Search

Objectives The 2021 Society for Hematopathology and European Association for Haematopathology Workshop addressed the molecular and cytogenetic underpinnings of transformation and transdifferentiation in lymphoid neoplasms. Methods Session 4, “Transformations of Follicular Lymphoma,” and session 5, “Transformations of Other B-Cell Lymphomas,” included 45 cases. Gene alteration analysis and expression profiling were performed on cases with submitted formalin-fixed, paraffin embedded tissue. Results The findings from session 4 suggest that “diffuse large B-cell lymphoma/high-grade B-cell lymphoma with rearrangements of MYC and BCL2” is a distinct category arising from the constraints of a preexisting BCL2 translocation. TdT expression in aggressive B-cell lymphomas is associated with MYC rearrangements, immunophenotypic immaturity, and a dismal prognosis but must be differentiated from lymphoblastic ­lymphoma. Cases in session 5 illustrated unusual morphologic and immunophenotypic patterns of transformation. Additionally, the findings support the role of cytogenetic abnormalities—specifically, MYC and NOTCH1 rearrangements—as well as single gene alterations, including TP53, in transformation. Conclusions Together, these unique cases and their accompanying molecular and cytogenetic data suggest potential mechanisms for and unusual patterns of transformation in B-cell lymphomas and indicate numerous opportunities for further study.

Objectives To summarize cases submitted to the 2021 Society for Hematopathology/European Association for Haematopathology Workshop under the categories of progression of Hodgkin lymphoma, plasmablastic myeloma, and plasma cell myeloma. Methods The workshop panel reviewed 20 cases covered in this session. In addition, whole-exome sequencing (WES) and whole-genome RNA expression analysis were performed on 10 submitted cases, including 6 Hodgkin lymphoma and 4 plasma neoplasm cases. Results The cases of Hodgkin lymphoma included transformed cases to or from various types of B-cell lymphoma with 1 exception, which had T-cell differentiation. The cases of plasma cell neoplasms included cases with plasmablastic progression, progression to plasma cell leukemia, and secondary B-lymphoblastic leukemia. Gene variants identified by WES included some known to be recurrent in Hodgkin lymphoma and plasma cell neoplasm. All submitted Hodgkin lymphoma samples showed 1 or more of these mutations: SOCS1, FGFR2, KMT2D, RIT1, SPEN, STAT6, TET2, TNFAIP3, and ZNF217. Conclusions Better molecular characterization of both of these neoplasms and mechanisms of progression will help us to better understand mechanisms of progression and perhaps develop better prognostic models, as well as identifying novel therapeutic targets.

Objectives Session 3 of the 2021 Workshop of the Society for Hematopathology/European Association for Haematopathology examined progression and transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and B-cell prolymphocytic leukemia (B-PLL). Methods Thirty-one cases were reviewed by the panel. Additional studies such as immunohistochemistry and molecular genetic testing, including whole-exome sequencing and expression profiling, were performed in select cases. Results Session 3 included 27 CLL/SLL cases and miscellaneous associated proliferations, 3 cases of B-PLL, and 1 case of small B-cell lymphoma. The criteria for ­accelerated CLL/SLL are established for lymph nodes, but extranodal disease can be diagnostically challenging. Richter transformation (RT) is a broad term and includes true transformation from original CLL/SLL clone(s) and clonally unrelated neoplasms. The morphologic, immunophenotypic, and genetic spectrum is diverse with classical and highly unusual examples. T-cell proliferations can also be encountered in CLL/SLL. B-cell prolymphocytic leukemia is a rare, diagnostically challenging disease due to its overlaps with other lymphoid neoplasms. Conclusions The workshop highlighted complexity of progression and transformation in CLL/SLL and B-PLL, as well as diagnostic caveats accompanying heterogeneous presentations of RT and other manifestations of disease progression. Molecular genetic studies are pivotal for diagnosis and determination of clonal relationship, and to predict response to treatment and identify resistance to targeted therapy.

SETD2 is the sole histone methyltransferase responsible for H3K36me3, with roles in splicing, transcription initiation, and DNA damage response. Homozygous disruption of SETD2 yields a tumor suppressor effect in various cancers. However, SETD2 mutation is typically heterozygous in diffuse large B-cell lymphomas. Here we show that heterozygous Setd2 deficiency results in germinal center (GC) hyperplasia and increased competitive fitness, with reduced DNA damage checkpoint activity and apoptosis, resulting in accelerated lymphomagenesis. Impaired DNA damage sensing in Setd2-haploinsufficient germinal center B (GCB) and lymphoma cells associated with increased AICDA-induced somatic hypermutation, complex structural variants, and increased translocations including those activating MYC. DNA damage was selectively increased on the nontemplate strand, and H3K36me3 loss was associated with greater RNAPII processivity and mutational burden, suggesting that SETD2-mediated H3K36me3 is required for proper sensing of cytosine deamination. Hence, Setd2 haploinsufficiency delineates a novel GCB context–specific oncogenic pathway involving defective epigenetic surveillance of AICDA-mediated effects on transcribed genes.Significance:Our findings define a B cell–specific oncogenic effect of SETD2 heterozygous mutation, which unleashes AICDA mutagenesis of nontemplate strand DNA in the GC reaction, resulting in lymphomas with heavy mutational burden. GC-derived lymphomas did not tolerate SETD2 homozygous deletion, pointing to a novel context-specific therapeutic vulnerability.This article is highlighted in the In This Issue feature, p. 1599

Supplementary Figure from SETD2 Haploinsufficiency Enhances Germinal Center–Associated AICDA Somatic Hypermutation to Drive B-cell Lymphomagenesis

PDF file - 80 KB, Supplementary Table S1 lists the cell lines and their respective IC50s for all three of the PI3K inhibitors evaluated in this study.

PDF file - 72 KB, Supplementary Figure S1 shows the results for the experiment to determine if there was a therapeutic window between malignant and normal cells. Both IPA-3 and BEZ235 individually and in combination were selectively toxic to malignant B cells (Ly8 cell line) compared to normal B cells.

Purpose: The phosphoinositide 3-kinase (PI3K) pathway is known to play an active role in many malignancies. The role of PI3K inhibition in the treatment of lymphomas has not been fully delineated. We sought to identify a role for therapeutic PI3K inhibition across a range of B-cell lymphomas.Experimental Design: We selected three small molecule inhibitors to test in a panel of 60 cell lines that comprised diverse lymphoma types. We tested the selective PI3K inhibitor BKM120 and the dual PI3K/mTOR inhibitors BEZ235 and BGT226 in these cell lines. We applied gene expression profiling to better understand the molecular mechanisms associated with responsiveness to these drugs.Results: We found that higher expression of the PAK1 gene was significantly associated with resistance to all three PI3K inhibitors. Through RNA–interference-mediated knockdown of the PAK1 gene, we showed a dramatic increase in the sensitivity to PI3K inhibition. We further tested a small-molecule inhibitor of PAK1 and found significant synergy between PI3K and PAK1 inhibition.Conclusion: Thus, we show that PI3K inhibition is broadly effective in lymphomas and PAK1 is a key modulator of resistance to PI3K inhibition. Clin Cancer Res; 19(5); 1106–15. ©2012 AACR.

PDF file - 38 KB, The Supplementary Data Legend provides the legends for Supplementary Table S1 and Supplementary Figure S1.

Supplementary Figure 7 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

Supplementary Figure 4 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

Supplementary Figure 5 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

Supplementary Figure 3 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

Supplementary Figure 9 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

Supplementary Figure Legends 1-9 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

PDF file - 843K, Unsupervised hierarchical clustering of cBCLs.

PDF file - 881K, Western blot comparing phospho-NF-κB (p65) levels in "ABC-like" and "GCB-like" canine samples.

Supplementary Figure 8 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

Supplementary Figure 6 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

XLSX file - 40K, Canine genes identified by Ingenuity Pathway Analysis as part of the NF-kB or B-cell receptor signaling pathways (Fig. 5).

PDF file - 60K

Supplementary Figure 2 from HER2 Overexpression Elicits a Proinflammatory IL-6 Autocrine Signaling Loop That Is Critical for Tumorigenesis

PDF file - 41K, Distribution of lymphoma samples into "Ongoing" or "Static" categories based on the proportion of IGHV subclones that are identical at the CDR3 region for each sample.

XLSX file - 116K, Canine genes that distinguish "ABC-like" and "GCB-like" subtypes (Fig. 5).

A comprehensive constellation of somatic nonsilent mutations and copy-number (CN) variations in ocular adnexa marginal zone lymphoma (OAMZL) is unknown. By utilizing whole-exome sequencing in 69 tumors, we define the genetic landscape of OAMZL. Mutations and CN changes in CABIN1 (30%), RHOA (26%), TBL1XR1 (22%), and CREBBP (17%) and inactivation of TNFAIP3 (26%) were among the most common aberrations. Candidate cancer driver genes cluster in the B-cell receptor (BCR), NF-κB, NOTCH, and NFAT signaling pathways. One of the most commonly altered genes is CABIN1, a calcineurin inhibitor acting as a negative regulator of the NFAT and MEF2B transcriptional activity. CABIN1 deletions enhance BCR-stimulated NFAT and MEF2B transcriptional activity, while CABIN1 mutations enhance only MEF2B transcriptional activity by impairing binding of mSin3a to CABIN1. Our data provide an unbiased identification of genetically altered genes that may play a role in the molecular pathogenesis of OAMZL and serve as therapeutic targets. Significance: We report systematic application of whole-exome sequencing and CN variations in OAMZL, revealing common alterations in regulation of NFAT signaling pathway that may facilitate identification of new therapies.

BACKGROUND Significant racial differences have been observed in the incidence and clinical outcomes of diffuse large B-cell lymphoma (DLBCL) in the United States, but to the authors' knowledge it remains unclear whether genomic differences contribute to these disparities. METHODS To understand the influences of genetic ancestry on tumor genomic alterations, the authors estimated the genetic ancestry of 1001 previously described patients with DLBCL using unsupervised model-based Admixture global ancestry analysis applied to exome sequencing data and examined the mutational profile of 150 DLBCL driver genes in tumors obtained from this cohort. RESULTS Global ancestry prediction identified 619 patients with >90% European ancestry, 81 patients with >90% African ancestry, and 50 patients with >90% Asian ancestry. Compared with patients with DLBCL with European ancestry, patients with African ancestry were aged >10 years younger at the time of diagnosis and were more likely to present with B symptoms, elevated serum lactate dehydrogenase, extranodal disease, and advanced stage disease. Patients with African ancestry demonstrated worse overall survival compared with patients with European ancestry (median, 4.9 years vs 8.8 years; P = .04). Recurrent mutations of MLL2 (KMT2D), HIST1H1E, MYD88, BCL2, and PIM1 were found across all ancestry groups, suggesting shared mechanisms underlying tumor biology. The authors also identified 6 DLBCL driver genes that were more commonly mutated in patients with African ancestry compared with patients with European ancestry: ATM (21.0% vs 7.75%; P

Epstein–Barr virus (EBV) is a ubiquitous herpesvirus that typically causes asymptomatic infection but can promote B lymphoid tumors in the immune suppressed. In vitro, EBV infection of primary B cells stimulates glycolysis during immortalization into lymphoblastoid cell lines (LCLs). Lactate export during glycolysis is crucial for continued proliferation of many cancer cells—part of a phenomenon known as the “Warburg effect”— and is mediated by monocarboxylate transporters (MCTs). However, the role of MCTs has yet to be studied in EBV-associated malignancies, which display Warburg-like metabolism in vitro. Here, we show that EBV infection of B lymphocytes directly promotes temporal induction of MCT1 and MCT4 through the viral proteins EBNA2 and LMP1, respectively. Functionally, MCT1 was required for early B cell proliferation, and MCT4 up-regulation promoted acquired resistance to MCT1 antagonism in LCLs. However, dual MCT1/4 inhibition led to LCL growth arrest and lactate buildup. Metabolic profiling in LCLs revealed significantly reduced oxygen consumption rates (OCRs) and NAD+/NADH ratios, contrary to previous observations of increased OCR and unaltered NAD+/NADH ratios in MCT1/4-inhibited cancer cells. Furthermore, U-(13)C(6)–glucose labeling of MCT1/4-inhibited LCLs revealed depleted glutathione pools that correlated with elevated reactive oxygen species. Finally, we found that dual MCT1/4 inhibition also sensitized LCLs to killing by the electron transport chain complex I inhibitors phenformin and metformin. These findings were extended to viral lymphomas associated with EBV and the related gammaherpesvirus KSHV, pointing at a therapeutic approach for targeting both viral lymphomas.

Burkitt lymphoma (BL) is an aggressive, MYC-driven lymphoma comprising 3 distinct clinical subtypes: sporadic BLs that occur worldwide, endemic BLs that occur predominantly in sub-Saharan Africa, and immunodeficiency-associated BLs that occur primarily in the setting of HIV. In this study, we comprehensively delineated the genomic basis of BL through whole-genome sequencing (WGS) of 101 tumors representing all 3 subtypes of BL to identify 72 driver genes. These data were additionally informed by CRISPR screens in BL cell lines to functionally annotate the role of oncogenic drivers. Nearly every driver gene was found to have both coding and non-coding mutations, highlighting the importance of WGS for identifying driver events. Our data implicate coding and non-coding mutations in IGLL5, BACH2, SIN3A, and DNMT1. Epstein-Barr virus (EBV) infection was associated with higher mutation load, with type 1 EBV showing a higher mutational burden than type 2 EBV. Although sporadic and immunodeficiency-associated BLs had similar genetic profiles, endemic BLs manifested more frequent mutations in BCL7A and BCL6 and fewer genetic alterations in DNMT1, SNTB2, and CTCF. Silencing mutations in ID3 were a common feature of all 3 subtypes of BL. In vitro, mass spectrometry–based proteomics demonstrated that the ID3 protein binds primarily to TCF3 and TCF4. In vivo knockout of ID3 potentiated the effects of MYC, leading to rapid tumorigenesis and tumor phenotypes consistent with those observed in the human disease.

Non-Hodgkin lymphomas (NHLs) are a diverse group of entities, both clinically and molecularly. Here, we review the evolution of classification schemes in B-cell lymphoma, noting the now standard WHO classification system that is based on immune cell-of-origin and molecular phenotypes. We review how lymphomas arise throughout the B-cell development process as well as the molecular and clinical features of prominent B-cell lymphomas. We provide an overview of the major progress that has occurred over the past decade in terms of our molecular understanding of these diseases. We discuss treatment options available and focus on a number of the diverse research tools that have been employed to improve our understanding of these diseases. We discuss the problem of heterogeneity in lymphomas and anticipate that the near future will bring significant advances that provide a measurable impact on NHL outcomes.

We report the results of a phase 1 dose-escalation study of belinostat and bortezomib in adult patients with acute leukemia or MDS or CML with blast crisis. Thirty-eight patients received IV belinostat days 1-5 and 8-12 with IV bortezomib days 1, 4, 8, and 11 every 21 days. QTc prolongation was the only identified DLT. The RP2Ds were 1.3 mg/m(2) bortezomib and 1000 mg/m(2) belinostat. One patient with highly refractory MLL-ENL rearranged biphenotypic AML with multiple karyotypic aberrations had a complete pathologic and karyotypic response. One patient with post-MPN AML remained on study with stable disease (SD) for 32 cycles. Whole-exome sequencing revealed no aberrations in the first patient and a hyper-mutator genotype in the second. Eighteen patients had a best response of SD. We conclude that this treatment strategy is feasible but has limited activity in this population. Nevertheless, the factors that predict exceptional responses to this strategy warrant further investigation.

INTRODUCTIONCanine Lymphoma (CL) is the most commonly diagnosed malignancy in the domestic dog, with estimates reaching 80,000 new cases per year in the United States. Understanding of genetic factors involved in development and progression of canine B-Cell Lymphoma (cBCL), the most common of the two major subtypes of CL, can help guide efforts to prevent, diagnose, and treat disease in dogs. Such findings also have implications for human Non-Hodgkin Lymphoma (NHL), as pet dogs have recently emerged as an important translational model due to the many shared histopathological, biological, and clinical characteristics between cBCL and NHL.OBJECTIVESWe aimed to identify potential driver mutations in cBCL and detect associations between affected genes and differential clinical outcomes.METHODSUsing exome sequencing of paired normal and tumor tissues from 71 dogs of various breeds with cBCL, we identified somatic variants with a consensus approach: keeping variants called by both MuTect2 and with high-confidence by VarScan 2. We predicted effects of these variants using SnpEff then measured associations between mutated genes and survival times from clinical data available for 62 cohort dogs using a multivariate Cox Proportional Hazards Model.RESULTSMutations in FBXW7, a gene commonly mutated in both human and canine cancers including lymphoma, were associated with shorter overall survival (OS; p=0.01, HR 3.3 [1.4-7.6]). The two most frequently mutated codons of FBXW7 in our cohort correspond to the most frequently mutated codons in human cancers.CONCLUSIONSOur findings show that exome sequencing results can be combined with clinical data to identify key mutations associated with prognosis in cBCL. These results may have implications for precision medicine in dogs and also allow subsets of dogs to serve as models for specific subtypes of human lymphoma.Translational RelevanceIdentifying tumor biomarkers associated with clinical outcomes has been a major driver in improved success in treating many types of human cancers, including Non-Hodgkin lymphoma (NHL). Since canine B-cell Lymphoma (cBCL) shares many clinically identifiable characteristics with NHL, our detection of recurring mutations in certain genes in cBCL and their association with clinical outcomes stands to benefit both humans and dogs. If common canine lymphoma subtypes show mutational similarity to certain human subtypes, then therapies found to be effective for a subtype in one species may be more likely to improve treatment response in the analogous subtype in the other.

We review the genetic foundations of different rare lymphomas to examine their shared origins. These data indicate the potential application of genomics to improve the diagnosis and treatment of these rare diseases.Next generation sequencing technologies have provided an important window into the genetic underpinnings of lymphomas. A growing body of evidence indicates that although some genetic alterations are specific to certain diseases, others are shared across different lymphomas. Many such genetic events have already demonstrated clinical utility, such as BRAF V600E that confers sensitivity to vemurafenib in patients with hairy cell leukemia.The rareness of many lymphoma subtypes makes the conduct of clinical trials and recruitment of significant numbers of patients impractical. However, a knowledge of the shared genetic origins of these rare lymphomas has the potential to inform 'basket' clinical trials in which multiple lymphoma subtypes are included. These trials would include patients based on the presence of alterations in targetable driver genes. Such approaches would be greatly strengthened by a systematic assessment of significant patient numbers from each subtype using next generation sequencing.

Background: Enhancer of zeste homolog 2 (EZH2) is an epigenetic regulator implicated as a genetic driver in multiple lymphoma types. Approximately 20% of patients with follicular lymphoma (FL) present with activating, gain-of-function (GoF) EZH2 mutations. The results of a phase 2 clinical trial of the first-in-class oral EZH2 inhibitor tazemetostat demonstrated clinically meaningful response in patients with relapsed/refractory (R/R) FL in wild-type (WT) and mutant (MT) EZH2 who were treated with single-agent tazemetostat. Tazemetostat is approved by the US Food and Drug Administration for treatment of patients with R/R FL. Beyond EZH2, the biologic drivers of response to tazemetostat remain unknown. To better understand the drivers of tazemetostat response, we performed DNA and RNA sequencing of archival tumor biopsy and cell-free DNA samples to determine the landscape of genetic mutations, copy number variations, and gene-expression profiles in trial patients. Methods: The clinical activity of tazemetostat was evaluated in an open-label, multicenter study (NCT01897571). Patients with MT or WT EZH2 R/R FL received oral tazemetostat 800 mg twice daily, and measures of clinical response, including objective response rate (ORR), duration of response, progression-free survival (PFS), and overall survival (OS), were determined. Molecular characterization of archival formalin-fixed, paraffin-embedded tumor biopsies was performed by generating whole-exome sequencing and transcriptome sequencing from 88 patients enrolled in the original study (MT EZH2, n=34; WT EZH2, n=54). In addition, higher-depth targeted DNA sequencing (tumor biopsies, 1500×; circulating tumor DNA [ctDNA], 20,000×) of tumor biopsy samples and ctDNA isolated from serum at baseline (cycle 1 day 1, predose) was conducted for a panel of 62 genes known to be mutated in >5% of FL or diffuse large B-cell lymphoma cases. These molecular data were compared to clinical outcomes, including ORR, PFS, and OS, to investigate drivers of response to tazemetostat. Results: We identified 29 driver genes mutated in the patient cohort at a frequency of ≥8% of patients and found differences in the overall profile of driver gene mutations between MT and WT EZH2 cohorts, including MYD88, GNA13, and chromatin regulators EP300 and KMT2D (all P Conclusions: This molecular analysis of tumor biopsy and ctDNA samples from patients with R/R FL treated with the EZH2 inhibitor tazemetostat indicates that patients with MT or WT EZH2 activate several distinct genetic drivers. These results have implications for understanding the underlying disease biology and development of new treatments such as tazemetostat. In addition, mutations in several genes influence PFS and/or OS associated with tazemetostat, as do specific immune cell populations in the tumor microenvironment. Taken together, these data generate novel hypotheses for the biologic factors driving response to tazemetostat in patients with FL. Disclosures Dave: Data Driven Bioscience: Current equity holder in publicly-traded company. Happ: Duke University: Ended employment in the past 24 months; Data Driven Bioscience: Current Employment, Divested equity in a private or publicly-traded company in the past 24 months. Yasso: Epizyme, Inc.: Current Employment, Current holder of stock options in a privately-held company. Salles: Incyte: Consultancy; Genmab: Consultancy; Epizyme: Consultancy, Honoraria; Debiopharm: Consultancy; Novartis: Consultancy; BMS/Celgene: Consultancy; Abbvie: Consultancy, Honoraria; Bayer: Honoraria; Regeneron: Consultancy, Honoraria; Takeda: Consultancy; Velosbio: Consultancy; Allogene: Consultancy; Rapt: Consultancy; Beigene: Consultancy; Morphosys: Consultancy, Honoraria; Miltneiy: Consultancy; Loxo: Consultancy; Kite/Gilead: Consultancy; Janssen: Consultancy; Ipsen: Consultancy; Genentech/Roche: Consultancy. Batlevi: Roche/Genentech: Research Funding; Medscape: Honoraria; Janssen: Research Funding; Viatris: Current holder of individual stocks in a privately-held company; Xynomic: Research Funding; Memorial Sloan Kettering Cancer Center: Current Employment; BMS: Current holder of individual stocks in a privately-held company; Moderna: Current holder of individual stocks in a privately-held company; Pfizer: Current holder of individual stocks in a privately-held company; TG Therapeutics: Consultancy; GLG Pharma: Consultancy; Regeneron: Current holder of individual stocks in a privately-held company; Novartis: Research Funding; Bayer: Research Funding; TouchIME: Honoraria; Dava Oncology: Honoraria; ADC Therapeutics: Consultancy; Karyopharm: Consultancy; Seattle Genetics: Consultancy; Life Sciences: Consultancy; Kite Pharma: Consultancy; Juno/Celgene: Consultancy; Epizyme: Research Funding; Autolus: Research Funding. Phillips: Bayer: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; ADCT, BeiGene, Bristol Myers Squibb, Cardinal Health, Incyte, Karyopharm, Morphosys, Pharmacyclics, Seattle Genetics: Consultancy; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; AstraZeneca: Consultancy; Incyte: Consultancy, Other: received travel expenses from Incyte, Research Funding. Yang: Epizyme, Inc.: Current Employment, Other: May own stock/options. Adib: Epizyme, Inc.: Consultancy. Michaud: Epizyme, Inc.: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; AstraZeneca LLC: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Patents & Royalties: US 7,498,420 , US 8,821,869, US 8,207,306 , US 8,569,459 ; Pfizer: Patents & Royalties: US 7,498,420 , US 8,821,869, US 8,207,306 , US 8,569,459 . Morschhauser: Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Speakers Bureau; Janssen: Honoraria; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech, Inc.: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Chugai: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees; Genmab: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees.

INTRODUCTION Diffuse large B-cell lymphoma (DLBCL) represents several distinct clinical pathologic entities recently identified by molecular profiling. Treatment with anti-CD19 chimeric antigen receptor (CAR) T-cell therapies is now standard for many patients with relapsed/refractory (R/R) disease. Although antigen loss of CD19 represents a known cause of late relapses, the majority of CAR-T cell treatment failure occurs very soon after treatment at which time the impact of molecular subtype and other somatic mutations of DLBCL is undefined. We sought to determine impact of molecular features of DLBCL tumors on clinical outcomes in a cohort of patients with R/R disease who were treated with axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) in order to provide insight into the mechanism of response or resistance to CAR-T cell therapy. METHODS We collected clinical data and formalin-fixed, paraffin embedded (FFPE) biopsy specimens from 121 DLBCL patients at the time of R/R disease after prior treatment with standard chemoimmunotherapy across 12 US academic medical centers who subsequently received commercial CAR-T cell treatment. Whole exome and transcriptome sequencing was performed on all cases to measure gene expression and gene copy number alterations. Genetic analysis was done on 96 patients with pre-treatment biopsies that passed sequencing quality filters, and expression analysis on 93 patients. Progression-free and overall survival (PFS, OS) measured from the day of CAR-T cell infusion were estimated using the Kaplan-Meier method and compared with the log-rank test. RESULTS Baseline demographics and treatment details of the patient population are shown in the Table (Panel A). Best overall response was CR in 43% of patients and PR in 10% patients. PFS and OS were significantly different based on best response to treatment (P CONCLUSIONS DLBCL patients whose tumors have molecular features that are predictive of inferior response to standard frontline treatment including the high-risk subgroups (C2/A53) and (C5/MCD) have favorable treatment outcomes with CAR-T cell therapy. In contrast, individual driver mutations including MYC and BCL2, CDKN2A, and KLHL6 are associated with inferior PFS with CAR-T cell therapy, while mutations in BTG2, MYD88, and CD79B are associated with a favorable PFS. In addition, gene expression analysis implicates a potential role for the microenvironment in modulating responses to CAR-T therapy. These findings suggest that predictive biomarkers for response to traditional chemoimmunotherapy and cellular immunotherapy are distinct. Our results provide insight into potentially targetable pathways for the development of rational treatment strategies that may augment response CAR-T cell therapy. Figure 1 Figure 1. Disclosures Hill: Celgene (BMS): Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Gentenech: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding. McKinney: Novartis: Research Funding; Nordic Nanovector: Research Funding; Molecular Templates: Consultancy, Research Funding; Kite/Gilead: Honoraria, Speakers Bureau; Incyte: Research Funding; Genetech: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy; Celgene: Consultancy, Research Funding; BTG: Consultancy; Beigene: Research Funding; ADC Therapeutics: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy; Verastem: Consultancy. Neff: Spring Discovery: Consultancy, Ended employment in the past 24 months; EUSA Pharma: Speakers Bureau; Enzyvant: Consultancy. Reshef: BMS, Regeneron, TScan, Synthekine, Atara, Jasper, Bayer: Consultancy; ilead, BMS, Precision, Immatics, Atara, Takeda, Shire, Pharmacyclics, Incyte: Research Funding; Bayer: Consultancy; Gilead and Novartis: Honoraria. Oluwole: Janssen: Consultancy; Pfizer: Consultancy; Curio Science: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Ghosh: Incyte: Consultancy, Honoraria; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Speakers Bureau; TG Therapeutics: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Genmab: Consultancy, Honoraria; Epizyme: Honoraria, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria; Adaptive Biotech: Consultancy, Honoraria; AbbVie: Honoraria, Speakers Bureau; Karyopharma: Consultancy, Honoraria; Genentech: Research Funding. Chen: Actinium Pharmaceuticals: Other: Principal Investigator, SIERRA Trial, Actinium. Hernandez-Ilizaliturri: AbbVie: Other: Advisory Boards; Incyte: Other: Advisory Boards; Celgene: Other: Advisory Boards; BMS: Other: Advisory Boards; Pharmacyclics: Other: Advisory Boards; Amgen: Other: Advisory Boards; Kite: Other: Advisory Boards; Gilead: Other: Advisory Boards; Epyzime: Other: Advisory Boards. Shah: Lily: Consultancy, Honoraria, Research Funding; Miltenyi Biotec: Consultancy, Honoraria, Research Funding; Kite: Consultancy; Epizyme: Consultancy; Legend: Consultancy; Incyte: Consultancy; Umoja: Consultancy. Stephens: Epizyme: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees; JUNO: Research Funding; Novartis: Research Funding; Abbvie: Consultancy; AstraZeneca: Consultancy; CSL Behring: Consultancy; Celgene: Consultancy; Mingsight: Research Funding; Arqule: Research Funding. Patel: Janssen: Consultancy; Kite Pharma: Consultancy, Speakers Bureau; TG Therapeutics: Consultancy, Speakers Bureau; MEI Pharma: Consultancy; Abbvie: Consultancy; Genentech: Consultancy; Bristol Myers Squibb: Consultancy, Speakers Bureau; BeiGene: Consultancy; Morphosys: Consultancy; Pharmacyclics: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; ADC Therapeutics: Consultancy; Lilly: Consultancy. Pagel: Gilead: Consultancy; Actinium Pharmaceuticals: Consultancy; Kite, a Gilead Company: Consultancy; Incyte/MorphoSys: Consultancy; AstraZeneca: Consultancy; Pharmacyclics/AbbVie: Consultancy; Epizyme: Consultancy; BeiGene: Consultancy; MEI Pharma: Consultancy. Hsi: AbbVie Inc, Eli Lilly: Research Funding. Goy: Genentech/Hoffman la Roche: Research Funding; AbbVie/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Consultancy, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Medscape: Consultancy; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; Xcenda: Consultancy, Honoraria; Genomic Testing Cooperative: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; LLC(Targeted Oncology): Consultancy; Hoffman la Roche: Consultancy; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Rosewell Park: Consultancy; Infinity/Verastem: Research Funding; MorphoSys: Honoraria, Other; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; Xcenda: Consultancy; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; OncLive Peer Exchange: Honoraria; COTA (Cancer Outcome Tracking Analysis): Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; Incyte: Honoraria; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Michael J Hennessey Associates INC: Consultancy; Novartis: Consultancy, Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Karyopharm: Research Funding; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Phamacyclics: Research Funding; Constellation: Research Funding; Hackensack Meridian Health, Regional Cancer Care Associates/OMI: Current Employment. Ohgami: Stemline Therapeutics: Research Funding. Andreadis: CRISPR Therapeutics: Research Funding; GenMAB: Research Funding; Novartis: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Epizyme: Honoraria; Incyte: Honoraria; TG Therapeutics: Honoraria; Kite: Honoraria; Karyopharm: Honoraria; Atara: Consultancy, Honoraria; BMS: Research Funding; Merck: Research Funding. Thacker: Data Driven Bioscience: Current Employment. Rozzi: Data Driven Bioscience: Current Employment. Parker: Data Driven Bioscience: Current Employment. Happ: Data Driven Bioscience: Current Employment. Dave: Data Driven Bioscience: Current equity holder in publicly-traded company.

Introduction ALK-negative anaplastic large cell lymphoma (ALK- ALCL) is an uncommon type of T-cell non-Hodgkin lymphoma (T-NHL) with worse prognosis compared to ALK-positive (ALK+) ALCLs. Most published studies on the genomics of T-NHL have focused on peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), and previous studies of ALCL described rearrangements in DUSP22 and TP63 and mutations in genes comprising the JAK/STAT pathway as common genetic drivers in ALK- ALCL. The degree to which these drivers affect survival or other molecular features of ALK- ALCL remains unknown. Here, we describe novel subgroups of ALK- ALCL that exhibit distinct survival. One subgroup appears molecularly similar to ALK+ALCLs and is associated with favorable survival while the second subgroup is quite distinct from ALK- ALCLs and associated with poor outcomes. Methods and Results Eighty-two ALK- ALCL patients were recruited to the Atlas of Blood Cancer (ABC) genomes project, a worldwide consortium established to define the molecular origins of blood cancers. Tumor biopsies from these patients, as well as 10 ALK+ ALCL samples for comparison were obtained from participating institutions. Each case was subjected to centralized pathology review by an experienced panel of hematopathologists to ensure the accuracy of the diagnosis. All cases, along with paired normal tissues, were subjected to DNA and RNA (whole exome-level) sequencing on the Illumina platform to identify mutations and expression changes for each of these cases using methods well established in our group and described previously. We first examined the genetic alterations in ALK- ALCLs. In addition to frequently described genetic alterations such as TP63 and DUSP22 rearrangements, as well as mutations in JAK1, STAT3 and TP53, we also detected mutations in ERBB4, SETD2 and KMT2D, which may serve as potential novel drivers and have not been described previously to our knowledge. We next performed comparative gene expression analysis of the ALK- and ALK+ ALCLs. Surprisingly, a proportion of ALK- ALCL cases (38%) clustered together with ALK+ ALCLs and had a signature resembling ALK+ cases, which we designated as "ALK-like ALCL" here. Both the ALK-like ALCLs and the other ALK- ALCL cases showed decreased ALK expression compared to the ALK+ ALCLs by gene expression analysis. These results point to downstream pathways that are common among ALK+ALCLs and ALK-like ALCLs, but different from the other ALK- ALCLs. Gene set enrichment analysis revealed that the ALK-like ALCLs overexpressed genes in pathways related to monocyte and fibroblast activation, whereas the remaining ALK- ALCLs overexpressed genes in the T follicular helper cells, memory T cells and adaptive immune response-related pathways (P Conclusion Our data indicate that ALK- ALCLs represent a heterogeneous group of diseases and comprise at least two distinct subgroups that can be identified based on their similarity to the ALK+ ALCLs. The ALK-like ALCLs demonstrated distinct molecular features and favorable outcomes. Our results provide a potentially new approach to patient risk-stratification and pathological classification of this disease. Disclosures Kwong: Celgene: Consultancy, Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Jaye: Stemline Therapeutics: Honoraria. Behdad: Roche/Foundation Medicine: Speakers Bureau; Thermo Fisher: Speakers Bureau; Lilly: Speakers Bureau. Hsi: AbbVie Inc, Eli Lilly: Research Funding. Dave: Data Driven Bioscience: Current equity holder in publicly-traded company.

Introduction Blood cancers are collectively common and strikingly heterogeneous diseases both clinically and molecularly. According to the WHO taxonomy, there are over 100 distinct myeloid and lymphoid neoplasms. Genomic profiling of blood cancers has been applied in a somewhat ad hoc fashion using diverse sequencing approaches including the use of targeted panels, whole exome sequencing, whole genome sequencing, RNA sequencing, etc. The lack of data uniformity has made it difficult to comprehensively understand the clinical and molecular spectrum within and across diseases. Systematic genomic approaches can address the central challenges in the diagnosis and treatment of blood cancers. For the diagnosis of blood cancers, the incorporation of genomics could greatly enhance the accuracy and speed of clinical diagnostics. Genomics could also inform their pathology classification. However, these applications must be preceded by a clear understanding of the particular genetic aberrations and expression profiles that unite and distinguish different leukemias and lymphomas. Therapeutic development can also be aided by genomic approaches through identification of new targets and establishing the relevance of existing targets and treatments. Targeted therapies including those directed at specific surface markers (e.g. CD19, CD30 and CD123) or molecular targets (e.g. BCR-ABL fusions, IDH1 mutations and EZH2 mutations) are rarely restricted to a single disease, with most occurring in multiple blood cancers. A systematic understanding of the presence or overlap of these targets within or across blood cancers would significantly expand the therapeutic possibilities and better enable the use of existing therapies in both common and rare cancers. However, such therapeutic possibilities need to be established through a rigorous, data-driven approach. We initiated the Atlas of Blood Cancers Genomes (ABCG) project to systematically elucidate the molecular basis of all leukemias and lymphomas by building upon advances in genomic technologies, our capabilities for data analysis and economies of scale. Using a uniform approach to systematically profile all blood cancers through DNA and RNA sequencing at the whole exome/whole transcriptome level, we aim to link genomic events with clinical outcomes, disease categories and subcategories, thereby providing a complete molecular blueprint of blood cancers. Methods/Results The ABCG project consists of collaborators from 25 institutions around the world who have collectively contributed samples from 10,481 patients comprising every type of blood cancer in the current WHO classification. The samples include thousands of myeloid leukemias and mature B cell lymphomas, hundreds of Hodgkin lymphoma and plasma cell myeloma, as well as every rare type of hematologic malignancy (along with case-matched normal tissue). All cases were de-identified and their associated pathology and detailed clinical information entered into a purpose-built web-based system that included disease-specific data templates. All cases were subjected to centralized pathology review and clinical data review by experienced hematopathologists and oncologists. All 10,481cases are being sequenced at the DNA and RNA level, and are being profiled to define the genetic alterations and expression changes that are characteristic of each disease. Analysis will include translocations, copy number alterations, and viral status. These molecular features will be examined in conjunction with genetic events, pathologic factors, and the clinical features. We have already generated results for ALK-negative anaplastic large B cell lymphoma and primary mediastinal B cell lymphomas (N=210). These data demonstrate novel subgroup and molecular discoveries that are enabled by integrative DNA and RNA sequencing analysis and the examination of molecular features across different diseases as well as within individual entities. In addition, other disease entities and the collective data will be presented in the meeting. Conclusion The ABCG project will comprehensively study the genetic and clinicopathological features of all blood cancers using systematic genomic approaches. We anticipate our data, approaches and results will serve as a lasting resource for the molecular classification and therapeutic development for leukemias and lymphomas. Disclosures McKinney: Novartis: Research Funding; Nordic Nanovector: Research Funding; Molecular Templates: Consultancy, Research Funding; Kite/Gilead: Honoraria, Speakers Bureau; Incyte: Research Funding; Genetech: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy; Celgene: Consultancy, Research Funding; BTG: Consultancy; Beigene: Research Funding; ADC Therapeutics: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy; Verastem: Consultancy. Behdad: Lilly: Speakers Bureau; Roche/Foundation Medicine: Speakers Bureau; Thermo Fisher: Speakers Bureau.