to patients without CNS involvement.

Quality of Life and Prognostic Awareness in Caregivers of Patients Receiving Chimeric Antigen Receptor T Cell Therapy

Caregivers of patients undergoing chimeric antigen receptor T cell therapy (CAR-T) play a critical role during treatment, yet their experience remains largely unaddressed. We aimed to longitudinally describe quality of life (QoL) and psychological distress, as well as prognostic awareness, in caregivers and explore the association of prognosis awareness with baseline psychological distress. We conducted a longitudinal study of caregivers of patients undergoing CAR-T and examined QoL (CAReGiverOncology QoL questionnaire) and psychological distress (Hospital Anxiety and Depression Scale) prior to CAR-T (baseline) and at days 7, 30, 90, and 180 post-CAR-T. At baseline, caregivers and patients completed the Prognostic Awareness Impact Scale, which examines cognitive understanding of prognosis, emotional coping with prognosis, and adaptive response (ie, capacity to use prognostic awareness to inform life decisions). We enrolled 58% (69 of 120) of eligible caregivers. Caregivers reported QoL impairments that did not change over time (B = 0.09; P = .452). The rates of clinically significant depression and anxiety symptoms were 47.7% and 20.0%, respectively, at baseline, and 39.1% and 17.4% at 180 days. One-third (32%) of the caregivers and patients reported that their oncologist said the cancer is curable. Caregivers' greater emotional coping with prognosis was associated with fewer symptoms of anxiety (B = -.17; P < .001) and depression (B = -.02; P < .001). Cognitive understanding of prognosis and adaptive response were not associated with psychological distress. Caregivers reported QoL impairments throughout the study period. A substantial proportion of caregivers experienced psychological distress and reported misperceptions about the prognosis, highlighting the need for supportive care interventions.

Safety and efficacy of eltrombopag in patients with post-CAR T cytopenias

BACKGROUND

While chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment outcomes of relapsed/refractory hematological malignancies, this therapy is associated with post-treatment cytopenias, which can pose a challenge to its safe administration. This study describes the management of post-CAR T cytopenias using the thrombopoietin mimetic eltrombopag.

METHODS

This retrospective analysis included adult patients with lymphoma or myeloma who received CAR T-cell therapy at two academic medical centers. Eltrombopag was initiated for patients who had persistent high-grade leukopenia and/or thrombocytopenia beyond 21 days post-CAR T infusion. Risk factors and outcomes were assessed and compared for patients who did or did not receive eltrombopag.

RESULTS

Among the 185 patients analyzed, a majority (88%) experienced thrombocytopenia or leukopenia at day +30 post-CAR T infusion. A total of 42 patients met the criteria for eltrombopag treatment and initiated therapy. Patients who received eltrombopag were more likely to have pre-existing cytopenias at lymphodepletion, receive bridging therapy, experience an infection, or require intensive care. Recovery from cytopenias occurred within 180 days for a majority (94%) of patients.

CONCLUSIONS

The use of eltrombopag for post-CAR T leukopenia and thrombocytopenia was considered safe without any significant toxicities. The use of eltrombopag for post-CAR T cytopenias might be effective in a high-risk patient population but requires further study.

BCMA-targeting chimeric antigen receptor T cell therapy for relapsed and/or refractory multiple myeloma

Recently, many new therapies have improved the outcomes of patients with relapsed and/or refractory multiple myeloma (RRMM). Nevertheless, recurrence is still unavoidable, and better treatment choices for RRMM are urgently needed. The clinical success of Chimera antigen receptor (CAR) T cell therapy in many hematological diseases, including leukemia and lymphoma, has drawn considerable attention to RRMM. As CAR T cell therapy continues to mature and challenge traditional therapies, it is gradually changing the treatment paradigm for MM patients. The B cell maturation antigen (BCMA), expressed in malignant plasma cells but not normal ones, is an ideal target for MM treatment, due to its high expression. The US Food and Drug Administration (FDA) and European Medicines Agency (EMA) has approved two BCMA-targeting CAR T cell products, idecabtagene vicleucel (Ide-cel) and ciltacabtagene autoleucel (Cilta-cel), for use in RRMM. In this review, we focus on data from RRMM patients involved in clinical trials of Ide-cel and Cilta-cel and discuss the present situation and future direction of CAR T cell therapy for this condition.

Mucin-1-Targeted Chimeric Antigen Receptor T Cells Are Effective and Safe in Controlling Solid Tumors in Immunocompetent Host

The chimeric antigen receptor (CAR) T-cell therapy in solid epithelial tumors has been explored, however, with limited success. As much of the preclinical work has relied on xenograft models in immunocompromised animals, the immune-related efficacies and toxicities may have been missed. In this study, we engineered syngeneic murine CAR T cells targeting the tumor form of human mucin-1 (tMUC1) and tested the MUC1 CAR T cells' efficacy and toxicity in the immunocompetent human MUC1-expressing mouse models. The MUC1 CAR T cells significantly eliminated murine pancreatic and breast cancer cell lines in vitro. In vivo, MUC1 CAR T cells significantly slowed the mammary gland tumor progression in the spontaneous PyVMT×MUC1.Tg (MMT) mice, prevented lung metastasis, and prolonged survival. Most importantly, there was minimal short or long-term toxicity with acceptable levels of transient liver toxicity but no kidney toxicity. In addition, the mice did not show any signs of weight loss or other behavioral changes with the treatment. We also report that a single dose of MUC1 CAR T-cell treatment modestly reduced the pancreatic tumor burden in a syngeneic orthotopic model of pancreatic ductal adenocarcinoma given at late stage of an established tumor. Taken together, these findings suggested the further development of tMUC1-targeted CAR T cells as an effective and relatively safe treatment modality for various tMUC1-expressing solid tumors.

[CHIMERIC ANTIGEN RECEPTOR T CELLS (CAR-T CELLS) THERAPY FOR B-CELL HEMATOLOGICAL MALIGNANCIES - FROM THE ISRAELI SOCIETY OF HEMATOLOGY AND TRANSFUSION MEDICINE]

INTRODUCTION

Using immunotherapy to fight cancer, and specifically, the use of engineered T-cells expressing a chimeric receptor against an antigen found on malignant cells (chimeric antigen receptor, CAR-T cells) constitutes a significant breakthrough in the treatment of the disease. In recent years, several CAR-T therapies have been approved in Europe and the USA, and some are already approved and funded through the national health basket in Israel, for the indications of diffuse large B-cell lymphoma, mantle cell lymphoma and B-cell acute lymphoblastic leukemia, after the failure of at least two lines of treatment. The treatment with CAR-T cells achieves prolonged remissions and even long-term cure of patients who had a very poor prognosis. However, the treatment involves significant side effects, and requires specific expertise in the management of patients both during the period of preparation for cell transplantation, and following the treatment. During the immediate post-infusion period, the most common adverse reactions are cytokine release syndrome (CRS) which stems from the activation of the immune system, and neurological toxicity that can accompany CRS. These effects require close monitoring, grading their severity, and providing anti-cytokine therapy or steroid therapy until control of symptoms is achieved. Later effects can be persistent cytopenias, immune over-activation, and prolonged immune deficiency. Treatments for additional indications and new CAR-T constructs are being developed and will allow more effective and safer treatment. This article summarizes the principles for CAR-T administration that, as currently provided in Israel, include the short- and long-term follow-up of the patients.

[Construction and Optimization of CD19 Chimeric Antigen Receptor T Cells Derived from C57BL/6J Mice]

OBJECTIVE

To explore the stimulation conditions, optimal culture time and infection time of C57BL/6J mice CD3+ T cells in vitro, so as to improve the infection efficiency of CD19 chimeric antigen receptor T cells (mCD19 CAR-T).

METHODS

Purified C57BL/6J mice CD3+ T cells were cultured in anti-CD3/CD28 coated, anti-CD3 coated+soluble anti-CD28 and anti-CD3 coated, respectively. The cells were stimulated in above three conditions for 12 h and 24 h, following with 24 h, 48 h and 72 h incubation and then the number of cell clones was recorded. C57BL/6J mice CD3+ T cells were stimulated for 12 h, 24 h, and 36 h under the above three conditions, then interleukin (IL)-2 (100 U/ml) was added. The number of cell clones was recorded under microscope at 24 h, 48 h, and 72 h of culture. After 24 h of stimulation, CD3+ T cells derived from C57BL/6J mice were infected with retrovirus for 48 h to establish mCD19 CAR-T cells, and the percentage of GFP+ CAR-T cells was detected by flow cytometry.

RESULTS

The infection efficiency of mCD19 CAR-T cells derived from C57BL/6J mice was only 5.23% under the optimized conditions of mCD19 CAR-T cells derived from BALB/c mice. The number of clones of C57BL/6J mice CD3+ T cells was the highest in anti-CD3 coated+soluble anti-CD28 group after stimulated for 24 h and followed cultured for 48 h. After 24 hours of stimulation under the above conditions and 48 hours of culture with IL-2, the number of T cell proliferating clones in the anti-CD3 coated+soluble anti-CD28 group was significantly increased compared with the same group without IL-2, and the infection efficiency of CAR-T cells in this group reached 17.63%±4.17%.

CONCLUSION

The optimal conditions for constructing CAR-T cells from C57BL/6J mice CD3+ T cells are different from those of BABL/c mice. T cells stimulated by anti-CD3 coated+soluble anti-CD28+IL-2 can obtain mCD19 CAR-T cells with the highest efficiency after retrovirus infection.

Multi-centers experience using therapeutic plasma exchange for corticosteroid/tocilizumab-refractory cytokine release syndrome following CAR-T therapy

The chimeric antigen receptor T (CAR-T) cell therapy significantly enhances the prognosis of various hematologic malignancies; however, the systemic expansion of CAR-T cells also gives rise to severe cytokine release syndrome (CRS), and immune effector cell-associated neurotoxicity syndrome (ICANS). Despite the successful application of corticosteroids and tocilizumab in alleviating severe CRS in most patients, there are still individuals who experience life-threatening CRS without responding to the aforementioned therapies. In our retrospective cohort, we conducted an analysis of clinical and laboratory parameters, including inflammatory cytokines, in 17 patients from three centers who underwent therapeutic plasma exchange (TPE) for refractory CRS with or without ICANS following CAR-T products treatment. Our findings demonstrate a significant improvement in both clinical symptoms and laboratory parameters subsequent to TPE treatment. The rapid decrease in temperature and levels of inflammatory indexes indicates the remarkable scavenging efficacy of TPE against cytokine storm following CAR-T therapy. In conclusion, TPE may serve as a valuable and safe adjunct to corticosteroids and tocilizumab in the management of severe CRS resulting from CAR-T cell infusion. We eagerly await further prospective studies to validate this finding.

Protocol for a mixed-methods study to develop and feasibility test a digital system for the capture of patient-reported outcomes (PROs) in patients receiving chimeric antigen receptor T-cell (CAR-T) therapies (the PRO-CAR-T study)

INTRODUCTION

Chimeric antigen receptor (CAR) T-cell therapies are novel, potentially curative therapies for haematological malignancies. CAR T-cell therapies are associated with severe toxicities, meaning patients require monitoring during acute and postacute treatment phases. Electronic patient-reported outcomes (ePROs), self-reports of health status provided via online questionnaires, can complement clinician observation with potential to improve patient outcomes. This study will develop and evaluate feasibility of a new ePRO system for CAR-T patients in routine care.

METHODS AND ANALYSIS

Multiphase, mixed-methods study involving multiple stakeholder groups (patients, family members, carers, clinicians, academics/researchers and policy-makers). The intervention development phase comprises a Delphi study to select PRO measures for the digital system, a codesign workshop and consensus meetings to establish thresholds for notifications to the clinical team if a patient reports severe symptoms or side effects. Usability testing will evaluate how users interact with the digital system and, lastly, we will evaluate ePRO system feasibility with 30 CAR-T patients (adults aged 18+ years) when used in addition to usual care. Feasibility study participants will use the ePRO system to submit self-reports of symptoms, treatment tolerability and quality of life at specific time points. The CAR-T clinical team will respond to system notifications triggered by patients' submitted responses with actions in line with standard clinical practice. Feasibility measures will be collected at prespecified time points following CAR T-cell infusion. A qualitative substudy involving patients and clinical team members will explore acceptability of the ePRO system.

ETHICS AND DISSEMINATION

Favourable ethical opinion was granted by the Health and Social Care Research Ethics Committee B(HSC REC B) (ref: 23/NI/0104) on 28 September 2023. Findings will be submitted for publication in high-quality, peer-reviewed journals. Summaries of results, codeveloped with the Blood and Transplant Research Unit Patient and Public Involvement and Engagement group, will be disseminated to all interested groups.

TRIAL REGISTRATION NUMBER

ISCTRN11232653.

Targeting Interleukin-13 Receptor α2 and EphA2 in Aggressive Breast Cancer Subtypes with Special References to Chimeric Antigen Receptor T-Cell Therapy

Breast cancer (BCA) remains the leading cause of cancer-related mortality among women worldwide. This review delves into the therapeutic challenges of BCA, emphasizing the roles of interleukin-13 receptor α2 (IL-13Rα2) and erythropoietin-producing hepatocellular receptor A2 (EphA2) in tumor progression and resistance. Highlighting their overexpression in BCA, particularly in aggressive subtypes, such as Her-2-enriched and triple-negative breast cancer (TNBC), we discuss the potential of these receptors as targets for chimeric antigen receptor T-cell (CAR-T) therapies. We examine the structural and functional roles of IL-13Rα2 and EphA2, their pathological significance in BCA, and the promising therapeutic avenues their targeting presents. With an in-depth analysis of current immunotherapeutic strategies, including the limitations of existing treatments and the potential of dual antigen-targeting CAR T-cell therapies, this review aims to summarize potential future novel, more effective therapeutic interventions for BCA. Through a thorough examination of preclinical and clinical studies, it underlines the urgent need for targeted therapies in combating the high mortality rates associated with Her-2-enriched and TNBC subtypes and discusses the potential role of IL-13Rα2 and EphA2 as promising candidates for the development of CAR T-cell therapies.

Choosing T-cell sources determines CAR-T cell activity in neuroblastoma

Introduction

The clinical success of chimeric antigen receptor-modified T cells (CAR-T cells) for hematological malignancies has not been reproduced for solid tumors, partly due to the lack of cancer-type specific antigens. In this work, we used a novel combinatorial approach consisting of a versatile anti-FITC CAR-T effector cells plus an FITC-conjugated neuroblastoma (NB)-targeting linker, an FITC-conjugated monoclonal antibody (Dinutuximab) that recognizes GD2.

Methods

We compared cord blood (CB), and CD45RA-enriched peripheral blood leukapheresis product (45RA) as allogeneic sources of T cells, using peripheral blood (PB) as a control to choose the best condition for anti-FITC CAR-T production. Cells were manufactured under two cytokine conditions (IL-2 versus IL-7+IL-15+IL-21) with or without CD3/CD28 stimulation. Immune phenotype, vector copy number, and genomic integrity of the final products were determined for cell characterization and quality control assessment. Functionality and antitumor capacity of CB/45RA-derived anti-FITC CAR-T cells were analyzed in co-culture with different anti-GD2-FITC labeled NB cell lines.

Results

The IL-7+IL-15+IL-21 cocktail, in addition to co-stimulation signals, resulted in a favorable cell proliferation rate and maintained less differentiated immune phenotypes in both CB and 45RA T cells. Therefore, it was used for CAR-T cell manufacturing and further characterization. CB and CD45RA-derived anti-FITC CAR-T cells cultured with IL-7+IL-15+IL-21 retained a predominantly naïve phenotype compared with controls. In the presence of the NB-FITC targeting, CD4+ CB-derived anti-FITC CAR-T cells showed the highest values of co-stimulatory receptors OX40 and 4-1BB, and CD8+ CAR-T cells exhibited high levels of PD-1 and 4-1BB and low levels of TIM3 and OX40, compared with CAR-T cells form the other sources studied. CB-derived anti-FITC CAR-T cells released the highest amounts of cytokines (IFN-γ and TNF-α) into co-culture supernatants. The viability of NB target cells decreased to 30% when co-cultured with CB-derived CAR-T cells during 48h.

Conclusion

CB and 45RA-derived T cells may be used as allogeneic sources of T cells to produce CAR-T cells. Moreover, ex vivo culture with IL-7+IL-15+IL-21 could favor CAR-T products with a longer persistence in the host. Our strategy may complement the current use of Dinutuximab in treating NB through its combination with a targeted CAR-T cell approach.