International Meeting Research Articles

Abstract A24: BTG1 mutations confer a fitness advantage and promote aggressive B cell lymphoma development by lowering the threshold for MYC induction

Abstract BTG1 somatic mutations are exclusively found in mature B cell malignancies, ~12% diffuse large B cell lymphoma (DLBCL) and are particularly enriched in the MCD/cluster 5 subtype of ABC-DLBCL, characterized by extranodal dissemination and poor clinical outcome. However, the mechanism of action and clinical relevance of BTG1 mutations remain unknown. We find that BTG1 mutations score among the top mutations with DLBCL driver potential, using a rigorous genomic and epigenomic covariates analysis. Most notably, BTG1 mutant patients presented with inferior clinical outcome (p=0.0011) in ABC-DLBCL cases from 5 cohorts and BTG1 mutation was independently associated with lower overall survival in a multivariable Cox regression analysis (p=0.0190) DLBCL originates from mature B cells having experienced the germinal center (GC) reaction. We therefore generated a conditional knockin mouse model to express the most frequent Btg1 Q36H in B cells. Btg1 Q36H GC B cells showed a dramatic fitness advantage in in vivo competitive assays. This effect was specific to the GC compartment and was dependent on T cells. RNAseq showed that Btg1Q36H GC B cells were markedly enriched for genes normally transiently induced upon positive selection by T cells, including MYC targets. The same signatures were enriched in BTG1 mutant DLBCL patients and isogenic BTG1Q36H vs BTG1WT human DLBCL cell lines. We observed a higher proportion of MYC-expressing cells in Btg1Q36H GCs without an increase in maximal MYC levels per cell, also confirmed in human DLBCL lines and primary human tonsillar B cells, suggesting a lowered threshold for MYC induction in mutant cells. Mechanistically, ~800 transcripts associated with BTG1WT, but not BTG1Q36H. These belong to the same gene sets that characterize positively selected GC B cell, including MYC itself. BTG1Q36H therefore showed reduced association with the MYC mRNA. We found that this associated with facilitated MYC protein synthesis. Polysome profiling also showed higher translation capacity in BTG1Q36H DLBCL cells. Crossing our Btg1 Q36H mice to the VavP-Bcl2 model showed that VavP-Bcl2+Btg1Q36H mice displayed shorter survival, earlier onset of lymphoma and dysplastic B cell infiltration into non lymphoid organs. Immunoglobulin genes sequencing showed that VavP-Bcl2+Btg1Q36H lymphoma B cells were highly clonal, extensively mutated and selected. Importantly, the lack of BTG1 deletions suggested that BTG1 missense mutations do not cause a full loss-of-function of the protein. Indeed, we observed that shRNA-mediated knockdown of BTG1 resulted in apoptosis. Collectively, BTG1 mutations contribute to the formation of aggressive lymphomas through an entirely novel mechanism, by lowering the threshold to MYC induction in response to T cell selection signals, conferring dramatic fitness. This effect appears to correspond to a partial loss of function disrupting a novel GC context-specific check point, whereby BTG1 normally attenuates spurious MYC translation to tightly restrict fitness potential. Citation Format: Coraline Mlynarczyk, Matt Teater, Juhee Pae, Ling Wang, Jonatan Ersching, Antonin Papin, Darko Barisic, Ersilia Barin, Kenneth B. Hoehn, Zhengming Chen, Diu T. T. Nguyen, Chiara Evans, Ashley S. Doane, Michael G. Kharas, David W. Scott, Gabriel Victora, Ari Melnick. BTG1 mutations confer a fitness advantage and promote aggressive B cell lymphoma development by lowering the threshold for MYC induction [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A24.

Abstract IA26: Understanding CLL and Richter’s syndrome biology through mouse models of human genetics

Abstract Large-scale human next generation sequencing studies have progressively defined the complex genetic landscape of chronic lymphocytic leukemia (CLL) and Richter’s syndrome (RS), yet the difficulties in rapid manipulation of primary CLL cells and the limited availability of cell lines have challenged studies aimed at interrogating the function of the so-called disease “drivers”, defined in human studies through statistical inference. Mouse models represent powerful tools to study mechanisms of normal and malignant B cell biology. Conditional knock-in/knock-out systems have allowed B-cell restricted modeling of CLL genetic lesions, with MDR mice being the first example of a genetically-faithful CLL model, recapitulating the most common genomic aberration of human disease, del(13q). Since then, a series of models generated by our group and others have allowed to uncover key functional changes underlying disease onset and transformation, including in the context of combined mutation in the splicing factor Sf3b1 and the DNA damage response gene Atm, sole mutation in the B cell developmental factor Ikzf3, the nuclear export receptor Xpo1, the ribosomal protein Rps15, and the DNA methyltransferase Dnmt3a (the latter not a CLL lesion per se, but recapitulating disordered methylation patterns typical of CLL). The CRISPR-Cas9 gene editing technology has further enabled B-cell restricted introduction of multiple combinatorial loss-of-function lesions, allowing the generation of faithful models not only of CLL but, importantly, of transformation into RS. In this presentation, I will describe the application of mouse models to studies of CLL and RS pathogenesis and treatment, with a focus on key aspects uncovered through the characterization of genetically- inspired mouse lines of recurrent disease drivers. I will provide a perspective on how these novel models combined with new technology allowed the dissection of mechanisms of disease evolution and response to therapy with greater depth than previously possible, representing valuable platforms for functional genomic analyses. Citation Format: Elisa ten Hacken. Understanding CLL and Richter’s syndrome biology through mouse models of human genetics [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr IA26.

Abstract A40: Evaluation of the tumor microenvironment in mycosis fungoides using the PanCancer IO 360™ assay and nCounter® platform

Abstract BACKGROUND: Alterations in the tumor microenvironment (TME) can result in a “T-cell inflamed” TME, which is characterized by activation of the PD1/PD-L1 pathway, immunosuppression, and production of anergic, “exhausted” CD8(+)-T-cells. Similar alterations in the TME of Mycosis Fungoides (MF) have been linked to disease progression. However, the relationship between progression and the TME in MF remains incompletely understood. We aimed to further study the TME in MF using the PanCancer IO 360™ 750-gene expression panel and nCounter® platform (Nanostring; Seattle, WA). DESIGN: Clinical and laboratory data from the electronic medical record were reviewed in combination with microscopic review of biopsies from 27 patients to confirm diagnosis of MF and assign samples as “low-grade” (patch/plaque; n=8) or “high-grade” (tumor/large cell transformation, n=19). Patients were also classified as having “limited stage” (TNMB1 <1B, n=8) or “advanced stage” (TNMB1 >1B, n=19) disease. All patients received prior, heterogenous treatment, but no patients received prior anti-PD1 therapy. RNA was extracted from formalin-fixed, paraffin-embedded (FFPE), punch biopsy sections and analyzed per manufacturer’s instructions. Gene expression scores (log2) and a “tissue inflammation score” (TIS) were calculated for each sample. A TIS of >5 has been associated with the presence of a “T-cell inflamed” microenvironment. Samples scores were compared by histologic group and disease stage as described above. RESULTS: Twenty-nine of 30 samples had sufficient RNA integrity for analysis. TIS was >5 in 26/30 samples (median, 7.6; range, 4.3-9.3). No significant differences in TIS were identified between low-grade/limited-stage and high-grade/advanced-stage samples. High-grade samples had significantly increased expression of PD1 and higher amounts of exhausted CD8(+)-cells than low-grade samples (p= 0.015, 0.027). Low-grade samples showed significantly higher expression of ARG1, B7-H3, and genes associated with tissue hypoxia. Expression of genes associated with tumor proliferation was higher in high-grade lesions (p= 0.0019). Limited stage samples showed higher levels of endothelial cells, mast cells, and T-regulatory cells (p=0.033, 0.024, 0.004,) than advanced stage samples. Proliferation, PD1, and exhausted CD8 scores trended higher in advanced stage disease but did not reach statistical significance. CONCLUSION: Our findings indicate that the IO 360™ panel provides comprehensive analysis of the TME in MF. Most samples showed a TIS of >5, suggesting a T-cell inflamed TME in MF. Increased PD1 and exhausted CD8(+) cells were found in high-grade lesions, supporting a role for this pathway in progression. Increased expression of factors associated with angiogenesis (endothelial cells, ARG1) and immunosuppression (B7-H3, tissue hypoxia, mast cells, T-regulatory cells) suggest these mechanisms may play a role in early stages of disease. These findings highlight the complex and dynamic nature of the TME during MF progression, and the need for further study. Citation Format: Stanton Miller, Akshat Patel, Kiran A Kumar, Farrukh Awan, Heather W Goff, Travis Vandergriff, Marisa Juntilla, Franklin Fuda, Weina Chen, Jesse M Jaso. Evaluation of the tumor microenvironment in mycosis fungoides using the PanCancer IO 360™ assay and nCounter® platform [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A40.

Abstract A11: The international prognostic score and HIV status predict red cell concentrate transfusion need in Hodgkin Lymphoma

Abstract Background There is a significant burden of anaemia in advanced Hodgkin Lymphoma (HL) in an HIV burdened setting, however there is a paucity of data evaluating red cell concentrate (RCC) transfusion in newly diagnosed HL receiving treatment. We performed a retrospective study to determine predictors of transfusion. Methods Patients 13 years and older consecutively diagnosed with and treated for HL from 2010 to 2019 in Groote Schuur Hospital, University of Cape Town, were retrospectively studied. Patients were staged according to the Lugano classification, with clinical staging according to the National Cancer Comprehensive Network and categorized with both the HL International Prognostic Score (IPS)-7 and the HL IPS-3. Results Two hundred and eighty-five patients received first-line treatment for HL from 2010 to 2019. Patients had a median age of 34.5 years and were predominantly male (62.9%). The HIV prevalence was 39.5% and majority of patients (74.2%) had advanced disease. Bone marrow involvement was confirmed in 41% of cases by trephine examination or PET-imaging; the majority (35%) of these cases the bone marrow appeared to be the primary site with no lymphadenopathy peripherally or on imaging. Primary bone marrow HL was strongly associated with HIV infection. RCC transfusion was observed in 24.6% patients, with significantly more HIV-positive patients (40.4%) transfused than HIV-negative patients (14.1%) (P<0.001). The median number of transfusions for the total cohort was 2 (IQR 1-5). HIV-positive patients received significantly more RCC units (median 3, IQR 2-5) than HIV-negative patients (median 2, IQR 1-3); P=0.035. In univariable logistic regression, each one-point increase in HL IPS-7 was associated with a two-fold increase in the odds of transfusion, while each one-point increase in HL IPS-3 was associated with a two-and-a-half-fold increase in the odds of transfusion. In multivariable analyses, HL IPS-7 and HIV positivity were significantly associated with transfusion after adjusting for B symptoms and ECOG. Similar results were observed after replacing the HL IPS-7 with HL IPS-3. Conclusion The HL IPS-7 as well as HIV status proved to be strong predictors of RCC transfusion need in a newly diagnosed HL cohort in the developing world. The HL IPS-3 consisting of only age, haemoglobin and Lugano stage IV, is equally predictive of transfusion need and simple in use. Lugano stage IV was a surrogate marker for the high (41%) HL bone marrow involvement. Citation Format: Estelle R Verburgh, Kudakwashe Simba, Zainab Mohamed, Jessica J Opie, Karryn Brown, Jenna Oosthuizen, Katherine R Antel, Lillian Andera, Cecile du Toit, Vernon J Louw. The international prognostic score and HIV status predict red cell concentrate transfusion need in Hodgkin Lymphoma [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A11.

Abstract A16: Liquid biopsy for the detection and characterization of canine lymphoma

Abstract Lymphoma is the most common hematologic malignancy in dogs, with some subtypes being highly similar to their human counterparts in terms of molecular, pathologic, and biologic features. Despite the rapid growth in our understanding of canine lymphoma, tools for early detection, personalized therapy, and treatment monitoring are still lacking. Blood-based liquid biopsy using next-generation sequencing (NGS) of cell-free DNA is gaining adoption in human medicine and is now available for canine patients. This non-invasive tool affords new opportunities to profile the genomic landscape of naturally occurring canine lymphomas across large cohorts of patients, and given the high homology (>90%) between human and canine cancer genomes, findings in canine lymphomas may afford unique opportunities for comparative oncology studies for the benefit of both species. One hundred sixteen dogs diagnosed with lymphoma (63 intermediate to large B-cell, 21 intermediate to large T-cell, 6 T-zone, and 26 unphenotyped) were included in this analysis, enrolled as part of a larger liquid biopsy clinical validation study. Lymphomas with inconclusive immunophenotype or other types of indolent lymphomas were excluded. A blood sample was collected from each dog following diagnosis and prior to undergoing therapy to evaluate the ability of liquid biopsy to non-invasively detect the presence and characterize the genomic signature of the cancer. In a subset of patients, longitudinal blood samples and clinical outcomes were also collected. Of all lymphoma-diagnosed dogs, 56% were purebred (representing 32 distinct breeds); 57% were male; median age was 8 years; and median weight was 28.4kg. The overall detection rate for lymphoma by liquid biopsy was 92.2% (107/116); with detection rates of 57% for localized/regional disease (Stages I and II) and 95% for disseminated/metastatic disease (Stages III, IV, and V). By immunophenotype, the detection rate for B-cell lymphoma was 97%, T-cell 91%, T-zone 50%, and unphenotyped 92%. A variety of genomic alterations were identified in patients with positive liquid biopsy results, including single nucleotide variants in common oncogenes and tumor suppressor genes, and copy number variants across the genome (including CNVs previously described in tumor tissue of canine lymphoma patients). In patients with longitudinal samples, the presence or absence of cancer signal appeared to be closely related to remission status at corresponding time points. A novel NGS-based liquid biopsy tool has demonstrated the ability to identify genomic alterations in blood samples of dogs with lymphoma, including alterations previously described in human and canine lymphoma tissue. This technology may also provide a non-invasive method for longitudinal monitoring of treatment response in dogs with lymphoma. These findings, and the high degree of homology between the human and canine disease, support the utility of liquid biopsy for the study of canine lymphoma as a comparative oncology model for accelerated biomarker discovery and therapeutic development. Citation Format: Angela L McCleary-Wheeler, Kristina M Kruglyak, Gilberto E Hernandez, Prachi Nakashe, Lisa M McLennan, Thuy Jennings, Jill M Rafalko, Lauren E Holtvoigt, Daniel S Grosu, Jason Chibuk, Susan C Hicks, John A Tynan, Ilya Chorny, Dana WY Tsui, Andi Flory. Liquid biopsy for the detection and characterization of canine lymphoma [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A16.

Abstract A07: BTM 3566, a novel activator of the mitochondrial stress response promotes robust therapeutic responses in vitro and in vivo in diffuse large B-cell lymphoma

Abstract Relapsed/refractory diffuse large B-cell lymphomas (r/r-DLBCL) are a therapeutic challenge as they are highly heterogeneous both clinically and molecularly, which imposes a pressing need to develop novel therapies to improve outcomes in patients independently of the molecular subtype. We describe here BTM-3566, a first-in-class, orally active compound with activity against DLBCL. BTM-3566 induces apoptosis and complete cell killing in DLBCL lines a with an IC50 of ~200 – 500 nM. Responsive DLBCL cell lines include ABC, GCB, and double-hit and triple-hit lymphoma type. Pharmacokinetic studies in mice showed suitability for once daily dosing, with > 50% oral bioavailability and ~6 hours of serum half-life. In xenograft models using the double-hit DLBCL line SU-DHL-10, BTM-3566 treatment resulted in complete response in all tumor-bearing animals and durable remission in 50% of animals with no tumor growth occurring for 2 weeks after dose cessation. Expansion studies into human DLBCL PDX models harboring a range of high-risk genomic alterations demonstrated response in 100% of the lines with complete response in 6 of 9 PDX models tested. Dose scheduling studies indicate that 7 days of continuous dosing is sufficient to induce tumor regression and maintenance of a complete response. The therapeutic activity of BTM-3566 is related to a novel effect on mitochondrial proteostasis and a robust induction of the ATF4 ISR. Of the four eIF2α -kinases in the human genome we determined that HRI was uniquely required for BTM-3566 activity in DLBCL. HRI is activated by mitochondrial-related stress resulting in activation of the mitochondrial protease OMA1. Molecular analysis revealed that BTM-3566 activates OMA1, leading to induction of the ATF4 ISR pathway and apoptosis in DLBCL cell lines. Deletion of OMA1 reduces the ability of BTM-3566’s to induce apoptosis in DBLCL. Substrates of OMA1 include the dynamin OPA1 and DELE1, a protein recently shown to signal mitochondrial dysfunction through activation of HRI kinase and ATF4. Transfection of BJAB cells with a cleavage resistant OPA1 mutant has no effect on BTM-3566 induced apoptosis. In contrast, DELE1 KO suppresses BTM-3566 mediated apoptosis. BTM-3566 activates OMA1 without acting as a classical mitochondrial toxin. Instead, BTM-3566 induces OMA1 activity through a novel mechanism regulated by the mitochondrial protein FAM210B. FAM210B expression is negatively correlated with response to BTM-3566, and overexpression of FAM210B blocks OMA1 activation and causes complete resistance to BTM-3566 induced apoptosis. Taken together, these data support a novel antitumor mechanism in DLBCL, where BTM3566 induces mitochondrial stress, activating the OMA1-DELE1-HRI-eIF2a-ATF4 pathway leading to apoptosis and tumor regression. An Investigational New Drug application for BTM3566 in B-cell malignancies will be submitted in Q2 2022 with initiation of first in human clinical trials planned for fall 2022. Citation Format: Adrian Schwarzer, Matheus Oliveira, Marc-Jens Kleppa, Andy Anantha, Alan Cooper, Mark Hannink, Todd Hembrough, Jedd Levine, Michael Luther, Michael Stocum, Linsey Stiles, Marc Liesa-Roig, Matthew Kostura. BTM 3566, a novel activator of the mitochondrial stress response promotes robust therapeutic responses in vitro and in vivo in diffuse large B-cell lymphoma [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A07.

Abstract A26: SOX11 drives B1a lineage commitment and B1a/MCL-like lymphoma formation in mice

Abstract Mantle cell lymphoma (MCL) is a highly aggressive B cell lymphoma that accounts for 6% of all non-Hodgkin lymphomas and is characterized by abnormal proliferation of mature antigen- naive B lymphocytes. Despite recent advances in patient risk stratification, MCL remains incurable due to frequent relapses and resistance to therapy. SOX11 is a key transcription factor in the pathogenesis of MCL and is highly expressed in conventional MCL, but it is not expressed in the normal B cells or in the indolent leukemic nonnodal MCL subtype. Although SOX11 was identified as crucial oncogene that supports maintenance of MCL, its role in the initiation of MCL remains largely unknown. Here, we developed a novel mouse model for condition overexpression of SOX11 and a eGFP reporter and found that elevated levels of SOX11 in B-cells are sufficient to drive MCL-like lymphomas in mice. Moreover, SOX11 expression synergized with loss of p53 and overexpression of Ccnd2 to form aggressive MCL-like CD19+CD5+CD23−IgM+IgD+ lymphomas, with a median survival of 314 (p53Mb1 ; n=11), 165 (SOX11/p53Mb1 ; n=19), and 134 (SOX11/Ccnd2/p53Mb1 ; n=15) days. These SOX11-driven lymphomas show transcriptional, immunophenotypic and functional similarities with both murine B1a cells and MCL patients. SOX11 overexpression skews B-cell development towards the B1a and marginal zone B-cell lineage and it block B2-cell development at the Pro-B and Pre-B cell stage, which coincides with onset eGFP that is a measure of expression of Cre and SOX11. In contrast to cyclin D2-driven MCL-like model, SOX11 is inducing a pre-lymphoma stage, in which there is a progressive accumulation of B1a cells in peripheral blood, peritoneal cavity, spleen and bone-marrow. The pre-lymphoma B1a cells have a BCR repertoire which was biased towards binding of self-antigens, such as phosphatidylcholine, and have increased BCR signaling activity. To prove that embryonic-derived B1a cells were the cell-of-origin of SOX11-driven MCL-like lymphoma, we transplanted CD19+ B-cells from SOX11/p53Mb1 fetal livers into secondary recipients and found that these embryonic cells could give rise to MCL-like lymphomas. Next, we wanted to determine how SOX11 is inducing the pre-lymphoma phase, either by expanding existing B1a cells, having a developmental bias towards B1a cells, or by the ability to reprogram B2-cells towards a B1a cell fate. Therefore, we crossed SOX11/p53 mice with a tamoxifen-inducible CreERT2 line and transplanted different sorted B1 and B2 subsets after a short tamoxifen induction ex vivo in immunocompromised mice. We found that SOX11 OE can redirect mature B2 cells to form B1a/MCL lymphomas. Overall, SOX11 is a key B1a lineage factor in mice and its aberrant expression is leading to the formation of MCL-like lymphomas in mice. Citation Format: Tim Pieters, Steven Goossens, Pieter Van Vlierberghe. SOX11 drives B1a lineage commitment and B1a/MCL-like lymphoma formation in mice [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A26.

Abstract A20: Treatment of elderly patients with Peripheral T-Cell Lymphoma (PTCL): A single institution experience

Abstract Introduction: While standard treatment for younger patients with PTCL is chemotherapy and HD consolidation with stem cell rescue, treatment of o lder patients with PTCL is less defined, due to lack of clinical trial data and comorbidities due to ageing. Here we detail our single center outcomes of patients who were 70 years of age or older. Methods: We retrospectively reviewed the clinical characteristics, treatment used and outcomes of patients 70 years of age or older who were treated at Roswell Park Cancer Center for PTCL between 1/1/2001 to 12/31/2021. The patients were divided into three groups, group 1 received single agent therapy, group 2 received multiagent chemotherapy and group 3 received palliative radiation or no therapy. The baseline characteristics were described using descriptive statistics and survival were compared using Kaplan Meier method. Results: Forty elderly T cell lymphoma patients were treated at our center. The median age of whole cohort was 77 years, with 24 males and 16 females. Thirty patients had stage 3/4 disease at the time of diagnosis. The most common diagnosis were ALK -ve ALCL (n=14) and AITL (n=14), while ten patients had PTCL-NOS, and one patient had ALK +ve ALCL and PTCL-TFH each. Seven patients received single agent treatment (G1, n=7), of which six received brentuximab while one received lenalidomide. Twenty nine patients received multiagent treatment (G2, n=29), of which 22 patients received CHOP/CHOEP based therapy, 4 reveived HyperCVAD, and 3 received other chemotherapy treatments. Four patients received no treatment or palliative radiation only (G3,n=4). The patients in G1 were older (median age 85 years), compared to G2 (median age 74 years) and G3 (median age 75 years). The median ECOG of G1, G2 and G3 were 2, 0 and 1 respectively. The ORR of patients in G1 and G2 was 6/7 and 18/29 with CR of 4/7 and 14/24 respectively. Three patients in G2 died due to complications related to induction chemotherapy. Only two patients received autologous transplant after multiagent therapy, none of patients in G1 received an autologous transplant. The median overall survival of patients in G1, G2, and G3 was 25 months, 31 months and 2 months respectively, with no statistically significant difference between G1 and G2 (p=0.63). The median progression free survival of G1 and G2 was 27 months and 14 months (p=0.7). Conclusions: Older patients with T-cell lymphoma can be treated with personalized treatment based on comorbidities and performance status. We found that single agent treatment in selected group of patients produced statistically similar PFS and OS as multiagent treatment. Citation Format: Muhammad Salman Faisal, Gabrielle Hartman, Francisco Hernandez-Ilizaliturri, Sucharita Sundaram, Pallawi Torka, Paola Ghione. Treatment of elderly patients with Peripheral T-Cell Lymphoma (PTCL): A single institution experience [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A20.

Abstract A37: Single-cell RNA sequencing reveals that childhood classical Hodgkin Lymphoma resembles normal inflammation except for T cell exhaustion

Abstract Cure rates of classical Hodgkin Lymphoma (cHL) in children and young adult patients currently exceed 90%. Nonetheless, survivors are confronted with chronic therapy-related health conditions such as infertility, cardiovascular disease, and high rates of novel second cancers. This calls for development of new targeted and less toxic treatments. cHL is characterized by a low frequency (~0.1-5%) of malignant Hodgkin Reed-Sternberg (HRS) cells, while most of the tissue is composed of nonmalignant immune cells. It is thought that the HRS cells depend on interactions with the tumor microenvironment (TME) for their survival. Indeed, a vast number of interactions between different immune and HRS cells have been reported; however, most of these reports are based on immunohistochemistry or in vitro studies. Here, we systematically characterized the in vivo interactions by applying single-cell RNA sequencing (scRNAseq) to nine primary pediatric and adolescent cHL biopsies and three noncancerous control biopsies of reactive lymph nodes. With scRNAseq, we first sorted live cells to get an unbiased overview of the TME. Then we used a previously published flow cytometry antibody panel to enrich for HRS cells, allowing us to directly assess interactions on a per-tumor basis. Tumor cell identity was confirmed by marker expression as identified by pathology, single-cell copy-number status and the ratio of immunoglobulin kappa/lambda expression. Immune cell identity was determined by canonical marker expression. Using the scRNAseq data, we found that the TME expression profiles in cHL and control biopsies mostly overlap but harbor some differences. First, we identified genes that are consistently overexpressed in HRS cells. These included transcription factors, neural markers, multiple interleukins and other signaling molecules. Second, the extensively described immunosuppressive interactions between HRS, T and NK cells (expressing CTLA-4, TIM-3, and LAG-3) were the strongest and most common interactions that we could identify in HL but not in noncancerous reactive lymph nodes. Third, while the inflammation in the reactive lymph nodes was driven by IFN-g signaling, this pathway was inactive in HL tumors. Other interactions like recruitment of CXCR3+ and CCR4+ T cells, CD47 signaling and interleukin signaling were less pronounced in cHL compared to the controls or were less consistent between tumors. These findings were validated in bulk RNA sequencing of 45 HL tumors. A model arises in which the presence of HRS cells induces inflammation that in most ways resembles lymph node infections. This inflammation and HRS survival are controled by patient-specific interactions between HRS cells and the TME, and by T cell exhaustion, which is universal and the most essential interaction in cHL. Citation Format: Jurrian K. de Kanter, Thanasis Margaritis, Auke Beishuizen, Marijn Scheijde-Vermeulen, Liset Westera, Arianne M. Brandsma, Ruben van Boxtel, Friederike Meyer-Wentrup. Single-cell RNA sequencing reveals that childhood classical Hodgkin Lymphoma resembles normal inflammation except for T cell exhaustion [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A37.

Abstract A12: Pervasive hypermutation of super-enhancer regions dysregulates oncogene expression in diffuse large B-cell lymphoma

Abstract Coding-genome sequencing efforts have identified several genes/pathways altered in Diffuse Large B-cell Lymphoma (DLBCL), including new potential therapeutic targets. However, the mutational contribution of the non-coding genome of DLBCL remains largely unexplored. To identify functionally relevant non-coding mutations targeting regulatory domains, we integrated enhancer (E)/super-enhancer (SE) identification, by ChIP-seq analysis of the hallmark H3K27 histone mark, with whole genome sequencing (WGS) and RNA-seq analysis in 29 DLBCL cell lines representative of the major DLBCL subtypes, along with germinal center (GC) B cells representing the normal counterpart of DLBCL. Following validation in 93 normal/tumor DLBCL biopsies, we found that active SEs are specifically hypermutated (≥3 somatic mutations/Kb) in 99% of DLBCLs, as compared to the same loci when not active as SE (in total, 159 hypermutated SEs, with at least 2/case). As evidence of oncogenic relevance, we have shown that the hypermutated SEs linked to the BCL6 and BCL2 proto-oncogenes prevent the binding and transcriptional downregulation by transcriptional repressors. Genetic correction of selected mutations using the CRISPR/Cas9 technology restored repressor DNA-binding, downregulated target gene expression, and led to the counter-selection of cells harboring corrected alleles, indicating oncogenic dependency from the SE mutations. A third recurrently hypermutated SE was the CXCR4-SE, affected in 19% of cases. CXCR4 encodes for a G-protein coupled chemokine receptor involved in cell migration within the GC, and is mutationally activated in 40% of Waldenström macrobulinemia (WM), a post-GC lymphoproliferative disease. We identified a mutational hotspot preventing the binding of the NR3C1 glucocorticoid receptor in 7.5% of DLBCL cases. Correction of the mutations in cell lines led to counter selection and reduced expression of CXCR4. Conversely, the introduction of a mutation disrupting NR3C1 binding in WT DLBCL cells increased CXCR4 expression. Together, these results are consistent with dependency of the mutant cells on the CXCR4-SE mutation, and confirm a direct link between SE mutations in this region and deregulated gene expression through escape from NR3C1-mediated suppression. In primary cases, mutations in the NR3C1 binding site of the CXCR4-SE were observed in the absence of NR3C1 coding mutations and correlated with increased CXCR4 transcript levels, as documented by RNA-seq. Together with the oncogenic role of CXCR4 in WM, these findings reveal this chemokine receptor as a potential oncogenic target in DLBCL. Collectively, these findings reveal a new layer of genetic alterations, which identifies novel mechanisms of dysregulation for known oncogenes, as well as new dysregulated genes and pathways, with implications for precision classification and therapeutic targeting of DLBCL. * Co-senior authors. Citation Format: Elodie Bal, Rahul Kumar, Mohammad Hadigol, Antony B. Holmes, Laura K. Hilton, Jui Wan Loh, Kostiantyn Dreval, Jasper Wong, Sofija Vlasevska, Clarissa Corinaldesi, Rajesh Kumar Soni Soni, Katia Basso, Ryan D. Morin, Hossein Khiabanian, Laura Pasqualucci, Riccardo Dalla-Favera. Pervasive hypermutation of super-enhancer regions dysregulates oncogene expression in diffuse large B-cell lymphoma [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A12.

Abstract A39: Targeting tumor-microenvironmental dependencies as a therapeutic approach in Chronic Lymphocytic Leukemia (CLL)

Abstract Interaction between CLL and its microenvironment is a major factor in drug resistance. Bone marrow derived stroma cells provide a protective and supportive niche to allow CLL cells to survive drug-induced apoptosis. Therefore, a current challenge is to develop new strategies to target the microenvironment. To understand the role of tumor microenvironment in CLL survival, we studied conditioned media (CM) derived from NKTert cells. Human NKTert stroma cells provide a survival advantage to primary CLL cells by protecting them from spontaneous apoptosis in ex-vivo culture. We identified three cytokines (IL6, IL8 and CCL2) from CM as candidates for mediating survival. We exposed CLL cells to neutralizing antibodies against each cytokine and found significant decrease in CLL viability in presence of anti-CCL2 suggesting its role in CLL survival. BH3 profiling revealed an increase in apoptotic priming with anti-CCL2 treatment as well. Using dynamic BH3 profiling (DBP), we found that anti-CCL2 increased dependence on BCL-2 as well as BCL-xL in primary CLL cells suggesting a potential role of CCL2 on CLL survival. To our surprise, we also identified a CLL group (CM independent, CMI) that were resilient to cell death in the absence of stroma support in ex-vivo culture. In addition to this, anti-CCL2 antibody showed no effect on their survival. Next, we exposed CMI CLL cells to venetoclax and found that these CLL cells were less sensitive to apoptosis compared to the CLL samples that are stroma dependent (CM dependent, CMD). BH3 profiling showed that CMI CLL cells are less primed for apoptosis. Consistent with our findings, DBP with anti-CCL2, venetoclax or the combination didn’t increase any drug induced apoptotic priming in CMI CLL samples. In our study, 80% of CMI harbor unmutated IgHV. To provide additional insight to the molecular mechanism, we performed western blot analyses for BCL-2 family proteins and found decreased BAX ad BCL-2 expression in CMI samples. This result suggests altered BCL-2 family proteins expression might be a mechanism for differential priming. Bulk RNA seq analysis revealed upregulation of focal adhesion genes and Ras signaling pathway in CMI samples. In summary, our study suggest that in the CMD subset of CLL, anti-CCL2 therapy enhances apoptotic priming and venetoclax efficacy. Furthermore, we have also functionally defined two biologically distinct CLL subgroups based on stroma dependence. Citation Format: Salma Parvin, Aditi Aryal, Shanye Yin, Matthew S. Davids, Geoffrey G. Fell, Catherine J. Wu, Anthony Letai. Targeting tumor-microenvironmental dependencies as a therapeutic approach in Chronic Lymphocytic Leukemia (CLL) [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A39.

Abstract A09: Telomerase activity as a biomarker to predict outcomes of CAR T-cell therapy

Abstract Introduction: Chimeric antigen receptor T-cells (CAR T-cells) and T-cells in general, remain in a quiescent state when unstimulated, showing no proliferative activity. In contrast, upon specific antigenic stimulation, CAR T-cells rapidly divide and kill their target cancer cells. However, one of the immunologic changes with aging is the progressive impairment of T-cell responses. This physiologic immunosenescence is associated with the shortening of telomeres. The telomerase enzyme is transiently upregulated in stimulated CAR T-cells preventing dramatic telomere shortening during rapid CAR T-cell division. Our previous study showed that during T-cell expansion, the period during which telomerase is active and the magnitude of its activity correlates with the donor’s age and overall health status (“healthy aging”) [1]. The aim of this study is to investigate whether the magnitude of telomerase activity in stimulated CAR T-cells is a predictive biomarker of outcomes in patients receiving CAR T-cell therapy.Methods: The study population comprises of older adult patients (age range: 50-84 years) receiving autologous anti-CD19 CAR T-cell therapy for relapsed or refractory diffuse large B-cell lymphoma, mantle cell lymphoma or follicular lymphoma. Peripheral blood samples are collected from patients pre-lymphodepletion and T-cells isolated from PBMCs (peripheral blood mononuclear cells). CAR T-cells are then generated from patient T-cells in the lab and telomerase activity analyzed over 2 weeks in culture. For each patient’s CAR T-cells, absolute values of telomerase activity are plotted to calculate the area under the curve (AUC). We are investigating the potential correlation of AUC of telomerase activity to disease response at 30- and 90-days post CAR T-cell infusion. Results: Preliminary data from eight patients is showing a clear correlation between telomerase activity and patient outcomes. Robust telomerase activity shows a positive correlation with complete responses on day 30 PET-CT scans and sustained clinical remission, while poor telomerase activity correlates with no response or progressive disease. We are expanding our study sample to 30-50 patients and updated data will be presented at the meeting. Conclusions: CAR T-cell therapy has been a game-changer for hematological malignancies; however therapeutic resistance and disease relapse remains a major concern. Understanding the mechanisms of resistance to CAR T-cell therapy is critical for advancing the field. Telomerase activity levels could be a potential predictive biomarker for CAR T-cell therapy outcomes and aid in personalizing treatment choices. Furthermore, future research on increasing telomerase activity may enhance CAR T-cell therapy function and ultimately patient outcomes. [1] Tedone et.al, Telomere length and telomerase activity in T cells are biomarkers of high-performing centenarians, Aging Cell, 2019 Citation Format: Mohammed E Sayed, Enzo Tedone, Emily Zhang, Helen Stephens, Farrukh T Awan, Jerry Shay, Praveen Ramakrishnan Geethakumari. Telomerase activity as a biomarker to predict outcomes of CAR T-cell therapy [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A09.

Abstract A27: Impact of a validated composite comorbidity score on outcomes in patients treated with CAR T-cell therapy for diffuse large B cell lymphoma (DLBCL): A multicenter real-world evidence (RWE) study

Abstract Introduction: CAR T-cell therapy (CART) has dramatically improved outcomes for patients (pts) with relapsed/refractory (r/r) DLBCL, but the majority of pts still have poor outcomes due to progressive disease and toxicities. Here we used a machine learning algorithm to rank the prognostic impact of specific comorbidities measured by the Cumulative Illness Rating Scale (CIRS) in DLBCL pts indicated for CART in a multicenter learning cohort (LC) and a separate validation cohort (VC). Methods: pts with r/r DLBCL included in RWE analysis underwent leukapheresis for CART at 10 academic centers. CIRS was assessed at the time of T-cell collection (Salvi et al, 2008). Progression-free survival (PFS) and overall survival (OS) were measured from T-cell collection. Random survival forest (RSF) modeling of PFS and OS was repeatedly applied to random subsets of the LC to determine the most important CIRS categories and comorbidity levels in the presence of known prognostic factors. Cox proportional hazards models of PFS and OS were fit to both cohorts. Associations between comorbidities and CART adverse events were evaluated with Fisher’s exact test. Results: The LC comprised 577 pts, median age of 63 (range, 19-90); 90% had ECOG 0-1. Median number of prior therapies was 3 (range, 1-11). GCB subtype was found in 54% of pts, with 38% non-GCB and 8% unknown. Twenty-seven pts (4.7%) died before CART infusion. Of the 550 pts who received CART, 71% got axicabtagene ciloleucel, 22% tisagenlecleucel, and 7% lisocabtagene maraleucel. The median CIRS score was 7 (range, 0-25) with 54% having CIRS ≥7. The median PFS was 11 months (95% CI: 8 – 15) and OS 30 months (95% CI: 23 – NA), with a median follow-up time of 20 months. Although CIRS ≥7 was significantly associated with PFS (HR=1.26) and OS (HR=1.35) in univariable analysis, it did not remain significant in multivariable models. According to a RSF tree depth-weighted nodal split score, severe comorbidities in the following CIRS categories had the greatest impact on PFS: respiratory, upper GI, renal, and hepatic (denoted Severe4, 9% of pts). When accounting for other significant variables, Severe4 was independently associated with inferior PFS (HR=2.45, p<0.001) and OS (HR=2.30, p<0.001) in the LC. This finding was recapitulated in a single-center VC (n=218, median follow-up of 35 months, median age 61 years, median of 3 prior therapies, ECOG 0-1 in 74%, Severe4 in 16% of pts, 98% receiving axicabtagene ciloleucel) as Severe4 remained independently associated with inferior PFS (HR=1.84, p=0.003) and OS (HR=1.82, p=0.007). Pts with Severe4 also had a higher rate of grade ≥3 CRS (16% vs 6%; p=0.013), while development of grade ≥3 ICANS was associated with CIRS ≥7 (26% vs 12%; p<0.001).Conclusions: In this large RWE study, we identify and validate a composite index comprising four organ systems (respiratory, upper GI, renal and hepatic; Severe4) that correlates with survival outcomes in CART recipients for r/r DLBCL. GS & AK contributed equally Citation Format: Geoffrey Shouse, Andy Kaempf, Max Gordon, David Yashar, Audrey M Sigmund, Gordon Smilnak, Steven M Bair, Agrima Mian, Lindsey Fitzgerald, Amneet Bajwa, Samantha Jaglowski, Neil Bailey, Mayzar Shadman, Krish Patel, Deborah M Stephens, Manali Kamdar, Brian T Hill, Jordon Gauthier, Reem Karmali, Loretta Nastoupil, Adam S Kittai, Alexey V Danilov. Impact of a validated composite comorbidity score on outcomes in patients treated with CAR T-cell therapy for diffuse large B cell lymphoma (DLBCL): A multicenter real-world evidence (RWE) study [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A27.

Current situation of endemic mycosis in the Americas and the Caribbean: Proceedings of the first international meeting on endemic mycoses of the Americas (IMEMA).

The Americas are home to biologically and clinically diverse endemic fungi, including Blastomyces, Coccidioides, Emergomyces, Histoplasma, Paracoccidioides and Sporothrix. In endemic areas with high risk of infection, these fungal pathogens represent an important public health problem. This report aims to summarise the main findings of the regional analysis carried out on the status of the endemic mycoses of the Americas, done at the first International Meeting on Endemic Mycoses of the Americas (IMEMA). A regional analysis for the Americas was done, the 27 territories were grouped into nine regions. A SWOT analysis was done. All territories reported availability of microscopy. Seventy percent of territories reported antibody testing, 67% of territories reported availability of Histoplasma antigen testing. None of the territories reported the use of (1-3)-β-d-glucan. Fifty two percent of territories reported the availability of PCR testing in reference centres (mostly for histoplasmosis). Most of the territories reported access to medications such as trimethoprim-sulfamethoxazole, itraconazole, voriconazole and amphotericin B (AMB) deoxycholate. Many countries had limited access to liposomal formulation of AMB and newer azoles, such as posaconazole and isavuconazole. Surveillance of these fungal diseases was minimal. A consensus emerged among meeting participants, this group concluded that endemic mycoses are neglected diseases, and due to their severity and lack of resources, the improvement of diagnosis, treatment and surveillance is needed.

22nd EAA Congress – 15th ISGA Congress – 5th International Conference of Evolutionary Medicine

This Abstract book covers material of the Joint International Meeting: 22nd EAA Congress, 15th ISGA Congress, 5th International Conference of Evolutionary Medicine. This event was organized at Vilnius University (Lithuania) in 2022 on August 24-27th in a hybrid way, which brought together 28 famous keynote speakers from Austria, Great Britain, the USA, Australia, Croatia, Poland, France, Switzerland, Germany and other countries. This book includes the abstracts of more than 180 presentations.
 The main theme of the 22nd Congress of EAA (European Anthropology Association) is Human variation and adaptation in a changing world with a particular focus on physical, biopsychosocial and general health changes in the human body. The topics of the 15th Congress of ISGA (International Society for the Study of Human Growth and Clinical Auxology) expand our understanding of human growth and development in health and disease. Special attention is paid to human growth in the period of early ontogenesis, to environmental factors affecting growth (including growth in war and other stressful conditions), children and adolescents’ nutrition and body composition, also modern analyses of growth data. The 5th International Conference on Evolutionary Medicine expands an interdisciplinary approach to understanding the diversity of human health and disease, sharing research from different fields to cooperate together in order to understand the mechanisms of different disease from the evolutionary point of view.
 The Abstract Book of this joint international event should not only be interesting to scientists of various scientific fields such as anthropology, human biology, public health, and health education, but also to clinical doctors, especially neonatologists, paediatricians, family practitioners and many others. Organisers believe that knowledge of the potential of human adaptation and evolutionary mechanisms in maintaining the health and wellbeing of our species will encourage fruitful interdisciplinary discussions in medical society as well as among biologists, sociologists and other specialists.

SEG 2022 Honors and Awards Citations

One of SEG's great traditions is the special recognition of individuals and organizations for their contributions to geophysics and to the Society. The following individuals and groups will be honored during a ceremony scheduled for the evening of 30 August at the International Meeting for Applied Geoscience and Energy (see https://www.imageevent.org for exact time and for schedule updates). Their names, as well as the names of past awardees, are listed at https://seg.org/about-seg/governance/honors-and-awards .

IMAGE Preview: Expand your horizons at IMAGE '22

The International Meeting for Applied Geoscience and Energy (IMAGE '22) will be fully live and in person 28 August through 1 September at the George R. Brown Convention Center in Houston, Texas.

LXI George Roerich Annual International Meeting (Text and cultural space: Ancient and Medieval India and Central Asia)

The article offers a review of the George Roerich Annual International Meeting, an annual conference in which researchers traditionally participate, continuing the main directions of scientific activity of George Roerich (russ.: Yurii Nikolaevich Rerikh, 1902-1960). In 2021, the 100th anniversary of the birth of the outstanding Russian Tibetologist Yuri Mikhailovich Parfionovich (1921-1990) was celebrated, and the conference was dedicated to his memory. It began with the memorial part, in which the speakers shared their memories of Y.M. Parfionovich and told about his role in the study of the Tibetan language and Tibetan Buddhist texts. The contributions of the main part of the conference were studies of Tibet, India and Central Asia. They covered several areas of humanitarian knowledge: philology, linguistics, history, art history, philosophy, religious studies. All of them were united by a common theme "Text and cultural space. Ancient and medieval India and Central Asia" and in one way or another were associated with the study of the worldview and cultural interactions of the studied regions.

70th International Congress of the European Society for Cardiovascular and Endovascular Surgery and 7th International Meeting on Aortic Diseases.

AORTA is proud to publish the abstracts from the 2022 joint IMAD (International Meeting on Aortic Diseases) and ESCVS (European Society for Cardiovascular Surgery) meeting in Liege, Belgium.

Abstracts Presented at the 22nd Annual International Meeting on Simulation in Healthcare, January 15-19, 2022, Los Angeles, CA.

Abstracts Presented at the 22nd Annual International Meeting on Simulation in Healthcare, January 15-19, 2022, Los Angeles, CA.