Cell non-Hodgkin Lymphoma Research Articles

Hepatitis C Associated B-Cell Non-Hodgkin Lymphoma: Impact of Combination Direct-Acting Antivirals and Chemotherapy

Objectives: Direct-acting antiviral agents (DAAs) have successfully eradicated chronic hepatitis C virus (HCV) infection. Since chronic HCV is known to have an increased risk of developing B cell non-Hodgkin lymphoma (B-NHL), successful HCV treatment may have virologic, hepatic, and oncologic benefits for B-NHL. Therefore, this study aimed to determine the efficacy of DAAs combined with chemotherapy in B-NHL patients with chronic HCV in Mongolia. Methods: This case-control study included newly diagnosed B-NHL patients with chronic HCV who received DAAs before chemotherapy (with DAAs group). The other is comprised of controls who have been treated by chemotherapy without DAAs. Patients who received courses of DAAs were monitored by the virological and hepatic responses. Results: Eleven patients received DAAs and none of them developed chemotherapy-associated hepatitis flare. Of the DAAs group, during DAAs treatment, 90.9% were clinically stable. In all cases of DAAs in combination with chemotherapy, the Sustained Viral Response (SVR)12 and 24 were 100%. However, 47.4% of those who received DAAs after chemotherapy developed hepatitis flare during chemotherapy. Patients with hepatitis flare had higher serum level of ALT before chemotherapy (15.7 U/L vs. 40.2 U/L; p = 0.014) than those without. Conclusion: DAAs administration results in a significant clinical benefit to B-NHL patients with chronic HCV.

High dose methotrexate in adult Egyptian patients with hematological malignancies: impact of ABCB1 3435C > T rs1045642 and MTHFR 677C > T rs1801133 polymorphisms on toxicities and delayed elimination

High dose methotrexate (HDMTX) is an essential agent in chemotherapeutic regimens used in various hematological malignancies in Egyptian adults. The research for the impact of gene polymorphism on HDMTX induced toxicities and delayed elimination is an important ongoing objective in many studies, variable and conflicting results produced in the past years to clarify that impact. This study aimed to investigate the role of ABCB1 3435 C > T rs1045642 and MTHFR 677 C > T rs1801133 polymorphisms on HDMTX induced toxicity outcomes and delayed elimination in Egyptian adult patients with hematological malignancies. A prospective, observational cohort study was conducted on a total of 62 Egyptian adult patients with hematological malignancies age ≥ 18-years-old. All demographic, medical, and laboratory data were continuously collected from the patients’ medical files in an up-to-date follow-up in selected clinics during the period from April 2018 to March 2020. Venous blood samples were collected for the purpose of genotyping, DNA extraction, and measurement of MTX levels. All the relevant data were statistically analyzed. The studied patients' median age was 25 years old with a range of (18–62) years. Forty-six patients were males with about 74%, and 16 were females with about 26%. Eighty-nine percent of the patients diagnosed with acute lymphoblastic leukemia ‘ALL’, 5% of the patients had B cell non-hodgkin lymphoma ‘B-NHL’ and 3% diagnosed with primary central nervous system lymphoma ‘PCNSL’ and Burkitt’s lymphoma ‘BL’ Hematological, hepatic, renal and gastrointestinal toxicities observed post-HDMTX were recorded with the hematological toxicities toping on all the others, also patients with delayed elimination at 72 hours post the HDMTX dose were determined. Statistical analysis revealed a significant association between ABCB1 3435 C > T rs1045642 and HDMTX delayed elimination with about 10 times higher risk among the minor allele ‘T’ carriers (p-value = 0.006) (odds ratio [OR]: 10.470; 95% CI: 1.961–55.904). No significant association observed between the studied gene polymorphisms: MTHFR 677 C > T rs1801133, ABCB1 3435 C > T rs1045642, and different toxicity outcomes. According to our best knowledge, this study is the first to conclude a significant association between ABCB1 3435 C > T rs1045642 gene polymorphism and HDMTX delayed elimination at 72 hours post HDMTX infusion; also, it is the first study to analyze the association between ABCB1 3435 C > T rs1045642 polymorphism with HDMTX toxicity and delayed elimination in adult Egyptian patients with hematological malignancies.

Association between c-Myc Expression with Clinicopathological Features in T And NK Cell Lymphomas.

Background:c-Myc has become significantly involved in aggressive B-cell non Hodgkin lymphoma (NHL), but little is known about its importance in T and NK cell NHL (TNKcNHLs) in association with prognostic factors. The study is to investigate the significance of c-Myc expression with clinicopathological features of TNKcNHLs patients. Methodology:A cross-sectional study of 32 archived tissue blocks of TNKcNHLs were immunohistochemically stained with c-Myc. The results were microscopically evaluated and statistically analysed to examine the association between the clinicopathological data with the c-Myc expression. Results:c-Myc protein expressions were detected in 25/32 (78.1%) cases. The median age was 38-years. Malay ethnicity (92.0%) with 21 males and 11 females. c-Myc expressions were seen in T lymphoblastic lymphoma (20%), ALK-positive ALCL (16%) ,PTCL,NOS (16%), extra nodal NK/T-cell lymphoma, nasal type (12%), extra-nodal involvement (78.1%), elevated serum LDH (83.3%) and high ECOG performance status (82.4%). However, no statistical significant of c-Myc in association with the clinicopathological parameters (p > 0.05). Conclusion:There was no statistically significant association of clinicopathological parameters and histological subtypes of TNKcNHLs contributed by small samples tested. However, the attribution of c-Myc in this disease should be further explored.

ZCL-082, a boron-containing compound, induces apoptosis of non-Hodgkin's lymphoma via targeting p90 ribosomal S6 kinase 1/NF-κB signaling pathway

IntroductionDespite the rapid progress in the diagnosis and treatment, the prognosis of some types of non-Hodgkin's lymphoma (NHL), especially those with double-hit or double-expressor genotypes, remains poor. Novel targets and compounds are needed to improve the prognosis of NHL. MethodsWe investigated the effect of ZCL-082, a novel boron-containing compound with anti-proliferating activity against ovarian cancer cells, on NHL cells and human peripheral blood mononuclear cells by CCK-8 assay, Annexin V/PI double staining assay, RH123/PI double staining, Western blot, and immunohistochemistry. NF-κB pathway activity was analyzed using luciferase reporter gene assay and RT-PCR. The location of p65 was detected by immunofluorescence and nuclear/cytoplasmic fractionation assay. Immunoprecipitation and chromatin immunoprecipitation assays were used to detect the binding between p65 and p300. CETSA and molecular docking assay were carried out to test the interaction between ZCL-082 and p90 ribosomal S6 kinase 1 (RSK1). Kinase reaction was conducted to examine the inhibition of RSK1 kinase activity by ZCL-082. ResultsWe found that ZCL-082 can induce the apoptosis of various NHL cell lines in vitro and in vivo. ZCL-082 significantly inhibits TNFα- or LPS-induced NF-κB activation without disturbing TNFα-induced IκBα degradation or the nuclear translocation and DNA-binding ability of p65. However, ZCL-082 markedly suppresses the phosphorylation of p65 on Ser536 and the interaction between p65 and p300. The overexpression of the phosphomimetic mutant of p65 at Ser536 partially abrogates ZCL-082-induced cell death. We further found that ZCL-082 directly binds to and inhibits the activity of RSK1. RSK1 can phosphorylate RelA/p65 on Ser536 and its overexpression is associated with the poor prognosis of lymphoma. The overexpression of RSK1 partially rescues ZCL-082-induced cell death. Molecular docking studies show that ZCL-082 fits well with the N-terminal kinase domain of RSK1. Furthermore, the combination of ZCL-082 and BCL-2 inhibitor ABT-199 has a synergistic apoptosis-inducing effect against double-hit lymphoma cell line OCI-Ly10. DiscussionWe found that ZCL-082 is a highly promising anti-lymphoma compound that targets RSK1 and interferes with the RSK1/NF-κB signaling pathway. The combination of ZCL-082 with BCL-2 inhibitor may represent a novel strategy to improve the outcome of double-hit or double-expressor lymphoma.

Epigenetic Regulation of miR-92a and TET2 and Their Association in Non-Hodgkin Lymphoma.

MicroRNAs (miRNAs) are well known for their ability to regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. In various cancers, miRNAs regulate gene expression by altering the epigenetic status of candidate genes that are implicated in various difficult to treat haematological malignancies such as non-Hodgkin lymphoma by acting as either oncogenes or tumour suppressor genes. Cellular and circulating miRNA biomarkers could also be directly utilised as disease markers for diagnosis and monitoring of non-Hodgkin lymphoma (NHL); however, the role of DNA methylation in miRNA expression regulation in NHL requires further scientific inquiry. In this study, we investigated the methylation levels of CpGs in CpG islands spanning the promoter regions of the miR-17–92 cluster host gene and the TET2 gene and correlated them with the expression levels of TET2 mRNA and miR-92a-3p and miR-92a-5p mature miRNAs in NHL cell lines, tumour samples, and the whole blood gDNA of an NHL case control cohort. Increased expression of both miR-92a-3p and miR-92a-5p and aberrant expression of TET2 was observed in NHL cell lines and tumour tissues, as well as disparate levels of dysfunctional promoter CGI methylation. Both miR-92a and TET2 may play a concerted role in NHL malignancy and disease pathogenesis.

G protein nucleolar 3 promotes Non-Hodgkin lymphoma progression by activating the Wnt/β-catenin signaling pathway

G protein nucleolar 3 (GNL3), which acts as an oncoprotein in various carcinomas, is associated with tumor progression; however, little is known regarding GNL3 function in non-Hodgkin lymphoma (NHL). In this study, we first used in silico analysis to determine associations between GNL3 and diffuse large B-cell lymphoma (DLBCL). We then examined the effect of GNL3 on NHL progression, including cell proliferation, apoptosis, and cell cycle progression, and determined its underlying molecular mechanism using in vitro lymphoma cell lines and in vivo mouse xenograft models. We found that GNL3 mRNA levels were markedly higher in DLBCL tissues than in normal tissues, with these higher levels associated with poor prognosis. Additionally, GNL3 overexpression promoted NHL cell proliferation and cell cycle progression and reduced apoptosis in vitro, and enhanced tumorigenesis in an in vivo xenograft model. Moreover, we found that GNL3 upregulated the levels of Wnt/β-catenin signaling pathway-related factors and downstream target genes, whereas the opposite result was observed in GNL3-silenced cells. Furthermore, a rescue experiment using a Wnt/β-catenin inhibitor (XAV939) confirmed that GNL3 promotes NHL progression by activating the Wnt/β-catenin signaling pathway. These findings demonstrated that GNL3 functions as an oncogenic driver in NHL via the Wnt/β-catenin pathway.

Transcriptional Reprogramming of Super-Enhancer Associated Oncogenes Following Inhibition of Cyclin-Dependent Kinase-9 (CDK9) in Aggressive Non-Hodgkin Lymphoma (NHL)

Introduction. CDKs are Ser/Thr kinases that associate with specific cyclins during the cell cycle to regulate its progression. We and others have shown that selective targeting of CDK9, a component of the positive transcription elongation factor b (pTEFb) complex which facilitates RNA transcription, is a promising approach in NHL leading to downmodulation of MYC and MCL1 (Hashiguchi et al, 2019). However, cells also exhibited resistance to CDK9i in vitro and in vivo. Here we studied the transcriptional and epigenetic effects of CDK9 inhibition using the novel selective CDK9 inhibitor AZD4573 which is under evaluation in clinical trials.Methods. A panel of NHL cell lines with variable sensitivity to CDK9i (OCI-LY3/19, SUDHL4/10/16, VAL, U2932) and primary NHL cells were employed. Response to CDK9i was characterized using RNA-Seq, ChIP-Seq and ATAC-Seq.Results. Treatment with AZD4573 potently inhibited proliferation of NHL cell lines and primary cells (IC 50 range 5-30 nM). RNA-Seq of cells treated with CDK9i demonstrated that up to 6,000 genes were significantly downregulated in NHL cells treated with CDK9i for 3 h, leading to downregulation of MAPK, PI3K, NFκB and TNFR signaling. However, following the initial nadir at 3 h, a subset of genes recovered transcription to at least baseline level (e.g., PIM1, MYC, IRF8, BCL6, BCL2L1, CXCR4 etc.), confirmed by RT-PCR and immunoblotting. Recovery was more prominent in less sensitive cells (OCI-LY3; by 6-8 h) and occurred despite continued p-RNAPII Ser2 blockade. ChIP-Seq analysis confirmed increased global RNAPII pausing at promoters in cells treated with AZD4573, including at recovery genes.Next, we conducted ChIP-Seq for H3K4me3 and H3K27ac in OCI-LY3 and VAL cells. We observed a global decrease in H3K4me3 signal across the promoters and gene bodies with AZD4573 treatment. Meanwhile, H3K27ac enhancer analysis showed a global decrease in VAL cells, but was stable/increased in OCI-LY3 cells, including at certain recovery genes (e.g., MYC and BCL2L1).BRD4 was previously shown to compensate for loss of CDK9 function to recover transcription of the MYC oncogene in HeLa cells, thereby compensating for loss of pTEFb activity. We observed increased interaction between BRD4 and RNAPII in OCI-LY3 cells treated with AZD4573 (by IP) and increased global BRD4 binding at transcription start sites (ChIP-Seq). Combination of BET bromodomain inhibitor JQ1 and CDK9i reduced expression of recovery genes including MYC and synergistically restricted proliferation of NHL cells.BRD4 inhibition leads to preferential loss of transcription at super enhancer (SE)-associated genes. Therefore we leveraged our H3K27ac ChIP-Seq data to elucidate the SE landscape in NHL cells. Enhancers were ranked by signal density and amplitude, followed by assignment of the closest gene. SE domains were identified near to genes known to contribute to lymphomagenesis. Notably the majority of the recovery genes had highly ranked SE association in the tested cell lines.Next, ATAC-Seq analysis of NHL cells revealed a significant number of genes with differential accessibility following CDK9i. Upon an 8 h treatment with AZD4573, 11121 and 4367 hyper-accessible chromatin regions were identified in VAL and OCI-LY3 cells, respectively, including MYC and BCL2L1 loci. E-box motif was found accessible across many genes at this timepoint.To investigate recovery genes as targets, we used PIM kinase inhibitors SGI1776 (PIM1) and AZD1208 (pan-PIM). Both drugs demonstrated synergy with AZD4573 in a panel of 4 cell lines and primary samples.Finally, to further elucidate genes and pathways which mediate susceptibility to CDK9i, we conducted a genome-wide loss of function CRISPR-Cas9 library screen. Cas9-expressing OCI-LY3 cells were transduced with a lentivirus encoding a CRISPR library comprised of ~5 unique sgRNA per gene. Knockout of genes in the PI3K/mTOR and DNA repair pathways sensitized cells to AZD4573. Confirming this result, combination treatment with AZD8835 (PI3K inhibitor) synergistically suppressed proliferation of the NHL cell lines and primary cells treated with AZD4573.Conclusions. CDK9i leads to transcriptional reprogramming including the upregulation of a subset of SE-associated oncogenes. Targeting recovery oncogenes may enhance sensitivity to CDK9i. DisclosuresDanilov: Gilead Sciences: Research Funding; Bristol-Meyers-Squibb: Honoraria, Research Funding; Bayer Oncology: Consultancy, Honoraria, Research Funding; SecuraBio: Research Funding; Abbvie: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; TG Therapeutics: Consultancy, Research Funding; Takeda Oncology: Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Astra Zeneca: Consultancy, Honoraria, Research Funding; Rigel Pharm: Honoraria.

A Phase 1 Safety and Efficacy Study of ADI-001 Anti-CD20 CAR-Engineered Allogeneic Gamma Delta (γδ) T Cells in Adults with B Cell Malignancies, in Monotherapy and Combination with IL-2

A Phase 1 Safety and Efficacy Study of ADI-001 Anti-CD20 CAR-Engineered Allogeneic Gamma Delta (γδ) T Cells in Adults with B Cell Malignancies, in Monotherapy and Combination with IL-2

CD30-Directed Chimeric Antigen Receptor (CAR)-T Cells for Treatment of Hodgkin Lymphoma and Non-Hodgkin Lymphoma in Pediatric Patients

Background:Chimeric antigen receptor (CAR)-T cell therapy targeting the CD19 antigen has been effective in treating B-cell acute lymphoblastic leukemia. As CAR-T cells targeting new antigens are being explored for the treatment of other cancers in adults, parallel studies are warranted for pediatric cohorts. We have previously shown the safety and efficacy in adults of CAR-T cells targeting CD30, which is expressed in classical Hodgkin Lymphoma (HL) and in some Non-Hodgkin Lymphoma (NHL). We have therefore sought to study the feasibility and the safety of CD30.CAR-T cells in pediatric patients with relapsed/refractory CD30-expressing HL and Anaplastic Large Cell Lymphoma (ALCL).Design/Methods:Six pediatric patients (ages 9 to 17 years) with CD30+ HL (4) and NHL (2) were enrolled on two trials at the University of North Carolina. One NHL patient with ALK+ ALCL was enrolled on both trials. Two patients, one HL and one NHL, were enrolled on a phase I study and received 2x10 7 CD30.CAR-T cells/m 2 as consolidation for high-risk of relapse after autologous stem cell transplant (ASCT, NCT02663297). Five patients, 3 HL and 2 NHL, were enrolled on a phase Ib/II study and received 1x10 8 CD30.CAR-T cells/m 2, as treatment for relapsed disease, after lymphodepletion with bendamustine and fludarabine (NCT02690545). HL patients had failed multiple lines of therapies (5-6), including 2 with prior pembrolizumab, 2 with prior ASCT, and all 3 with prior brentuximab vedotin (BV) and radiation therapy. The two NHL patients both had ALCL, one was ALK positive and one was ALK negative. Both had been treated with prior BV. The ALK negative patient had been treated with 3 prior lines of therapy and the ALK positive patient had been treated with 6 lines of prior therapy including ASCT and two ALK inhibitors, crizotinib and brigatinib. The brigatinib was stopped 3 weeks prior to starting lymphodepletion.Results:CD30.CAR-T cells were successfully manufactured for all 7 patients and no differences were observed as compared to products manufactured for adults, based on cell number, transduction, potency or immunophenotype. For all patients, infusions were well-tolerated and no neurotoxicity experienced.On the post-ASCT study, 1 patient with HL and 1 with ALCL were treated. All adverse events (AE) were less than grade 4. The patient with HL remains in complete remission (CR) 41 months following therapy, while the patient with ALCL progressed.Five patients with relapsed/refractory disease (3 HL and 2 ALCL) were treated on the post-lymphodepletion study. Most grade 3 or higher AEs were anticipated hematologic toxicity secondary to lymphodepletion. The youngest HL patient on the study developed symptoms consistent with grade 2 cytokine release syndrome (CRS) and a concomitant pneumonia based on imaging, accompanied by a marked inflammatory response based on labs with maximum ferritin 9,920 ng/mL and CRP 150.7 mg/L. He responded to antibacterial agents and two doses of tocilizumab, as well as brief supplemental oxygen by nasal cannula. He did not require vasopressors. One patient with ALK+ ALCL had symptoms compatible with CRS and macrophage activation syndrome (maximum ferritin >100,000 ng/mL and CRP 39.7 mg/L), which were ultimately determined to be secondary to progressive disease, confirmed at autopsy 5 weeks post therapy. The other four patients (3 HL and 1 ALCL) achieved CR and remain in CR 4 to 27 months post CAR-T cell infusion. Of note, 2 of the HL patients chose to come off study while in CR to receive treatment with checkpoint inhibitor therapy.Conclusion:Our studies show that CD30.CAR-T cells are well tolerated in pediatric patients. CRs were observed in all heavily pre-treated and refractory HL patients, highlighting the potential of this strategy. All patients treated on both studies had previously received BV, which suggests CD30.CAR-T cells are effective even post BV progression. We continue to investigate how to better tailor CD30.CAR-T cells in NHL given the need for better therapies in ALCL, which is often aggressive at relapse. One patient with ALK negative ALCL remains in CR while the patient with ALK+ ALCL had rapid relapse.After study initiation, UNC entered into a research collaboration with Tessa Therapeutics. DisclosuresSavoldo: Tessa: Patents & Royalties: Approach for CD30.CAR-T Cells for Hodgkin Lymphoma. Dotti: Tessa: Patents & Royalties: Approach for CD30.CAR-T Cells for Hodgkin Lymphoma. Grover: Tessa: Consultancy; Kite: Other: Advisory Board; Novartis: Consultancy; Genentech: Research Funding; ADC: Other: Advisory Board. Morrison: Vesselon: Consultancy. Riches: Jazz Pharmaceuticals: Other: Payment; ATARA Biotherapeutics: Other: Payment; BioIntelect: Membership on an entity's Board of Directors or advisory committees. Serody: Tessa: Patents & Royalties: Approach for CD30.CAR-T Cells for Hodgkin Lymphoma.

Diversity of Intratumoral Regulatory T Cells in Non-Hodgkin Lymphoma

Introduction: Regulatory T cells (Tregs), a highly immunosuppressive subset of CD4 + T cells, represent a key challenge in the tumor microenvironment by limiting potent antitumor immune responses. While high densities of tumor-infiltrating Tregs are associated with poor prognosis in patients with various types of solid cancers, their prognostic impact in B-cell non-Hodgkin lymphoma (NHL) remains unclear. Emerging studies suggest substantial heterogeneity in the phenotype and suppressive capacities of Tregs, emphasizing the importance of understanding Treg diversity and the need for additional markers to identify highly suppressive Tregs. Our in-depth characterization of Tregs in NHL tumors could open new paths for rational drug design, facilitating selective therapeutic manipulation of Tregs to reduce immunosuppression and improve anti-tumor immunity.Methods: Single-cell suspensions from NHL patients (diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and healthy donors (tonsils and peripheral blood)) were analyzed by fluorescent flow- and mass cytometry to characterize Tregs, focusing on their expression of co-stimulatory and co-inhibitory checkpoint receptors. The immunosuppressive capacity of Tregs was measured by in vitro co-culture of FACS-sorted subsets of Tregs together with autologous CellTrace Violet-labelled T effector cells as responder cells, using samples from FL and tonsils. Live CD4 + T cells were obtained by FACS sorting from DLBCL (n = 3), FL (n = 3) and healthy donor tonsils (n = 3) and subjected to single-cell RNA sequencing (scRNA-seq), Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-seq) and scTCR-seq by the 10X Genomics platform. The computational framework of CIBERSORTx was used to generate unique signature matrices for the three Treg subsets identified by scRNA-seq, to facilitate validation in separate scRNA-seq cohorts (King, Sci Immunol 2021; Roider, Nat Cell Biol 2020), and to impute frequencies of the Treg subsets in cohorts with bulk RNA-seq data (Chapuy, Nat Med 2018; Schmitz, NEJM 2018; Pastore, Lancet Oncol 2015).Results: Immunophenotyping by mass cytometry revealed a subset of activated Tregs identified by co-expression of TIGIT, CTLA-4, PD-1, ICOS and OX40, and higher expression of FOXP3, CD25 and CD45RO, that was present in DLBCL and tonsils, but lacking in peripheral blood. This was validated by fluorescent flow cytometry, demonstrating significantly higher frequencies of activated Tregs in NHL tumors compared to PBMCs and tonsils from healthy donors. The phenotypic heterogeneity of intratumoral Tregs reflected different suppressive capacities as activated Tregs more potently suppressed the proliferation of autologous effector CD4 + and CD8 + T cells than naïve Tregs. For global transcriptomic profiling of CD4 + T cells from FL, DLBCL and tonsillar samples, we integrating scRNA-seq and CITE-seq data from 17,774 cells, revealing 13 distinct cellular states including three states of Tregs: naïve, activated and non-conventional LAG3 +FOXP3 - Tregs. Activated Tregs had higher expression of checkpoint receptors (TNFRSF4, TNFRSF18, ICOS), phosphatases (DUSP2, DUSP4), NF-κB pathway (NFKBIA, TNFAIP3, NFKBIZ, REL), chemokine receptors (CXCR4) and transcription factors (JUNB, IRF1, STAT3) as compared to naïve Tregs. We next used a computational approach to develop unique signature matrices for each Treg subset. This approach demonstrated strong concordance between CIBERSORTx estimated cell abundances of the three Treg subsets and the ground truth, and was validated in two external scRNA-seq cohorts. The development of unique signature matrices for Treg subsets facilitated imputation of their frequencies in bulk RNA-seq datasets. These analyses revealed that higher frequency of activated Tregs was enriched in the germinal B cell subtype of DLBCL and was associated with adverse outcome in FL.Conclusion: This study demonstrates that Tregs infiltrating NHL tumors are transcriptionally and functionally diverse and include highly immunosuppressive activated Tregs co-expressing several checkpoint receptors, which distinguish them from peripheral blood Tregs. Activated intratumoral Tregs could hamper clinical responses to checkpoint blockade, and identifying and targeting their vulnerabilities has the potential to improve anti-tumor immune responses. DisclosuresHolte: Gilead: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Nordic: Membership on an entity's Board of Directors or advisory committees; Nanovector: Membership on an entity's Board of Directors or advisory committees, Other: lectures honorarias; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Alizadeh: Cibermed: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; CAPP Medical: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Forty Seven: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Foresight Diagnostics: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Roche: Consultancy, Honoraria; Janssen Oncology: Honoraria; Celgene: Consultancy, Research Funding; Gilead: Consultancy; Bristol Myers Squibb: Research Funding.

First Line B+R in Elderly Patients with Indolent Non-Hodgkin's Lymphoma and Mantle Cell Lymphoma: A Real-World Experience

Background: Bendamustine plus rituximab (B+R) was established as a preferred first-line therapy for indolent non-Hodgkin's lymphoma (iNHL) and mantle cell lymphoma (MCL); however, few reports on the performance of this combination in the real-world setting in elderly patients are available to date.Methods: A retrospective review of adult patients over 70 years (elderly) vs younger (<70 years) with iNHL and MCL who received first-line B+R at our institution from June 2013 to January 2021. We assessed safety, acute and late toxicity, and efficacy of B+R in elderly patients, compared to younger group.Results: Among 201 assessed patients, 133 were elderly (mean age 77.9 years) and 88 younger (mean age 61.1 years) at time of B+R initiation. Baseline patient characteristics are presented in Table 1. There were more MCL in the elderly group: 20.3% vs 3.2% in the younger group. Significantly more patients in the elderly group had history of second malignancy. Prostate, breast, colon, and bladder cancer were more common in elderly, and lymphoid and thyroid in younger groups. Bulky lymphadenopathy, cytopenia, and constitutional symptoms were the most common indications for B+R initiation both in elderly (74.4%) and younger (79.26%) patients. Median number of B+R cycles was 6 for both groups. Mean dose of bendamustine received was 83.6 mg/m 2 in the elderly vs 88 mg/m 2 in the younger groups (p=0.0001). Full doses of bendamustine were given in 54% of elderly patients as compared to 79.5% younger patients. Treatment was delayed in 54% of the elderly and 43.2% of the younger patients. The mean delay time was similar in both groups: 20.1 [7-147] vs 17.1 [7-35 days].The number of adverse events (AE) per patient was similar between the groups across each cycle (Table 2). Rituximab-associated infusion reactions were the most common adverse events in both groups. One patient in younger group developed prolonged neutropenia, lasting over 15 months. G-CSF support received 12.4% elderly and 22.7% younger patients. Nine patients (8%) in elderly and six patients (6.8%) in younger group (p=0.7604) developed transformed aggressive B-Cell lymphoma. Thirteen patients (11.5%) in elderly and five patients (5.7%) in younger group (p=0.1530) had secondary malignancies. Melanoma, metastatic squamous cell and renal carcinoma were more common in elderly group. Younger patients had metastatic squamous cell carcinoma and renal carcinoma, Kaposi sarcoma, MDS and thyroid cancer.Overall response rate was 91.2% in elderly group vs 98.9% in younger group, including complete remission in 71.7% vs 84.1%. Median follow-up was 42 months [4.0-97.0]. Although median overall survival (OS) was not reached in both groups, it was shorter in elderly compared to younger group (HR 0.24, CI 0.14-0.42, p<0.0001) (Figure 1A). Relapse rate was 10.6% in elderly vs 4.5% in younger groups. Median event free survival (defined as time between the first treatment and one of the following events: progressive disease, relapse or death) for follicular lymphoma, the most common histological subgroup in both cohorts, was shorter in the elderly compared to younger groups (82.0 months vs not yet reached; HR 0.19, CI 0.05-0.71, p=0.0385) (Figure 1B)Conclusion: In the real-world setting elderly patients had more advanced and high-risk disease, as well as higher ECOG status. B+R was associated with greater dose reduction and treatment delays. Adverse events profile and incidence did not differ significantly from the younger group. Response rates were lower, but relapse rate was higher in elderly patients. OS was inferior in elderly patients as compared to the younger group, due to higher rate of relapse and secondary malignancies. [Display omitted] DisclosuresPrica: Astra-Zeneca: Honoraria; Kite Gilead: Honoraria.

Efficacy and Safety of CD19-Targeted CAR-T Cell Therapy for Refractory/Relapsed B-Cell Lymphoma: A Single Center of Real World Data

【Abstract】 Objective To investigate the efficacy and safety of CD19-targeted chimeric antigen receptor T cell (CAR-T cell) for refractory/relapsed B-cell lymphoma. Methods The efficacy and safety of CD19-CAR-T cells(4-1BB costimulatory domain) in treatment of 12 patients with relapsed/refractory B-cell lymphoma from March 2018 to December 2019 in the Department of Hematology of Guangdong Second Province Hospital were collected analyzed retrospectively. There were 9 patients (75%) with diffuse large B cell lymphoma, 1 patient with blastic variant of mantle cell lymphoma, 1 patient(8.3%) with Burkitt lymphoma, 1 patient with B cell non-Hodgkin lymphoma that cannot be classified. 3 patients (25%) with large mass (≥7.5cm) and 9 patients (75%) with ECOG score ≥2. The number of chemotherapy courses received before transfusion was 4-9, the median number of chemotherapy courses was 7. All 12 patients were autogenous mouse CAR-T cells. Fludarabine + Cyclophosphamide (FC) regimen was used for pretreatment before transfusion, and the number of CAR-T cells was 1 ~ 3.69×10 6/kg. Results All 12 patients received CD19-targeted CAR-T cell therapy. There were 9 patients had treatment response, and the total effective rate was 75%. Among them, there were 3 patients with complete response (CR), with CR rate of 25%, and 6 patients with partial response (PR), with PR rate of 50%. Among the 3 patients with CR remained CR at the follow-up date. Among the 6 patients with PR, 4 showed disease progression in the second month after transfusion, and 2 showed disease progression in the third month after transfusion. All the 9 patients with effective treatment had different degrees of cytokine release syndrome (CRS), including 3 level-1 CRS, 4 level-2 CRS, and 2 level-3 CRS. Two of them had grade 2 CRES, and all CRS and CRES were controlled after treatment with IL-6 receptor antagonists and glucocorticoids. None of the 3 patients failed to respond to treatment had CRS. Conclusion CD19-targeted CAR-T cell immunotherapy has been shown to be effective in CD19-antigen positive B-cell lymphoma, and adverse CRS reactions during treatment can be controlled after treatment. Patients who obtained CR seemed to be able to maintain long-term CR status, while patients who failed to obtain CR showed disease progression within a short period of 3 months, suggesting that patients who obtained CR at an early stage could achieve better efficacy. Therefore, how to identify patients who receive CR at an early stage may be a research direction for the clinical application of CAR-T cell immunotherapy in B-cell lymphoma.【Key words】Chimeric antigen receptor T-cell; Relapsed/refractory B cell lymphoma; Efficacy; Safety; Cytokine release syndrome DisclosuresNo relevant conflicts of interest to declare.

Clinical Characteristics, Treatment and Outcome of Patients with Mantle Cell Lymphoma: A Large, Multicenter Retrospective Analysis in China

Background Mantle cell lymphoma (MCL) is an uncommon heterogeneous subtype of B cell non-Hodgkin lymphoma, most MCL cases have a rapid evolution and an aggressive behavior with an unfavorable outcome. Clinical features in mantle cell lymphoma appeared regional characteristics and the epidemiology of MCL in Asia is not accurate documented. MCL treatment opinions are not uniform between country/region within Asia and China. At present, the large-scale Asian patient-specific data for the treatment of MCL are lacking.Aims To obtain ‘real world’ clinical characteristics,treatment patterns and prognosis factors of MCL patients in China and to address the knowledge gap in Chinese MCL patients.Methods Patients diagnosed with MCL between April 1999 and December 2019 at 19 comprehensive hospitals in China were included in this retrospective analysis. The median follow-up times was 36.0 months. The data of total 805 patients with mantle cell lymphoma were collected, 112 patients with incomplete clinical data, no chemotherapy and missing follow-up data were excluded. Finally, 693 patients with complete clinical data, treatment information and survival follow-up data were included in this study.Fully detailed information of patients, disease characteristics, treatments and outcomes were collected. Fisher's exact test or Pearson's Chi-squared test were used to compare categorical variables.Survival analysis was performed by Kaplan-Meier.Results The median age of the cohort was 60.0 years with a male-to-female ratio of 3.36:1. 477 patients (68.8%) were younger than 65 years at diagnosis.Advanced stage of diseases were 90.0%. Extranodal organ involvement was 83.4% and the most frequently involved extranodal organs were bone marrow(46.2%), spleen(36.1%), gastrointestinal tract(24.8) and oropharynx(17.7%). Blastic/pleomorphic mantle cell lymphoma accounted for 12.8%, and non-nodular mantle cell lymphoma accounted for 3.3%. Ki-67 more than 30% was 57.7% and Ki-67 ≥ 50% was 26.1%. The intermediate /high risk group was 49.8% according to MIPI score. The first-line therapeutic schedule is not completely unified, the most frequently regimen was CHOP/CHOP-like±R (n=312,45.0%) ,then high-dose cytarabine (n=222,32.0%), VR-CAP(n=44,6.3%), BR(n=30,4.3%), R-EPOCH (n = 17, 2.5%), FC / FCM±R regimen (n = 13,1.9%),and 55 patients(7.9%) uesd chemo-free regimen including IR / R2 / IR2 .Only 80 patients (11.5%) received autologous hematopoietic stem cell transplantation as consolidation therapy after chemotherapy remission. The ORR rate was 85.0%with 46.6% CR and 38.4% PR in the initial treatment.During the follow-up to June 2021(2-204months), 222 patients(32.0%) had died. The 5-year PFS and OS was 30.9% and 65.0%respectively.In the multivariate Cox regression model, ki67 ≥ 50% (HR 1.27, 95%CI 1.01-1.60, p = 0.038) ,stageⅢ/Ⅳ (HR1.56, 95%CI 1.05-2.33, p = 0.029),high- intermediate/high risk group accouding to MIPI-c (HR1.56, 95%CI 1.05-2.33, p = 0.008),spleen involvment (HR1.35, 95%CI 1.08-1.69, p = 0.009),without maintenance treatment (HR0.71, 95%CI 0.56-0.88, p = 0.003) ,SD/PD in inital treatment (HR6.20, 95%CI4.71-8.14, p < 0.001) were independently associated with poorer PFS while ki67 ≥50% (HR 1.74, 95%CI 1.31-2.31, p< 0.001),B symtom (HR 1.52, 95%CI 1.15-2.00, p = 0.003), high-intermediate/high risk group accouding to MIPI-c (HR1.43, 95%CI 1.24-1.64, p < 0.001),without high-dose cytarabine (HR0.47, 95%CI 0.31-0.70 ,p < 0.001) ,without maintenance treatment (HR0.40, 95%CI 0.28-0.58,p < 0.001)and relapse/refractory state (HR 4.04, 95%CI 2.21-7.39, p < 0.001) were independently associated with poorer OS.Conclusions This study describes the characteristics of mantle cell lymphoma in Chinese population with younger onset age and a higher tumor proliferation index. High dose cytarabine treatment and maintenance treatment have shown survival benefits in real-world.Recurrence and refractory is an important factor affecting survival,the strategy of combining molecular biological characteristics with novel strategies may improve outcome in these patients. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

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.

Clinical Outcome of Refractory Lymphoma Patients with Non Response to Chimeric Antigen Receptor T Cell Therapy

BackgroundChimeric antigen receptor T cell (CART) therapy has remarkably improved the outcome of patients (pts) with relapsed refractory B cell non-Hodgkin lymphoma. Anti-CD19 directed CART therapy have shown to yield durable remission in 40%-50% of patients with relapsed refractory (r/r) diffuse large B cell lymphoma (Neelapu et al. NEJM 2017; NCT 02348216). However, pts who had disease progression post CART therapy (non-responders) have poor outcomes. There is paucity of information regarding negative predictors for disease progression and outcome of non-responders post CART therapy.MethodsWe conducted a single center retrospective study of 11 patients with relapsed refractory large B cell lymphoma who underwent treatment with CART in our institution from December 2019 to June 2021 and further studied the baseline characteristics, and clinical outcome of 8 pts who were non responders to CART therapy.ResultsAll patients received low dose fludarabine cyclophosphamide based lymphodepleting conditioning regimen followed by anti-CD19 directed CART cells using CD28 as costimulatory domain with a target dose of 2 x 10 6 cells /kilogram of body weight.Baseline characteristics as shown in [Table 1]. Median age at CART therapy was 61 years (range 49-71). Median ECOG score at CART therapy was 1. All patients had chemo refractory disease at time of CART therapy with 9 patients having refractory diffuse large B cell lymphoma and 2 patients had transformed large B cell lymphoma. Genomic studies showed high risk disease in 4 patients with double hit lymphoma, 3 patients with complex cytogenetics with one having 17 p deletion and 2 patients with double expressors of c-myc and bcl2. Only 5 patients had available Ki-67 score > 80%. All patients had stage III-IV disease at the time of CART therapy. Seven pts had extra nodal disease and one patient had CNS involvement. Median R-IPI score at time of CART therapy was 3 (range 2-4). Median LDH, serum ferritin and serum CRP at the time of CART therapy was 388 (range 136-1489); 831 (range 116.9-1503); and 28.1 (range 7.4-226) respectively. Median number of prior therapies were 3 (range 2-9). One patient had prior autologous stem cell transplant. Median absolute lymphocyte count (ALC) and platelet count at CART therapy was 0.01/ul (range 0.01-2.5) and 89 x 10 3/ul (range 10-385) respectively. Median time from last salvage chemotherapy to CART therapy was 62 days (range 28-492).Total six pts had cytokine release syndrome (CRS) with median time for CRS onset was 3.5 days (range 1-8) with all of them having grade 1-2 CRS. Total seven pts had neurotoxicity with median time for onset was 5 days (range 1-41) post CART with 4 pts having > grade 3 immune effector cell associated neurotoxicity syndrome (ICANS). Overall, six and seven pts received tociluzumab and steroids respectively for treatment of CART related CRS and ICANS. Day 30 PET/CT scan showed three responders (2CR,1PR) and eight non responder patients with disease progression.Non responder pts to CART, when compared with responders had higher value of median LDH (438 vs 300; p = 0.92); median CRP (29 vs 13; p = 0.497) ; higher extra nodal involvement ( 6 pts vs one), median R-IPI score at the time of CART ( 4 vs 3), median number of prior therapies (4 vs 3), and median time from last salvage therapy to CART ( 73 days vs 50 days ; p = 0.91). No difference in baseline ALC count and platelet count was noted between the two groups. Compared to responders, non-responder pts had lower incidence of CRS (100% vs 37.5%) and ICANS (100% vs 50%). Post CART therapy, non-responder pts were treated with Nivolumab based immunotherapy in 5 pts, Ipilimumab based therapy in 1 pt, Selinexor in 1 patient and Polatuzumab based therapy in 2 pts.Median progression free survival and overall survival of non-responders was only 30.5 days and 94 days respectively. 5 out of 8 non responder pts died (4 due to disease progression and 1 due to sepsis). All three responder pts were alive and disease free at the end of study. Median follow up of our study was 108 days (range 32- 561).ConclusionsDespite smaller sample size, our study showed dismal outcome of pts who don't respond to CART therapy, showing an unmet need for better salvage therapies in such pts. Refractory lymphoma pts with extra nodal disease involvement, higher LDH and CRP at the time of CART therapy could be negative predictors for response. Further prospective studies with larger sample size required to further validate these findings. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Outcomes of High Grade B- Cell Lymphoma with MYC and BCL2 and/or BCL6 Rearrangements: An Atlantic Canadian Centre Perspective

Background: High Grade B cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (also known as Double-hit lymphoma (DHL)) is an aggressive B cell Non-Hodgkin lymphoma which has recently been recognized by the WHO as a distinct clinical entity from Diffuse Large B cell lymphoma (DLBCL). Compared to patients with DLBCL, patients with DHL have poor outcomes with standard R-CHOP chemoimmunotherapy, and the optimal treatment regimen for this high-risk lymphoma is unknown. Due to clinical and genetic overlap with Burkitt lymphoma (which shares translocations involving MYC), treatment of DHL with more intensive Burkitt lymphoma protocols is a common approach. However, these regimens are associated with significant toxicity, and the superiority of these regimens over standard R-CHOP remains uncertain. At our institution, R-CODOX-M/IVAC has been the preferred regimen for fit younger patients with DHL.Objective: To review the outcomes of patients with DHL treated with R-CODOX-M/IVAC at our institution.Methods: In this retrospective single-centre study, patients with DHL receiving R-CODOX-M/IVAC were identified by cross-referencing provincial cancer care data and hospital pharmacy data. All adult patients with a diagnosis of DHL and who were treated with R-CODOX-M/IVAC between January 2009 and January 2019 were included in the analysis. The primary outcomes is complete response (CR) per standard lymphoma response criteria. Secondary outcomes include median progression-free survival (PFS), overall survival at 1 year, and median overall survival. Kaplan-Meier analysis was used for survival analyses.Results: 14 patients with DHL and meeting the inclusion criteria were identified and included in the analysis. The complete response rate was 35.7%. With a median followup time of 26 months, the median PFS was 31.8 months, and the median OS was 54.3 months. The overall survival at 1 year was 77%.Conclusions: A previous meta-analysis demonstrated inferior outcomes for patients with DHL receiving RCHOP, with a median PFS of only 12.1 months. The optimal treatment of these patients remains to be defined. Dose-adjusted regimens have been associated with a significant improvement in PFS compared to RCHOP (21.6 months versus 12.1 months). Previous retrospective data suggests R-CODOX-M/IVAC results in more favourable outcomes 2 year PFS of 41% and 2 year OS of 53% (Sun et al., Clinical Lymphoma, Myeloma & Leukemia, 2015). Our data, although limited, that R-CODOX-M/IVAC may be associated with improved outcomes compared to published results with RCHOP. The limitations of this study include its retrospective design, lack of matched controls receiving RCHOP, and its small sample size. Nevertheless, this study adds to the small body of available evidence on this difficult to treat clinical entity. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Cepp in Previously Untreated Patients with Mature T Cell Lymphomas

▪IntroductionThere is currently no standard of care for the upfront management of patients with mature T cell non-Hodgkin lymphomas (T-NHL). The role of anthracyclines in the treatment of T-NHL remains unclear and is also associated with significant toxicity. CEPP (cyclophosphamide, etoposide, procarbazine, and prednisone), a non-anthracycline regimen, is an effective salvage regimen for relapsed/refractory NHL and has shown a favourable toxicity profile. Since 2005, CEPP has been used in Singapore in the upfront treatment of T-NHL patients either with a contraindication to anthracyclines or at physicians' discretion. Our study aimed to assess the efficacy of CEPP in the upfront treatment of T-NHL.MethodsA retrospective study of all patients with newly diagnosed T-NHL treated with CEPP with curative intent from 2005-2021 was undertaken across 2 national cancer centers in Singapore. Outcomes of this population was also compared with a 1:1 control group treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) in the same time period, and matched for age, T-NHL subtype, clinical stage and international prognostic index (IPI). Patient demographics, disease characteristics and clinical outcomes (progression free survival, PFS and overall survival, OS) were evaluated. None of the patients had upfront autologous transplantation.ResultsWe identified 34 patients treated with CEPP who met the inclusion criteria. Clinical characteristics were as follows: Median age was 71 (range 39-85), 24 (71%) were male, 26 (76%) had advanced disease (Stage III-IV) and 21 (62%) had a high intermediate or high risk IPI ( IPI 3, 14 (41%) and IPI 4-5, 21 (21%)). The most common T-NHL subtypes were peripheral T-NHL (PTCL-NOS) not otherwise specified, 11 (32%) as well as angioimmunoblastic T cell lymphoma (AITL), 16 (47%). At a median follow up of 20 months (range 2-197months), the median PFS and OS were 17.6mths and 37.2mths respectively for the CEPP group. 15/34 (44%) CEPP patients have died (8 with lymphoma, 2 from treatment toxicity and 5 from unrelated causes). In the matched control comparison, the 5yr PFS and OS were both similar for patients treated with CEPP compared to patients in the CHOP control group, PFS 30% vs 32%, p= 0.43 and OS 47% vs 52%, p = 0.32, respectively (Figure 1)ConclusionOur findings show that CEPP is a well-tolerated regimen which can cure a proportion of patients with T-NHL even without autologous transplantation consolidation. Outcome of these patients do not seem to be significantly different compared to a similar population treated with standard CHOP. This study supports CEPP as a tolerable treatment option for selected patients who cannot tolerate anthracyclines and as an alternative to CHOP regimen for older patients who are not planned for ASCT. [Display omitted] DisclosuresJeyasekharan: Turbine Ltd: Consultancy; Janssen: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Perkin Elmer: Other: travel funding ; MSD: Consultancy.

Randomized Phase II/III Study of DA-EPOCH-R +/- Venetoclax in Previously Untreated Double Hit Lymphoma: Initial Results from Alliance A051701

Randomized Phase II/III Study of DA-EPOCH-R +/- Venetoclax in Previously Untreated Double Hit Lymphoma: Initial Results from Alliance A051701

Treatment Outcomes and Prognostic Factors in 40 Patients with Primary Effusion Lymphoma

Background: Primary effusion lymphoma (PEL) is a rare, B cell non-Hodgkin lymphoma (NHL) caused by Kaposi sarcoma herpesvirus (KSHV), also known as human herpesvirus 8, that is strongly associated with HIV infection. PEL often presents as malignant body cavity effusions but can also present as extracavitary masses. Patients may also have concurrent Kaposi sarcoma (KS) or multicentric Castleman disease (MCD). 80% of PEL is also positive for EBV, and in a cohort of 20 patients we previously showed EBV + PEL had improved overall survival (OS) (Lurain et al. Blood 2019). PEL prognosis is poor compared to other HIV-associated NHL with median survival of 6-10 months. While patients are often treated with chemotherapy regimens used in other NHL, the optimal front-line and subsequent-line treatments are unknown. In this largest cohort of patients with PEL in the United States, we evaluated survival, prognostic markers, and second-line treatments in relapsed/refractory disease.Methods: We analyzed clinical records of all patients with PEL treated in the HIV and AIDS Malignancy Branch at the National Cancer Institute from 2000-2021. We collected demographics, disease characteristics, concurrent KS and MCD, EBV status of tumor by EBER staining, and laboratory data at diagnosis as well as at progression and subsequent lines of therapy. We calculated overall survival (OS) of all patients and progression-free survival (PFS) in those who received front-line EPOCH by Kaplan-Meier method. The survival of extracavitary vs. cavitary PEL was compared using an exact log-rank test. A univariate Cox proportional hazard model was performed to determine prognostic variables associated with OS.Results: We identified 40 patients with PEL: 38 cisgender men, 2 cisgender women; 18 non-Hispanic Black, 6 Hispanic, 16 non-Hispanic White; median age 41 years. At diagnosis of PEL, 29 patients had concurrent KS, and 7 had concurrent MCD. Eight patients had only extracavitary disease, and 5 had leptomeningeal disease. All but 1 had HIV, and all with HIV received antiretroviral therapy. At diagnosis, median HIV viral load (VL) was 50 (IQR: 27-8323) copies/mL, median CD4 + cell count was 100 (IQR:44-395) cells/µL, and median KSHV VL was 4147 copies/10 6 cells (IQR:178-68,526). One patient died prior to receiving treatment. Of the 39 patients who received front-line treatment, 38 received combination chemotherapy (EPOCH [36], CHOP [1], ICE [1]) with rituximab added in 34 patients to treat concurrent MCD or deplete the KSHV-infected B cell reservoir. One patient received pembrolizumab as up-front therapy due to concurrent progressive multifocal leukoencephalopathy. Twenty-three (57%) had complete remission (CR) by Lugano criteria. Median PFS after front-line EPOCH was 16.4 months (Figure 1a), and median OS in all patients was 35.6 months (Figure 1b), with 5-year OS of 44%. Median OS for patients with extracavitary disease was significantly higher than in patients with cavitary disease (p=0.023, Figure 1c). EBER-positive tumors (HR=0.21, p=0.005) were associated with improved survival, while concurrent KS, MCD, leptomeningeal disease, and baseline CD4 and KSHV VL were not associated with OS outcomes.Eleven patients with relapsed/refractory disease received second-line therapy, including combination chemotherapy (3); brentuximab (3); pembrolizumab (1); pembrolizumab and pomalidomide (1); interferon-alpha, ganciclovir, and bevacizumab (1); bortezomib, ganciclovir, and zidovudine (1); and radiation to pelvic lymph nodes (1). Five of these patients received subsequent treatment after disease progression, including 2 patients with leptomeningeal PEL, 1 who received daratumumab and 1 who received pomalidomide and pembrolizumab with ongoing CRs at 12 months and 33 months, respectively.Conclusion: Patients with PEL had a median OS of 35.6 months, which is improved from previous reports. Patients with extracavitary PEL appear to have improved OS, and we confirmed our prior study noting EBER-positive PEL is a positive prognostic marker. Promising chemotherapy-sparing treatment regimens in relapsed/refractory PEL, include pembrolizumab, pomalidomide, and daratumumab. [Display omitted] DisclosuresUldrick: Regeneron: Current Employment; Roche: Research Funding; Merck: Other: Receives study drug; Celgene: Research Funding. Yarchoan: Celgene: Research Funding; Merck: Other: Clinical Trial Support; EMD-Serano: Other: Clinical Trial Support; Eli Lilly: Other: Clinical Trial Support; CTI BioPharma: Other: Clinical Trial Support; Janssen Pharmaceuticals: Other: Clinical Trial Support; U.S. Dept of Health and Human Services: Patents & Royalties. Lurain: EMD-Serrono: Research Funding; BMS-Celgene: Research Funding; CTI Biopharma: Research Funding; Merck: Research Funding; Janssen: Research Funding.

Characteristics of Environmental Exposure-Associated Versus Unexposed High-Grade B-Cell Lymphomas in Veterans: A Single Center, Matched Case-Control Study

Introduction: Environmental exposures, such as Agent Orange and other chemicals, are associated with the development of non-Hodgkin lymphomas (NHL). Military personnel and civilians in theaters of conflict are especially at high risk. The mechanism is still not well understood. We have initiated studies to examine the association of dioxin exposure, changes in DNA methylation, and the development of high-grade B-cell NHL.Methods: Patients diagnosed with high grade B-cell NHL were identified from the VA Long Beach medical record system for database abstraction and tissue analysis. Subjects with sufficient clinical data including diagnosis, date of diagnosis, age of diagnosis, exposure to toxins, treatments, date of last follow up, date of death, cause of death were included in the study. Patients were matched by exposure vs no exposure and international prognostic index (IPI), as well as duration in military and tour of duty when possible. Formalin-fixed paraffin-embedded specimens from a subset of these patients (where sufficient tissue was available for analysis) with and without known exposures were analyzed for differences in DNA methylation by enzymatic methyl sequencing. Descriptive statistics were used to summarize patient characteristics. Two sample t- and chi-square tests were used to compare the exposed and unexposed lymphoma groups. Overall survival was calculated from time of diagnosis to death from any cause and plotted on a Kaplan-Meier curve and compared using the Log rank test. The Fisher's exact test was used to compare the causes of death between the two groups using SAS 9.Results: Fifty-two patients were included in the study. Patient characteristics were well-balanced between the two groups. The duration of active duty, interval from military enlistment to diagnosis of NHL, and first-line therapy (generally anthracycline-based) were similar. There was a trend toward higher proportion of patients with advanced (stage III or IV) disease and younger age of diagnosis in patients with exposure-associated NHL (p=0.07). The median duration of response to first-line therapy (DOR1) trended towards being shorter (median, 0.8 years; range 0.03-25 years) in patients with exposure related NHL compared to median DOR1 of 2.7 (range, 0.02-25 years) in those without exposure, p=0.056. Median overall survival was 11.5 years in the exposure group and 10 years in the unexposed group, p=0.31. A higher portion of patients in the exposed group died from NHL compared to unexposed group (38% vs 15%), p=0.057. Other competing causes of death, which were more likely in the unexposed group, included other cancers, cardiac disease, infection, end stage kidney disease, dementia and unknown. Six exposed and six unexposed samples were sequenced with over 10,000 statistically significant differentially methylated regions (DMRs) out of 40,605 DMRs tested. Details of differences in methylation of specific genes and their potential pathophysiological and therapeutic implications will be discussed in the presentation.Conclusions: Patients with exposure-related high-grade B cell NHL who were matched by IPI with unexposed lymphomas did not differ significantly in baseline characteristics including time from enlistment to diagnosis and overall survival. In the exposure-related NHL group, certain findings trended toward significance, including younger age at diagnosis, higher proportion diagnosed at an advanced stage, shorter DOR1, and higher proportion died of NHL. This single center cohort, however, was small and heterogeneous. We are therefore currently expanding this study to examine a larger, multi-center cohort to confirm and extend our clinical and translational findings. DisclosuresNo relevant conflicts of interest to declare.