Adult T-cell Leukemia Research Articles

High Expression of Inflammatory Cytokines and Chemokines in Human T-lymphotropic Virus 1-Associated Adult T-cell Leukemia/Lymphoma

Background: Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma (ATLL) without any specific antiviral. Objectives: This study aimed to evaluate the expression level of inflammatory chemokines and pro-inflammatory cytokines in ATLL patients, asymptomatic carriers (ACs), and healthy individuals to assess the role of these inflammatory markers in ATLL pathogenicity. Methods: This study was conducted from May 2021 to August 2022. The ATLL blood samples were collected from the oncology wards of Imam Khomeini, Shariati, and Imam Hossein hospitals, in Tehran, Iran. The blood samples of ACs and normal control subjects were collected from blood donors referred to blood transfusion centers of Tehran and Alborz provinces, Iran. RNA extraction, complementary DNA (cDNA) synthesis, and real-time polymerase chain reaction (PCR) were done in targeted sample groups to investigate the correlation and expression rate of C-C motif chemokine ligand 3 (CCL3), C-C motif chemokine ligand 4 (CCL4), C-X-C motif chemokine ligand 8 (CXCL8), interleukin 23 subunit alpha (IL-23A), and interleukin 17 A (IL-17A). Results: A total of 30 samples were collected from 3 groups. The CCL3, CCL4, CXCL8, and IL-17A messenger RNA (mRNA) expression levels were significantly upregulated in the ATLL groups. There was a significant difference between CCL3 expression between the ACs and ATLL groups. In addition, CCL4 and CXCL8 expression levels were more significant in the ATLL group than in the normal control group. The IL-17A expression level significantly increased between groups. The IL-23A expression levels had no significant differences between the ATLL, ACs, and normal control groups. Conclusions: This study showed significant upregulation of pro-inflammatory cytokines and chemokines mRNAs in HTLV-1–associated ATLL compared to the ACs and normal control groups. Conducting more experiments to investigate the therapeutic effect of chemokines/cytokines in ATLL is essential.

A newly identified interaction between nucleolar NPM1/B23 and the HTLV-I basic leucine zipper factor in HTLV-1 infected cells.

Human T-cell leukemia virus type 1 is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis and adult T-cell leukemia-lymphoma (ATL). The HTLV-1 basic leucine zipper factor (HBZ) has been associated to the cancer-inducing properties of this virus, although the exact mechanism is unknown. In this study, we identified nucleophosmin (NPM1/B23) as a new interaction partner of HBZ. We show that sHBZ and the less abundant uHBZ isoform interact with nucleolar NPM1/B23 in infected cells and HTLV-1 positive patient cells, unlike equivalent antisense proteins of related non-leukemogenic HTLV-2, -3 and-4 viruses. We further demonstrate that sHBZ association to NPM1/B23 is sensitive to RNase. Interestingly, sHBZ was shown to interact with its own RNA. Through siRNA and overexpression experiments, we further provide evidence that NPM1/B23 acts negatively on viral gene expression with potential impact on cell transformation. Our results hence provide a new insight over HBZ-binding partners in relation to cellular localization and potential function on cell proliferation and should lead to a better understanding of the link between HBZ and ATL development.

Case Report: Spontaneous remission of early T-cell precursor acute lymphoblastic leukemia

Background: Spontaneous remission (SR) has been reported in different hematological malignancies. It has been observed in adult T-cell lymphoma, chronic lymphocytic leukemia (CLL) and myelodysplastic syndrome (MDS). It is generally associated with recovery from an infectious or immunological process, and more recently possibly with clonal hematopoiesis. Case: We reviewed the literature and reported a new case of a 40 year-old man with a morphologic and cytogenetic diagnosis of early T-cell precursor acute lymphoblastic leukemia (ALL) associated with an appendicular abscess. During his hospitalization and surgical management of his appendicitis, we noted SR of the rate of blast cells until cytological and cytogenetic remission of his ALL but unfortunately it did not last too long, moreover our patient relapsed after nine months, received intensive chemotherapy, underwent a placental blood allograft but relapsed again and died. Conclusions: In contrast to SR in other types of cancer, all documented cases of SR in ALL were only transient, so is there a need for early cytotoxic therapy in SR in ALL to delay relapse?

CARD11 mutation and HBZ expression induce lymphoproliferative disease and adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is caused by human T-cell leukemia virus type 1 (HTLV-1). In addition to HTLV-1 bZIP factor (HBZ), a leukemogenic antisense transcript of HTLV-1, abnormalities of genes involved in TCR-NF-κB signaling, such as CARD11, are detected in about 90% of patients. Utilizing mice expressing CD4+ T cell-specific CARD11(E626K) and/or CD4+ T cell-specific HBZ, namely CARD11(E626K)CD4-Cre mice, HBZ transgenic (Tg) mice, and CARD11(E626K)CD4-Cre;HBZ Tg double transgenic mice, we clarify these genes’ pathogenetic effects. CARD11(E626K)CD4-Cre and HBZ Tg mice exhibit lymphocytic invasion to many organs, including the lungs, and double transgenic mice develop lymphoproliferative disease and increase CD4+ T cells in vivo. CARD11(E626K) and HBZ cooperatively activate the non-canonical NF-κB pathway, IRF4 targets, BATF3/IRF4/HBZ transcriptional network, MYC targets, and E2F targets. Most KEGG and HALLMARK gene sets enriched in acute-type ATL are also enriched in double transgenic mice, indicating that these genes cooperatively contribute to ATL development.

Endothelial function testing before conditioning therapy is useful for predicting transplant-related complications after allogeneic hematopoietic cell transplantation.

Hematopoietic stem cell transplantation (HSCT) is a useful tool for the treatment of hematologic malignancies. However, transplantation-related complications are the main cause of non-relapse mortality. Previous reports suggest that endothelial damage is related to early complications after HSCT. Non-invasive reactive hyperemia peripheral arterial tonometry (RH-PAT) was performed to evaluate endothelial function as a predictive marker for these complications. The reactive hyperemia index (RHI) obtained from RH-PAT was evaluated before the conditioning regimen. The relationship between the RHI and the appearance of engraftment syndrome, thrombotic microangiopathy, and acute graft-versus-host disease (aGVHD) was assessed. Receiver operating characteristic curve analysis showed that an RHI value of 1.58 was the optimal cut-off for predicting transplantation-related complications. In total, 49 patients (22 acute myelogenous leukemia, 7 acute lymphocytic leukemia, 6 myelodysplastic syndrome, 6 adult T-cell leukemia, 6 non-Hodgkin lymphoma, and 2 others) were enrolled; 34 had a normal RHI (≥ 1.59), and 15 had an abnormally low RHI (≤ 1.58). Thrombotic microangiopathy (20.2% vs 0.0%, P = 0.025) and aGVHD (80.0% vs 41.2%, P = 0.015) were significantly more frequent in patients with a low RHI. Endothelial dysfunction assessed by RH-PAT before HSCT was able to predict transplantation-related complications.

A frequent PLCγ1 mutation in adult T-cell leukemia/lymphoma determines functional properties of the malignant cells

BackgroundDevelopment of adult T-cell leukemia/lymphoma (ATL) involves human T-cell leukemia virus type 1 (HTLV-1) infection and accumulation of somatic mutations. The most frequently mutated gene in ATL (36 % of cases) is phospholipase C gamma1 (PLCG1). PLCG1 is also frequently mutated in other T-cell lymphomas. However, the functional consequences of the PLCG1 mutations in cancer cells have not been characterized. MethodsWe compared the activity of the wild-type PLCγ1 with that of a mutant carrying a hot-spot mutation of PLCγ1 (S345F) observed in ATL, both in cells and in cell-free assays. To analyse the impact of the mutation on cellular properties, we quantified cellular proliferation, aggregation, chemotaxis and apoptosis by live cell-imaging in an S345F+ ATL-derived cell line (KK1) and a KK1 cell line in which we reverted the mutation to the wild-type sequence using CRISPR/Cas9 and homology-directed repair. FindingsThe PLCγ1 S345F mutation results in an increase of basal PLC activity in vitro and in different cell types. This higher basal activity is further enhanced by upstream signalling. Reversion of the S345F mutation in the KK1 cell line resulted in reduction of the PLC activity, lower rates of proliferation and aggregation, and a marked reduction in chemotaxis towards CCL22. The PLCγ1-pathway inhibitors ibrutinib and ritonavir reduced both the PLC activity and the tested functions of KK1 cells. InterpretationConsistent with observations from clinical studies, our data provide direct evidence that activated variants of the PLCγ1 enzyme contribute to the properties of the malignant T-cell clone in ATL. FundingMRC (UK) Project Grant (P028160).

Majocchi Granuloma in a Patient with Adult T-cell Leukemia.

Majocchi Granuloma in a Patient with Adult T-cell Leukemia.

Development of a Novel HTLV-1 Protease: Human Fcγ1 Recombinant Fusion Molecule in the CHO Eukaryotic Expression System.

Human T-cell leukaemia virus type 1 (HTLV-1) is the causative agent of two life-threatening diseases, adult T cell leukaemia/lymphoma (ATLL), and HTLV-1-associated myelopathy/tropical spastic (HAM/TSP). HTLV-1 protease (HTLV-1-PR) is an aspartic protease that represents a promising target for therapeutic purposes like human immunodeficiency virus-PR inhibitors (HIV-PR). Therefore, in this study, the human Fc fusion recombinant-PR (HTLV-1-PR:hFcγ1) was designed and expressed for two applications, finding a blocking substrate as a potential therapeutic or a potential subunit peptide vaccine. The PCR amplified DNA sequences encoding the HTLV-1-PR from the MT2-cell line using specific primers with restriction enzyme sites of Not1 and Xba1. The construct was then cloned to pTZ57R/T TA plasmid and, after confirming the PR sequence, subcloned into the pDR2ΔEF1α Fc-expression vector to create pDR2ΔEF1α.HTLV-1-PR:hFcγ1. The integrity of recombinant DNA was confirmed by sequencing to ensure that the engineered construct was in the frame. The recombinant fusion protein was then produced in the Chinese hamster ovary cell (CHO) system and was purified from its supernatant using HiTrap-rPA column affinity chromatography. Then, the immunofluorescence assay (IFA) co-localisation method showed that HTLV-1-PR:hFc recombinant fusion protein has appropriate folding as it binds to the anti-Fcγ antibody; the Fcγ1 tag participates to have HTLV-1-PR:hFcγ1 as a dimeric secretory protein. The development and production of HTLV-1-PR can be used to find a blocking substrate as a potential therapeutic molecule and apply it in an animal model to assess its immunogenicity and potential protection against HTLV-1 infection.

Highly Sensitive Detection Method Reveals Significant Anti-Tumor Activity of Valemetostat in Patients with Relapsed/Refractory Adult T Cell Leukemia

Background: Enhancer of zeste homolog 2 (EZH2) and its close homolog, EZH1, catalyze the attachment of 3 methyl groups to histone H3 at lysine 27 (H3K27me3). H3K27me3 is an epigenetic mark involved in downregulating gene expression associated with tumor suppression and cell differentiation. Adult T-cell leukemia/lymphoma (ATL) is an aggressive non-Hodgkin lymphoma (NHL) subtype that arises from CD4 positive T cells associated with human T-lymphotropic virus type 1 (HTLV-1) infection. During asymptomatic period, genetic and epigenetic abnormalities in the HTLV-1 infected cells accumulates and finally leads to ATL development. Current therapy for aggressive type ATL is still unsatisfactory and prognosis of relapsed and refractory (r/r) ATL after lenalidomide or mogamulizumab treatment is poor. Dysregulation of EZH2/PRC2-mediated epigenome status has been reported to be highly involved in tumorigenesis in ATL as well as other tumors such as B cell lymphoma. Valemetostat is a potent dual inhibitor of EZH1 and 2 which are key catalytic subunits of PRC2. The safety and efficacy of valemetostat in patients with r/r ATL were evaluated in a multicenter, single-arm, open-label phase 2 study (NCT04102150) and the results were presented at ASH 2021. Here we show clinical biomarker data using peripheral blood obtained over time, accompanying clinical outcomes. Also we discuss relevance of the measured data in blood to clinical outcomes among assay formats. Method: In the Ph2 study, valemetostat 200mg was orally administrated once daily in continuous 28-day cycles until disease progression or intolerance. Nine of 25 patients in the Ph2 study had abnormal lymphocytes in their peripheral blood. Peripheral blood from these 9 patients (7 acute and 2 unfavorable chronic) was drawn at pre-dosing and every 4-weeks for the analysis of this study. Abnormal lymphocytes (Ably) and soluble IL-2R (sIL-2R) are indicator of ATL prognosis. For HTLV-1 proviral load (PVL) detection, genomic DNA was extracted from PBMC from each patient. Droplet Digital PCR (ddPCR) was performed using probes specific for HTLV-1 provirus and RNase 5’ pyrophospgohydrolase (RPPH) gene. % PVL was determined from the copy number ratio of HTLV-1 to RPPH1 genes. For HTLV-1 Analysis System (HAS)-flow cytometry, frozen cell suspensions were thawed and stained with anti- CD3/4/7/14/CADM1 Abs. The data from live T cells was analyzed by CD7 versus CADM1 plot. CADM1+CD7- population ratio was denoted as %N. We analyzed changes of each measured parameter in every patient in comparison with clinical outcome. Result: In the 9 patients who met criteria in blood collection for blood biomarker evaluation at screening, 1 CR, 6 PRs and 1 SD were observed as the best response by blood assessment (not evaluable in one patient, who failed to meet criteria for blood assessment at pre-treatment evaluation). Significant decrease in Ably number and blood sIL-2R concentration was observed after 4-week valemetostat treatment in all 9 patients and this decrease was maintained during the treatment until PD. Valemetostat also decreased the %PVL and %N in HAS-flow. The reduction trends were weaker in comparison with Ably and sIL-2R. As for %PVL, most of the patients experienced modest reduction and sustained around 50%. Especially HAS-flow results exhibited two patient groups with either lower (<25%) or higher %N at pre-dosing. Two patients in the lower %N group showed CR or PR, and in overall response the remaining 7 patients with higher %N showed SD or PR. Conclusion: Valemetostat significantly reduced markers of ATL progression. Ably and sIL-2R to very low levels in all patients. In contrast, PVL assay did not exhibit complete %PVL reduction. HAS-flow showed variable %N at pre-dosing and the patients with higher %N exhibited SD or PR throughout the treatment in overall response and blood assessment. These data suggest that PVL assay and HAS-flow can detect ATL cells with a high resolution, which cannot be detected by Ably and sIL-2R, when valemetostat has significant therapeutic efficacy in ATL patients. Further analyses, such as gene mutation, transcription, chromatin state and histone methylation, using the collected blood samples will be performed next.

HTLV-1 Carriers with Circulating Dominant Clones Harbor ATL-like Mutational and Transcriptomic Profiles Which Identify an Ultra-High Risk Group for Disease Transformation

Background: Identifying carriers of human T cell leukaemia virus type -1 (HTLV-1) at high risk of developing the aggressive T-cell malignancy adult T-cell leukaemia/lymphoma (ATL) is important as it will provide the opportunity for therapeutic intervention before disease transformation, which typically results in dismal outcomes. This further provides a rationale for broadening HTLV-1 screening. The pre-transformation processes take decades but remain elusive, with the main established risk factor being a high proviral load (proportion of infected mononuclear cells >4%) but this lacks specificity. We recently reported that ATL-like clonal T cell expansions can be identified by flow-cytometry based on T cell receptor (TCR)Vβ subunits in a subset of high-load HTLV-1 carriers ('oligoclonality-flow, OCI-flow') and that a high degree of oligoclonality (OCI flow-score >0.770), usually with a single dominant clone, predicts transformation risk. In this study, we characterize the mutational and transcriptomic profiles in these dominant clones in otherwise healthy carriers. Methods: A cohort of 19 high proviral load HTLV-1 infected individuals was selected, of whom 9 had a high OCI-flow consistent with ATL-like clonal expansion, and 10 had low OCI-flow (<0.770). Flow-sorting was used to isolate hyper-expanded ATL-like clones based on the immunophenotype CD3+CD4+CCR4+CD26-TCRVβX+ (representing the major clone) as well sorting fractions CD3+CD4+CCR4+CD26-TCRVβOther (infected polyclonal cells), CD3+CD4+CCR4-/CCR4+CD26+ cells (uninfected populations- termed 'other CD4+') and CD33/19+ (germline) cells. RNA was extracted from all flow-sorted populations for sequencing (RNA-Seq). DNA was extracted from CD33+/19+ cells for whole exome sequencing (WES). TCRα and -β complementarity-determining region 3 (CDR3) sequences were extracted and analysed with MiXCR software. Variant calling was performed using Mutect2 using paired RNA ('tumor') and DNA from CD33/CD19+ cells ('normal') samples. Differential gene expression was performed using DeSeq2. Results: Presence of a hyper-expanded major clone in high OCI samples was confirmed by analysis of CDR3 sequence diversity. Two of the nine subjects with a major clone also had an additional 'minor’ hyper-expanded T cell clone within the HTLV-1 infected polyclonal cell population. Eight of nine major clones (89%) harbored at least one mutation in a gene reported to be frequently mutated in ATL (VAF > 0.1, median 1 mutation, range 0-4). Both minor clones also harbored mutations in ATL driver genes. In total, sixteen mutations in genes that are frequently mutated in ATL were identified (Figure 1). These included mutations in CSNK2B (n =2), PRKCB (n =2), and CIC (n = 2) and CCR4 (n =1). Three subjects had mutations in a gene in the T-cell receptor/nuclear factor kappa B (TCR/NFkB) pathway, and all three subsequently transformed to ATL (median time since first detection of mutation(s) = 5.2 months). No other subject has yet transformed to ATL. There were no mutations detected in genes that are frequently mutated in ATL in any subject with low OCI-flow. Differential expression analysis demonstrated similarity in patterns of gene expression between major clones and ATL cells, and were distinct from patterns observed in infected polyclonal populations. Most differentially expressed genes in major clones were downregulated relative to uninfected CD4+ cells, and the majority (58%) of downregulated genes were downregulated in major clones compared to other HTLV-1 infected cells. Gene ontology analysis of differential gene expression in major clones showed enrichment of ATL-related pathways as well as suppression of pathways in lymphocyte differentiation and immune receptor activity. Conclusions: High proviral load HTLV-1 carriers with high OCI-flow cytometry scores carry hyper-expanded T cell clones with mutational and transcriptomic profiles that resemble ATL prior to transformation. TCR/NFkB pathway mutations were detected in cases who subsequently developed ATL and may represent a later stage in the transformation process. This offers the potential to identify ultra high-risk HTLV-1 carriers for novel pre-emptive, therapeutic intervention. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

T-Cell Receptor Amino Acid Sequence Selected By Cytotoxic T Cells Specific to HTLV-1 in HLA-A02:01-Positive ATL Patients

Purpose: Adult T cell leukemia/lymphoma (ATL) is an aggressive peripheral malignancy of T cells caused by human T cell lymphotropic virus type-1 (HTLV-1). Its prognosis remains very poor. Tax is the most important regulatory protein for HTLV-1, which is associated with the proliferation of host cells. Tax has been considered as an important target antigen for CD8+cytotoxic T cells (CTLs). We aimed to reveal such a unique sequence of complementarity-determining region 3 (CDR3) of the T cell receptor (TCR)-α and-β chain of HLA-A*02:01-restricted Tax11-19-specific CTLs (Tax-CTL). Methods: We serially analyzed Tax-CTLs from ATL patients with HLA-A*02:01 who had received allogeneic hematopoietic cell transplantation (all-HCT), chemotherapies alone, or had not ever received any treatment. Tax-CTLs were defined as a living CD3+CD8+Tax-tetramer+cells. After sorting Tax-CTLs directly from an actual patient sample into a PCR tube, TCR-α and -β chains of individual CTL clones were determined by the next-generation sequence (NGS) method with SMARTer technology. In addition, we cultured and established individual Tax-CTL clones from a sorted single cell, and finally evaluated the cytotoxicity of Tax-CTLs by calcein-acetoxymethyl (AM)-based cytotoxicity assay. Results: Peripheral blood samples were obtained from 7 patients (Pt-1,-2,-3,-4,-5,-6 and -7). Pt-1 had received allo-HCT and the samples were available 270 days, 1 year, 3 years, 5 years and 7 years after allo-HCT. Samples before treatment were available in the other 5 patient (acute ATL Pt-2,-3, and -6; chronic ATL, Pt-4; HTLV-1 asymptomatic charrier, Pt-5), while the samples after treatment were available in 1 patient (acute ATL Pt-7). Tax-specific CTLs were detected in 0.03-0.58% of total peripheral blood mononuclear cells, and 144-1000 cells per sample (median; 250 cells) were sorted and analyzed for TCR determination. Of them, 2 to 30 Tax-specific CTL clones were identified for each patient. Tax-specific CTLs seemed oligoclonal, and their usage of BV and BJ genes were restricted in TCR-BV28(30.5%), -BV6-5(33.3%), and -BJ2-1(30.5%), while their usage of AV and AJ genes were restricted in TCR-AV12-2(54.5%) and -AJ24(24.2%) gene families. The length of amino acids (AA) in TCR-α and TCR-β CDR3 of all Tax-CTLs clones seemed to be symmetrically distributed, and the most frequently observed AA length was 13 in TCR-α, and 15 in TCR-β. The unique motifs of "DSWGK" in TCR-α and "LAGG" in TCR-β at CDR3 were observed in almost all ATL patients. The 'DSWGK' motif was observed in 0-81.7% (median; 55.5%), and the 'LAGG' motif was observed in 5.2%-80.3% (median; 48%). Pt-2 didn't have any clones with 'DSWGK' motif in TCR-α, whereas regarding 'LAGG' motif in TCR-β, all patients had it in this study. We established Tax11-19-specific CTL clones from a single cell of Pt-4, which showed killing activities against Tax-peptide-pulsed HLA-A2+ T2 cell lines. Conclusion: These methods and results can help us to better understand immunity against ATL, leading to future studies on the clinical application of adoptive T-cell therapies in the future.

Progression of Disease within 5 Months of Adult T-Cell Leukemia-Lymphoma (ATL5) As a Clinical Endpoint for High-Risk Mortality Outcomes in the Real-World Setting: A Multinational Cohort Analysis

Introduction Adult T-cell leukemia-lymphoma (ATL) is an aggressive hematological malignancy associated to poor outcomes. Most of these patients experience a rapid and aggressive disease course characterized by early progression and death. Previous studies have identified clinical and laboratory factors of prognostic value. However, their incorporation in the clinical setting has not been validated due to unstandardized management practices. Risk stratification based on time to progression has not been explored in patients with ATL. Therefore, we develop a clinical endpoint to evaluate whether patients that relapse early have a higher risk of death. Methods We designed a multicenter retrospective cohort study among treated patients with a serological and pathology confirmation of ATL. Included patients with acute or lymphomatous ATL subtypes received systemic treatment (e.g., chemotherapy; zidovudine plus interferon). The training cohort consists of patients from endemic regions treated in tertiary care centers across Latin America and the United States. A validation set of 193 patients from Japan was used for reproducibility. Our exploratory analysis identified that at least 20% of relapsed patients experienced this event within 5 months after diagnosis in both training and validation cohorts. Therefore, we used a 5-month landmark for patients with ATL (ATL5) to define early progression. Median follow-up (reverse Kaplan-Meier) was 48 and 40 months in the training and validation cohorts, respectively. Overall survival was defined from date progression for early-ATL5, and from the 5-month landmark for non-early-ATL5 (reference group). Patients that died without relapse within 5 months (n=62 training, n=54 validation) or those alive with less than 5 months of follow-up time (n=13 training, n=3 validation) were excluded from the analysis. We plotted Kaplan-Meier curves and used the log-rank test to compare groups across the datasets. Univariate and multivariate Cox regression analyses were employed to model the effect of ATL5 on all-cause mortality. Missing values were added as a missing category in the adjusted models. Results Of the 253 patients in the training cohort, 38% (n=96) relapsed within 5 months after diagnosis, and 62% (n=157) did not (reference group). There were 96 (38%) with acute (early-ATL5: n=55, reference: n=41) and 157 (62%) with lymphoma (early-ATL5: n=41, reference: n=116) ATL subtype. The median age at diagnosis was similar between both groups (early relapse: 55 years, reference: 54 years; p=0.831). Patients with early-ATL5 had poor performance status (ECOG 2-4 68% vs. 49%, p=0.009), higher frequency of acute ATL (57% vs. 26%, p<0.001), B symptoms (83% vs. 63%, p=0.034), advanced stage (III-IV 97% vs. 84%, p=0.002), hypercalcemia (51% vs. 35%, p=0.023), and higher values of lactate dehydrogenase (96% vs. 77%, p<0.001). Overall survival at 3 years was poorer among patients with early-ATL5 (12% vs. 30%; p=0.0001; Figure 1A). The univariate Cox analysis identified a hazard ratio (HR) of 2.02 (95% confidence interval [CI] 1.49-2.74) for early progression. After adjusting for ATL subtype, cancer stage, skin involvement, ECOG score, extranodal involvement, and hypercalcemia, patients with early-ATL5 remained with a higher risk of death (adjusted HR: 2.02, 95% CI 1.43-2.86). In the validation cohort, the 23 (12%) patients with early progression were deceased within 18 months after the landmark basal time (Figure 1B). The risk of death was higher among individuals with early-ATL5 in the validation set (adjusted HR: 1.84, 95% CI 1.14-2.95, Figure 1B). Conclusions Patients with ATL who relapse within 5 months after diagnosis had a higher risk of death. Treatment of ATL varies between and within countries, limiting the comparison and validation of current prognostic factors. Therefore, we developed a time-based marker to evaluate the prognosis of these patients. Our findings remain robust in the validation set, suggesting that ATTL5 is a clinically relevant endpoint in the real-world setting. Future studies should validate its applicability in prospective studies and determine its relevance for risk-based treatment in clinical trials. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Adult T-Cell Leukemia/Lymphoma Diagnosed in North American Is Characterized By a Requirement for BCL6 and a Cell Cycle Program Associated with DNA Replication Stress

Adult T-cell leukemia/lymphoma (ATLL) is a rare and aggressive disease of malignant CD4+ T cells that develops in human T-lymphotropic virus-1 (HTLV-1) carriers. Patients diagnosed with ATLL have the worst survival among all peripheral T-cell lymphomas. At the moment, no outcome-changing targeted therapy is available for ATLL highlighting an urgent need for in-depth understanding of its pathogenesis and development of new treatment strategies. We and others have shown that ATLLs diagnosed in the Japanese (J-ATLL) and North American (NA-ATLL) patients have very different clinical behavior, with the NA-ATLL variant characterized by a higher rate of chemo-refractory disease and worse prognosis. Differences are also seen in the somatic mutation patterns and responsiveness to an immune checkpoint blockade therapy, Nivolumab. To explore additional aspects of ATLL biology where NA-ATLL and J-ATLL may exhibit distinct characteristics, we examined immunophenotypic features of 5 J-ATLL cell lines and cultures from 7 NA-ATLL patients using a panel of 17 flow cytometry markers. Our results show that, while the J-ATLL cell lines have a surface marker profile resembling classic regulatory T (Treg) cells, NA-ATLL samples are more similar to follicular T regulatory (Tfr) cells. This conclusion is also supported by GSEA analysis of of bulk RNA-seq. Consistent with a Tfr-like phenotype, NA-ATLL samples are characterized by more frequent expression of PD-1 and variable levels of BCL6. We also detected BCL6 in patient biopsy samples by IHC. Interestingly, although some J-ATLL cell lines express BCL6 as well, only NA-ATLL but not J-ATLL cell lines are sensitive to the BCL6-specific inhibitor FX1. Inactivating BCL6 by either FX1 treatment or siRNA-mediated BCL6 knock-down in NA-ATLL cells triggered rapid activation of the DNA damage response and death of S phase cells. These results suggest that in transformed NA-ATLL cells, BCL6 promotes survival by suppressing replication stress. Our experiments also demonstrate that compared to J-ATLL cell lines, NA-ATLL cell lines are more sensitive to S phase-targeting drugs including Wee1i (AZD-1775), ATRi (AZD-6738), and PARPi (Olaparib). These results support the concept that the cell cycle S phase is an Achilles’ Heel of NA-ATLL cells and an attractive therapeutic target. In summary, despite the involvement of the same HTLV-1 subtype (HTLV-1a) in ATLLs diagnosed in Japan and North America, these two ATLL variants have distinct features in clinical behavior, mutational landscape, and immunophenotype. Our experiments described here point to additional differences in the cell cycle program and roles played by BCL6. Further studies are needed to fully characterize the cellular phenotype of NA-ATLL and develop S phase-based targeting strategies to treat this devastating disease.

The Cause and Consequence of Replication Stress in Adult T-Cell Leukemia

EP300 and its homolog CBP are transcriptional co-activators of genes involved in a broad range of cellular processes, including proliferation, differentiation, apoptosis and DNA repair. Inactivating mutations in both EP300 and CBP have been reported in developmental disorders, such as Rubinstein-Taybi Syndrome, and several hematological malignancies. Most recently, somatic hypermutations in EP300 (but not CBP) were identified in Adult T-cell leukemia/lymphoma (ATLL) patients, diagnosed in Northern America. The mechanistic contribution of EP300 dysregulation to NA-ATLL etiology is currently unknown. ATLL is caused by infection by the Human T-cell Lymphotrophic Virus Type-1 (HTLV-1), that is endemic to Japan, the Caribbean basin, South America, southern parts of North America, Eastern Europe and certain areas of Africa. Unlike patients diagnosed in Japan (J-ATLL), NA-ATLL patient display a severe case of chemo-refractory disease with very poor prognosis. While prominent differences in the transcriptional and epigenetic landscape, particularly the p300 mutational status, has been identified between J-ATLL and NA-ATLL patients, the mechanistic contribution of p300 dysregulation to disease severity is yet to be established. Studies have revealed that the independent inhibition of EP300 in human cells results in a unique transcriptional landscape, involving the differential expression of genes involved in regulating the cell cycle, DNA replication and DNA damage response. Here, we show that EP300-mutated ATLL cells display a protracted S-phase, extensive genomic instability, dysregulations in DNA replication and repair dynamics. Using a powerful locus specific single molecule assay and genome-wide DNA fiber analysis, we show that perturbed DNA replication in EP300-mutated ATLL cells is characterized by elevated origin firing, increased replisome pausing and prominent nucleolytic degradation of nascent DNA at collapsed forks. The elevated origin firing in the absence of EP300 is likely driven by the inherent endogenous increase in c-MYC expression, which has been previously seen in EP300-mutated MCF7 cells. The striking replication pausing, fork collapse and nascent strand degradation observed in EP300-deficient NA-ATLL cells results in the persistence of single stranded DNA (ssDNA) genome-wide, resulting in the hyperphosphorylation of RPA at Ser4/8. Inhibition of Mre11 nuclease partially rescued the ssDNA accumulation indicating a dysregulation in downstream mechanisms that restrain nuclease activity at stalled forks. Elevated endogenous genomic instability, observed in ATLL cells during the S-phase is exacerbated by EP300 deficiency, even in the absence of exogenous stress/damage. Analysis of the consequences of S-phase abnormalities and genomic instability revealed elevated micronuclei and cytosolic DNA in ATLL cells exposed to DNA damage. Preliminary studies evaluating the innate immune system activation (cGAS-STING-pIRF3) by immunoblotting, in response to stress, has led to some intriguing results. There is a clear separation in the ability of J-ATLL versus NA-ATLL cells in activating the innate immune system, a response that appears to be EP300 independent. These results raise the possibility of the contribution of a suppressed innate immune response, a phenomenon seen in many fast-progressing cancers, to the etiology of NA-ATLL. In addition to increasing our understanding of the mechanisms contributing to ATLL in general, the results from this study have helped identify new mechanism-based treatment regimens that could target the replicative and innate immune system vulnerabilities observed in North American ATLL patients.

Allogeneic but Not Autologous Stem Cell Transplantation Improves Outcome in HTLV-1-Associated North American Adult T-Cell Leukemia/Lymphoma

Background: Adult T-cell leukemia/lymphoma (ATLL) is a rare mature T-cell malignancy driven by the human T-cell lymphotropic virus type I (HTLV-1) that remains challenging to treat and is associated with a dismal prognosis. While some reports have shown encouraging results with allogeneic stem-cell transplantation (allo-SCT), data remains scarce and mostly limited to Japanese patients. Patients and Methods: This is a retrospective single center analysis with 100 HTLV-1-associated North American ATLL patients. Variables collected included age, sex, ethnicity, CMV/HTLV1 serologies, karnofsky performance score (KPS), diagnosis date, disease subtype, number of prior therapy lines, transplant type, status at transplant, transplant date, prior SCT, donor sex, CMV/HTLV1 serologies, stem cell source, donor type, in-vivo T-cell depletion, engraftment, conditioning regimen, GVHD prophylaxis, maximum acute and chronic GVHD grade, relapse date when applicable, and main cause of death. The Kaplan-Meier method was used to calculate overall survival (OS) and progression-free survival (PFS). Cumulative incidence functions were used to estimate relapse incidence (RI) and non-relapse mortality (NRM) in a competing risk setting. Death and relapse were considered as competing events for acute and chronic GVHD. Univariate analyses were done using the Gray's test for cumulative incidence functions and the log rank test for OS and PFS. A Cox proportional hazards model was used for multivariate regression, results were expressed as hazard ratio (HR) with a 95% confidence interval (CI). All tests were two-sided, type-1 error was fixed at 5%. Results: One hundred patients met eligibility criteria, 18-87 years old, 69 of which were Black, 27 Hispanic, and 2 of Asian descent. Sixty-seven patients had acute ATLL and 22 lymphomatous. In total, 22 patients underwent SCT with 17 allo-SCT and 5 autologous SCT (ASCT) between 2005-2020 with a median follow-up of 62 months. Ten patients (45%) were transplanted in first complete remission (CR1), and 15 (68%) had KPS ≥90. Among patients undergoing allo-SCT, 41% had matched sibling donors (MSD), 18% matched unrelated (MUD), and 35% haploidentical. The 1-year and 3-years rates of overall survival from diagnosis of the cohort were 42% and 21%, respectively. Acute ATLL subtype was a strong predictor of worse outcome (Figure 1) with 1-year and 3-years OS of 32% vs 71% (p=0.004) and 11% vs 46% (p=0.002), respectively, compared to lymphomatous disease. To account for immortal time bias, 37 non-transplanted patients with early mortality within 4 months of diagnosis that were not able to make it to transplant were excluded from the Kaplan-Meier survival analysis. Patients undergoing transplant had improved outcomes compared to non-transplanted patients (Figure 1, Table 1), with allo-SCT reaching statistical significance in multivariate analysis compared to the non-transplant group with OS HR of 0.3 (p=0.004) compared to 0.7 (p=0.6) in ASCT vs non-transplant. In transplanted patients, the 3-year RI and NRM were 51% and 37%, respectively, and 3-year PFS and OS were 31% and 39%, respectively. Four of five patients who received ASCT rapidly relapsed with 3 dying from disease progression and one lost to follow-up, with 1-year RI of 80% vs 30% in allo-SCT (p=0.03). In exploratory multivariate analysis, patients achieving CR1 and with good baseline performance scores (KPS >90) had significantly better outcomes compared to their counterparts regardless of transplant type, and surprisingly, race was a strong and significant predictor of outcomes affecting PFS and OS with Hispanic vs Black PFS and OS HRs of 6 (p=0.04) and 10 (p=0.04), respectively. Thirteen patients died within 2 years, eight from relapse/progression including 3 ASCT patients, and 4 from transplant-related toxicities. Conclusion: Our data suggest that allo-SCT, but not ASCT, is a valid option in select ATLL patients. It also appears that patients of Hispanic descent have worse outcome post-transplant but not overall, which could be explained by lack of compatible donors or barriers to early transplant. Although this is the largest NA-ATLL transplant cohort presented to date outside of Japan and Europe, further studies are necessary to fully explain these discrepancies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical Characteristics and Outcomes of Infection with Human T-Cell Lymphotropic Virus (HTLV) in a Non-Endemic Area: A Single Institution Study

Introduction: The first human oncogenic retrovirus discovered, human T cell lymphotropic virus (HTLV) remains poorly understood. Etiologically associated with adult T-cell leukemia (ATL), HTLV type 1 (HTLV-1) causes lifelong latent infection in CD4+ T cells and is estimated to affect between 5 to 20 million individuals globally. Despite being closely related, HTLV-2 infection has not been casually linked to clinical disease. In recent years, there has been an increased incidence of HTLV in the United States, however, affected patients are often under- and mis-diagnosed. While great strides have been made in understanding the virology, epidemiology, and clinical course of HTLV-1 and HTLV-2 infection, much of our current knowledge of HTLV and HTLV-related diseases is based on research in endemic areas, particularly Japan. We sought to characterize the epidemiology, clinical features, comorbidities, and survival of HTLV-1- or HTLV-2-positive individuals identified in a non-endemic area, using patient information from our academic institution. Methods: Our study was a single institution, retrospective case-control analysis of HTLV-1 or HTLV-2 patients between 1998 and 2020. We utilized two HTLV-negative controls, matched for age, sex, and race, for each one HTLV-positive case. Hematologic, neurologic, and rheumatologic covariates, including viral co-infection, opportunistic illnesses, malignancy, and clinical characteristics, were evaluated as variables affecting overall survival (OS). Results: We identified 38 cases of HTLV infection, of whom 23 were HTLV-1 and 15 were HTLV-2 positive. Median follow up was 39.7 months and median OS was 67.2 months for HTLV-seropositive patients, compared to 49.6 months and 131.2 months, respectively, for HTLV-seronegative patients. HTLV-1 positive patients had lower median OS compared to HTLV-2 patients (47.7 months vs. 77.36 months). During follow-up, 21 of 38 HTLV-seropositive patients died, compared to 33 of 76 HTLV-seronegative patients who died. Underlying reasons for HTLV testing were grouped into eight mutually exclusive categories: transplant evaluation, neurologic deficit(s), hematologic disorder, dermatologic, gastrointestinal, lymphadenopathy, infection, and other/unknown. Notably, the majority (53.9%) of patients in our control group received HTLV testing for transplant evaluation testing, compared to 23.7% of HTLV-seropositive patients. In evaluation of co-morbidities associated with HTLV, hepatitis C seropositivity was higher in HTLV-seropositive patients compared to controls (OR 16.8, 95% CI = 3.4 - 81.8, p < 0.001). There were no cases of HIV infection in our study. In Kaplan Meier analysis, hepatitis C and HTLV co-infection resulted in decreased 1-year and 3-year OS, compared to no infection, hepatitis C infection alone, or HTLV infection alone (Figure 1). Similarly, patients with any cancer diagnosis and HTLV infection had worse 1-year OS compared to patients with cancer or HTLV alone. There was no significance in 1-year OS with other risk factors, including CMV/HTLV co-infection or blood stream bacterial/HTLV co-infection. In univariate analysis, the hazard for 1-year all-cause mortality was increased among patients with HTLV-seropositivity (unadjusted HR 3.4, 95% CI 1.4- 8.2, P = 0.006), ATL (unadjusted HR 4.8, 95% CI 1.8 - 13.3, P = 0.08), AML (unadjusted HR 4.3, 95% CI 1.6-11.9, P = 0.01), and hepatitis C infection (unadjusted HR 3.2, 95% CI 1.2-8.5, P = 0.03) (Table 1). When corrected, multivariate analysis showed that HTLV seropositivity was no longer associated with 1-year all-cause mortality; however association with AML (adjusted HR 10.0, 95% CI 2.8-35.2, P = 0.0003) and hepatitis C infection (adjusted HR 7.0, 95% CI 1.5 - 32.0, P = 0.01) remained significant. Conclusions: HTLV-seropositivity was not associated with increased 1-year mortality in multivariate analysis. Our study is limited by our small patient sample size, as well as the biased patient control population due to HTLV testing. These studies warrant continued evaluation of clinical characteristics and outcomes of HTLV infection in non-endemic regions. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Real World Experience of Combined Treatment with Romidepsin and Azacitidine in Patients with Peripheral T-Cell Lymphoma - a Bridge to Transplant and an Effective Salvage for the Unfit

Introduction Patients with peripheral T cell lymphoma (PTCL) lack good treatment options, particularly in the relapsed and refractory setting (Mak V et al. J Clin Oncol 2013). The development of the targeted therapies in PTCL has been lagging behind those developed for B cell lymphomas. Our work suggested that combination of epigenetic therapies could be a safe and effective approach in PTCL, particularly in T cell lymphomas with follicular helper phenotype (Marchi E et al. Br. J Haematol 2015; O'Connor AO et al; Blood 2019; Falchi L et al. Blood 2020). This could be explained by the presence of recurrent mutations in epigenetic factors, including Ten-Eleven Translocation-2 (TET2), DNA methyl transferase-3A (DNMT3A), and isocitrate dehydrogenase-2 (IDH2). that specifically clusters in PTCL (Couronné L. et al. N Eng J Med 2012; Lemonnier F et al. Blood 2012). Despite these observations, a direct link between presence of the mutations and sensitivity to treatment remain to be established. Objectives To evaluate the merits of romidepsin plus azacitidine in patients with PTCL when administered in a 'real-world’ scenario (both subcutaneous and oral azacytidine). Our phase 2 study of oral azacitidine in combination with romidepsin showed remarkable results and we wanted to evaluate the efficacy of these two drugs in patients who were not enrolled on a clinical study for following reasons: 1) Rarity of PTCL prevents wide availability of clinical studies for this patient population; 2) Enrollment criteria, including performance status, prevent enrollment of all patients who are too frail but could possibly benefit from this treatment; 3) Second synchronous or recent malignancies. Methods We retrospectively identified PTCL patients that were treated with azacitidine and romidepsin outside of a clinical trial based upon queries regarding off study use. The study was reviewed and approved by each Medical Center Institutional Review Board. We have identified 26 patients world-wide and these patients were treated using 4 different schedules: Schedule A: azacitidine 75mg/m2 s.c. on days 1-7, romidepsin 14 mg/m2 on day 1, 8 and 15 of a 28 day cycle (total of 7 patients); Schedule B: azacitidine 75mg/m2 s.c. on days 1-5, romidepsin 14 mg/m2 on day 8, 15 and 22 of a 35 day cycle; Schedule C (6 patients): azacitidine 75mg/m2 s.c. on days 1-7, romidepsin 12-14 mg/m2 on day 8, 15 and 22 of a 28 day cycle (6 patients); and Schedule D (as per Falchi L. et al. Blood 2020, 7 patients). Results In our retrospective analysis we have identified 18 patients who had angioimmunoblastic lymphoma (AITL), 2 with adult T-cell leukemia/lymphoma (ATLL), 3 with TFH PTCL, 1 with PTCL-NOS and 2 with composite lymphoma (TFH PTCL with diffuse large B cell lymphoma and ALK- ALCL with FL). Twelve of the 26 patients had next generation sequencing performed. Most common mutations found were those of TET2 (8 pts), RHOA (4pts), IDH2 (3pts) and DNMT3A (2 pts). Among these 26 patients, overall response rate (ORR) was 73% and the complete response rate (CR) was 53%. Median number of cycles was 3.5 (range 1-12). Treatment was well tolerated and notable adverse effects included nausea, fatigue, rash, neutropenia and thrombocytopenia. One patient experienced febrile neutropenia while another had pulmonary infiltrates (drug toxicity vs. infection). Thrombocytopenia was the most common reason for dose reduction of romidepsin (to 12mg/m2) or its omission on day 8, 15 or 22. Median OS and PFS were not reached and 13.3 months respectively (Figure 1). Median DOR was not reached. In 8 patients, azacitidine and romidepsin were used to achieve remission prior to stem cell transplant (1 auto, 7 allo), with all 7 patients were in CR at their last disease assessment. One patient died of transplant related mortality 8 months after his allogeneic stem cell transplant. Conclusion Subcutaneous azacitidine and romidepsin administered in a 'real-world’ situation is highly effective in patients with relapsed PTCL with tolerable toxicity, and can be used to successfully bridge patients to stem cell transplant and to treat frail patients that would not be candidate for enrollment in clinical trials.. Notably, the efficacy was similar to the one reported on a clinical study with oral azacitidine and romidepsin. A randomized phase 2B trial of romidepsin and oral azacitidine versus investigator's choice in patients with R/R PTCL is currently ongoing and open to enrollment (NCT04747236). Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Durable Clinical Impacts and Mechanisms of Action and Resistance in EZH1/2-Targeting Epigenetic Therapy

Background: Epigenomes allow the rectification of disordered gene expressions, thereby providing new targets for pharmacological interventions in cancer therapy. The clinical utility of targeting histone H3 lysine tri-methylation (H3K27me3) as an epigenetic hallmark has been demonstrated. However, in actual therapeutic settings, the mechanism by which H3K27me3-targeting therapies exert their effects and the response of tumor cells remain unclear. Results and Discussion: We conducted intensive molecular monitoring of three patients enrolled in the valemetostat first-in-human phase 1 clinical trial (NCT02732275) for adult T-cell leukemia/lymphoma (ATL). Valemetostat was administered orally once daily (200 mg/day) until a sign of disease progression could be observed. The number of abnormal lymphocytes (Ably) in these three patients drastically decreased after one week of treatment. All patients could stay on valemetostat single agent for more than 2 years with acceptable safety and durable response. PBMC samples (n = 55) were collected from these three patients immediately before (Pre) and during treatment, as well as during the progressive disease (PD) stage. Flow cytometry-based histone methylation assay demonstrated that tumor H3K27me3 level was generally high in the Pre-samples, but the valemetostat treatment reduced it to a normal level in all patients. In addition, ChIP sequencing (ChIP-seq) could directly assess how valemetostat affects the tumor epigenome. The pre-treatment tumor cells showed an overall increasing trend in H3K27me3. For all H3K27me3 peaks (51,683 peaks), 85.9% of the peak signals decreased at the average fold-change of 0.742 after the valemetostat treatment. Focusing on the gene loci, an overall decrease could be observed around the TSS and across the gene body. The characteristic H3K27me3 clusters initially observed in the tumor cells were demethylated. We also conducted integrative multilayered single-cell analyses (scATAC-seq and scRNA-seq) and showed that valemetostat abolishes the highly condensed chromatin structure formed by the plastic H3K27me3 and neutralizes multiple gene loci, such as tumor suppressor genes (TSGs), in all patients. These results demonstrated that valemetostat sufficiently restored the epigenome of the tumor cells close to the healthy state, leading to clinical improvements. Although all tested cases showed a durable response for more than 2 years, these responses were eventually interrupted due to the recurrence of ATL. We identified characteristic somatic mutations of EZH2 during clonal repopulation at PD. The identified amino acid substitutions were all located at the interface between EZH2 and valemetostat. Direct evaluation of the H3K27me3 level in the PD sample harboring the acquired EZH2 mutation showed that tumor cells in a hypermethylated state were repopulating. The scATAC-seq analysis also showed strong chromatin compaction of the same gene set occurred in the rapidly propagating resistant clone, indicating that the clonally selected mutations should be responsible for resistance. In patients free of the EZH2 resistant mutations, we detected TET2 mutation or elevated DNMT3A expression in the propagated resistant clones. Genome-wide DNA methylation analysis revealed increased DNA methylation near the TSS in the resistant clones. The genes characterized by the H3K27me3-related chromatin condensation were restored by valemetostat treatment but were again strongly re-condensed by mCpG gain at PD. Consequently, the gene regulation of several important TSGs restored by valemetostat was repressed again. Furthermore, in the single-cell platform, we successfully identified subpopulations with distinct metabolic and gene translation characteristics implicated in primary susceptibility until the acquisition of the heritable (epi)mutations. Conclusion: This study illustrates, for the first time, the molecular and cellular dynamics in patients in response to a molecular-targeting inhibitor designed for histone methyltransferases. Eliminating H3K27me3 leads to the reprogramming of the cancer epigenome, thereby exerting a sustained benefit on tumors. Targeting chromatin homeostasis might provide opportunities for further sustained epigenetic therapies.

Clinical Impact of the Intensity of Induction Regimens Prior to Consolidation in Treatment-Naïve Patients with Peripheral T-Cell Lymphoma (PTCL)

Introduction: Frontline treatment of peripheral T-cell lymphoma (PTCL) remains a challenge because, despite good overall response rate (ORR 60-70%) to chemotherapy, more than 50% of patients (pts) relapse quickly and die of their disease. (Mehta-Shah, ASH 2019). Two prospective clinical trials (D'Amore, JCO 2012 - non-randomized study- and Horwitz, Lancet 2019 - randomized) demonstrated improved outcomes by adding Brentuximab Vedotin (BV-CHP) or etoposide (CHOEP) to the cyclophosphamide-vincristine-adriamycine-prednisone (CHOP) backbone in selected PTCL populations. Intensive induction chemotherapy (IIC) regimens commonly used in high grade B-cell malignancies (i.e. HyperCVAD) have also been used in PTCL based on phase I-II trial data (Abramson, Ann Oncol 2014). However, IIC regimens have not been compared to CHOP or CHOP+ (CHOEP/BV-CHP) in prospective studies. Methods: Naïve PTCL treated at Roswell Park Comprehensive Cancer Center between 1997 to 2020 were identified. Pts were divided in three groups based on front-line therapy: CHOP vs. CHOP+ (CHOEP/BV-CHP) vs. IIC (HyperCVAD, ICE). We retrospectively analyzed pre-treatment characteristics, clinical outcomes (overall and complete response rate (ORR, CR), incidence rate ratio of relapse or death within 2 years of treatment (IRR), progression free (PFS), and overall survival (OS) at 5 years) and gross toxicity indices (treatment interruptions unrelated to progression of disease (POD), and causes of death). We used the chi square test and logistic regression to compare categorical variables, the Poisson distribution to compare IRR, log rank to compare time to event curves (PFS/OS). Analysis and graphs were done with SAS and STATA software programs. Results: We identified 151 newly diagnosed PTCL treated at RPCCC. Twenty pts who received palliative therapy or comfort care were excluded from the study. We excluded 6 NK/T-cell lymphoma nasal type (NKTL), 5 hepatosplenic gamma delta TCL (HSTCL) and 1 Adult T-cell leukemia/lymphoma (ATLL) for which CHOP-like regimens are not standard of care. In addition, we also excluded 18 ALK+ Anaplastic large cell lymphoma (ALCL) from the analysis as this good prognosis group exclusively received CHOP or CHOP+, potentially confounding the analysis. A total of 101 pts were included in the analysis representing the following subtypes: angioimmunoblastic T cell lymphoma (AITL) (N=22, 21.8%), PTCL-not otherwise specified (NOS) (N=36, 35.6%), PTCL-with T follicular helper phenotype (TFH) (N=2, 2.0%) or ALK- ALCL (N=41, 35.6%). CHOP was used in 54 pts, 27 received CHOP+ (18 CHOEP, 8 BV-CHP, 1 EPOCH), and 20 received IIC chemo (17 HyperCVAD, 3 ICE). Consolidation with HDC-ASCT was performed in 7 pts after CHOP (14%), 5 pts after CHOP+ (18%) and 8 pts after IIC treatment (40%). Baseline characteristics including sex, age, comorbidities, performance status (ECOG), international prognostic index (IPI) and histology were balanced in the CHOP, CHOP+ and IIC chemo treatment groups, after we excluded ALK+ ALCL as described above (all p values > 0.4). ORR was 69% (61% CR), 86% (81% CR) and 80% (80% CR) in the CHOP, CHOP+ and IIC groups (p=0.3). A multivariate analysis including treatment type, ECOG performance status, Charlson comorbidity score and age did not show any significant correlation with ORR (lowest p value was 0.07 for the Charlson comorbidity score). Incidence rate ratio of progression or death was 3.1, 3.4 and 4.6 per 100-person months respectively for CHOP, CHOP+ and IIC chemo (proportions: 46%, 44%, 60% respectively). PFS and OS did not show significant differences among treatment groups (Log Rank test p = 0.90 for PFS and p = 0.79 for OS). The proportion of treatment interruptions without evidence of POD was 23% in the CHOP, 28% in the CHOP+ and 40% in the IIC group (p=0.31). Of all death events per group, POD was the cause of 43%, 41% and 36% deaths respectively in the CHOP, CHOP+ and IIC groups (p=0.92), death for treatment related toxicity occurred in 21% (CHOP), 41% (CHOP+) and 45% (ICC chemo) of all deaths per group, p=0.19. Conclusions: In our population, the intensity of front-line chemotherapy does not seem to impact on IRR PFS or OS. CHOP+ and IIC might have a tendency towards better ORR and CR rates vs CHOP. However, IIC have a tendency (non-statistically significant) of an increase in adverse events leading to treatment interruptions unrelated to POD and deaths for toxicity. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Clinical Features, Treatment Patterns, and Outcomes Among 837 Patients with Adult T-Cell Leukemia-Lymphoma in the Real-World Setting: A Comparison of Endemic Regions

Clinical Features, Treatment Patterns, and Outcomes Among 837 Patients with Adult T-Cell Leukemia-Lymphoma in the Real-World Setting: A Comparison of Endemic Regions