A CAR-T response prediction model for r/r B-NHL patients based on a T cell subset nomogram.

BACKGROUND: Chimeric antigen receptor (CAR) T cells for refractory or relapsed (r/r) B cell no-Hodgkin lymphoma (NHL) patients have shown promising clinical effectiveness. However, the factors impacting the clinical response of CAR-T therapy have not been fully elucidated. We here investigate the independent influencing factors of the efficacy of CD19 CAR-T cell infusion in the treatment of r/r B-NHL and to establish an early prediction model. METHODS: A total of 43 r/r B-NHL patients were enrolled in this retrospective study. The patients' general data were recorded, and the primary endpoint is the patients' treatment response. The independent factors of complete remission (CR) and partial remission (PR) were investigated by univariate and binary logistic regression analysis, and the prediction model of the probability of CR was constructed according to the determined independent factors. Receiver operating characteristic (ROC) and calibration plot were used to assess the discrimination and calibration of the established model. Furthermore, we collected 15 participators to validate the model. RESULTS: Univariate analysis and binary logistic regression analysis of 43 patients showed that the ratio of central memory T cell (Tcm) and naïve T cell (Tn) in cytotoxic T cells (Tc) was an independent risk factor for response to CD19 CAR-T cell therapy in r/r B-NHL. On this basis, the area under the curve (AUC) of Tcm in the Tc and Tn in the Tc nomogram model was 0.914 (95%CI 0.832-0.996), the sensitivity was 83%, and the specificity was 74.2%, which had excellent predictive value. We did not found the difference of the progression-free survival (PFS). CONCLUSIONS: The ratio of Tcm and Tn in Tc was found to be able to predict the treatment response of CD19 CAR-T cells in r/r B-NHL. We have established a nomogram model for the assessment of the CD19 CAR-T therapy response presented high specificity and sensitivity.

Modified EASIX scores predict severe CRS/ICANS in patients with acute myeloid leukemia following CLL1 CAR-T cell therapy.

Chimeric antigen receptor T (CAR-T) cell therapy targeting CLL1 has been considered a potent weapon for patients with acute myeloid leukemia (AML). This study aims to evaluate the efficacy and toxicity of CLL1 CAR-T cell therapy in a larger cohort, with particular attention to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Among the 32 patients assessed for efficacy, complete remission occurred in 71.88% (23/32) of cases and undetectable minimal residual disease in 14 patients. The CRS developed in all patients, with 8 individuals experiencing ICANS. Severe CRS and ICANS were observed in 11 and 2 patients, respectively. Furthermore, the Endothelial Activation and Stress Index (EASIX) and its derivatives measured before and after CLL1 CAR-T cell infusion were employed for predicting the severe complications. Significant differences were observed in EASIX scores on the day before lymphodepletion (Day BL, P = 0.023), -1 (P < 0.001), +1 (P < 0.001), and +3(P = 0.014); sEASIX scores on Day BL (P = 0.007), -1 (P < 0.001), +1 (P < 0.001), and +3 (P < 0.001); and mEASIX score on Day -1 (P = 0.004) between patients with mild and severe CRS/ICANS. Additionally, there was a significant difference in mEASIX scores between responders and non-responders on Day BL (P = 0.004) and Day -1 (P = 0.044). Our findings indicate that pre- and post-infusion assessments of EASIX/mEASIX/sEASIX scores serve as reliable prognostic indicators for severe CRS/ICANS and treatment response following CLL1 CAR-T cell therapy, which can assist physicians in implementing preemptive treatment strategies for potential severe complications and screening patients who are suitable candidates for CLL1 CAR-T cell therapy. EASIX/mEASIX/sEASIX scores serve as reliable prognostic indicators for severe CRS/ICANS following CLL1 CAR-T cell therapy. The preinfusion mEASIX scores of CLL1 CAR-T cells can effectively predict treatment response.

The diagnostic/prognostic roles and biological function of the IFIT family members in acute myeloid leukemia.

BACKGROUND: The Interferon-induced protein with tetratricopeptide repeat (IFIT) family, IFIT1/2/3/5, play an important role in different tumors progression. However, the prognosis significance and biological role of IFIT family members in acute myeloid leukemia (AML) remains unclear. METHODS: We obtained the gene expression data and clinical information of 173 AML patients from The Cancer Genome Atlas (TCGA) database. Several databases were used in our study, including GEPIA, MethSurv, STRING, GSCA and GeneMANIA database. RESULTS: The mRNA expression of IFIT1/2/3/5 was elevated in AML patients and had a high ability to distinguish AML from controls based on the receiver operating characteristic (ROC) curve (AUC > 0.9). Kaplan-Meier survival analysis showed that higher levels of IFIT2/3/5 expression predict poor prognosis in AML patients. Besides, the DNA methylation analysis suggested that 7 CpG sites of IFIT2, 4 CpG sites of IFIT3 and 10 CpG sites of IFIT5 were significantly associated with the prognosis of AML patients. In addition, IFIT2/3/5 expression was significantly positively associated with the immune cell infiltration and immune checkpoint expression, such as CTLA4, PDCD1, LAG3, and TIGIT. Finally, drug sensitivity analysis revealed that AML patients with high expression of IFIT2/3/5 were resistant to multiple drugs, but sensitive to dasatinib. CONCLUSION: IFIT family genes might serve as biomarkers for diagnosis, prognosis and drug sensitivity in AML patients. The activation or blocking of IFIT-related signaling pathways may provide novel insights into immunotherapy for patients with AML.

Efficacy and safety-related factors of BTK inhibitors as a bridge to CAR-T therapy in R/R FL.

Although anti-CD19 chimeric antigen receptor (CAR) T cell therapy has achieved satisfactory results in relapsed/refractory (R/R) follicular lymphoma (FL), patients with R/R FL and high-risk disease characteristics, previous hematopoietic stem cell transplantation, bulky disease, and progression of disease within 2 years (POD24) had a low complete response (CR). Twenty-seven patients with R/R FL, later disease stages, higher tumor burden, or higher previous treatment lines who had received Bruton tyrosine kinase (BTK) inhibitors before anti-CD19 CAR T cell therapy, or received BTK inhibitors as combination therapy, were included in this study. The clinical response and adverse events (AEs) in anti-CD19 CAR T cell therapy were observed. All patients with R/R FL who received BTK inhibitors combined with anti-CD19-CAR T cell therapy had later disease stages, higher tumor burden, and higher treatment lines than those who did not receive BTK inhibitor combination therapy. However, no difference in the clinical response was found between the two groups. The clinical response in the POD24 group was lower than that in the non-POD24 group; however, no difference in the clinical response was found between the FL and transformed FL (tFL) groups, between the follicular lymphoma international prognostic index (FLIPI) 1 1-2 and FLIPI 1 3-5 groups, and between the FLIPI 2 1-2 and FLIPI 2 3-5 groups. The mean anti-CD19 CAR T cell peak was higher in the CAR-T group with BTK inhibitor than in the CAR-T group without BTK inhibitor. Meanwhile, a higher proportion of patients in the non-POD24 group, FL group, and PR group achieved CR after 2 months. No difference in cytokine secretion was found between the CAR-T group with and without BTK inhibitors. It was higher in the non-POD24 group, FLIPI 1 3-5 group, and FLIPI 2 3-5 group. No difference in cytokine release syndrome and immune effector cell-associated neurotoxic syndrome grades was found between the CAR-T groups with or without BTK inhibitors and between the other groups. Poor prognostic factors, other than POD24, did not affect the clinical response to BTK inhibitors in combination with anti-CD19 CAR T cell therapy in patients with R/R FL. Therefore, BTK inhibitors combined with anti-CD19 CAR-T therapy may be an effective and safe approach for patients with R/R FL and high-risk factors.Trial registration: The study was registered at http://www.chictr.org.cn/index.aspx as ChiCTR-ONN-16009862 and http://www.chictr.org.cn/index.aspx as ChiCTR1800019622.

Donor Hematopoietic Stem Cell/Lymphocyte Maintenance Treatment After CAR T-Cell Therapy in Patients With B-Cell Acute Lymphoblastic Leukemia Relapse Following Stem Cell Transplant.

Maintaining the efficacy of anti-CD19 chimeric antigen receptor modified (CAR) T-cell therapy in patients with B-cell acute lymphoblastic leukemia (B-ALL) relapse after allogeneic hematopoietic stem cell transplant (allo-HSCT) is an urgent problem. In this study, we aimed to compare the efficacy of donor hematopoietic stem cell infusion (DSI) therapy and donor lymphocyte infusion (DLI) therapy as a maintenance therapy after R/R B-ALL patients achieved CR in anti-CD19-CAR T-cell therapy but relapsed after allo-HSCT. In total, 22 B-ALL patients who relapsed after allo-HSCT received anti-CD19-CAR T-cell therapy. Patients who responded to CAR T-cell therapy received DSI or DLI as maintenance therapy. We compared the clinical responses, acute graft versus host disease (aGVHD), expansion of CAR-T-cells, and adverse events between the two groups. In our study, 19 patients received DSI/DLI as maintenance therapy. After DSI/DLI therapy, progression-free survival and overall survival were higher in the DSI group than in the DLI group at 365 days. The grades I and II of aGVHD was observed in four patients (36.4%) in the DSI group. Only one patient developed grade II aGVHD in the DLI group. The peaks of CAR T-cells in the DSI group were higher than those in the DLI group. IL-6 and TNF-α levels increased again in nine of 11 patients after DSI but not in the DLI group. Our findings indicate that for B-ALL patients who relapse after allo-HSCT, DSI is a feasible maintenance therapy if CR is obtained with CAR-T-cell therapy.

Knockdown SENP1 Suppressed the Angiogenic Potential of Mesenchymal Stem Cells by Impacting CXCR4-Regulated MRTF-A SUMOylation and CCN1 Expression.

The angiogenic potential of mesenchymal stem cells (MSCs) is critical for adult vascular regeneration and repair, which is regulated by various growth factors and cytokines. In the current study, we report that knockdown SUMO-specific peptidase 1 (SENP1) stimulated the SUMOylation of MRTF-A and prevented its translocation into the nucleus, leading to downregulation of the cytokine and angiogenic factor CCN1, which significantly impacted MSC-mediated angiogenesis and cell migration. Further studies showed that SENP1 knockdown also suppressed the expression of a chemokine receptor CXCR4, and overexpression of CXCR4 could partially abrogate MRTF-A SUMOylation and reestablish the CCN1 level. Mutation analysis confirmed that SUMOylation occurred on three lysine residues (Lys-499, Lys-576, and Lys-624) of MRTF-A. In addition, SENP1 knockdown abolished the synergistic co-activation of CCN1 between MRTF-A and histone acetyltransferase p300 by suppressing acetylation on histone3K9, histone3K14, and histone4. These results revealed an important signaling pathway to regulate MSC differentiation and angiogenesis by MRTF-A SUMOylation involving cytokine/chemokine activities mediated by CCN1 and CXCR4, which may potentially impact a variety of cellular processes such as revascularization, wound healing, and progression of cancer.

Efficacy of programmed cell death 1 inhibitor maintenance therapy after combined treatment with programmed cell death 1 inhibitors and anti-CD19-chimeric antigen receptor T cells in patients with relapsed/refractory diffuse large B-cell lymphoma and high tumor burden.

We studied the efficacy and safety of the combined treatment with programmed cell death 1 (PD-1) inhibitors and anti-CD19 chimeric antigen receptor (CAR) T-cell therapy and subsequent PD-1 inhibitor maintenance treatment in patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and high tumor burden. Forty-four R/R DLBCL patients with high tumor burden were enrolled in this study. The experimental group of 26 patients received combined therapy with PD-1 inhibitors and anti-CD19-CAR T cells, while the control group of 18 patients received anti-CD19-CAR T-cell therapy alone. The objective response rate (ORR) was 65.39% and 61.11% in the combination and control groups, respectively. The PD-1 inhibitor maintenance therapy was selected for patients who achieved complete response or partial response in the combination therapy group. Progression-free survival and overall survival rates in the combination group were higher than those in the control group 3 and 12 months after CAR T-cell infusion. There was no significant difference in the grade of cytokine release syndrome or immune effector cell associated neurotoxic syndrome between the two groups. In the maintenance therapy group, only eight patients experienced grade 1 Common Terminology Criteria for Adverse Events (CTCAE) and three grade 2 CTCAE. Overall, we found that the ORR was not affected by the combination therapy with PD-1 inhibitors and anti-CD19-CAR T cells. However, patients who had achieved the ORR might benefit from PD-1 inhibitor maintenance therapy after combination therapy without increased side effects.

Risk factors for inhibitors in hemophilia A based on RNA-seq and DNA methylation.

Background: The development of factor VIII (FVIII) inhibitor is a severe complication during replacement therapy for hemophilia A patients. Objectives: We investigated the potential risk factors for FVIII inhibitor formation based on genome-wide RNA-sequencing and whole-genome bisulfite sequencing analysis. Methods: RNA-sequencing and whole-genome bisulfite sequencing analysis were applied on 17 blood samples with F8 intron 22 inversion, including seven with inhibitors and 10 without. Results: Altogether, 344 mRNA transcripts and 20 long noncoding RNAs (lncRNA) transcripts were differentially expressed. Among the differentially expressed transcripts, 200 mRNAs and 12 lncRNAs were upregulated, and 144 mRNAs and eight lncRNAs were downregulated. Gene ontology enrichment analysis of differentially expressed mRNAs showed that genes involved in immune stimulation, especially those for T-cell activation, were upregulated, whereas genes involved in negative immune response regulation were downregulated. Coexpression analysis revealed that the targeted upregulated genes of differentially expressed lncRNA were similarly closely related to immune activation, especially T-cell activation. Methylation analysis showed inhibitor patients exhibited a slightly lower methylation status in the CpG islands, 5' untranslated region, and exon regions (p < 0.01). Genes with differentially methylated regions were also related to T-cell activation. Conclusions: There is an upregulation of genes involved in activation of the immune system in hemophilia A patients with inhibitors. The lncRNA and methylation modifications may play important roles in inhibitor production. These findings are potentially to reveal novel therapeutic targets for prevention and treatment of inhibitors.

A Prospective Trial Comparing Haploidentical Donor Transplantation With Cord Blood Versus HLA-Matched Sibling Donor Transplantation for Hematologic Malignancy Patients.

TRIAL REGISTRATION: Effect of co-infusion third party umbilical cord blood stem cells on haploidentical hematopoietic stem cell transplantation https://www.chictr.org.cn Reg. No. ChiCTR-OIN-17011426.

Evaluation of the safety and efficacy of humanized anti-CD19 chimeric antigen receptor T-cell therapy in older patients with relapsed/refractory diffuse large B-cell lymphoma based on the comprehensive geriatric assessment system.

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has led to unprecedented results to date in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), yet its clinical application in elderly patients with R/R DLBCL remains somewhat limited. In this study, a total of 31 R/R DLBCL patients older than 65 years of age were enrolled and received humanized anti-CD19 CAR T-cell therapy. Patients were stratified into a fit, unfit, or frail group according to the comprehensive geriatric assessment (CGA). The fit group had a higher objective response (OR) rate (ORR) and complete response (CR) rate than that of the unfit/frail group, but there was no difference in the part response (PR) rate between the groups. The unfit/frail group was more likely to experience AEs than the fit group. The peak proportion of anti-CD19 CAR T-cells in the fit group was significantly higher than that of the unfit/frail group. The CGA can be used to effectively predict the treatment response, adverse events, and long-term survival.

Intensive Debulking Chemotherapy Improves the Short-Term and Long-Term Efficacy of Anti-CD19-CAR-T in Refractory/Relapsed DLBCL With High Tumor Bulk.

Anti-CD19 chimeric antigen receptor T (CAR-T) therapy has achieved remarkable effects in refractory/relapsed (R/R) diffuse large B-cell lymphoma (DLBCL). However, when high tumor bulk occurs, patients tend to early progression after CAR-T therapy. Here, we investigated whether pretreatment with intensive debulking chemotherapy could improve the outcome of CAR-T in such patients. Fifty-seven patients with R/R DLBCL were enrolled, and 42 patients received anti-CD19-CAR-T therapy, among which, 25 patients (the combined group) with high tumor bulk received debulking chemotherapy and anti-CD19-CAR-T therapy sequentially. Another 17 patients (the control group) without high tumor bulk received anti-CD19-CAR-T therapy only. According to the response to debulking chemotherapy, patients of the combined group were divided into chemo-sensitive and chemo-refractory groups. Within 2 months, the objective response rate (ORR) was higher in the chemo-sensitive group than in the chemo-refractory group (P = 0.031). Grades 1-3 cytokine release syndrome (CRS) was reported, and no difference was shown in CRS grade distribution between the chemo-sensitive and chemo-refractory groups (P = 0.514). The chemo-sensitive group demonstrated longer overall survival (OS) than the chemo-refractory group (P = 0.042). Of the chemo-sensitive group, the 1-year disease free survival (DFS) and OS rates were 52.6 and 57.9%, respectively. Besides, no significant differences were found in ORR, DFS, and OS between the chemo-sensitive and control groups (ORR: P = 0.593; DFS: P = 0.762; OS: P = 0.531). In summary, effective debulking chemotherapy improved the short-term ORR and long-term OS of CAR-T therapy in R/R DLBCL with high tumor bulk, with outcomes comparable to those of R/R DLBCL without high tumor bulk. The clinical trial of our study was registered at http://www.chictr.org.cn/index.aspx as ChiCTR-ONN-16009862 and ChiCTR1800019622. CLINICAL TRIAL REGISTRATION: http://www.chictr.org.cn/index.aspx, identifier (ChiCTR-ONN-16009862 and ChiCTR1800019622).

Anti-CD22 CAR-T Cell Therapy as a Salvage Treatment in B Cell Malignancies Refractory or Relapsed After Anti-CD19 CAR-T therapy.

BACKGROUND: To observe efficacy of the anti-CD22 chimeric antigen receptor modified (anti-CD22-CAR) T cell salvage therapy in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and B cell acute lymphoid leukemia (B-ALL) patients whose disease did not reach CR or progressed again after anti-CD19-CAR T cell therapy. METHODS: In our study, seven R/R DLBCL patients reached stable disease (SD) or progression of disease (PD) after their anti-CD19-CAR T cell therapy. Only three in all the six R/R B-ALL patients obtained complete response (CR)/CR with incomplete count recovery (Cri) in their anti-CD19-CAR T cell therapy, but they relapsed again in the following three, six and one months. Then, all these thirteen R/R DLBCL and B-ALL patients received anti-CD22 CAR-T cell salvage therapy because their disease did not reach CR or progressed again. RESULTS: Four R/R DLBCL patients obtained CR, while two R/R DLBCL patients achieved PR and one patient achieved SD. But only two R/R B-ALL patients obtained Cri in their anti-CD22 CAR-T cell salvage therapy. The overall survival (OS) of R/R DLBCL patients after the anti-CD22 CAR-T cell therapy was 6.142±3.395 months until August 31, 2020. There was no different of the median expansion peaks of the two kinds of CAR T cells (P=0.920). The time of anti-CD22-CAR T cell proportion peak days was later than that of the time of anti-CD19-CAR T cell peak days post infusion (P=0.022). Their cytokine release syndrome (CRS) was graded 2-4 in their anti-CD19-CAR T cell therapy, while the notable CRS was graded 1-2 in their anti-CD22-CAR T cell therapy. But there was no difference in the CRS and the immune effect or cell associated neurotoxic syndrome (ICANS) grades in the two kinds of therapies. And there was no difference in the hematological toxicity grades in the two kinds of therapies. CONCLUSION: The anti-CD22-CAR T cell salvage therapy is highly effective in R/R DLBCL patients than in R/R B-ALL patients who failed in anti-CD19-CAR T cell therapy before. We need to expand the number of R/R DLBCL or B-ALL patients and continue to observe. TRIAL REGISTRATION: ChiCTR-ONN-16009862 and ChiCTR1800019298.

Vitronectin-activated αvß3 and αvß5 integrin signalling specifies haematopoietic fate in human pluripotent stem cells.

OBJECTIVES: Vitronectin (VTN) has been widely used for the maintenance and expansion of human pluripotent stem cells (hPSCs) as feeder-free conditions. However, the effect of VTN on hPSC differentiation remains unclear. Here, we investigated the role of VTN in early haematopoietic development of hPSCs. MATERIALS AND METHODS: A chemically defined monolayer system was applied to study the role of different matrix or basement membrane proteins in haematopoietic development of hPSCs. The role of integrin signalling in VTN-mediated haematopoietic differentiation was investigated by integrin antagonists. Finally, small interfering RNA was used to knock down integrin gene expression in differentiated cells. RESULTS: We found that the haematopoietic differentiation of hPSCs on VTN was far more efficient than that on Matrigel that is also often used for hPSC culture. VTN promoted the fate determination of endothelial-haematopoietic lineage during mesoderm development to generate haemogenic endothelium (HE). Moreover, we demonstrated that the signals through αvß3 and αvß5 integrins were required for VTN-promoted haematopoietic differentiation. Blocking αvß3 and αvß5 integrins by the integrin antagonists impaired the development of HE, but not endothelial-to-haematopoietic transition (EHT). Finally, both αvß3 and αvß5 were confirmed acting synergistically for early haematopoietic differentiation by knockdown the expression of αv, ß3 or ß5. CONCLUSION: The established VTN-based monolayer system of haematopoietic differentiation of hPSCs presents a valuable platform for further investigating niche signals involved in human haematopoietic development.

Humanized anti-CD19 chimeric antigen receptor-T cell therapy is safe and effective in lymphoma and leukemia patients with chronic and resolved hepatitis B virus infection.

Chimeric antigen receptor-T (CAR-T) cell therapy is a promising treatment for CD19+ B-cell malignancies. However, elimination of B cells by anti-CD19 CAR-T cells may lead to the reactivation of hepatitis B virus (HBV) and related hepatitis in patients with HBV infection. This study aims to evaluate the safety and efficacy of humanized anti-CD19 CAR-T (hCAR-T) therapy in B-cell malignancies with HBV infection. Twenty relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL) and acute lymphoblastic leukemia (ALL) patients with HBV infection were treated with hCAR-T therapy. Among them, five hepatitis B antigen-positive patients who received antiviral prophylaxis did not develop HBV reactivation, including two patients who received both hCAR-T and allogeneic hematopoietic stem cell transplantation (allo-HSCT). Among 15 patients with resolved HBV infection, two received antiviral prophylaxis, and the other 13 did not experience HBV reactivation without antiviral prophylaxis. One patient with resolved HBV infection experienced HBV reactivation 6 months after hCAR-T therapy and sequential allo-HSCT. Moreover, HBV infection did not affect in vivo expansion of hCAR-T cells or increase the risk of severe cytokine release syndrome. In conclusion, hCAR-T therapy is safe and effective in DLBCL and ALL patients with chronic and resolved HBV infection under proper antiviral prophylaxis.

Acute Graft-Versus-Host Disease After Humanized Anti-CD19-CAR T Therapy in Relapsed B-ALL Patients After Allogeneic Hematopoietic Stem Cell Transplant.

We studied the acute graft-versus-host disease (GVHD) after humanized anti-CD19-CAR T therapy in relapsed B-acute lymphoblastic leukemia (ALL) patients after allogeneic hematopoietic stem cell transplant (allo-HSCT). Fifteen B-ALL patients were enrolled in our study. Thirteen patients (86.67%) achieved a complete response (CR) or CR with incomplete count recovery. The donor chimerism of the 13 patients reached 99.86 ± 0.21%. The development of aGVHD was observed in 10 patients (66.67%). Six patients developed grade I-II of aGVHD, while the other four patients developed grade III-IV of aGVHD. The notable adverse events were grade 1-2 cytokine release syndrome (CRS) in 10 patients and grade 3-4 CRS in five patients. Two patients died of infection, while another patient died of sudden cardiac arrest. The anti-CD19-CAR T cells were not eliminated in peripheral blood when the patients developed aGVHD. However, we did not observe their expansion peaks again in the process of aGVHD. During the aGVHD, the peaks of IL-6 and TNF-a were correlated with aGVHD levels. By May 31, 2020, the rates of leukemia-free survival (LFS) and overall survival (OS) at 180 days were 53.846 and 61.638%, respectively. All the patients who survived to date experienced aGVHD after humanized anti-CD19-CAR T cell therapy. Trial registration: The patients were enrolled in clinical trials of ChiCTR-ONN-16009862 and ChiCTR1800019622.

Synergistic effect of programmed death-1 inhibitor and programmed death-1 ligand-1 inhibitor combined with chemotherapeutic drugs on DLBCL cell lines in vitro and in vivo.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL). Chemotherapy is one of the main treatments for cancer, but the antitumor effect of chemotherapeutic drugs is affected by the patient's immune status. The programmed cell death 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) axis is an important central checkpoint in tumor progression. The present study demonstrated a significant synergistic effect of PD-1 inhibitor and oxaliplatin, cisplatin, etoposide, cytarabine, ifosfamide and carboplatin. There was no difference in cytotoxicity between the groups with or without PD-L1 inhibitor. It was also observed that cytotoxicity of T cells combined with PD-1 inhibitor against DLBCL cells was inhibited by dexamethasone addition to the culture system at 24, 48 and 72 h. There was no difference in cytotoxicity between the group of dexamethasone added at 96 h and the group without dexamethasone at 96 h. Then, we selected a PD-1 inhibitor combined with a chemotherapeutic regimen in a Pfeiffer cell mouse xenograft model. At 21 days, the reduction in tumor size was more obvious in the DHAP combined with PD-1 inhibitor group (dexamethasone after 96 h of PD-1) compared with that in the DHAP (P=0.007), the PD-1 inhibitor (P=0.001) and the DHAP combined with PD-1 inhibitor (dexamethasone after 24 h of PD-1) (P=0.005) groups. However, the reduction in tumor size was more obvious in the GemOx combined with PD-1 inhibitor group compared with that in the GemOx group (P=0.037). Therefore, the present study demonstrated the synergistic effects of PD-1 inhibitor combined with chemotherapeutic regimens in DLBCL.

Anti-CD19 Chimeric Antigen Receptor T Cells in Combination With Nivolumab Are Safe and Effective Against Relapsed/Refractory B-Cell Non-hodgkin Lymphoma.

Chimeric antigen receptor (CAR) T cells are emerging as a novel treatment for patients with refractory/relapsed B-cell non-Hodgkin lymphoma (B-NHL), and combination with PD1 inhibitors may further improve the efficacy of anti-CD19 CAR (CD19 CAR)-T cells in the treatment of lymphomas. In a single-center study, we evaluated the safety and efficacy of a combination therapy with CD19 CAR-T cells and an anti-PD-1 antibody (nivolumab) in patients with relapsed/refractory B-NHL. A total of 11 patients with refractory/relapsed B-NHL were recruited and subsequently received CD19 CAR-T cells and nivolumab. The primary end points were safety and feasibility. The infusions were safe, and no dose-limiting toxicities occurred. Grade 1 or 2 cytokine release syndrome (CRS) was observed in 25% (3/11) and 50% (6/11) of the patients, respectively, and only one patient (1/11) experienced neurotoxicity. The objective response rate (ORR) and complete response (CR) rate were 81.81% (9/11) and 45.45% (5/11), respectively. The median follow-up time was 6 (1~15) months. The median progression-free survival (PFS) time was 6 months (1~14 months), and 3 patients continued to have a response at the time of this writing. Our study demonstrated that the combination of CD19 CAR-T cells and nivolumab was feasible and safe and mediated potent anti-lymphoma activity, which should be examined further in prospective clinical trials in refractory/relapsed B-NHL.