Search

Purpose:The histone-methyl transferase EZH2, catalytic subunit of the PRC2 complex involved in transcriptional regulation, is mutated in approximately 25% of germinal center B-cell lymphomas. Aberrant proliferative dependency on EZH2 activity can be targeted by the orally available EZH2 inhibitor tazemetostat (EPZ-6438). We report the results of the phase Ib tazemetostat plus R-CHOP combination (NCT02889523), in patients 60 to 80 years of age with newly diagnosed diffuse large B-cell lymphoma.Patients and Methods:The primary objective of this dose-escalation study was to evaluate the safety of the combination and to determine the recommended phase II dose (RP2D) of tazemetostat.Results:A total of 17 patients were enrolled. During C1 and C2, two dose-limiting toxicities were observed: one grade 3 constipation at 400 mg and one grade 5 pulmonary infection at 800 mg. Grade 3 or more toxicities observed in more than 10% of the patients were constipation (24%), nausea (12%), and hypokalemia (12%). Grade 3 to 4 hematologic adverse events were recorded in 8 patients (47%): neutropenia (47%), leukopenia (29%), anemia (18%), and thrombocytopenia (12%). The tazemetostat RP2D was 800 mg. No organ-oriented toxicity increased with tazemetostat dosage escalation (severity and incidence). At 800 mg, AUC and Cmax of tazemetostat were similar compared with the single-agent study (E7438-G000-101).Conclusions:The RP2D of tazemetostat combined with R-CHOP is 800 mg twice a day. The association presents safety and PK comparable with R-CHOP alone. Preliminary efficacy data are encouraging and further investigations in phase II trial are warranted.

Supplementary table 1: incidence of Grade 3-5 hematologic toxicities with Epi-R-CHOP compared to recent R-CHOP trial and other R-CHOP / novel agent combinations. - Supplementary table 2: metabolic CR rate for the recent R-CHOP and R-CHOP combination studies. - Supplementary figure 1: Pharmacokinetic analysis - Supplementary figure 2: mutation frequencies for the 15 evaluable cases

Advances in molecular profiling of newly diagnosed diffuse large cell B lymphoma (DLBCL) have recently refine genetic subgroups. Genetic subgroups remain undetermined at the time of relapse or refractory (RR) disease. This study aims to decipher genetic subgroups and search for prognostic molecular biomarkers in patients with RR-DLBCL. From 2015 to 2021, targeted next-generation sequencing analyses of germline-matched tumor samples and fresh tissue from RR-DLBCL patients were performed. Unsupervised clustering of somatic mutations was performed and correlations with patient outcome were sought. 120 patients with RR-DLBCL were included in LNH-EP1 study and a molecular tumor landscape was successfully analyzed in 87% of patients (104/120 tumor samples). The median age was 67.5 years (range 27.4-87.4), median number of previous treatments was 2 (range 1-9). The most frequently mutated genes were TP53 (n=53 mutations; 42% of samples), CREBBP (n=39; 32%), BCL2 (n=86; 31%), KMT2D (n=39; 28%) and PIM1 (n=54; 22%). Unsupervised clustering separated three genetic subgroups entitled BST (enriched in BCL2, SOCS1 and TNFRSF14 mutations); TKS (enriched in TP53, KMT2D and STAT6 mutations); and PCM (enriched in PIM1, CD79B and MYD88 mutations). Median overall survival was 11.0 (95%CI: 8.1-12.6) months. Overall survival was not significantly different between the three genetic subgroups. GNA13 mutant was significantly associated with an increased risk of death (HR: 6.6 [95%CI: 2.1-20.6]; p=0.0011) and shorter overall survival (p=0.0340). At the time of relapse or refractory disease, three genetic subgroups of DLBCL patients were delineated, which could help advance precision molecular medicine programs. This article is protected by copyright. All rights reserved.

Follicular lymphoma (FL) is the most common indolent form of non-Hodgkin lymphoma. Histological transformation of FL to a more aggressive form of lymphoma occurs with a linear incidence of 2-3% per year and is associated with poor outcome. Divergent clonal evolution and an altered tumour microenvironment (TME) have both been implicated in the transformation process. However, the phenotypic consequences of this evolution and its implication in reshaping the TME remain unknown. To address this knowledge gap we performed single cell whole genome (scWGS) and single cell whole transcriptome sequencing (scWTS) of paired pre/post transformation samples of 11 FL patients. We further performed scWTS analysis of additional 11 FL samples from patients that had not undergone transformation within 7 years. Our comprehensive single cell analysis revealed the evolutionary dynamics of transformation at unprecedented resolution. Computational integration of scWGS and scWTS allowed us to identify gene programs upregulated and positively selected during evolution. Furthermore, our scWTS analysis revealed a shifting TME landscape, with an exhausted CD8 T cell signature emerging during transformation. Using multi-color immunofluorescence we transferred these findings to a novel TME based biomarker of transformation, subsequently validated in 2 independent cohorts of pretreatment FL samples. Taken together, our results provide a comprehensive view of the combined genomic and phenotypic evolution of malignant cells during transformation, and the shifting cross-talk between malignant cells and the TME.Graphical abstract

In this retrospective study, we report 70 cases of Epstein-Barr virus (EBV)+ diffuse large B-cell lymphoma not otherwise specified (DLBCL-NOS) among 1696 DLBCL-NOS cases diagnosed between 2006 and 2019 (prevalence of 4.1%). At diagnosis, median age was 68.5 years; 79% of the cases presented with an advanced-stage disease (III-IV), 48% with extranodal lesions, and 14% with an hemophagocytic lymphohistiocytosis (HLH) (8 at diagnosis and 1 on therapy). A total of 46 cases presented a polymorphic pattern, and 21 were monomorphic. All had a non-germinal center B phenotype, with the majority of tumor cells expressing CD30 and programmed death ligand 1 (98% and 95%, respectively). Type II and III EBV latency was seen in 88% and 12% of the cases, respectively. Patients were treated with immunochemotherapy (59%) or chemotherapy (22%), and 19% received palliative care due to advanced age and altered performance status. After a median follow-up of 48 months, progression-free survival (PFS) and overall survival (OS) at 5 years were 52.7% and 54.8%, respectively. Older age (>50 years) and HLH were associated with shorter PFS and OS in multivariate analysis (PFS: hazard ratio [HR], 14.01; 95% confidence interval [CI], 2.34-83.97; and HR, 5.78; 95% CI, 2.35-14.23; OS: HR, 12.41; 95% CI, 1.65-93.53; and HR, 6.09; 95% CI, 2.42-15.30, respectively). Finally, using a control cohort of 425 EBV− DLBCL-NOS, EBV positivity was associated with a shorter OS outcome within patients >50 years (5-year OS, 53% [95% CI, 38.2-74] vs 60.8% [95% CI, 55.4-69.3], P = .038), but not in younger patients.

International audience; Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma (NHL) characterized by the translocation t(11;14) (q13;q32) and a poor response to rituximab–anthracycline-based chemotherapy. High-dose cytarabine-based regimens offer a durable response, but an important number of MCL patients are not eligible for intensive treatment and are ideal candidates for novel targeted therapies (such as BTK, proteasome or BCL2 inhibitors, Immunomodulatory Drugs (IMiDs), bispecific antibodies, or CAR-T cell therapy). On the bench side, several studies aiming to integrate the tumor within its ecosystem highlighted a critical role of the tumor microenvironment (TME) in the expansion and resistance of MCL. This led to important insights into the role of the TME in the management of MCL, including potential targets and biomarkers. Indeed, targeted agents often have a combined mechanism of action on the tumor B cell but also on the tumor microenvironment. The aim of this review is to briefly describe the current knowledge on the biology of the TME in MCL and expose the results of the different therapeutic strategies integrating the TME in this disease.

Not available.

Purpose: The histone-methyl transferase EZH2, catalytic subunit of the PRC2 complex involved in transcriptional regulation, is mutated in approximately 25% of germinal center B-cell lymphomas. Aberrant proliferative dependency on EZH2 activity can be targeted by the orally available EZH2 inhibitor tazemetostat (EPZ-6438). We report the results of the phase Ib tazemetostat plus R-CHOP combination (NCT02889523), in patients 60 to 80 years of age with newly diagnosed diffuse large B-cell lymphoma. Patients and Methods: The primary objective of this dose-escalation study was to evaluate the safety of the combination and to determine the recommended phase II dose (RP2D) of tazemetostat. Results: A total of 17 patients were enrolled. During C1 and C2, two dose-limiting toxicities were observed: one grade 3 constipation at 400 mg and one grade 5 pulmonary infection at 800 mg. Grade 3 or more toxicities observed in more than 10% of the patients were constipation (24%), nausea (12%), and hypokalemia (12%). Grade 3 to 4 hematologic adverse events were recorded in 8 patients (47%): neutropenia (47%), leukopenia (29%), anemia (18%), and thrombocytopenia (12%). The tazemetostat RP2D was 800 mg. No organ-oriented toxicity increased with tazemetostat dosage escalation (severity and incidence). At 800 mg, AUC and Cmax of tazemetostat were similar compared with the single-agent study (E7438-G000-101). Conclusions: The RP2D of tazemetostat combined with R-CHOP is 800 mg twice a day. The association presents safety and PK comparable with R-CHOP alone. Preliminary efficacy data are encouraging and further investigations in phase II trial are warranted.

Mantle cell lymphoma has a dismal prognosis at relapse or in the refractory setting. Among therapies, mTor pathway targeting by temsirolimus has been the first strategy approved for relapse in Europe. While its efficacy in monotherapy has long been demonstrated, its use remains limited. In the T3 phase Ib clinical trial, we investigated the recommended dose of temsirolimus in association with R-CHOP (R-CHOP-T), or high-dose cytarabine plus rituximab (R-DHA-T), or fludarabine, cyclophosphamide plus rituximab (R-FC-T). From November 11, 2011 to February 26, 2015, forty-one patients were enrolled. Patients presented with high MIPI (47.5%) at relapse and a median number of treatments of 1 (1–3). Patients were treated by R-CHOP-T (n = 10), R-FC-T (n = 14), or R-DHA-T (n = 17) according to the choice of local investigators. The maximum tolerated dose (MTD) was 15 mg in the R-CHOP-T arm and has not been determined in other treatment arms because of toxicities. All patients experienced ≥ Grade 3 adverse events, mainly thrombocytopenia (76%). Twenty-six patients discontinued prematurely the treatment, mostly for toxicity (n = 12) and progression of the disease (n = 8). Of note, 6 patients of the R-DHA-T arm reached complete remission (35%). Temsirolimus with immuno-chemotherapy is associated with a high rate of toxicities. Determination of MTD could only be achieved for R-CHOP-T arm. Associations between temsirolimus and other targeted therapies may be warranted for R/R MCL patients.

Gray zone lymphoma (GZL), a B-cell lymphoma with features intermediate between large B-cell lymphoma (LBCL) and classic Hodgkin lymphoma (cHL), is a rare and poorly defined entity. Alongside GZL, a subset of Epstein-Barr virus (EBV)–positive diffuse large B-cell lymphoma (DLBCL) has been described with polymorphic/GZL-like morphology (polymorphic-EBV-L). To fill the important gap in our understanding of the pathogenic process underlying these entities, we performed a gene expression study of a large international cohort of GZL and polymorphic-EBV-L, combined with cHL and primary mediastinal large B-cell lymphoma (PMBCL) cases. In an unsupervised principal component analysis, GZL cases presented with intermediate scores in a spectrum between cHL and PMBCL, whereas polymorphic-EBV-L clustered distinctly. The main biological pathways underlying the GZL spectrum were related to cell cycle, reflecting tumor cell content, and extracellular matrix signatures related to the cellular tumor microenvironment. Differential expression analysis and phenotypic characterization of the tumor microenvironment highlighted the predominance of regulatory macrophages in GZL compared with cHL and PMBCL. Two distinct subtypes of GZL were distinguishable that were phenotypically reminiscent of PMBCL and DLBCL, and we observed an association of PMBCL-type GZL with clinical presentation in the “thymic” anatomic niche. In summary, gene expression profiling (GEP) enabled us to add precision to the GZL spectrum, describe the biological distinction compared with polymorphic-EBV-L, and distinguish cases with and without thymic involvement as 2 subgroups of GZL, namely PMBCL-like and DLBCL-like GZL.

Composite and sequential lymphomas involving both classical Hodgkin lymphoma (CHL) and primary mediastinal B-cell lymphoma (PMBCL) are rare phenomena. Beyond the relevant biological interest raised by these cases, treatments and outcome data are poorly covered in the recent literature. This retrospective analysis describes the pathological and clinical characteristics of 10 composite and 15 sequential cases included after a central pathological review. At diagnosis, 70% of the composite lymphomas presented a disseminated and extranodal disease. Among the 15 sequential lymphomas, 12 were CHL at first occurrence and three were PMBCL. Based on their clinical evolution, these sequential lymphomas could be divided into early (i.e., diagnosis of second lymphoma within a year) and late [(i.e., a second lymphoma occurrence occurring after a long period of complete remission]). All composite cases were alive in complete remission after a median follow-up of 34 months. If the early sequential lymphoma presented a particularly poor outcome with a median overall survival shorter than one year, the late cases were efficiently salvaged. Further molecular studies are needed to describe the underlying biology of these rare diseases, possibly representing the extreme of tumour cell plasticity found in grey-zone lymphoma.

Background: Primary refractory (PREF) follicular lymphoma (FL) has a completely different clinical course from that of FL that responds to front-line treatments. In addition to having poor responses to salvage therapies, it seems that patients with PREF are at increased risk of histological transformation (HT). The Aristotle consortium presented the opportunity of investigating the risk of HT in a very large series of cases. Thus, we investigated the risk of HT in patients with PREF FL compared with that of responding patients or in stable disease and ultimately their outcome. Methods: Six thousand three hundred thirty-nine patients from the Aristotle database were included in the analysis. These patients had a histologically confirmed grade 1, 2 or 3a FL diagnosed between 1997 and 2013. The primary end-points were the cumulative incidence (CI) of HT at the first progression or relapse and the survival after transformation. Findings.: The 5-year CI of HT among patients with PREF was 34% (95% confidence interval (CI): 27–43), whilst it was 7.1% (95% CI: 6.0–8.5) in the group of patients with partial response (PR) or stable disease (SD) (PR + SD) and 3.5% (95% CI: 3.0–4.2) in the group of patients achieving complete response (CR). The 5-year survival after relapse (SAR) was 33% (95% CI: 28–39) for the PREF group, 57% (95% CI 54–61) in patients with PR, 51% (95% CI 43–58) in the SD group after first-line therapy and 63% (95% CI: 66–72) in patients with CR after initial treatment (p-value

Introduction: Primary mediastinal large B-cell lymphoma (PMBL) is a rare subtype of lymphoma, clinically and biologically distinct from diffuse large B-cell lymphoma (DLBCL) that shows overlapping ...

Classical Hodgkin lymphoma is a neoplastic hematological disease. Standard first-line therapy, including chemotherapy and radiotherapy, is curative in >85% of early-stage patients, with a 5-year survival rate of >95%. However, approximately 15% of patients have hard-to-treat lymphoma with poor outcomes, and new treatment strategies are needed for these young adults. There are several well-documented cases in the medical literature on hematologic cancer remission following natural human viral infections. Therefore, hoping to reproduce these spontaneous tumor regressions, researchers have been investigating various viruses with oncolytic properties. There is a high rationale for using virotherapy in the treatment of Hodgkin lymphoma, in which tumor cells are often infected with the Epstein-Barr virus. Modern viral technologies and current knowledge about the relationship between viruses and cancer could accelerate the discovery of effective viral oncolytic therapies. This article reviews the use of oncolytic viruses as innovative therapies for treating Hodgkin lymphoma.

Primary mediastinal large B-cell lymphoma (PMBL) represents a clinically and pathologically distinct subtype of large B-cell lymphomas. Furthermore, molecular studies, including global gene expression profiling, have provided evidence that PMBL is more closely related to classical Hodgkin lymphoma (cHL). Although targeted sequencing studies have revealed a number of mutations involved in PMBL pathogenesis, a comprehensive description of disease-associated genetic alterations and perturbed pathways is still lacking. Here, we performed whole-exome sequencing of 95 PMBL tumors to inform on oncogenic driver genes and recurrent copy number alterations. The integration of somatic gene mutations with gene expression signatures provides further insights into genotype–phenotype interrelation in PMBL. We identified highly recurrent oncogenic mutations in the Janus kinase-signal transducer and activator of transcription and nuclear factor κB pathways, and provide additional evidence of the importance of immune evasion in PMBL (CIITA, CD58, B2M, CD274, and PDCD1LG2). Our analyses highlight the interferon response factor (IRF) pathway as a putative novel hallmark with frequent alterations in multiple pathway members (IRF2BP2, IRF4, and IRF8). In addition, our integrative analysis illustrates the importance of JAK1, RELB, and EP300 mutations driving oncogenic signaling. The identified driver genes were significantly more frequently mutated in PMBL compared with diffuse large B-cell lymphoma, whereas only a limited number of genes were significantly different between PMBL and cHL, emphasizing the close relation between these entities. Our study, performed on a large cohort of PMBL, highlights the importance of distinctive genetic alterations for disease taxonomy with relevance for diagnostic evaluation and therapeutic decision-making.

Points essentiels Les lymphomes a petites cellules non folliculaires regroupent plusieurs entites dont la description clinique et pathologique s’est affinee dans les 20 dernieres annees. Le lymphome du MALT, developpe aux depends du tissu lymphoide associe aux muqueuses, se manifeste par une atteinte d’organe en general isolee, mais une extension a distance peut exister. Certains patients atteints de lymphomes du MALT peuvent etre traites en eradiquant l’agent infectieux associe, tandis que le traitement local doit etre privilegie pour les autres cas ; et les formes disseminees et les patients en rechute relevent d’une association avec anticorps anti-CD20 et agent cytotoxique. Les patients atteints de lymphomes a cellules du manteau ont pu beneficier de nombreuses avancees, incluant l’utilisation de la cytarabine et de la bendamustine, les anticorps anti-CD20, les traitements intensifs (autogreffe) et dernierement une therapie ciblee (ibrutinib, inhibiteur de la tyrosine kinase de Bruton – BTK). Les patients atteints de lymphome de la zone marginale splenique ou ganglionnaire doivent etre evalues pour differentes options, parmi lesquelles l’immunochimiotherapie reste importante. Pour toutes ces entites, la mise en place des traitements pourra etre retardee de plusieurs annees pour certains groupes de patients. Bien que consideres comme incurables, le pronostic de ces pathologies s’est nettement ameliore et la majorite des patients pourront vivre de nombreuses annees avec des intervalles sans traitement souvent prolonges.

Gray-zone lymphoma (GZL) with features intermediate between classic Hodgkin lymphoma (cHL) and large B-cell lymphoma (LBCL) was introduced as a provisional entity into the World Health Organization classification in 2008. However, as diagnostic criteria are imprecise, reliable identification of GZL cases remains challenging. Here, we describe the histopathologic features of 139 GZL cases from a retrospective Lymphoma Study Association (LYSA) study with the goal to improve classification accuracy. Inclusion criteria were based on literature review and an expert consensus opinion of the LYSA hematopathologist panel. We observed 86 cases with a morphology more closely related to cHL, but with an LBCL immunophenotype based on strong and homogenous B-cell marker expression (CD20 and/or CD79a, OCT2, BOB1, PAX5) on all tumor cells (cHL-like GZL). Fifty-three cases were morphologically more closely related to LBCL but harbored a cHL immunophenotype (LBCL-like GZL). Importantly, we observed a continuous morphologic and immunophenotypic spectrum within these 2 GZL categories. The majority of cases presented genetic immune escape features with CD274/PDCD1LG2 and/or CIITA structural variants by fluorescence in situ hybridization. Patients without mediastinal involvement at diagnosis (17%) were older than those with mediastinal tumors (median: 56 vs. 39 y). Cases associated with Epstein-Barr virus (24%) presented with similar patient characteristics and outcome as Epstein-Barr virus negative cases. In summary, we provide refined diagnostic criteria that contribute to a more precise pathologic and clinical characterization of GZL within a broad spectrum from cHL-like to LBCL-like disease.

Follicular lymphoma (FL) is a common indolent lymphoma in which clinical and biological heterogeneity is increasingly recognized.[1][1] Although median survival for newly diagnosed FL patients may be as high as 18 years,[2][2] a significant subset of patients is at risk of adverse outcomes. In

The mutational landscape of gray zone lymphoma (GZL) has not yet been established, and differences from related entities are largely unknown. Here, we studied coding sequence mutations of 50 Epstein-Barr virus (EBV)-negative GZLs and 20 polymorphic EBV+ diffuse large B-cell lymphoma (DLBCL) not otherwise specified (poly-EBV-L) in comparison with classical Hodgkin lymphoma (cHL), primary mediastinal large B-cell lymphoma (PMBCL), and DLBCL. Exomes of 21 GZL and 7 poly-EBV-L cases, along with paired constitutional DNA, were analyzed as a discovery cohort, followed by targeted sequencing of 217 genes in an extension cohort of 29 GZL and 13 poly-EBV-L cases. GZL cases with thymic niche involvement (anterior mediastinal mass) exhibited a mutation profile closely resembling cHL and PMBCL, with SOCS1 (45%), B2M (45%), TNFAIP3 (35%), GNA13 (35%), LRRN3 (32%), and NFKBIA (29%) being the most recurrently mutated genes. In contrast, GZL cases without thymic niche involvement (n = 18) had a significantly distinct pattern that was enriched in mutations related to apoptosis defects (TP53 [39%], BCL2 [28%], BIRC6 [22%]) and depleted in GNA13, XPO1, or NF-κB signaling pathway mutations (TNFAIP3, NFKBIE, IKBKB, NFKBIA). They also exhibited more BCL2/BCL6 rearrangements compared with thymic GZL. Poly-EBV-L cases presented a distinct mutational profile, including STAT3 mutations and a significantly lower coding mutation load in comparison with EBV− GZL. Our study highlights characteristic mutational patterns in GZL associated with presentation in the thymic niche, suggesting a common cell of origin and disease evolution overlapping with related anterior mediastinal lymphomas.

Follicular lymphoma (FL) accounts for about 20% of all non-Hodgkin lymphoma (NHL) and is the most common indolent form. The disease is characterized by an extremely heterogeneous clinical course dr...

Mantle cell lymphoma has a dismal prognosis at relapse or in the refractory setting. Among therapies, mTor pathway targeting by temsirolimus has been the first strategy approved for relapse in Europe. While its efficacy in monotherapy has long been demonstrated, its use remains limited. In the T

In the rituximab era, one-third of diffuse large B-cell lymphoma patients experience relapse/refractory disease after first-line anthracycline-based immunochemotherapy. Optimal management remains an unmet medical need. The aim of this study was to report the outcomes of a cohort of refractory patients according to their patterns of refractoriness and the type of salvage option. We performed a retrospective analysis, which included 104 diffuse large B-cell lymphoma patients treated at Lyon Sud University Hospital (2002-2017) who presented with refractory disease. Refractoriness was defined as progressive/stable disease during first-line treatment (primary refractory, N = 47), a partial response after the end of first-line treatment that required subsequent treatment (residual disease, N = 19), or relapse within 1 year of diagnosis after an initial complete response (CR) (early relapse, N = 38). The 2-year overall survival (OS) rates for primary refractory, early relapse, and residual disease patients were 27%, 25%, and 52%, respectively, while the event-free survival rates for those groups were 13%, 13%, and 42%, respectively. In a univariate analysis, lactate dehydrogenase level, Ann Arbor stage, poor performance status, high age-adjusted International Prognostic Index score, and age > 65 years were associated with shorter OS. The use of rituximab and platinum-based chemo during the first salvage treatment was associated with prolonged OS. In a multivariate analysis, age (HR:2.06) and rituximab use (HR:0.54) were associated with OS. Among patients

Background: Diffuse large B cell lymphoma (DLBCL) is an aggressive malignancy of mature B cells. The disease has traditionally been subdivided into cell-of-origin (COO) subtypes - germinal centre B cell-like (GCB) or activated B cell-like (ABC) - as determined by expression profiling or immunohistochemistry of the tumor cells. However the role of the immune microenvironment, and how the tumor and immune system interact to influence patient outcomes, remains to be fully investigated. Methods: In this project, we used mass cytometry (CyTOF) to deeply profile both tumor cell phenotypes and the immune microenvironments, alongside ABC/GCB classification and mutation profiling, in a discovery cohort of 54 DLBCL cases. As well, a validation cohort of 129 DLBCL patients were immunologically profiled by high-dimensional conventional flow cytometry, and their immune profiles alongside ABC/GCB classification, mutation profiling, and RNAseq data, were correlated with patient outcomes as measured by progression-free survival (PFS). Results: Analysis of the CyTOF/discovery cohort demonstrated that DLBCL tumor cells are phenotypically unique to each patient, with a small number of samples displaying distinct sub-clonal structure, often distinguished by differential expression of immune-related proteins like MHC-II. ABC/GCB classifications could be recapitulated based on tumor cell phenotypes, demonstrating that while COO was a robust feature, a great deal of heterogeneity exists within these established subtypes. Immunological profiling of the CyTOF/discovery cohort revealed that DLBCL samples could be divided into three distinct groups which roughly correlated with abundances of naïve, activated, or terminally differentiated T cells, respectively. This profiling schema was extended to the validation cohort of 129 patients which in turn led to identification of a subset of patients with a very high risk of disease progression (5-year PFS; 30% high risk vs. 80% low risk, p This final classifier was based on a combination of ABC-DLBCL designation, combined with the presence of an immune microenvironment dominated by terminally differentiated (CD57+) T cells. We performed a limited series of functional studies using primary DLBCL biopsy samples to characterize further these CD57+ T cells as clonally restricted and incapable of responding to antigenic challenge. Interestingly, traditional immune markers of T cell exhaustion such as PD-1, TIM3, LAG3 and TIGIT were not correlated with patient outcomes. Conclusions: Overall, this study demonstrates the utility of immune profiling in risk stratification based on initial diagnostic biopsy material and highlights a subset of DLBCL patients who may benefit from immune-based therapies to rejuvenate the anti-tumor T cell response. We conclude that T cell senescence, rather than exhaustion, is the more relevant feature in DLBCL disease biology and highlights an alternate target for immunomodulatory therapy. Figure 1 Figure 1. Disclosures Craig: Bayer: Consultancy. Slack: Seagen: Consultancy, Honoraria. Scott: Abbvie: Consultancy; AstraZeneca: Consultancy; Celgene: Consultancy; NanoString Technologies: Patents & Royalties: Patent describing measuring the proliferation signature in MCL using gene expression profiling.; BC Cancer: Patents & Royalties: Patent describing assigning DLBCL COO by gene expression profiling--licensed to NanoString Technologies. Patent describing measuring the proliferation signature in MCL using gene expression profiling. ; Rich/Genentech: Research Funding; Janssen: Consultancy, Research Funding; Incyte: Consultancy. Steidl: Epizyme: Research Funding; Bayer: Consultancy; Curis Inc.: Consultancy; Seattle Genetics: Consultancy; AbbVie: Consultancy; Trillium Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding.

Follicular lymphoma (FL) is an indolent lymphoma of mature B-cells but may transform to a more aggressive histology, most commonly diffuse large B cell lymphoma. Recurrent mutations associated with transformation have been identified; however, biological predictors to guide initial therapy have remained elusive. We hypothesized that clonal heterogeneity and patient-specific immune responses would contribute to variable clinical outcomes and that understanding the complexity of the entire tumor "ecosystem" would allow more individualized matching of patients with specific therapies. In prior ASH meetings, we presented preliminary analyses of B and T cell-focused phenotypic profiling of 155 newly diagnosed pre-treatment FL biopsy samples at single cell resolution by mass cytometry (CyTOF). These prior analyses unexpectedly revealed two distinct evolutionary trajectories which were independently reflected in both B and T cell compartments. One trajectory expectedly involved germinal center B cells (GCB); however, the other was more related to naïve/memory B-cells (NMB). Interestingly, cluster co-occurrence analysis suggested that the GCB and NMB trajectories were mutually exclusive of another and tended not to be found within the same tumor despite their high prevalences (χ 2 = 29.8, DF=1, p=4.8e-8; χ 2 test). Clustering analysis based on relative abundances of T cell subsets revealed 4 distinct immune patterns: Group 1 was characterized by naive T cells; Group 2 by T follicular helper (Tfh) cells; Group 3 by CD4+ regulatory T (Treg) and CD8 effector memory cells (CD8EM); and Group 4 by a diverse complement of naive, memory, and differentiated effector subsets. We report here further analyses, now incorporating DNA mutational and clinical outcome information. Tumors were parsed into 3 types based on the phenotype of the majority (>50%) of tumor cells present in the diagnostic biopsy: Type A tumors dominated by GCB cells (28% of samples), type B tumors dominated by NMB cells (18% of samples), and type nonA/nonB tumors dominated by neither GCB nor NMB cells (54% of samples). Type A tumors were significantly enriched for mutations in EZH2, TNFRSF14, and MEF2B, while no significant mutational associations were seen in type B and nonA/nonB tumors. Type B was significantly associated with increased risk of transformation, and when combined with a measure of intratumoral phenotypic diversity ("Entropy"), we found that type B tumors with high (above median) Entropy, representing 8.5% of all cases, exhibited a hazard ratio (HR) of 5.9 for transformation risk in comparison to all others combined (log-rank p We also investigated survival outcomes using a sub-cohort of 108 patients who had received bendamustine + rituximab (BR) as their primary therapy. Despite the association of type B tumors with transformation risk, patients with type nonA/nonB tumors exhibited the poorest outcomes as measured by disease-specific survival (DSS; 5yr survival 78% vs 98% for all others combined, log-rank p=0.0241). Combining type nonA/nonB with high Entropy defined 20% of patients with significantly shorter DSS (HR 5.3, log-rank p=0.0019). In multivariate analysis, type nonA/nonB and high risk FLIPI score were significant (p=0.038 and 0.035, respectively), while high Entropy trended with inferior DSS (HR 2.8, 95% CI 0.76-10; p=0.123). Taken together, these data support that CyTOF-defined phenotypic subtypes of FL and intratumoral phenotypic diversity identify clinically significant subgroups at initial diagnosis and compare favorably against FLIPI score in predicting both risk of transformation and inferior DSS. Figure 1 Figure 1. Disclosures Freeman: Incyte: Honoraria; Seattle Genetics: Honoraria; Sanofi: Honoraria, Speakers Bureau; Bristol Myers Squibb: Honoraria, Speakers Bureau; Amgen: Honoraria; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria; Teva: Research Funding; Abbvie: Honoraria; Roche: Research Funding. Sehn: Genmab: Consultancy; Novartis: Consultancy; Debiopharm: Consultancy. Savage: BMS: Consultancy, Honoraria, Other: Institutional clinical trial funding; Seattle Genetics: Consultancy, Honoraria; Astra-Zeneca: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Other: Institutional clinical trial funding; Takeda: Other: Institutional clinical trial funding; Roche: Research Funding; Servier: Consultancy, Honoraria; Beigene: Other: Institutional clinical trial funding; Genentech: Research Funding. Craig: Bayer: Consultancy. Scott: Abbvie: Consultancy; AstraZeneca: Consultancy; Incyte: Consultancy; Celgene: Consultancy; NanoString Technologies: Patents & Royalties: Patent describing measuring the proliferation signature in MCL using gene expression profiling.; BC Cancer: Patents & Royalties: Patent describing assigning DLBCL COO by gene expression profiling--licensed to NanoString Technologies. Patent describing measuring the proliferation signature in MCL using gene expression profiling. ; Rich/Genentech: Research Funding; Janssen: Consultancy, Research Funding. Steidl: Trillium Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; AbbVie: Consultancy; Seattle Genetics: Consultancy; Curis Inc.: Consultancy; Bayer: Consultancy; Epizyme: Research Funding.

BackgroundT-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory domains (TIGIT), and costimulatory receptor CD226 competitively bind 2 ligands, CD155 and CD112, which are expressed by tumor cells and antigen-presenting cells in the tumor microenvironment.1 2 Dual TIGIT/programmed cell death protein-1 (PD-1) blockade increased tumor antigen-specific CD8+ T-cell expansion and function in vitro and promoted potent antitumor response in vivo.3 4 TIGIT/PD-1 dual blockade using a TIGIT monoclonal antibody (mAb) with intact Fc produced clinical responses in advanced cancer.5 SEA-TGT is an investigational, human, nonfucosylated mAb directed against TIGIT. SEA-TGT binds to TIGIT, blocking inhibitory checkpoint signals directed at T cells. SEA-TGT enhances binding to activating FcγRIIIa and decreases binding to inhibitory FcγRIIb; this depletes immunosuppressive regulatory T cells and amplifies naive and memory T cells, potentially augmenting PD-1 inhibition effects. Preclinically, at suboptimal doses, SEA-TGT plus anti-PD-1 mAbs had superior antitumor activity than either agent alone.6MethodsSafety and antitumor activity of SEA TGT in ~377 adults (≥18 years) will be evaluated in this phase 1, multicenter, open-label, dose-escalation/expansion study. Part A will assess the safety/tolerability of SEA TGT to determine maximum tolerated and recommended doses. Part B will assess the safety and antitumor activity of the recommended dose in disease-specific expansion cohorts. Part C will assess SEA-TGT plus sasanlimab in dose-expansion cohorts after an initial safety run-in. Patients with histologically/cytologically confirmed relapsed/refractory/progressive metastatic solid tumors including non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), gastric/gastroesophageal junction carcinoma, cutaneous melanoma, bladder, cervical, ovarian or triple-negative breast cancer, or selected lymphomas will be eligible for Parts A and B. Part C will enroll patients with histologically confirmed advanced NSCLC (high [tumor proportion score (TPS) ≥50%] and low [TPS=1–49%] PD ligand 1 [PD-L1] expression), cutaneous melanoma, and HNSCC without previous anti–PD-1/PD-L1 therapy exposure. SEA TGT will be administered on Day 1 of 21-day cycles.Laboratory abnormalities, adverse events, dose-limiting toxicities, and dose-level safety and activity are primary endpoints. Secondary endpoints are objective response (OR) and complete response (CR) rates, duration of OR/CR, progression-free survival, overall survival, pharmacokinetics (PK), and antidrug antibodies. Exploratory analysis will include pharmacodynamics (PD), PK/PD relationships, biomarkers, and resistance to SEA-TGT. This trial is recruiting in Europe and North America.Trial RegistrationNCT04254107ReferencesBlake SJ, Dougall WC, Miles JJ, et al. Molecular pathways: Targeting CD96 and TIGIT for cancer immunotherapy. Clin Cancer Res 2016;22(21):5183–5188.Chauvin JM, Zarour HM. TIGIT in cancer immunotherapy. J ImmunoTher Cancer 2020;8:e000957.Johnston RJ, Comps-Agrar L, Hackney J, et al. The immunoreceptor TIGIT regulates antitumor and antiviral CD8+ T cell effector function. Cancer Cell 2014;26(6):923–937.Chauvin JM, Pagliano O, Fourcade J, et al. TIGIT and PD-1 impair tumor antigen-specific CD8+ T cells in melanoma patients. J Clin Invest 2015;125(5):2046–2058.Rodriguez-Abreu D, Johnson ML, Hussein MA, et al. Primary analysis of a randomized, double-blind, phase 2 study of the anti-TIGIT antibody tiragolumab (tira) plus atezolizumab (atezo) versus placebo plus atezo as first-line (1L) treatment in patients with PD-L1-selected NSCLC (CITYSCAPE). J Clin Oncol 2020;38(15 suppl):9503.Smith A, Zeng W, Lucas S, et al. Poster 1583. SEA-TGT is an empowered anti-TIGIT antibody that displays superior combinatorial activity with several therapeutic agents. Presented at: American Association for Cancer Research Annual Meeting; April 9–14, 2021; Virtual Meeting.Ethics ApprovalInstitutional review boards or independent ethics committees of participating sites approved the trial, which will be conducted in compliance with the Declaration of Helsinki and International Conference on Harmonisation Guidelines for Good Clinical Practice. All patients will provide written informed consent.

The aim of this retrospective cohort study was to investigate the incidence of delayed methotrexate elimination in patients treated with high-dose methotrexate (≥1 g/m2 ) for haematological malignancy and to identify the impact of interacting drugs, especially proton-pump inhibitors (PPIs) and ranitidine. All patients treated with high-dose methotrexate over a 6 year period in the haematology department of the Lyon Sud University Hospital (Hospices Civils de Lyon, France) were included. Potential risk factors for delayed methotrexate elimination were tested in a generalized linear model by univariate analysis: patient age, gender, methotrexate dose, administration of PPI or ranitidine, and concomitant nephrotoxic drugs. A total of 412 cycles of methotrexate were administered to 179 patients. Proton-pump inhibitors were co-administered with methotrexate in 127 cycles and ranitidine in 192 cycles. Ninety-three cycles included no antacid drugs. A total of 918 plasma methotrexate assays were performed. Methotrexate concentrations were checked at 24 hours in 92% of cycles. Delayed methotrexate elimination was observed in 20.9% of cycles. A total of 63 cycles with delayed methotrexate elimination were only identified on plasma methotrexate measures at 72 hours: ie, plasma methotrexate was in the normal range at 24 and 48 hour post injection. Use of PPI/ranitidine or no antacid drugs did not increase risk of delayed elimination, with respectively delayed methotrexate elimination in 20.5%, 21.9%, and 19.4% of cycles (P = .89). Impaired baseline creatinine clearance showed significant association in univariate analysis. Fifteen patients showed grade 1 acute kidney injury, 1 grade 2, 2 grade 3, and none grade 4. For half of these cases, delayed methotrexate elimination was observed and the 2 grade 3 events appeared in patients treated with PPIs. This retrospective study suggests that there is no association between concomitant use of proton-pump inhibitors (pantoprazole and esomeprazole) or ranitidine and delayed methotrexate elimination.

Recent advances in next-generation sequencing (NGS) have enabled the quantitation of circulating tumour DNA (ctDNA) encoding the clonal rearranged V(D)J immunoglobulin locus. We aimed to evaluate the clonal heterogeneity of follicular lymphoma (FL) in the tumour and the plasma at diagnosis and to assess the prognostic value of the ctDNA level. Plasma samples at diagnosis were available for 34 patients registered in the PRIMA trial (NCT00140582). One tumour clonotype or more could be detected for 29 (85%) and 25 (74%) patients, respectively, in the tumour or plasma samples. In 18 patients, several subclones were detected in the tumour (2 to 71 subclones/cases) and/or in the plasma (2 to 20 subclones/cases). In more than half of the cases, the distribution of subclones differed between the tumour and plasma samples, reflecting high clonal heterogeneity and diversity in lymphoma subclone dissemination. In multivariate analysis, a high level of ctDNA was the only independent factor associated with patients’ progression-free survival (HR 4, IC 95 (1.1-37), p=.039). In conclusion, an NGS-based immunosequencing method reveals the marked clonal heterogeneity of follicular lymphoma in patients with FL, and quantification of ctDNA at diagnosis represents a potential powerful prognostic biomarker that needs to be investigated in larger cohorts.

Background. Diffuse large B cell lymphoma (DLBCL) is the most common adult non-Hodgkin lymphoma. Despite therapeutic advances, 40% of the patients (pts) and especially pts older than 65 years old (y/o), will experience a relapsed or refractory (R/R) disease. Novel therapies as well as predictive biomarkers are required for these patients with a poor prognosis after standard salvage regimens. We aimed at establishing whether tumor molecular characterization by a customized target panel in pts with R/R DLBLC prior to enrollment in a phase I clinical trials might impact therapeutic decision making and outcome prediction. Methods. Paired targeted next generation sequencing for all consecutive pts with R/R DLBCL from germline sample and fresh tumor biopsy were performed at the time of enrollment in phase I clinical trials within the early phase clinical department. Tumor and germline samples of enrolled patients were sequenced using Ion Torrent technology on an in-house customized panel of 44 genes. Molecular and cluster mapping of recurrent molecular abnormalities was determined by integrated completed likelihood (ICL) in patients with relapsed diffuse large B-cell lymphoma. Predictive and prognostic impact of molecular profile was assessed on overall survival (OS). Results. Between 2013 and 2020, 89 pts with R/R DLBCL were included in the study. At time of inclusion, mean age was 62 (range 23-83) y/o, 50 pts (56%) were male, median prior lines of systemic treatment was 2 (range 1-9). Age adjusted international prognostic index (aaIPI) score was 0-1 in 42 pts (47%) and 2-3 in 47 pts (53%). Among the 82 cases with a cell of origin (COO) status assessed by immunohistochemistry, 55 (67%) pts had a germinal center (GC) and 27 pts (33%) a non-GC. The sequencing panel was informative in 86 pts (97%) and 3 pts (3%) had no variants identified. The most recurrently altered genes by mutations (m) were TP53m (n=38; 43%), CREBBPm (n=29; 33%), KMT2Dm (n=24; 27%), PIM1m (n=23; 26%) and BCL2m (n=20; 22%). Mutual exclusivity and co-occurrence analysis underlined that KMT2Dm were fully exclusive from MEF2Bm (p Conclusion. A molecular tumor characterization of patients with R/R DLBCL emphasizes high incidence of TP53 and epigenetic modifying oncogenes CREBBP and KMT2D mutations. Four distinct genetic clusters were identified that could serve as the basis for a molecular-matched therapeutic approach. Disclosures Michot: Medimmune: Research Funding; Lytix Biopharma: Research Funding; Lysarc: Research Funding; Janssen: Other, Research Funding; Celgene: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Agios: Research Funding; AZD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Xencor: Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other; Sanofi: Research Funding; Roche: Research Funding; Argen-x: Research Funding; Abbvie: Research Funding; Gustave Roussy: Honoraria, Other: Abbvie, Aduro, Agios, Amgen, Argen-x, Astex, AstraZeneca, Aveo pharmaceuticals, Bayer, Beigene, Blueprint, BMS, Boeringer Ingelheim, Celgene, Chugai, Clovis, Daiichi Sankyo, Debiopharm, Eisai, Eos, Exelixis, Forma, Gamamabs, Genentech, Gortec, GSK, H3 bio, Research Funding; Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Exelixis: Research Funding; Eos: Research Funding; Eisai: Research Funding; Lilly: Research Funding; Mundi Pharma: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Amgen: Research Funding; AstraZeneca: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Debiopharm: Research Funding; Daiichi Sankyo: Research Funding; Forma: Research Funding; Genentech: Research Funding; Kyowa: Research Funding. Varga:Astra Zeneca: Current Employment. Ribrag:Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; arGEN-X-BVBA: Research Funding; BAY1000394 studies on MCL: Patents & Royalties; Nanostring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Eisai: Honoraria; AZD: Honoraria, Other; Institut Gustave Roussy: Current Employment; Pharmamar: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; argenX: Current equity holder in publicly-traded company, Research Funding; Epizyme: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Background: Early drug development is associated with a high rate of failure in patients with relapsed or refractory diffuse large B-cell lymphoma (R/R DLBLC), partly due to genomic heterogeneity. Precision medicine aims at identifying patients with cancer who are likely to respond to targeted therapies. Here we assessed the clinical impact of characterizing actionable and molecular targets and matching targeted therapy in pts with R/R DLBCL prior enrollment in early phase clinical trials (epCT). Methods: Pts with R/R DLBCL enrolled in epCT, provided paired samples including germline and fresh tumor tissue sample. Paired samples were analyzed by targeted next generation sequencing (NGS) using a customized panel of 44 genes (Ion Torrent). Clinical actionability of genomic alterations and orientation to targeted therapy were prospectively assessed at the Hematological Tumor Board from our Institution according to the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT) tiers (ESCAT scale; J. Mateo, Annals of Oncology, 2018[1]). Pts were classified as molecularly matched (MM) i.e. treated based on the presence of an ESCAT actionable molecular abnormality, or non-molecularly matched (no-MM). Tumor and clinical characteristics and outcome of pts were collected. Results: From 2013 to 2020, 90 pts with R/R DLBCL screened for early clinical trial had tumor & germline samples sequenced by NGS. The mean age was 62 years old (range, 23-83) and median prior lines of systemic therapy was 2 (range 1-9). Sixteen (18%) pts were enrolled in epCT and treated with MO drugs, 43 pts (48%) were enrolled in epCT and treated with no-MM drugs, and 31 (34%) pts were not enrolled in epCT. The main clinical characteristics of the pts were similar in both MM and no-MM groups (table 1). Based on ESCAT scale, targeted therapies of the 16 pts MM were distributed as "investigational-level" tier II in 6 pts (3 pts EZH2 mutant [m] treated with EZH2 inhibitors; 3 patients with a CD79Bm treated with BTK inhibitors); "hypothetical-level" tier III in 1 pt BRAFm treated with a BRAF inhibitor; and "hypothetical-level" tier IV in 9 pts (6 pts MYD88m treated with cereblon modulator drugs; 2 pts with BCL7Am/ARID1Am treated with investigational epigenetic modifier drugs; 1 pt with MYCm treated with a PI3K inhibitor). Median progression-free survival in MM and no-MM pts, were 3.3 and 1.7 months, respectively (p=0.0092; HR=0.47 [CI95:0.27-0.83]). Median overall survival in MM and no-MM pts were 20.0 and 6.7 months, respectively (p=0.0238; HR=0.49 [CI95: 0.26-0.91]) (figure 1). Conclusions: Molecular orientation before inclusion in early phase clinical trials was associated with better outcomes in patients with R/R DLBCL. A molecular tumor profile could be useful to manage patients with R/R DLBCL with precision medicine helping to identify patients likely to respond to targeted therapies. Reference. 1- Mateo J, Chakravarty D, Dienstmann R et al. A framework to rank genomic alterations as targets for cancer precision medicine: the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT). Annals of Oncology 2018; 29(9):1895-1902. Table 1.Patient's characteristics at time of R/R DLBCL relapse and tumor sample in molecularly matched patients (MM group) and non-molecularly matched patients (no-MM group). Data presented are n (%) unless otherwise stated. MM= Molecularly matched. no-MM= Non-molecularly matched. R/R DLBCL= relapsed or refractory diffuse large B-cell lymphoma. y.o. = years old. mo.= months. ECOG PS= Eastern Cooperative Oncology Group performance status. NHL=non-Hodgkin lymphoma. ASCT= Autostem cell transplantation. IHC= Immunohistochemistry. COO= Cell of origin. GC= Germinal center. ABC= Activated B-cell. NA= Not available. LDH= Lactate deshydrogenase. *the p-value indicates the comparison between the proportions of the groups from a contingency table, and was calculated by the exact Fisher test. All tests were non-parametric. The p values were calculated by two-tailed and a 95% confidence interval was used, with values less than 0.005 considered being significantly different. Disclosures Michot: Argen-x: Research Funding; Eos: Research Funding; Exelixis: Research Funding; Amgen: Research Funding; Astex: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Research Funding; Daiichi Sankyo: Research Funding; AstraZeneca: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Lysarc: Research Funding; Lilly: Research Funding; Kyowa: Research Funding; Genentech: Research Funding; Forma: Research Funding; Agios: Research Funding; AZD: Honoraria, Membership on an entity's Board of Directors or advisory committees; Mundi Pharma: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Celgene: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other; Xencor: Research Funding; Sanofi: Research Funding; Roche: Research Funding; Medimmune: Research Funding; Lytix Biopharma: Research Funding; Janssen: Other, Research Funding; Debiopharm: Research Funding; Gustave Roussy: Honoraria, Other: Abbvie, Aduro, Agios, Amgen, Argen-x, Astex, AstraZeneca, Aveo pharmaceuticals, Bayer, Beigene, Blueprint, BMS, Boeringer Ingelheim, Celgene, Chugai, Clovis, Daiichi Sankyo, Debiopharm, Eisai, Eos, Exelixis, Forma, Gamamabs, Genentech, Gortec, GSK, H3 bio, Research Funding; Abbvie: Research Funding. Varga:Astra Zeneca: Current Employment. Ribrag:argenX: Current equity holder in publicly-traded company, Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; arGEN-X-BVBA: Research Funding; BAY1000394 studies on MCL: Patents & Royalties; Institut Gustave Roussy: Current Employment; Epizyme: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AZD: Honoraria, Other; Pharmamar: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Eisai: Honoraria; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Honoraria; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Nanostring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses; Infinity: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Although rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard treatment for patients with diffuse large B-cell lymphoma (DLBCL), ∼30% to 50% of patients are not cured by this treatment, depending on disease stage or prognostic index. Among patients for whom R-CHOP therapy fails, 20% suffer from primary refractory disease (progress during or right after treatment) whereas 30% relapse after achieving complete remission (CR). Currently, there is no good definition enabling us to identify these 2 groups upon diagnosis. Most of the refractory patients exhibit double-hit lymphoma (MYC-BCL2 rearrangement) or double-protein-expression lymphoma (MYC-BCL2 hyperexpression) which have a more aggressive clinical picture. New strategies are currently being explored to obtain better CR rates and fewer relapses. Although young relapsing patients are treated with high-dose therapy followed by autologous transplant, there is an unmet need for better salvage regimens in this setting. To prevent relapse, maintenance therapy with immunomodulatory agents such as lenalidomide is currently undergoing investigation. New drugs will most likely be introduced over the next few years and will probably be different for relapsing and refractory patients.

Diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype of non-Hodgkin lymphoma and is notorious for its clinical heterogeneity. Patient outcomes can be predicted by cell-of-origin (COO) classification, demonstrating that the underlying transcriptional signature of malignant B-cells informs biological behavior in the context of standard combination chemotherapy regimens. In the current study, we used mass cytometry (CyTOF) to examine tumor phenotypes at the protein level with single cell resolution in a collection of 27 diagnostic DLBCL biopsy specimens from treatment naive patients. We found that malignant B-cells from each patient occupied unique regions in 37-dimensional phenotypic space with no apparent clustering of samples into discrete subtypes. Interestingly, variable MHC class II expression was found to be the greatest contributor to phenotypic diversity. Within individual tumors, a subset of cases showed multiple phenotypic subpopulations, and in one case, we were able to demonstrate direct correspondence between protein-level phenotypic subsets and DNA mutation-defined subclones. In summary, CyTOF analysis can resolve both intertumoral and intratumoral heterogeneity among primary samples and reveals that each case of DLBCL is unique and may be comprised of multiple, genetically distinct subclones. © 2019 International Society for Advancement of Cytometry.

Single-cell RNA sequencing (scRNA-seq) has transformed biomedical research, enabling decomposition of complex tissues into disaggregated, functionally distinct cell types. For many applications, investigators wish to identify cell types with known marker genes. Typically, such cell type assignments are performed through unsupervised clustering followed by manual annotation based on these marker genes, or via "mapping" procedures to existing data. However, the manual interpretation required in the former case scales poorly to large datasets, which are also often prone to batch effects, while existing data for purified cell types must be available for the latter. Furthermore, unsupervised clustering can be error-prone, leading to under- and over- clustering of the cell types of interest. To overcome these issues we present CellAssign, a probabilistic model that leverages prior knowledge of cell type marker genes to annotate scRNA-seq data into pre-defined and de novo cell types. CellAssign automates the process of assigning cells in a highly scalable manner across large datasets while simultaneously controlling for batch and patient effects. We demonstrate the analytical advantages of CellAssign through extensive simulations and exemplify real-world utility to profile the spatial dynamics of high-grade serous ovarian cancer and the temporal dynamics of follicular lymphoma. Our analysis reveals subclonal malignant phenotypes and points towards an evolutionary interplay between immune and cancer cell populations with cancer cells escaping immune recognition.

Single-cell RNA sequencing (scRNA-seq) has enabled decomposition of complex tissues into functionally distinct cell types. Often, investigators wish to assign cells to cell types, performed through unsupervised clustering followed by manual annotation, or via “mapping” procedures to existing data. However, manual interpretation scales poorly to large datasets, mapping approaches require purified or pre-annotated data, and both are prone to batch effects. To overcome these issues we present CellAssign (www.github.com/irrationone/cellassign), a probabilistic model that leverages prior knowledge of cell type marker genes to annotate scRNA-seq data into pre-defined or de novo cell types. CellAssign automates the process of assigning cells in a highly scalable manner across large datasets while controlling for batch and sample effects. We demonstrate the advantages of CellAssign through extensive simulations and analysis of tumor microenvironment composition in high grade serous ovarian cancer and follicular lymphoma.

International audience; We present results of a prospective, multicenter, phase II study evaluating rituximab, bendamustine, bortezomib and dexamethasone as first-line treatment for patients with mantle cell lymphoma aged 65 years or older. A total of 74 patients were enrolled (median age, 73 years). Patients received a maximum of six cycles of treatment at 28-day intervals. The primary objective was to achieve an 18-month progression-free survival rate of 65% or higher. Secondary objectives were to evaluate toxicity and the prognostic impact of mantle cell lymphoma prognostic index, Ki67 expression, [18F]fluorodeoxyglucose-positron emission tomography and molecular minimal residual disease, in peripheral blood or bone marrow. With a median follow-up of 52 months, the 24-month progression-free survival rate was 70%, hence the primary objective was reached. After six cycles of treatment, 91% (54/59) of responding patients were analyzed for peripheral blood residual disease and 87% of these (47/54) were negative. Four-year overall survival rates of the patients who did not have or had detectable molecular residual disease in the blood at completion of treatment were 86.6% and 28.6%, respectively (P

International audience; Supplemental Digital Content is available in the text.

Plasma-cell post-transplantation lymphoproliferative disorder (PC-PTLD) is a rare monomorphic PTLD entity divided into plasma cell myeloma (PCM) and plasmacytoma-like lesion (PLL) PTLD. To date, there are no exhaustive published cytogenetic data on PC-PTLD. We report array-based comparative genomic hybridization (aCGH) of 10 cases of PCM and PLL-PTLD. Patients had received kidney (n = 6), heart (n = 2), lung (n = 1) or bone marrow (n = 1) transplantation. There were six men and median age at time of PTLD was 56.5 years (3–74). We identified two different cytological features, plasmacytic and plasmablastic, among six PLL and three PCM PTLD. Eight cases were associated with EBV. First line treatment was heterogeneous: rituximab alone (n = 5), CHOP-like (n = 3) and multiple myeloma-like (n = 1). One patient died before any treatment. After a median follow-up of 19.5 months (0–150), five patients died (four from PTLD) and five were alive without evidence of disease. By aCGH, 5/10 demonstrated a complex profile. The most frequent abnormalities were +7q (5/10), +16q (5/10), +17q (5/10), +17p (4/10), +5q (4/10), t7 (4/10), t9 (3/10), del1p (3/10). No del17p13 (TP53) were observed. Del1p32.3 (CDKN2C) was observed in 2 cases. On univariate prognostic analysis, a complex aCGH was associated with a shorter OS. Thus, cytogenetic abnormalities seem to be closely related to those reported in multiple myeloma or diffuse large B cell lymphoma. Complex aCGH constitutes an unfavorable prognostic marker and aCGH should be integrated in the evaluation of patients with PLL/PCM-PTLD. © 2016 Wiley Periodicals, Inc.