Non-viral, specifically targeted CAR-T cells achieve high safety and efficacy in B-NHL.

Recently, chimeric antigen receptor (CAR)-T cell therapy has shown great promise in treating haematological malignancies1-7. However, CAR-T cell therapy currently has several limitations8-12. Here we successfully developed a two-in-one approach to generate non-viral, gene-specific targeted CAR-T cells through CRISPR-Cas9. Using the optimized protocol, we demonstrated feasibility in a preclinical study by inserting an anti-CD19 CAR cassette into the AAVS1 safe-harbour locus. Furthermore, an innovative type of anti-CD19 CAR-T cell with PD1 integration was developed and showed superior ability to eradicate tumour cells in xenograft models. In adoptive therapy for relapsed/refractory aggressive B cell non-Hodgkin lymphoma (ClinicalTrials.gov, NCT04213469 ), we observed a high rate (87.5%) of complete remission and durable responses without serious adverse events in eight patients. Notably, these enhanced CAR-T cells were effective even at a low infusion dose and with a low percentage of CAR+ cells. Single-cell analysis showed that the electroporation method resulted in a high percentage of memory T cells in infusion products, and PD1 interference enhanced anti-tumour immune functions, further validating the advantages of non-viral, PD1-integrated CAR-T cells. Collectively, our results demonstrate the high safety and efficacy of non-viral, gene-specific integrated CAR-T cells, thus providing an innovative technology for CAR-T cell therapy.

Sequential CD7 CAR T-Cell Therapy and Allogeneic HSCT without GVHD Prophylaxis.

BACKGROUND: Patients with relapsed or refractory hematologic cancers have a poor prognosis. Chimeric antigen receptor (CAR) T-cell therapy as a bridge to allogeneic hematopoietic stem-cell transplantation (HSCT) has the potential for long-term tumor elimination. However, pre-HSCT myeloablation and graft-versus-host disease (GVHD) prophylaxis agents have toxic effects and could eradicate residual CAR T cells and compromise antitumor effects. Whether the integration of CAR T-cell therapy and allogeneic HSCT can preserve CAR T-cell function and improve tumor control is unclear. METHODS: We tested a novel "all-in-one" strategy consisting of sequential CD7 CAR T-cell therapy and haploidentical HSCT in 10 patients with relapsed or refractory CD7-positive leukemia or lymphoma. After CAR T-cell therapy led to complete remission with incomplete hematologic recovery, patients received haploidentical HSCT without pharmacologic myeloablation or GVHD prophylaxis drugs. Toxic effects and efficacy were closely monitored. RESULTS: After CAR T-cell therapy, all 10 patients had complete remission with incomplete hematologic recovery and grade 4 pancytopenia. After haploidentical HSCT, 1 patient died on day 13 of septic shock and encephalitis, 8 patients had full donor chimerism, and 1 patient had autologous hematopoiesis. Three patients had grade 2 HSCT-associated acute GVHD. The median follow-up was 15.1 months (range, 3.1 to 24.0) after CAR T-cell therapy. Six patients remained in minimal residual disease-negative complete remission, 2 had a relapse of CD7-negative leukemia, and 1 died of septic shock at 3.7 months. The estimated 1-year overall survival was 68% (95% confidence interval [CI], 43 to 100), and the estimated 1-year disease-free survival was 54% (95% CI, 29 to 100). CONCLUSIONS: Our findings suggest that sequential CD7 CAR T-cell therapy and haploidentical HSCT is safe and effective, with remission and serious but reversible adverse events. This strategy offers a feasible approach for patients with CD7-positive tumors who are ineligible for conventional allogeneic HSCT. (Funded by the National Natural Science Foundation of China and the Key Project of Science and Technology Department of Zhejiang Province; ClinicalTrials.gov numbers, NCT04599556 and NCT04538599.).

Reprogramming natural killer cells for cancer therapy.

The last decade has seen rapid development in the field of cellular immunotherapy, particularly in regard to chimeric antigen receptor (CAR)-modified T cells. However, challenges, such as severe treatment-related toxicities and inconsistent quality of autologous products, have hindered the broader use of CAR-T cell therapy, highlighting the need to explore alternative immune cells for cancer targeting. In this regard, natural killer (NK) cells have been extensively studied in cellular immunotherapy and were found to exert cytotoxic effects without being restricted by human leukocyte antigen and have a lower risk of causing graft-versus-host disease; making them favorable for the development of readily available "off-the-shelf" products. Clinical trials utilizing unedited NK cells or reprogrammed NK cells have shown early signs of their effectiveness against tumors. However, limitations, including limited in vivo persistence and expansion potential, remained. To enhance the antitumor function of NK cells, advanced gene-editing technologies and combination approaches have been explored. In this review, we summarize current clinical trials of antitumor NK cell therapy, provide an overview of innovative strategies for reprogramming NK cells, which include improvements in persistence, cytotoxicity, trafficking and the ability to counteract the immunosuppressive tumor microenvironment, and also discuss some potential combination therapies.

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

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

Efficacy and safety of CD19-specific CAR T cell-based therapy in B-cell acute lymphoblastic leukemia patients with CNSL.

Few studies have described chimeric antigen receptor (CAR) T-cell therapy for patients with B-cell acute lymphoblastic leukemia (B-ALL) with central nervous system leukemia (CNSL) because of concerns regarding poor response and treatment-related neurotoxicity. Our study included 48 patients with relapsed/refractory B-ALL with CNSL to evaluate the efficacy and safety of CD19-specific CAR T cell-based therapy. The infusion resulted in an overall response rate of 87.5% (95% confidence interval [CI], 75.3-94.1) in bone marrow (BM) disease and remission rate of 85.4% (95% CI, 72.8-92.8) in CNSL. With a median follow-up of 11.5 months (range, 1.3-33.3), the median event-free survival was 8.7 months (95% CI, 3.7-18.8), and the median overall survival was 16.0 months (95% CI, 13.5-20.1). The cumulative incidences of relapse in BM and CNS diseases were 31.1% and 11.3%, respectively, at 12 months (P = .040). The treatment was generally well tolerated, with 9 patients (18.8%) experiencing grade ≥3 cytokine release syndrome. Grade 3 to 4 neurotoxic events, which developed in 11 patients (22.9%), were associated with a higher preinfusion disease burden in CNS and were effectively controlled under intensive management. Our results suggest that CD19-specific CAR T cell-based therapy can induce similar high response rates in both BM and CNS diseases. The duration of remission in CNSL was longer than that in BM disease. CD19 CAR T-cell therapy may provide a potential treatment option for previously excluded patients with CNSL, with manageable neurotoxicity. The clinical trials were registered at www.clinicaltrials.gov as #NCT02782351 and www.chictr.org.cn as #ChiCTR-OPN-16008526.

Donor-derived stem cell infusion for sustained pancytopenia after CD19 CAR-T therapy for relapsed patients post allogeneic stem cell transplantation.

OBJECTIVES: To investigate the effectiveness of donor-derived chimeric antigen receptor T (CAR-T) cells in the treatment of relapsed cases after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and whether donor-derived peripheral blood stem cells (PBSCs) have a therapeutic effect on pancytopenia after CAR-T cell therapy. METHODS: We analyzed data from five adults with B-cell acute lymphoblastic leukemia (ALL) who had relapse after allo-HSCT and received donor-derived CAR-T cell therapy and donor-derived PBSCs to promote hematopoietic recovery. RESULTS: All patients had negative minimal residual disease after CAR-T therapy, grade 1-2 cytokine release syndrome, and developed grade 4 hematologic toxicity. During the pancytopenia stage after CAR-T cell therapy, donor-derived PBSCs were transfused without graft-versus-host disease (GVHD) prophylaxis. Four patients had grade I-II acute GVHD (aGVHD). After corticosteroid treatment, aGVHD resolved and hematopoiesis was restored. Although steroids in combination with etanercept and ruxolitinib relieved symptoms in one patient with grade IV aGVHD, complete hematopoietic recovery was not achieved, and the patient died due to severe infection. CONCLUSIONS: Donor-derived CAR-T cell therapy is safe and effective in patients with relapsed/refractory ALL after allo-HSCT. Donor-derived PBSCs infusion could achieve hematopoietic recovery with controllable aGVHD in patients with persistent pancytopenia.

Application of thromboelastography to predict the severity of bleeding after chimeric antigen receptor (CAR)-T cell therapy in patients with hematological malignancy.

OBJECTIVES: We aim to analyze the predictive value of thromboelastography on bleeding severity of patients with chimeric antigen receptor (CAR)-T cell therapy. METHODS: A total of 80 patients with refractory/relapsed hematological malignancy were enrolled and divided into two groups: the severe bleeding group and the non-severe bleeding group. The thromboelastography data was collected on the day of CAR-T infusion and the 3rd, 7th, 10th, 13th, 17th, and 20th day after CAR-T cell infusion. RESULTS: The patients of the severe bleeding group had lower platelet (p < .007), maximum amplitude (p = .002), coagulation index (p = .005), and longer coagulation time (p = .019). Increasing trend in reaction time and coagulation time and decreasing trend in Alpha, maximum amplitude, and coagulation index on Days 0-10, opposite on Days 10-20. Univariate logistic regression analysis and multivariable logistic regression analysis showed maximum amplitude on the 3rd day after CAR-T cell infusion (MA3) (OR = 0.9; 95% CI = 0.84-0.95; p < .001) and cytokine release syndrome grade (OR = 2.57; 95% CI = 1.35-5.32; p = .006) were significantly associated with high bleeding severity. CONCLUSIONS: Thromboelastography was considered to be a good predictor of bleeding severity.

A rare KMT2A::CBL transcript in an acute monoblastic leukemia patient with an unfavorable outcome.

BACKGROUND: Lysine [K] methyltransferase 2A (KMT2A, previously known as MLL) gene rearrangements are common in acute leukemias of various lineages and are associated with features such as chemotherapy resistance and rapid relapse. KMT2A::CBL is a rare fusion of unknown pathogenesis generated by a unique interstitial deletion of chromosome 11 that has been reported across a wide age range in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients. The leukemogenic effect of the KMT2A::CBL rearrangement and its association with clinical prognosis have not been well clarified. METHODS AND RESULTS: We report the case of a 64-year-old female who was diagnosed with acute monoblastic leukemia (M5a) and who acquired the rare KMT2A::CBL fusion. The patient received multiple cycles of therapy but did not achieve remission and eventually succumbed to severe infection and disease progression. Additionally, we characterized the predicted KMT2A-CBL protein structure in this case to reveal the underlying leukemogenic mechanisms and summarized reported cases of hematological malignancies with KMT2A::CBL fusion to investigate the correlation of gene rearrangements with clinical outcomes. CONCLUSIONS: This report provides novel insights into the leukemogenic potential of the KMT2A::CBL rearrangement and the correlation between gene rearrangements and clinical outcomes.

Survival and late mortality among patients who survived disease-free for 2 years after stem cell transplantation.

Most events that limit life expectancy after allogeneic haematopoietic stem cell transplantation (allo-HSCT) occur within the first 2 years; however, treatment outcomes in long-term survivors who survive for at least 2 years post-HSCT without relapse are yet to be elucidated. To explore the life expectancy trends and late complications and to assess the main mortality-related factors, we investigated the characteristics of patients who received allo-HSCT for haematological malignancies from 2007 to 2019 in our centre and survived in remission for 2 years. A cohort of 831 patients was enrolled; of these, 508 received grafts from haploidentical-related donors (61.1%). The estimated overall survival rate at 10 years was 91.9% (95% confidence interval [CI], 89.8-93.5), which was affected by prior grade III-IV acute graft-versus-host disease (GVHD) (hazard ratio [HR], 2.98; 95% CI, 1.47-6.03; p = 0.002) and severe chronic GVHD (HR, 3.60; 95% CI, 1.93-6.71; p < 0.001). The probability of late relapse and non-relapse mortality at 10 years was 8.7% (95% CI, 6.9-10.8) and 3.6% (95% CI, 2.5-5.1) respectively. The top cause of late mortality was relapsed (49.0%). Projected long-term survival in 2-year disease-free survivors following allo-HSCT was excellent. Strategies should be implemented to minimise the late death-specific hazards in recipients.

Derivation and validation of a novel score for early prediction of severe CRS after CAR-T therapy in haematological malignancy patients: A multi-centre study.

Chimeric antigen receptor T (CAR-T) cell therapy is highly effective in inducing complete remission in haematological malignancies. Severe cytokine release syndrome (CRS) is the most significant and life-threatening adverse effect of this therapy. This multi-centre study was conducted at six hospitals in China. The training cohort included 87 patients with multiple myeloma (MM), an external validation cohort of 59 patients with MM and another external validation cohort of 68 patients with acute lymphoblastic leukaemia (ALL) or non-Hodgkin lymphoma (NHL). The levels of 45 cytokines on days 1-2 after CAR-T cell infusion and clinical characteristics of patients were used to develop the nomogram. A nomogram was developed, including CX3CL1, GZMB, IL4, IL6 and PDGFAA. Based on the training cohort, the nomogram had a bias-corrected AUC of 0.876 (95% CI = 0.871-0.882) for predicting severe CRS. The AUC was stable in both external validation cohorts (MM, AUC = 0.907, 95% CI = 0.899-0.916; ALL/NHL, AUC = 0.908, 95% CI = 0.903-0.913). The calibration plots (apparent and bias-corrected) overlapped with the ideal line in all cohorts. We developed a nomogram that can predict which patients are likely to develop severe CRS before they become critically ill, improving our understanding of CRS biology, and may guide future cytokine-directed therapies.

A distinct cytokine network distinguishes chimeric antigen receptor T cell (CAR-T)-associated hemophagocytic lymphohistiocytosis-like toxicity (carHLH) from severe cytokine release syndrome following CAR-T therapy.

BACKGROUND AIMS: With the increasing application of chimeric antigen receptor (CAR)-T cell therapy in various malignancies, an extra toxicity profile has been revealed, including a severe complication resembling hemophagocytic lymphohistiocytosis (HLH), which is usually disguised by severe cytokine release syndrome (CRS). METHODS: In a clinical trial in whom 99 patients received B-cell maturation antigen CAR-T cells, we identified 20 (20.20%) cases of CAR-T cell-associated HLH (carHLH), most of whom possessed a background of severe CRS (grade ≥3). The overlapping features of carHLH and severe CRS attracted us to further explore the differences between them. RESULTS: We showed that carHLH can be distinguished by extreme elevation of interferon-γ, granzyme B, interleukin-1RA and interleukin-10, which can be informative in developing prevention and management strategies of this toxicity. Moreover, we developed a predictive model of carHLH with a mean area under the curve of 0.81 ± 0.07, incorporating serum lactate dehydrogenase at day 6 post-CRS and serum fibrinogen at day 3 post-CRS. CONCLUSIONS: The incidence of carHLH in CAR-T recipients might be relatively higher than we previously thought. relatively higher than we previously. A cytokine network distinguished from CRS is responsible for carHLH. And corresponding cytokine-directed therapies, especially targeting IL-10, are worth trying.

Cytokine profiles are associated with prolonged hematologic toxicities after B-cell maturation antigen targeted chimeric antigen receptor-T-cell therapy.

BACKGROUND AIMS: The considerable efficacy of B-cell maturation antigen-targeted chimeric antigen receptor (CAR)-T-cell therapy has been extensively demonstrated in the treatment of relapsed or refractory multiple myeloma. Nevertheless, in clinical practice, prolonged hematologic toxicity (PHT) extends hospital stay and impairs long-term survival. METHODS: This retrospective study reviewed 99 patients with relapsed or refractory multiple myeloma who underwent B-cell maturation antigen CAR-T-cell therapy at our institution between April 2018 and September 2021 (ChiCTR1800017404). RESULTS: Among 93 evaluable patients, the incidence of prolonged hematologic toxicities was high after CAR-T-cell infusion, including 38.71% (36/93) of patients with prolonged neutropenia, 22.58% (21/93) with prolonged anemia and 59.14% (55/93) with prolonged thrombocytopenia. In addition, 9.68% (9/93) of patients experienced prolonged pancytopenia. Our multivariate analyses identified that cytokine profiles were independent risk factors for PHTs, whereas a sufficient baseline hematopoietic function and high CD4/CD8 ratio of CAR-T cells were protective factors for PHTs after CAR-T-cell infusion. Subgroup analyses found that the kinetics of post-CAR-T hematologic parameters were primarily determined by the collective effects of cytokine release syndrome and baseline hematopoietic functions, and showed influential weights for the three lineages. CONCLUSIONS: Our findings improve the understanding of the impact of cytokines on hematopoietic functions, which could contribute to the mechanism investigation and exploration of potential intervention strategies.

Cytokine release syndrome was an independent risk factor associated with hypoalbuminemia for patients with relapsed/refractory hematological malignancies after CAR-T cell therapy.

BACKGROUND & AIMS: This study aims to assess the nutritional status of patients during the different phases of the Chimeric Antigen Receptor (CAR)-T cell therapy and to identify prominent risk factors of hypoalbuminemia in patients after CAR-T treatment. The clinical consequences of malnutrition in cancer patients have been highlighted by growing evidence from previous clinical studies. Given CAR-T cell therapy's treatment intensity and possible side effects, it is important to provide patients with sufficient medical attention and support for their nutritional well-being. METHODS: This study was conducted from May 2021 to December 2021 among patients undergoing CAR-T cell therapy at the Bone Marrow Transplantation Center in The First Affiliated Hospital of Zhejiang University School of Medicine. Logistic regression analysis was performed to investigate the risk factors associated with hypoalbuminemia. Participants were divided into the cytokine release syndrome (CRS) group (n = 60) and the non-CRS group (n = 11) to further analyze the relationship between hypoalbuminemia and CRS. RESULTS: CRS (OR = 13.618; 95% CI = 1.499-123.709; P = 0.013) and baseline albumin (ALB) (OR = 0.854; 95% CI = 0.754-0.967; P = 0.020) were identified as the independent clinical factors associated with post-CAR-T hypoalbuminemia. According to the nadir of serum albumin, hypoalbuminemia occurred most frequently in patients with severe CRS (78.57%). The nadir of serum albumin (r = - 0.587, P < 0.001) and serum albumin at discharge (r = - 0.315, P = 0.01) were negatively correlated for the duration of CRS. Furthermore, patients with hypoalbuminemia deserved longer hospitalization (P = 0.04). CONCLUSIONS: CRS was identified as a significant risk factor associated with post-CAR-T hypoalbuminemia. An obvious decline in serum albumin was observed as the grade and duration of CRS increase. However, further research is still needed to elucidate the mechanisms of CRS-associated hypoalbuminemia.

Nutritional status alterations after chimeric antigen receptor T cell therapy in patients with hematological malignancies: a retrospective study.

PURPOSE: The influence of innovative chimeric antigen receptor T cell (CAR-T) therapy for hematological malignancies on nutritional status remains unknown. Therefore, we aim to explore the alterations of nutritional status after CAR-T cell therapy in patients with hematological malignancies. METHODS: We retrospectively collected the data of patients with acute leukemia (AL), lymphoma, and multiple myeloma (MM), who underwent CAR-T therapy at our hospital from 2018 to 2020. The serum albumin, triglyceride, and cholesterol before and 7, 14, and 21 days after CAR-T cell infusion were compared and analyzed. RESULT: A total of 117 patients were enrolled, consisting of 39 AL, 23 lymphoma, and 55 MM patients. The baseline albumin, triglyceride, and cholesterol were 37.43 ± 5.08 mg/L, 1.63 ± 0.74 mmol/L, and 3.62 ± 1.03 mmol/L, respectively. The lowest albumin level was found at 7 days after CAR-T cell infusion compared with baseline (P < 0.001), while the levels of triglyceride increased at 14 and 21 days (P < 0.001, P = 0.036). The levels of cholesterol at 7, 14, and 21 days after CAR-T cell infusion were lower than baseline (all P < 0.05). Spearman's correlation coefficient showed cytokine release syndrome grade was negatively correlated with the levels of albumin at 7 days and cholesterol at 21 days after CAR-T cell infusion (r = - 0.353, P < 0.001; r = - 0.395, P = 0.002). CONCLUSION: The alterations of different nutrition-related biochemical parameters varied after CAR-T cell therapy. The levels of albumin and total cholesterol after CAR-T cell infusion were negatively correlated with the grade of cytokine release syndrome. Specific screening and intervention for malnutrition in patients receiving CAR-T cell therapy need to be explored in further studies.

Single-Cell Transcriptomic Analysis Reveals BCMA CAR-T Cell Dynamics in a Patient with Refractory Primary Plasma Cell Leukemia.

Chimeric antigen receptor T cell (CAR-T) therapy has revolutionized the clinical treatment of hematological malignancies due to the prominent anti-tumor effects. B cell maturation antigen (BCMA) CAR-T cells have demonstrated promising effects in patients with relapsed/refractory multiple myeloma. However, the dynamics of CAR-T cell proliferation and cytotoxicity in clinical patients remains unexplored. Here, we longitudinally profiled the transcriptomes of 55,488 T cells including CAR-T products, CAR-T cells, and endogenous T cells at the peak and remission phases in a plasma cell leukemia (PCL) patient treated with BCMA CAR-T cells by single-cell transcriptomic analysis. Our results showed distinct CAR-T and endogenous T cell subsets indicating stage-specific expression in proliferation, cytotoxicity, and intercellular signaling pathways. Furthermore, we found that CAR-T cells at peak phase gradually convert to a highly cytotoxic state from a highly proliferative state along a development trajectory. Moreover, re-analysis of a single cell study from CD8+ CD19 CAR-T confirmed our findings. These commonalities suggest conserved mechanisms for CAR-T treatment across hematological malignancies. Taken together, our current study provides insight into CAR-T cell dynamics during CAR-T therapy and proves that both BCMA CAR-T and CD19 CAR-T have similar transcriptional characteristics, especially at the CAR-T peak phase.

Progress on CAR-T cell therapy for hematological malignancies.

Chimeric antigen receptor (CAR) T cell therapy is an effective treatment for hematological malignancies, which have experienced the development of CD19 CAR-T cells for B lymphoblastic leukemia and lymphoma, B cell maturation antigen (BCMA) CAR-T cells for multiple myeloid, and more recently, the development of CD7 CAR-T cells for T cell malignancies. There are more obstacles for myeloid malignancies compared to other hematological malignancies in this field, thus concerning researches are in more diverse ways. In order to obtain more effective clinical CAR-T cells with lower side effects, scientists have developed multi-target CAR-T cells, universal CAR-T cells, as well as CAR-T cells, CAR-NK cells, CAR-iMac cells derived from induced pluripotent stem cells (iPSC) by genetic engineering. Chinese scientists have made significant contribution to the invention and manufacture of origin CAR-T cells and the establishment of an intact clinical research system. This review introduces the latest progress involving CAR-T cell therapy for hematological malignancies including B lymphoblastic malignancies, T lymphoblastic malignancies and myeloid malignancies, and also discuss the future developments including multi-target, universal and iPSC-derived CAR-related cell therapy.

Long-term efficacy of CAR-T cell therapy for patients with relapsed/refractory B cell non-Hodgkin lymphoma.

OBJECTIVE: To evaluate the long-term efficacy of chimeric antigen receptor (CAR) T cell therapy in treatment of relapsed/refractory B cell non-Hodgkin lymphoma (B-NHL). METHODS: Clinical data of 27 patients with relapsed/refractory B-NHL treated with CAR-T cell in Bone Marrow Transplantation Center, the First Affiliated Hospital of Zhejiang University School of Medicine from June 2016 to June 2020 were analyzed. Patients were followed up to February 1, 2022. The overall survival rate, progression free survival (PFS) rate were evaluated by Kaplan-Meier analysis, and the adverse reactions were recorded. RESULTS: The median follow-up time of 27 patients was 32  (1, 56) months. The total response rate was 85.2% (23/27), the complete response rate was 63.0% (17/27), and the partial response rate was 22.2% (6/27). The 3-year overall survival rate was (50.0±10.1)%, and the PFS rate was (44.4±9.6)%. After CAR-T cell therapy, the overall survival and PFS of patients in the complete response group were significantly better than those in the non-complete response group [overall survival rate: (66.9±12.7)% vs. (20.0±12.6)%, P=0.01; PFS rate: (64.7±11.6)% vs. (10.0±9.5)%, P<0.01]. There was no significant difference in overall survival rate and PFS rate between CD19 targeted and CD19/CD22 dual-targeted CAR-T cell therapy (both P>0.05). Cytokine release syndrome developed in 92.6% (25/27) of patients, and 88.9% (24/27) of patients had grade Ⅲ-Ⅳ myelosuppression. Other adverse reactions include immune effector cell-associated neurotoxicity syndrome, hepatitis B virus activation, and lung or gastrointestinal infections. No long-term adverse reactions occurred. CONCLUSIONS: CAR-T cell therapy is effective for patients with relapsed/refractory B-NHL, and the adverse reactions are controllable. The patients who obtain complete response after CAR-T cell therapy or survive for one year after therapy may have better long-term survival.

Research advance in lipid nanoparticle-mRNA delivery system and its application in CAR-T cell therapy.

Chimeric antigen receptor (CAR) T cell therapy has shown significant efficacy for hematological malignancies, however, it needs to be further optimized. Recently, the lipid nanoparticle (LNP)-mRNA delivery system as a nonviral gene transfer vector has gained rapid progress in CAR-T cell therapy. The claudin-6 (CLDN6) mRNA is delivered to antigen presenting cells (APCs) through LNP system, thereby enhancing the function of CLDN6 CAR-T cells for the clearance of solid tumor cells. For treatment of acute cardiac injury, the fibroblast activation protein (FAP) CAR mRNA can be delivered to T cells through LNP system for the in vivo production of FAP CAR-T cells, thereby blocking the process of myocardial fibrosis. The LNP-mRNA delivery system has advantages including having no integration in host genome, inexpensiveness, low toxicity and modifiability; on the other hand, it has certain disadvantages such as limited cell persistence caused by transient protein expression and limitations in preparation techniques. This article reviews the research advance in LNP-mRNA in vivo delivery system and its application in CAR-T cell therapy.

Risk factors of tumor lysis syndrome in relapsed/refractory multiple myeloma patients undergoing BCMA CAR-T cell therapy.

OBJECTIVE: To investigate the risk factors of tumor lysis syndrome (TLS) in relapsed/refractory multiple myeloma (MM) patients undergoing B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T cell therapy. METHOD: The clinical data of 99 relapsed/refractory MM patients receiving BCMA CAR-T cell therapy in the First Affiliated Hospital, Zhejiang University School of Medicine from July 2018 to December 2021 were collected in this study. Univariate analysis and multivariate logistic regression were performed to evaluate the risk factors of TLS following BCMA CAR-T cell therapy. RESULTS: Among the 99 patients, TLS occurred in 17 cases (17.2%) with an onset time of (8.9±3.0) d after BCMA CAR-T cell therapy. All TLS patients developed TLS-related clinical manifestations, including 17 cases with renal dysfunction, 8 cases with arrhythmia. All TLS patients developed cytokine release syndrome (CRS) with an onset of 1.0 (1.0, 6.5) d after CAR-T cell therapy, and 13 cases developed grade 3-4 CRS. The levels of serum uric acid, serum creatinine and the ratio of cases with grade 3-4 CRS were significantly higher in TLS patients than in non-TLS patients (all P<0.05). Multivariate logistic regression revealed that serum creatinine ( OR=1.015, P<0.01) and severe CRS ( OR=9.371, P<0.01) were independent risk factors of TLS. CONCLUSIONS: Relapsed/refractory MM patients undergoing BCMA CAR-T therapy shows high incidence of TLS, which are related to elevated levels of serum creatinine and severe CRS. TLS can be prevented clinically by reducing serum creatinine and controlling CRS severity.