Chimeric Antigen Receptor-modified T-cell Therapy Research Articles

Co-infusion of CAR T cells with aAPCs expressing chemokines and costimulatory ligands enhances the anti-tumor efficacy in mice

Chimeric antigen receptor-modified T (CAR-T) cell therapy has shown curable efficacy for treating hematological malignancies, while in solid tumors, the immunosuppressive microenvironment causes poor activation, expansion and survival of CAR-T cells, accounting mainly for the unsatisfactory efficacy. The artificial antigen-presenting cells (aAPCs) have been used for ex vivo expansion and manufacturing of CAR-T cells. Here, we constructed a K562 cell-based aAPCs expressing human epithelial cell adhesion molecule (EpCAM), chemokines (CCL19 and CCL21) and co-stimulatory molecular ligands (CD80 and 4-1BBL). Our data demonstrated that the novel aAPCs enhanced the expansion, and increased the immune memory phenotype and cytotoxicity of CAR-T cells recognizing EpCAM, in vitro. Of note, co-infusion CAR-T and aAPC enhances the infiltration of CAR-T cells in solid tumors, which has certain potential for the treatment of solid tumors Moreover, IL-2-9-21, a cytokine cocktail, prevents CAR-T cells from entering the state of exhaustion prematurely after continuous antigen engagement and boosts the anti-tumor activity of CAR-T cells co-infused with aAPCs. These data provide a new strategy to enhance the therapeutic potential of CAR-T cell therapy for the treatment of solid tumors.

CT radiomics can predict disease progression within 6 months after chimeric antigen receptor-modified T-cell therapy in relapsed/refractory B-cell non-Hodgkin's lymphoma patients

To predict progression within 6 months after chimeric antigen receptor-modified (CAR) T-cell therapy for relapsed/refractory (R/R) B-cell non-Hodgkin's lymphoma (B-NHL) patients by radiomic indexes derived from contrast-enhanced computed tomography (CECT) examinations. Seventy R/R B-NHL patients who underwent CECT before treatment with CAR T-cells were examined retrospectively. In total, 297 volumes of interest for lesions were segmented from CECT images. Patients without and with disease progression were assigned to groups 1 and 2, respectively. Radiomic and combined predictive models were constructed by three machine-learning algorithms using features from the training set, respectively. Furthermore, predictive models were constructed based on multi-lesion-based and largest-lesion-based radiomic features, respectively. In the test set, no marked differences were observed between the areas under the curves (AUCs) of the combined and radiomic models for all three machine-learning algorithms (all p>0.05). Differences in machine-learning algorithms did not significantly affect the predictive performances of the models. Radiomics and combined models constructed with multi-lesion-based radiomic features showed better predictive performances than those applying largest-lesion-based radiomic features (all p<0.05 for comparisons between combined models). CECT-based radiomic features may be applied to predict disease progression in R/R B-NHL patients within 6 months after CAR T-cell treatment, and radiomic features from multiple lesions may have better predictive efficacy. Different machine-learning algorithms may not show significant differences in prediction performance.

Utilizing induced neural stem cell-based delivery of a cytokine cocktail to enhance chimeric antigen receptor-modified T-cell therapy for brain cancer.

Chimeric antigen receptor (CAR)-modified T-cell therapy has shown enormous clinical promise against blood cancers, yet efficacy against solid tumors remains a challenge. Here, we investigated the potential of a new combination cell therapy, where tumor-homing induced neural stem cells (iNSCs) are used to enhance CAR-T-cell therapy and achieve efficacious suppression of brain tumors. Using in vitro and in vivo migration assays, we found iNSC-secreted RANTES/IL-15 increased CAR-T-cell migration sixfold and expansion threefold, resulting in greater antitumor activity in a glioblastoma (GBM) tumor model. Furthermore, multimodal imaging showed iNSC delivery of RANTES/IL-15 in combination with intravenous administration of CAR-T cells reduced established orthotopic GBM xenografts 2538-fold within the first week, followed by durable tumor remission through 60 days post-treatment. By contrast, CAR-T-cell therapy alone only partially controlled tumor growth, with a median survival of only 19 days. Together, these studies demonstrate the potential of combined cell therapy platforms to improve the efficacy of CAR-T-cell therapy for brain tumors.

Humoral and cellular responses to SARS-CoV-2 vaccines before and after chimeric antigen receptor-modified T-cell therapy.

Humoral and cellular responses to SARS-CoV-2 vaccines before and after chimeric antigen receptor-modified T-cell therapy.

Anti-CD 19 CAR-T Cell Therapy with Tisagenlecleucel for Ritcher Syndrome

About 2-10 percent of patients with chronic lymphocytic leukemia (CLL) will transform into an aggressive large cell lymphoma, called Ritcher syndrome (RS). The transformation is to DLBCL in 90-95% of cases and Hodgkin lymphoma in the remaining 5-10%. Current treatment strategies that typically mirror DLBCL have not significantly improved the historically dismal outcomes of RS. Chimeric antigen receptor-modified T (CAR-T) cells have revolutionized the treatment of B-cell malignancies and are currently approved for relapsed/refractory DLBCL. The impact of CAR-T cell therapy in the management of RS is limited by the small number of affected patients and published reports. We report the outcomes in 2 patients with RS treated with tisagenlecleucel (Tisa-cel) at our institution. Patient 1. This is a 75-year-old lady diagnosed with CLL at the age of 64, Rai stage 1, trisomy 12, mutated IGVH. She was on observation until she became symptomatic 5 yrs. after diagnosis and had a biopsy which showed CLL with RS, fluorescent in-situ hybridization (FISH) negative for C-MYC, BCL2 and BCL6. She was treated with RCHOP x 6 cycles with complete remission (CR) on PET. She received high dose chemotherapy with R-BEAM followed by autologous stem cell transplant, followed by 4 cycles of maintenance brentuximab given every 3 weeks for her CD30 positive large B cell lymphoma. About 5 yrs. later, surveillance PET showed hypermetabolic cervical lymph nodes and excisional biopsies showed CLL and DLBCL, non-germinal center type, concerning for relapsed RS. She was referred to us for CAR-T cell therapy evaluation. Bone marrow biopsy was negative for marrow involvement, minimal residual disease (MRD) by ClonoSEO was positive. She received lymphodepleting chemotherapy with fludarabine and cyclophosphamide followed by CAR-T cell infusion with tisa-cel 5x10^8 anti CD19 CAR-T cells on 4/18/22. Treatment was complicated by grade 1-2 cytokine release syndrome (CRS) (treated with tocilizumab and dexamethasone) requiring brief hospitalization. Day 90 PET showed CMR and bone marrow biopsy was negative for disease, MRD negative. She continues to be in CR 100 days post CAR-T cell therapy. Patient 2. A 63 years-old lady originally diagnosed with CLL in 2016 at the age of 57, with 17p deletion, 13q deletion and IgHV unmutated. She was started on ibrutinib shortly after due to a short lymphocyte doubling time. Three years later (in 2020), she developed worsening lymphadenopathy while on ibrutinib, underwent excisional biopsy and this showed RS with TP53 mutation, 17p deletion, gain of 13q, BCL2 positive. Venetoclax was added to ibrutinib and later, 2 cycles of Obinutuzumab were also given. Subsequent PET 7 months after showed disease progression with a lugano score of 5. She received 6 cycles of RCHOP in addition to venetoclax/ibrutinib but end of treatment PET showed disease progression. She was then referred to us for CAR-T cell evaluation. She received lymphodepleting chemotherapy with fludarabine and cyclophosphamide followed by CAR-T cell infusion with tis-cel 3.7 x 10^8 cells anti CD19 CAR-T cells on 6/7/21. This was complicated by grade 2 CRS that was treated with tocilizumab. Day 30 PET showed PR. Ibrutinib was resumed and the patient received radiation to right cervical lymph nodes. Day 100 PET reaffirmed PR and she subsequently underwent FluCyTBI RIC followed by haploidentical alloSCT from her daughter on 09/29/21. On day 180 post-transplant, the patient remained in CR by PET and bone marrow biopsy. She continues to be in CR now 1 year since her CAR-T cell infusion. Conclusion CAR-T cell therapy with Tisagenlecleucel shows promising activity in patients with RS. It is an evolving treatment strategy and more follow up is needed to assess the durability of the responses observed in these patients.

Clinical characteristics and prognosis of 16 relapsed/refractory B-cell malignancy patients with CAR T-cell-related hyperferritinaemia.

With the success of chimeric antigen receptor-modified (CAR) T-cell therapy for relapsed/refractory (r/r) B-cell malignancies, severe complications after CAR T-cell infusion have emerged as nonnegligible prognosis-related factors. However, the prognosis of patients with CAR T-cell-related hyperferritinaemia (HFA) is unclear. We report the efficacy and safety of CAR T-cell therapy in 16 r/r B-cell malignancy patients with CAR T-cell-related HFA. The rates of serum ferritin levels above 10,000 ng/ml during CAR T-cell therapy were 6.2% and 14.3% in B-cell non-Hodgkin’s lymphoma (B-NHL) and acute B lymphocyte leukemia (B-ALL), respectively. These patients were characterized by an extremely high tumor burden and a high rate of extranodal involvement. In lymphoma, the complete remission (CR) rate was 37.5% (3/8), which was lower than that in the control group with the lowest value of ferritin (CR was 87.5% (7/8), P=0.0406), and it could also be seen that the OS of the control group (1-year OS rate 100%) had a better trend than HFA group (1-year OS rate 50%). In the B-ALL patients, the OS of the control group (1-year OS rate 100%) was higher than HFA group (1-year OS rate 45%, P=0.0189), although there was no significant difference in CR rate. High-grade CRS (≥3) occurred in 56.25% of the patients, and the mortality rate was 56.25%, which was significantly higher than control group (12.5% and 12.5%, P=0.009). The peak serum ferritin level in the patients who died of CRS was significantly higher than others (P=0.0168). Regardless of whether the CAR T-related MAS diagnostic criteria were met, there was no significant difference in ORR and OS in HFA group, however patients with MAS showed a higher rate of high-grade CRS. Interestingly, in our study, glucocorticoid intervention in HFA group showed little impact on expansion of CAR-T cells, whether compared with control group or compared within HFA group by dividing patients into high and low dosage subgroups based on the median dose of glucocorticoid. High mortality was observed in patients with CAR T-cell-related HFA. Early glucocorticoid intervention might be worth trying to improve the safety of CAR T therapy in these patients.

ABCL-101 Cost-Effectiveness of Polatuzumab Vedotin in Previously Untreated Diffuse Large B-Cell Lymphoma

Polatuzumab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) significantly increased progression-free survival (PFS) (HR, 0.73; 95% CI: 0.57-0.95) vs rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in the POLARIX clinical trial (NCT03274492). The objective of this analysis was to evaluate the cost-effectiveness of Pola-R-CHP vs R-CHOP in frontline diffuse large B-Cell lymphoma (DLBCL). In our cost-effectiveness model, we derived PFS, overall survival (OS), drug utilization, adverse events (AE), and subsequent treatment from POLARIX, including higher utilization of chimeric antigen receptor-modified T-cell therapy (CAR-T) and stem-cell transplantation in the R-CHOP arm compared with Pola-R-CHP arm. Costs included drug acquisition, AE management, routine medical care, subsequent treatments, end-of-life care, and work productivity. A scenario analysis was conducted to assess the future impact of increased second-line CAR-T utilization. We estimated the life years, quality-adjusted life years (QALY), cost impacts, and incremental cost-effectiveness ratio (ICER) of Pola-R-CHP vs R-CHOP. Probabilistic sensitivity analyses (PSA) were performed to assess the impact of uncertainty on cost per QALY-gained outcomes. The ICER of Pola-R-CHP vs R-CHOP was $80,920/QALY gained from a societal perspective and $96,014/QALY gained from a payer perspective. From a societal perspective, the total cost of Pola-R-CHP was $41,159 higher than R-CHOP, primarily due to higher drug costs ($125,623 vs $34,034, respectively). Drug cost offsets for Pola-R-CHP included subsequent treatment costs (-$42,269), routine care (-$1,195), end-of-life care (-$393), and work productivity (-$7,677). AE management costs were $1,069 higher with Pola-R-CHP vs. R-CHOP. Pola-R-CHP resulted in an increase of 0.50 life years and 0.51 QALYs vs R-CHOP. PSA results demonstrated that Pola-R-CHP was cost-effective in 63.0% of simulations at a willingness-to-pay of $150,000/QALY gained from a societal perspective, and 60.8% of simulations from a payer perspective. In the increased CAR-T use scenario, the ICER was $61,220/QALY gained. Pola-R-CHP was projected to be cost-effective vs R-CHOP in previously untreated DLBCL. Our economic model demonstrates an improvement in QALYs with Pola-R-CHP vs R-CHOP and savings in costs relating to DLBCL progression. These cost-effectiveness results reinforce the clinical findings from POLARIX suggesting that Pola-R-CHP should be considered as a frontline standard of care.

Pneumococcal Conjugate Vaccine Does Not Induce Humoral Response When Administrated Within the Six Months After CD19 CAR T-Cell Therapy

CD19 targeted chimeric antigen receptor-modified T cell therapy (CAR-T) leads to B cell aplasia and low serum immunoglobulin levels. Long-lived CD19–negative plasma cells may persist through the therapy and generate antibodies. There is a paucity of data describing how CAR-T impacts the persistence of antibodies against vaccine-related antigens and the degree to which CAR-T recipients may respond to vaccines. We characterized the effect of CAR-T on pneumococcal immunoglobulin G (IgG) titers and determine whether pneumococcal conjugate vaccine (PCV13) administered after CAR-T develops long-term humoral protection against pneumococcus. A retrospective chart review was performed to identify CAR-T recipients who had serum pneumococcal IgG titers drawn before (baseline) or at days +90, +180, +270, +360, or +540 after CAR-T. We then determined whether they received PCV13 vaccination at these timepoints. IgG concentration ≥1.3 μg/mL was considered protective for that serotype, and patients with ≥6/11 tested vaccine-specific serotypes meeting this threshold were deemed to have humoral protection against pneumococcus. Absolute pneumococcal IgG titers and the proportion of patients with humoral protection, stratified by serotype, and vaccination status were compared by paired nonparametric t-tests. Absolute counts for lymphocyte, CD4 T-cell, and CD19 cell and total IgG level, along with the rate of invasive pneumococcal infections, were measured at these timepoints. A total of 148 CAR-T recipients with pneumococcal IgG titers measured for at least one of the defined time points were identified. At baseline, 25% (19/76) patients with evaluable pneumococcal IgG titers met the definition of humoral protection. Among 44 patients with paired pneumococcal IgG titers at baseline and day+90, absolute IgG titers of all serotypes decreased (geometric mean = 0.41 and 0.32 µg/mL, respectively; P < .001). Thirteen patients were vaccinated following the titer blood draw at day+90 and had paired pneumococcal IgG titers at day+90 and day180. Absolute IgG titers of all vaccine specific serotypes in these vaccinated patients decreased from day+90 to day+180 (geometric mean = 0.36 and 0.29 µg/mL, respectively; P = .03). The proportion of patients meeting the criteria of humoral protection remained the same at day+180 despite vaccination at day+90. The results were similar among 8 patients vaccinated at day+180, as well as 7 patients consecutively vaccinated at day+90 and day+180 with corresponding pneumococcal IgG titers. When all vaccine-specific pneumococcal IgG titers were pooled together by timepoint regardless of vaccination status, the proportion of patients with humoral protection decreased until day+540. Some patients developed humoral protection after vaccination at day+360, maintained seroprotective IgG titers from baseline, or developed protection after receiving intravenous immunoglobulin treatment secondary to recurrent infections. Our study demonstrated that few large B cell lymphoma patients had humoral protection against pneumococcus at baseline, and existing IgG titers decreased after CAR-T. PCV13 vaccination at day+90 or day+180 after CAR-T did not increase humoral protection against pneumococcus. Only at day+540 was there evidence of humoral protection against pneumococcus in a modest proportion of patients. Clinical trials are needed to determine the optimal timing of vaccination, before or after CAR-T, to develop protective immunity against Streptococcus pneumoniae infections.

Suppressed Fibrinolytic Activity Demonstrated By Simultaneous Thrombin and Plasmin Generation Assay during Cytokine Release Syndrome after CD19 Chimeric Antigen Receptor-Modified T-Cell Therapy

Introduction: Infusion T cells engineering to express CD19-specific chimeric antigen receptor T cells (CAR-T) following lymphodepleting chemotherapy has shown promising efficacy in patients with relapsed and/or refractory CD19-positive B-cell malignancies including B-cell acute lymphoblastic leukemia (B-ALL), and diffuse large B-cell lymphoma (DLBCL). CAR-T therapy can often be associated with cytokine release syndrome (CRS), which has been reported to present severe coagulopathy. Conventional coagulation and fibrinolysis parameters have been reported to worsen in correlation with CRS grading [Hay KA et al. Blood 2017]. In the present study, we hypothesized that the change of balance between coagulation and fibrinolysis due to coagulopathy is associated with CRS after CAR-T therapy. To clarify our hypothesis, we investigated the global coagulation and fibrinolytic function of patients receiving CD19 CAR-T therapy using simultaneous thrombin and plasmin generation assay (T/P-GA). Patients: We enrolled 13 consecutive patients aged 23-69 years (8 males and 5 females, DLBCL; n = 11, B-ALL; n = 2) receiving CD19 CAR-T therapy from May 2020 to December 2020 at a single center in Japan. Due to a history of internal jugular venous thrombosis, one patient received edoxaban, an anticoagulant. Methods: We evaluated the global functions of coagulation and fibrinolysis using T/P-GA [Matsumoto et al. TH 2013]. This clotting was initiated by the mixture of recombinant human tissue factor (Innovin ®, f.c. 1 pM), phospholipid vesicles (f.c. 4 μM), and tissue-type plasminogen activator (f.c. 3.2 nM). We simultaneously monitored thrombin and plasmin generation using thrombin- and plasmin-specific fluorogenic substrate (Z-Gly-Gly-Arg-AMC and BOC-Glu-Lys-Lys-MAC, respectively) in separate microtiter wells. The first derivatives (velocity) of thrombin and plasmin generation were utilized to derive the parameters, lag time (LT), endogenous potential (EP), peak levels (Peak), and time to peak (ttPeak). In this study, EP of thrombin generation (T-EP) and plasmin-peak (P-Peak) were selected as parameters for evaluation. We calculated the ratio of T-EP and P-Peak of patients' plasmas to those of control normal plasma. A ratio > 1.0 was defined as high coagulation or fibrinolytic potential relative to normal. Using fibrinogen (Fbg), D-dimer, and antithrombin (AT), we also monitored the conventional laboratory markers of hemostasis. Soluble IL-2 receptor (sIL-2R) was also measured as a marker of inflammatory cytokines. Day 0 was defined as the day of CAR-T infusion. Plasmas were collected at T0; pre-lymphodepleting chemotherapy, T1; Days -2-0, T2; Days 1-3, T3; Days 4-6, T4; Days 7-9, T5; Days 10-12, T6; Days 13-18, and T7; Days 19-23. Results: All patients had Grade ≤ 2 CRS. Two cases developed CRS-associated coagulopathy, one of whom required fresh frozen plasma transfusion and cryoprecipitate for low Fbg level, and the other required tranexamic acid for hemorrhagic cystitis. The median values of AT remained within the reference value (RV). The median Fbg values were 229-525 mg/dL, and which were significantly greater at T0-T3 than at T5-T7 (p < 0.05). The median D-dimer values were 0.45-3.9 µg/mL, which were within or above the RV with no significant change between time points. The median values of sIL-2R were 819-3,953 U/mL, and which were significantly increased at T3-T4 than at T0-T1 (p < 0.05). T-EP/P-Peak revealed a median of 1,877/21.9, 1,659/18.6, 1,731/19.8, 1,856/15.0, 1,931/16.3, 1,758/18.5, 1,600/19.1, 1,634/20.3, and 1,594/17.4 nM for T0-T7 and control plasma, respectively, indicating the reduced P-Peak ratios (Fig. 1). T-EP ratios showed consistently maintaining > 1 with no significant difference between time points, while P-Peak ratios were significantly lower at T3 and T4 than at T0 (p < 0.01) (median ratios of T-EP/P-peak; T0; 1.23/1.22, T1; 1.08/1.05, T2; 1.12/1.09, T3; 1.23/0.81, T4; 1.27/0.91, T5; 1.19/1.11, T6; 1.07/1.12, and T7; 1.20/1.15, respectively). Conclusion: The results of T/P-GA showed that hemostatic kinetics in patients with Grade ≤ 2 CRS were likely to shift to hypercoagulable states throughout the entire period and that they were likely to experience hypofibrinolytic activity during the CRS phase. These results suggest that the imbalance of coagulation and fibrinolysis might cause organ disorder due to thrombotic tendency associated with CRS after CAR-T therapy. [Display omitted] DisclosuresTakaori-Kondo: Bristol-Myers K.K.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Research Funding; Celgene: Research Funding. Nogami: Chugai Pharmaceutical Co., Ltd.: Consultancy, Research Funding.

Chimeric Antigen Receptor T Cell Targeting to CD19 and CD22 Combined with Anti-PD-1 Antibody Induce High Response in Patients with Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma

Objective: Despite the remarkable success of chimeric antigen receptor modified T (CAR-T) cell therapy for refractory or relapsed B cell non-Hodgkin lymphoma (R/R B-NHL), high rates of treatment failure and relapse after CAR-T cell therapy are considerable obstacles to overcome. Preclinical models have demonstrated that anti-PD-1 antibody is an attractive option following CAR-T therapy to reverse T cell exhaustion. Thus, we investigated their combination in R/R B-NHL.Methods: We performed a prospective, single-arm study of CAR-T cell combined with anti-PD-1 antibody treatment in R/R B-NHL (NCT04539444). Anti-PD-1 antibody was administrated on day 1 after patients received sequential infusion of anti-CD19 and anti-CD22 second-generation CAR-T cells, and the efficacy and safety of the combination treatment were evaluated.Results: From August 1, 2020 to June 30, 2021, a total of 11 patients were enrolled and completed at least 3 months follow-up. The median follow-up time is 5.8 months. Overall response was achieved in 9 of 11 patients (81.8%), and the complete response (CR) was achieved in 8 of 11 patients (72.7%). All 8 patients achieving CR still sustained remission at the last follow-up. The progression-free survival (PFS) and overall survival (OS) rates at 6 months were 80.8% and 100.0%, respectively. Cytokine release syndrome (CRS) occurred in only 4 patients (all were grade 1), and no neurotoxicity were observed.Conclusion: This study suggests that CAR-T cells combined with anti-PD-1 antibody elicit a safe and durable response in R/R B-NHL.Keywords: chimeric antigen receptor modified T cell, anti-PD-1 antibody, CD19/CD22, refractory or relapsed B cell non-Hodgkin lymphoma DisclosuresNo relevant conflicts of interest to declare. OffLabel Disclosure:We use the T cells were transduced with a lentivirus encoding the CD19-4-1BB-CD3 z and CD22-4-1BB-CD3 ztransgene to produce CAR-T cells. The main purpose of our study is to improve the response rate in patients with R/R B-NHL.

Infectious complications following chimeric antigen receptor T-cell therapy for a hematologic malignancy within 28 days

目的探讨血液肿瘤患者在回输嵌合抗原受体T细胞（CAR-T细胞）后28 d内感染的发生率、临床和微生物学特征及危险因素。方法回顾性分析2016年1月至2020年12月在华中科技大学同济医学院附属协和医院血液科成功接受CAR-T细胞输注的170例血液肿瘤患者基线资料以及回输后28 d内发生感染的临床与病原菌特征。使用泊松回归评估基线特征与感染密度的相关性，单因素和多因素Cox比例风险回归模型评估CAR-T细胞回输后感染的高危因素。结果170例患者中急性淋巴细胞白血病（ALL）72例、非霍奇金淋巴瘤（NHL）56例、多发性骨髓瘤（MM）42例，99例患者在28 d内共发生119次感染，累积感染发生率为（58.2±3.8）％；其中细菌感染98次（45.9％），总感染密度为2.01，首次感染发生的中位时间为回输后12（1～18）d。多因素泊松回归显示ALL患者、难治性疾病、既往30 d内感染病史、回输前ANC<0.5×109/L、前期治疗方案≥4种的患者在28 d内与感染密度有更高的相关性；多因素Cox回归显示≥3级细胞因子释放综合征（CRS）是发生感染的独立危险因素（HR＝3.74，95％CI 1.29～5.72，P<0.001）。结论感染是血液病患者CAR-T治疗后常见的并发症之一，不同肿瘤的感染发生率与类型有所差异，但均以细菌感染为主。ALL患者、难治性疾病、既往30天内感染病史、回输前ANC<0.5×109/L、前期治疗方案≥4种与感染密度相关；3级以上CRS是感染发生的独立危险因素。中国临床试验注册中心：ChiCTR-OIC-17011180、ChiCTR1800018143

Antibodies against vaccine-preventable infections after CAR-T cell therapy for B cell malignancies.

BACKGROUNDLittle is known about pathogen-specific humoral immunity after chimeric antigen receptor–modified T (CAR-T) cell therapy for B cell malignancies.METHODSWe conducted a prospective cross-sectional study of CD19-targeted or B cell maturation antigen–targeted (BCMA-targeted) CAR-T cell therapy recipients at least 6 months posttreatment and in remission. We measured pathogen-specific IgG against 12 vaccine-preventable infections and the number of viral and bacterial epitopes to which IgG was detected (“epitope hits”) using a serological profiling assay. The primary outcome was the proportion of participants with IgG levels above a threshold correlated with seroprotection for vaccine-preventable infections.RESULTSWe enrolled 65 children and adults a median of 20 months after CD19- (n = 54) or BCMA- (n = 11) CAR-T cell therapy. Among 30 adults without IgG replacement therapy (IGRT) in the prior 16 weeks, 27 (90%) had hypogammaglobulinemia. These individuals had seroprotection to a median of 67% (IQR, 59%–73%) of tested infections. Proportions of participants with seroprotection per pathogen were comparable to population-based studies, but most individuals lacked seroprotection to specific pathogens. Compared with CD19-CAR-T cell recipients, BCMA-CAR-T cell recipients were half as likely to have seroprotection (prevalence ratio, 0.47; 95% CI, 0.18–1.25) and had fewer pathogen-specific epitope hits (mean difference, –90 epitope hits; 95% CI, –157 to –22).CONCLUSIONSeroprotection for vaccine-preventable infections in adult CD19-CAR-T cell recipients was comparable to the general population. BCMA-CAR-T cell recipients had fewer pathogen-specific antibodies. Deficits in both groups support the need for vaccine and immunoglobulin replacement therapy studies.FUNDINGSwiss National Science Foundation (Early Postdoc Mobility grant P2BSP3_188162), NIH/National Cancer Institute (NIH/NCI) (U01CA247548 and P01CA018029), NIH/NCI Cancer Center Support Grants (P30CA0087-48 and P30CA015704-44), American Society for Transplantation and Cellular Therapy, and Juno Therapeutics/BMS.

Secretion of bispecific protein of anti-PD-1 fused with TGF-β trap enhances antitumor efficacy of CAR-T cell therapy

Despite the remarkable success of chimeric antigen receptor-modified T (CAR-T) cell therapy for blood malignancies, the clinical efficacy of this novel therapy in solid tumor treatment is largely limited by the immunosuppressive tumor microenvironment (TME). For instance, immune checkpoints (e.g., programmed cell death protein 1 [PD-1]/programmed death ligand 1 [PD-L1]) in TME play an important role in inhibiting T cell proliferation and functions. Transforming growth factor β (TGF)-β secreted by cancer cells in TME induces regulatory T cells (Tregs) and inhibits cytotoxic T cells. To overcome the inhibitory effect of immune checkpoints, we have previously engineered CAR-T cells to secrete anti-PD-1 to block the PD-1/PD-L1 pathway activity, a step demonstrating superior antitumor efficacy compared with conventional CAR-T cells. In this study, we engineered CAR-T cells that secrete bispecific trap protein co-targeting PD-1 and TGF-β, with the aim of further improving antitumor immunity. Compared with conventional CAR-T cells and anti-PD-1-secreting CAR-T cells, data from in vitro and in vivo experiments showed that CAR-T cells with trap protein secretion further attenuated inhibitory T cell signaling, enhanced T cell persistence and expansion, and improved effector function and resistance to exhaustion. In the xenograft mouse model, CAR-T cells with trap protein secretion exhibited significantly enhanced antitumor immunity and efficacy. With these observations, we demonstrate the potential of trap protein self-secreting CAR-T cells as a potent therapy for solid tumors.

Invasive Fungal Infections after Anti-CD19 Chimeric Antigen Receptor-Modified T-Cell Therapy: State of the Evidence and Future Directions.

Studies describing invasive fungal infections (IFIs) after chimeric antigen receptor-modified T-cell (CAR-T-cell) therapy are limited. Although post-CAR-T-cell IFIs appear to be uncommon, they are associated with significant morbidity and mortality. Specific risk factors for IFIs in CAR-T-cell recipients have not been fully characterized and are often extrapolated from variables contributing to IFIs in patients with other hematologic malignancies or those undergoing hematopoietic cell transplant. Optimal prophylaxis strategies, including the use of yeast versus mold-active azoles, also remain ill-defined. Further research should investigate key risk factors for IFIs and establish an evidence-based approach to antifungal prophylaxis in these patients in order to improve clinical outcomes.

Intractable Coronavirus Disease 2019 (COVID-19) and Prolonged Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Replication in a Chimeric Antigen Receptor-Modified T-Cell Therapy Recipient: A Case Study.

A chimeric antigen receptor-modified T-cell therapy recipient developed severe coronavirus disease 2019, intractable RNAemia, and viral replication lasting >2 months. Premortem endotracheal aspirate contained >2 × 1010 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA copies/mL and infectious virus. Deep sequencing revealed multiple sequence variants consistent with intrahost virus evolution. SARS-CoV-2 humoral and cell-mediated immunity were minimal. Prolonged transmission from immunosuppressed patients is possible.

Overcoming resistance to targeted therapies in chronic lymphocytic leukemia.

Insight into the critical role of B-cell receptor signaling for the pathogenesis of chronic lymphocytic leukemia (CLL) led to the development of targeted therapies directed at key regulators of cell survival. Agents targeting B-cell lymphoma-2 protein, Bruton's tyrosine kinase (BTK), and phosphatidylinositol 3-kinase are approved for treatment of CLL, and have significantly improved the disease management. Nevertheless, acquired resistance to the targeted therapies is a challenge still to be resolved. The mechanisms underlying resistance are becoming clearer, and include secondary mutations within the drug target and activation of bypass pathways. This knowledge has allowed development of strategies to prevent and overcome treatment resistance. Approaches to prevent resistance include targeting bypass mechanisms by combination therapies, temporally sequencing of therapies, improved clinical trial designs, and real-time monitoring of patient response. A rational design of drug sequencing may secure effective treatment options at the relapsed setting. Next-generation inhibitors and bispecific antibodies have the potential to overcome resistance to the BTK inhibitor ibrutinib. Immunotherapy, including chimeric antigen receptor-modified T-cell therapy, is explored for relapsed CLL. Here, recent advances that have contributed to the understanding of resistance to targeted therapies in CLL are discussed. Strategies for managing resistance are reviewed, including translational, real-world, and clinical perspectives.

Efficacy and Safety of CAR-Modified T Cell Therapy in Patients with Relapsed or Refractory Multiple Myeloma: A Meta-Analysis of Prospective Clinical Trials.

Background: In recent years, chimeric antigen receptor-modified T (CAR-T) cell therapy for B-cell leukemia and lymphoma has shown high clinical efficacy. Similar CAR-T clinical trials have also been carried out in patients with refractory/relapsed multiple myeloma (RRMM). However, no systematic review has evaluated the efficacy and safety of CAR-T cell therapy in RRMM. The purpose of this study was to fill this literature gap. Methods: Eligible studies were searched in PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), CNKI, and WanFang from data inception to December 2019. For efficacy assessment, the overall response rate (ORR), minimal residual disease (MRD) negativity rate, strict complete response (sCR), complete response (CR), very good partial response (VGPR), and partial response (PR) were calculated. The incidence of any grade cytokine release syndrome (CRS) and grade ≥3 adverse events (AEs) were calculated for safety analysis. The effect estimates were then pooled using an inverse variance method. Results: Overall, 27 studies involving 497 patients were included in this meta-analysis. The pooled ORR and MRD negativity rate were 89% (95% Cl: 83–94%) and 81% (95% Cl: 67–91%), respectively. The pooled sCR, CR, VGPR, and PR were 14% (95% Cl: 5–27%), 13% (95% Cl: 4–26%), 23% (95% Cl: 14–33%), and 15% (95% Cl: 10–21%), respectively. Subgroup analyses of ORR by age, proportion of previous autologous stem cell transplantation (ASCT), and target selection of CAR-T cells revealed that age ≤ 55 years (≤55 years vs. > 55 years, p = 0.0081), prior ASCT ≤70% (≤70% vs. > 70%, p = 0.035), and bispecific CAR-T cells (dual B-cell maturation antigen (BCMA)/BCMA + CD19 vs specific BCMA, p = 0.0329) associated with higher ORR in patients. Subgroup analyses of remission depth by target selection suggested that more patients achieved a better response than VGPR with dual BCMA/BCMA + CD19 CAR-T cells compared to specific BCMA targeting (p = 0.0061). In terms of safety, the pooled incidence of any grade and grade ≥ 3 CRS was 76% (95% CL: 63–87%) and 11% (95% CL: 6–17%). The most common grade ≥ 3 AEs were hematologic toxic effects. Conclusion: In heavily treated patients, CAR-T therapy associates with promising responses and tolerable AEs, as well as CRS in RRMM. However, additional information regarding the durability of CAR-T cell therapy, as well as further randomized controlled trials, is needed.

Anti CD19/22 Cocktail CAR T-Cell Therapy Can Improve the Outcomes of Patients with TP53-Mutated Relapsed/Refractory B-Cell Lymphoma

Mutations of the Tp53 gene occur in a subset of patients with refractory/relapse B-cell lymphoma and confer an exceedingly adverse prognosis. Chimeric antigen receptor-modified (CAR) T-cell immunotherapy represents a novel promising treatment and has achieved impressive anti-tumor responses in patients with refractory or relapsed B cell malignancies. Whether CAR T cell therapy can improve the outcomes of refractory/relapse B-cell lymphoma with Tp53 mutations or high-risk functional classification of Tp53 mutations has not been fully investigated yet. In phase 2 trial, we evaluated the anti-CAR 19/22 cocktail therapy in patients with relapsed or refractory B-cell lymphoma with Tp53 mutations. The primary endpoint was the percentage of patients with an objective response (complete and partial response). The high-risk Tp53 mutations were defined as missense mutations, 'disruptive' mutations and the 'high-risk group of evolutionary action (EAp53) score. The outcome impact of CAR T cell therapy on high-risk Tp53 mutations were also assessed. Between September 2016 to January 2020, a total of 30 patients [median age, 44.0 years (range: 28.0 to 61.0)] were enrolled. The primary efficacy analysis showed that 76.7 % (95%CI: 61% to 93%) patients have best objective response(Figure 1A), while 60.0 % (95%CI: 41% to 79%) patients at month three maintained the objective response(Figure 1B). At a median follow-up of 7.95 months (range: 1.13 to 42.76), the 12-months progression-free survival and overall survival rate were 43.33% and 45.33% respectively(Figure 1C-D). The therapy led to similar serious and life-threatening toxic effects with those reported with other CAR T-cell therapies. For all 30 enrolled patients, total 32 Tp53 Mutations were detected in this cohort including 23 missense, 4 splice site mutations, 4 insertions, 2 deletions and 1 nonsense mutation. Two Tp53 mutations were found in 2 patients. 21 patients were assessed with Tp53 FISH and 14 patients (66.66%) had 17p-. There is no difference on ORR,OS and PFS in patients based on three different Tp53-specific scoring systems. The ORR at three months predicts the long-term survival of this group of patients (Figure 1E-F). CAR19/22 T-cell cocktail therapy can improve the outcome of r/r B-cell lymphoma with high-risk of functional classification of Tp53 mutation. The patients who achieved overall response at month three can greatly benefit from CAR19/22 T-cell cocktail therapy with long-term favorable outcome. Trial registration: ChiCTR-OPN-16008526. Key words: B cell lymphoma; CAR T-cell therapy; Tp53 mutation; outcome Figure 1 Disclosures No relevant conflicts of interest to declare.

Factors Associated with Survival and Severe Cytokine Release Syndrome of Patients with Relapsed/Refractory B-ALL Receiving CD19 CAR-T Cell Therapy

Background : Chimeric antigen receptor-modified T (CAR-T) cells against CD19 have achieved great therapeutic effect in patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL). However, factors associated with the duration of survival and the occurrence of severe cytokine release syndrome (CRS) after CD19 CAR-T cell therapy have not been fully defined. Patients and Methods: We analyzed 24 patients with relapsed/refractory B-ALL who received CD19 CAR-T cell therapy in a phase Ⅰ/Ⅱ clinical trial (ClinicalTrials.gov, NCT02349698). Infused CAR-T cell characteristics, its expansion kinetics in vivo, patient characteristics and laboratory parameters were analyzed for their correlation with overall survival (OS), progression-free survival (PFS), and the incidence of severe CRS. Results: Sixteen patients achieved complete remission (CR), among which 13 achieved minimal residual disease-negative CR. Patients achieved CR had significantly prolonged OS and PFS compared with those who did not. Multivariable cox regression showed that lower peak of CAR-T cell expansion and the occurrence of severe CRS were significantly associated with both inferior OS and inferior PFS, and higher proportion of effector memory T cells in the infused cells was only significantly associated with inferior PFS. Nineteen patients developed CRS, among which 6 developed severe CRS. Compared patients with mild CRS, patients with severe CRS experienced worse vital sign instability and pancytopenia, higher incidences of coagulation and organ dysfunctions, and higher concentrations of procalcitonin and cytokines. Multivariable logistic regression showed that higher pretreatment disease burden was independent predictor of severe CRS. Conclusions: Clinical and biological factors correlated with survival and severe CRS of refractory/relapsed B-ALL patients receiving CD19 CAR-T cell therapy were identified. These data may be helpful for improving the efficacy of CAR-T cell therapy, facilitating the recognition and early intervention of severe CRS. Disclosures No relevant conflicts of interest to declare.

Safety of Axicabtagene Ciloleucel for the Treatment of Relapsed or Refractory Large B-Cell Lymphoma

BackgroundDiffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma. Recent advances in immunotherapy have resulted in the development of chimeric antigen receptor–modified T-cell (CAR-T) therapy, such as axicabtagene ciloleucel (axi-cel). However, axi-cel administration is not without risks of toxicity. Patients and MethodsThis retrospective study of 37 patients with relapsed or refractory diffuse large B-cell lymphoma evaluated the incidence and severity of common and severe safety events after axi-cel treatment in a real-world setting. Ninety percent of patients had received 3 or more prior lines of therapy (median prior therapies 3, range 2-7) before receiving CAR-T therapy, and 32.4% had relapsed after prior stem-cell transplantation. ResultsAll but one patient experienced cytokine release syndrome (CRS) of any grade (97.3%). Of those 36 patients, 83.3% experienced maximum CRS grade of 1 or 2, occurring after a median of 27 hours and persisting for a median of 6 days. Twenty-seven patients (73.0%) experienced neurotoxicity of any grade. Of those 27 patients, 96.3% experienced maximum neurotoxicity grade of 2 or higher, occurring after a median of 145 hours (6 days) and persisting for a median of 7 days. All 10 patients aged 65 or older had neurotoxicity of grade 2 or higher, compared to 59.3% (11/27) under age 65 (P = .02). Patients with baseline Eastern Cooperative Oncology Group performance status score of 2 were significantly more likely to have shorter time to neurotoxicity compared to patients with performance status of 0 (P = .01). ConclusionWith more real-life experience and data, we will be able to define and refine management of toxicities unique to CAR-T therapy.