Habermann, Thomas M.

Introduction. The VES-13 is a simple, self-reported, function based tool originally developed to screen community-dwelling populations to identify persons age 65 years and older at risk of death and functional decline, including death in the next 12 months. The VES-13 items include patient's age, self-rated overall health status, functional limitations in physical activity, and functional disabilities in more complex activities of daily living. As part of the Lymphoma Epidemiology of Outcomes (LEO) cohort study, we collected self-reported VES-13 data at study enrollment on all participants regardless of age, and here we report on the prevalence of vulnerable status defined by the VES-13 and its association with 1-year mortality, overall, stratified at age 65 years, and in the subset of diffuse large B-cell lymphoma (DLBCL) treated with immunochemotherapy. Methods. From 7/2015 to 6/2017, 3253 participants with NHL were enrolled within 6 months of their diagnosis into the LEO cohort. 2004 were evaluable on VES-13, and 1183 (59%) completed it before the initiation of therapy. VES-13 scores range from a minimum of 0 (low risk for decline) to a maximum of 10 (greatest risk for decline), and a score ≥3 was classified as vulnerable. Clinical, pathology and treatment data were abstracted using a standard protocol, and participants were contacted every 6 months for the first three years and then annually thereafter to identify outcomes. Medical records were reviewed by LEO clinicians to classify cause of death according to a standard protocol. Therapy was determined by the treating physician, and this was independent of knowledge of the VES-13 score. The association of VES-13 with 1-year mortality from date of diagnosis was estimated using odds ratios (OR) and 95% confidence intervals (CI) from logistic regression models, which also provided model c-statistics. Results. The median age of the 2004 participants in this analysis was 62 years (range 18-94); 57% were male; 54% were ≥65 years; and 28% had a normal body mass index (BMI), 1% were underweight, 35% were overweight, and 36% were obese. Clinically, 59% of participants had an aggressive subtype, 65% were stage III-IV, 24% had B-symptoms, and 11% had a performance status (PS) of ≥2. Overall, 28% of participants were classified as vulnerable (95% CI 26%-30%), with a higher prevalence among those completing the survey after initiation of therapy (38%, 95% 34%-41%) versus before initiation of therapy (22%, 95% CI 20%-24%), and a higher prevalence for those ≥65 years (32%, 95% CI 29%-34%) versus <65 (25%, 95% CI 22%-28%). During the first year of follow-up, there were 147 deaths, with 61% due to lymphoma, 14% therapy-related, 12% due to another malignancy, 3% other causes, and 10% unknown. Significant univariate predictors of 1-year mortality included vulnerable status, older age, PS 2+, stage III-IV, aggressive subtype, lower quality of life score, lower BMI, and 1 or more comorbidities, and were included the backward stepwise modeling. Vulnerable status (OR=3.26, 95% CI 2.15-4.96) was retained in the final model that also included age, PS, stage, and NHL subtype (Table), with a model c-statistic of 0.81. As shown in the Table, these associations were similar whether VES-13 was assessed before (c-statistic 0.77) or after (c-statistic 0.81) initiation of therapy. After adjustment for age, PS, stage and NHL subtype, vulnerable status predicted 1-year mortality in participants ≥65 years (OR=1.96, 95% CI 1.15-3.36; model c-statistic 0.80) as well as <65 years (OR=6.38, 95% CI 3.07-13.3; model c-statistic 0.83). Finally, in the DLBCL patients treated with immunochemotherapy (N=521), vulnerable status (38% of patients) also predicted 1-year mortality (OR=2.11, 95% CI 1.05-4.26) after adjusting for age, PS and stage (model c-statistic 0.78). Conclusion. Based on a self-administered VES-13, 28% of newly diagnosed NHL patients in the LEO cohort were classified as vulnerable, including 25% of those <65 years, and vulnerable status was a strong predictor of 1-year-mortality, even in the subset of DLBCL patients treated with presumed curative intent. These results highlight the potential value of screening for vulnerable status overall and across a wider age spectrum in order to optimize patient management and reduce early mortality. Disclosures Martin: Karyopharm: Consultancy; Sandoz: Consultancy; I-MAB: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Teneobio: Consultancy. Casulo:Gilead: Honoraria, Other: Travel, accommodation, expenses; Celgene: Research Funding; Roche: Other: Travel, accommodation, expenses. Cohen:Takeda Pharmaceuticals North America, Inc.: Research Funding; Bristol-Meyers Squibb Company: Research Funding; Hutchison: Research Funding; Astra Zeneca: Research Funding; Lymphoma Research Foundation: Research Funding; ASH: Research Funding; LAM Therapeutics: Research Funding; UNUM: Research Funding; Gilead/Kite: Consultancy; Janssen Pharmaceuticals: Consultancy; Seattle Genetics, Inc.: Consultancy, Research Funding; Genentech, Inc.: Consultancy, Research Funding. Farooq:Kite Pharma: Research Funding; Celgene: Honoraria. Friedberg:Acerta: Other: Data & Safety Monitoring Committee; Bayer: Honoraria, Other: Data & Safety Monitoring Committee. Kahl:Seattle Genetics: Consultancy; ADC Therapeutics: Consultancy, Research Funding; BeiGene: Consultancy; TG Therapeutics: Consultancy. Lossos:Janssen Scientific: Membership on an entity's Board of Directors or advisory committees; NIH: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Maurer:Nanostring: Research Funding; Celgene: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees. Nastoupil:Spectrum: Honoraria; Genentech, Inc.: Honoraria, Research Funding; Gilead: Honoraria; Janssen: Honoraria, Research Funding; Novartis: Honoraria; TG Therapeutics: Honoraria, Research Funding; Bayer: Honoraria; Celgene: Honoraria, Research Funding. Rutherford:Heron: Consultancy, Honoraria; Janssen Scientific Affairs: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Juno Therapeutics Inc: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Verastem: Consultancy, Honoraria; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees. Flowers:National Cancer Institute: Research Funding; BeiGene: Consultancy, Research Funding; Eastern Cooperative Oncology Group: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Pharmacyclics/Janssen: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Bayer: Consultancy; Spectrum: Consultancy; Karyopharm: Consultancy; Acerta: Research Funding; TG Therapeutics: Research Funding; Millenium/Takeda: Research Funding; AstraZeneca: Consultancy; Optimum Rx: Consultancy; V Foundation: Research Funding; Celgene: Consultancy, Research Funding; Burroughs Wellcome Fund: Research Funding; Denovo Biopharma: Consultancy; Gilead: Consultancy, Research Funding. Cerhan:NanoString: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding.

Background: Diffuse large B cell lymphoma (DLBCL) is the most common aggressive lymphoid malignancy in adults. Though standard immunochemotherapy regimens can result in clinical remission and cure in a majority of patients, approximately 30% of patients are primary refractory or eventually relapse, and their prognosis is very poor. Recent progress by large scale genomic and transcriptomic profiling of DLBCL patients has resulted in a deep understanding of disease drivers in newly diagnosed DLBCL (ndDLBCL). However, previous genomic studies of relapsed and/or refractory DLBCL (rrDLBCL) are limited by small sample sizes and much less is known about the genomic landscape or the changes in clonal populations that occur within a patient undergoing R-CHOP therapy. Analysis of a large cohort of rrDLBCL is needed to uncover the importance of known drivers, define clonal shifts that occur in relapsing patients, and discover novel mutations that impact resistance to therapy. Methods: DNA sequencing (whole exome or genome sequencing) was performed on tumor and matching germline samples from two rrDLBCL patient cohorts (N=143). The first rrDLBCL cohort consisted of 68 formalin fixed paraffin embedded (FFPE) tumor samples with matched germline obtained from the Mayo/Iowa Lymphoma SPORE Molecular Epidemiology Resource (MER); including 18 diagnostic/relapse paired samples. The second cohort consisted of 75 FFPE samples from 2 rrDLBCL clinical trials CC-122-ST-001 and CC-122-DLBCL-001 (NCT01421524 and NCT02031419). In addition, a ndDLBCL cohort (n=364) consisting of MER front line samples were also analyzed. CNV and SV calling was performed with Sclust and Manta, respectively. Mutational drivers were identified with cDriver. Cosmic mutational signatures were calculated for all samples. Results: For comparison of overall mutation rates between the ndDLBCL and rrDLBCL we analyzed the frequency of mutations in known driver genes [n=211, Chapuy et al, 2018; Schmitz et al, 2018; Reddy et al 2017]. Of these, the top 5 most mutated genes found in the relapse cohort were KMT2D (34.3%), IGLL5 (25.9%), CREBBP (22.4%), TP53 (21.0%), and HIST1H1E (19.6%) all of which were previously reported as mutated genes in rrDLBCL [Morin et al. 2016; Park et al. 2016;Greenawalt et al. 2017]. None of these frequencies changed significantly from the MER ndDLBCL cohort. However, frequencies of 2 genes NCOR1 and ACTB were increased significantly from 3.3% to 13.3% (p= 5.85 x 10-05) and 0.5% to 6.3% (p=2.56 x 10-04), respectively, in the rrDLBCL cohorts. Analysis of the previously reported driver mutations in 18 paired samples revealed a significant increase in the mean variant allele frequency (VAF) from diagnosis to relapse of mutations in BCL2 and BIRC6 from 18.5% to 28.8%(p=0.016) and 4.3% to 13.7%(p=0.011), respectively. In our analysis of novel drivers in rrDLBCL cohorts, 59 significant driver mutations (FDR 0.1) were identified, 23 were novel driver mutations while the remaining 36 have been previously reported as drivers of newly diagnosed DLBCL. These include novel mutations in genes such as IL4R (8.8%), CDK5R1 (6.7%), LAPTM5 (3.7%) and others whose function in lymphoma are unknown. In a secondary analysis, we performed mutational signature analysis for rrDLBCL and identified groups of patients with COSMIC mutational signatures that are associated with aging, defects in homologous end joining resulting in large insertions/deletions, and with defective mismatch repair often found in microsatellite unstable tumors. Together with the high prevalence of TP53 mutations, these results indicate genetic instability as a hallmark of relapse/refractory DLBCL. Analysis of CNV and SV will also be reported. Conclusion: Here we report to our knowledge the largest genomic dataset in relapsed and /or refractory DLBCL using tumor biopsies. Previously identified mutated genes in rrDLBCL were confirmed and novel drivers identified. Paired samples analysis reveals clonal shifts which occur during treatment and at time of relapse. Whether the novel driver mutations appeared as a function of selection of a rare clone over the course of therapy or a therapy induced mutation will be the focus of ongoing work. Novel variants including SNV, CNV and SV can potentially lead to new insights and deepen our understanding of the mechanisms of resistance in DLBCL. * Wenzl, Ortiz and Stong contributed equally **Novak and Gandhi contributed equally Disclosures Ortiz: Celgene Corporation: Employment, Equity Ownership. Stong:Celgene Corporation: Employment, Equity Ownership. Huang:Celgene Corporation: Employment, Equity Ownership. Maurer:Morphosys: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Nanostring: Research Funding. Towfic:Celgene Corporation: Employment, Equity Ownership. Hagner:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Nikbakht:Celgene Corporation: Employment, Equity Ownership. Stokes:Celgene Corporation: Employment, Equity Ownership. Lata:Celgene Corporation: Employment, Equity Ownership. Kamalakaran:Celgene Corporation: Employment, Equity Ownership. Mavrommatis:Celgene Corporation: Employment, Equity Ownership. Trotter:Celgene Corporation: Employment, Equity Ownership. Czuczman:Celgene Corporation: Employment, Equity Ownership. Ansell:Regeneron: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding. Cerhan:Celgene: Research Funding; NanoString: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees. Nowakowski:Bayer: Consultancy, Research Funding; Curis: Research Funding; Celgene: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding. Novak:Celgene Coorperation: Research Funding. Gandhi:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties.

Background: Follicular lymphoma (FL) is the most frequent indolent lymphoma. While immunochemotherapy (IC) treated FL patients who achieve event-free status at 24 months after diagnosis (EFS24) have the subsequent life expectancy of the general population, those who fail to achieve EFS24 have aggressive disease with poor outcomes. Similarly, in FL patients initially observed or treated with rituximab monotherapy, EFS at 12 months (EFS12) is a strong predictor of subsequent outcome. Thus, an unmet patient need is to predict at diagnosis those at greatest risk of early failure in order to identify better treatments. The lymphoma microenvironment may be a key determinant of early failure. Therefore, we aimed to improve risk stratification of newly diagnosed FL patients by using a discovery and validation study design to identify microenvironment determinants of early failure and then integrate them into the Follicular Lymphoma International Prognostic Index (FLIPI). Patients and Methods: We evaluated 496 patients with FL grade 1-3A who were prospectively enrolled into the Molecular Epidemiology Resource (MER) cohort from 2002-2012. In the discovery set of patients (N=166), we stained tissue microarrays for CD4, CD8, FOXP3, CD32b, CD14, CD68, CD70, SIRPa, TIM3, PD-1 and PDL1. Immunohistochemical staining was determined both within and between malignant follicles. Stains were scored to the nearest decile as the percentages of cells positive. Scores for each stain were dichotomized as 0% vs >0% except for CD32b (<20% vs ≥20%), CD70 (<10% vs ≥10%), and SIRPa (<30% vs ≥30%). EFS was defined as time from diagnosis to progression, relapse, retreatment, or death. Early failure was defined as failing to achieve EFS24 for patients treated with IC at diagnosis and failing to achieve EFS12 for patients who were observed or received other treatments. Risk of early failure was estimated using odds ratios (ORs) and 95% confidence intervals (CI) from logistic regression models. Markers at P≤0.15 were brought forward for validation in a separate set of patients from the MER cohort (N=330), with P<0.005 being declared statistically significant after a Bonferroni correction (0.05/10 tests). In the combined dataset, we also used Cox regression to assess associations with continuous EFS and overall survival (OS). Mass cytometry (CyTOF) was then performed on a subset of patients (N=51) to comprehensively characterize the phenotype of intratumoral immune cells associated with outcome. Results: In the discovery set, CD4, CD8, FOXP3, PD-1, and SIRPα were associated with risk of early failure at P≤0.15 and were subsequently evaluated in the validation set. Only CD4 expression inside the follicle validated. Specifically, lack of CD4 expression inside the follicle was associated with higher risk of early failure in the discovery (OR=1.77, P=0.15) and validation (OR=2.59, P=0.001) sets, with a pooled OR=2.29 (95% CI 1.47-3.58; P<0.001). CyTOF analysis characterized the favorable CD4+ T-cell population associated with achieving EFS12/24 as activated effector memory T cells lacking exhaustion markers (Figure 1A). Adjustment of CD4 expression for FLIPI in the combined dataset did not weaken this association (OR=2.38, 95% CI 1.51-3.79), and lack of CD4 expression was prognostic within each FLIPI group 0-1 (OR=2.65; p=0.036), 2 (OR=2.07; P=0.064) and 3-5 (OR=2.51; P=0.015). We next established a bio-clinical risk model (termed BioFLIPI) that combined CD4 intrafollicular expression and FLIPI into a 1-4 scale, where any expression of intrafollicular CD4 moved a patient up one FLIPI risk group, adding a fourth (high) risk group for FLIPI 3-5 and any CD4 inside expression. The BioFLIPI score was strongly associated with risk of early failure: compared to a BioFLIPI score of 1 (24% of patients), patients with a score of 2 (35% of patients; OR=2.17, 95% CI 1.08-4.69), 3 (31% of patients; OR=3.53, 95% CI 1.78-7.54), and 4 (10% of patients; OR=8.92, 95% CI 4.00-21.1) had increasing risk of early failure. The c-statistic for BioFLIPI was 0.665, which was higher than that for FLIPI alone (0.636). BioFLIPI was also strongly predictive of continuous EFS [Figure 1B], OS [Figure 1C], and for EFS and EFS24 when restricted to IC-treated patients [Figure 1D]. Conclusion: Integration of CD4 expression inside the follicle at diagnosis with FLIPI improves identification of FL patients at risk for early failure. Disclosures Novak: Celgene Coorperation: Research Funding. Nowakowski:Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; Genentech, Inc.: Research Funding; MorphoSys: Consultancy, Research Funding. Cerhan:NanoString: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Ansell:LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment.

95 Background: The incidence of immune-related adverse events (irAEs) in patients (pts) with Hodgkin lymphoma (HL) treated with PD-1 antibodies (ICI) is reported at 28 - 36%. However, clinically relevant information on irAE onset, duration, or impact on ability to continue therapy in HL is lacking. Additionally, these incidence rates reflect CTCAE definition and grading, and not ASCO Clinical Practice Guidelines irAE-specific criteria (Brahmer et al, JCO 2018). The objectives of this study were to evaluate the rate and severity of irAEs in HL pts using ASCO criteria, to characterize irAE time profile and to assess their impact on continued therapy. Methods: HL pts who received a PD-1 inhibitor for the treatment of HL at Mayo Clinic Rochester between January 1, 2011 and March 1, 2018 were identified. We conducted a detailed, longitudinal retrospective chart review with definition and grading of irAEs in accordance with ASCO guidelines. Results: Fifty-one pts were identified (35% women, median age at ICI initiation 35 years [range: 19-87]). Median duration of follow up from ICI start was 30 months (range: 1-70). Thirty-one pts (61%) had any irAE. Most common irAEs were inflammatory/bullous dermatoses (23.5%/5.9% any grade/grade3-4; median onset/duration of 81/57 days[d]), followed by thyroiditis (22%/0%; 86/84 d), colitis (14%/8%; 82/106 d), pneumonitis (14%/10%; 241/182 d), and hepatitis (14%/4%; 71/35 d). Fifteen pts (29%) required treatment with steroids. Among the total cohort, ICI was held for an irAE 28 times (50% of 56 total irAEs). Median treatment cycles held was 2.5 and ICI was permanently discontinued due to irAE in 18%. The most common irAE leading to treatment discontinuation was pneumonitis, followed by neuritis (5.9%/3.9%; 179/374 d), colitis, and rash. Conclusions: The rate of irAEs of 61% in this cohort as defined by ASCO consensus criteria was higher than reported in trials. Most irAEs were characterized by delayed onset of several months and prolonged duration, particularly pneumonitis and neuritis. Treatment discontinuation due to irAEs was infrequent overall. Further studies are needed to determine whether the development or duration of irAEs is predictive of treatment outcomes in HL.

SummaryNon‐endemic Burkitt lymphoma (BL) is a rare germinal centre B‐cell‐derived malignancy with the genetic hallmark of MYC gene translocation and with rapid tumour growth as a distinct clinical feature. To investigate treatment outcomes, loss of lifetime and relapse risk in adult BL patients treated with intensive immunochemotherapy, retrospective clinic‐based and population‐based lymphoma registries from six countries were used to identify 264 real‐world patients. The median age was 47 years and the majority had advanced‐stage disease and elevated LDH. Treatment protocols were R‐CODOX‐M/IVAC (47%), R‐hyper‐CVAD (16%), DA‐EPOCH‐R (11%), R‐BFM/GMALL (25%) and other (2%) leading to an overall response rate of 89%. The two‐year overall survival and event‐free survival were 84% and 80% respectively. For patients in complete remission/unconfirmed, the two‐year relapse risk was 6% but diminished to 0·6% for patients reaching 12 months of post‐remission event‐free survival (pEFS12). The loss of lifetime for pEFS12 patients was 0·4 (95% CI: −0·7 to 2) months. In conclusion, real‐world outcomes of adult BL are excellent following intensive immunochemotherapy. For pEFS12 patients, the relapse risk was low and life expectancy similar to that of a general population, which is important information for developing meaningful follow‐up strategies with increased focus on survivorship and less focus on routine disease surveillance.

AbstractHistological transformation in Waldenström macroglobulinemia (WM) is an uncommon complication, with limited data, particularly regarding the impact of MYD88 L265P mutation on transformation. We examined risk factors and outcomes associated with transformation in WM, highlighting the role of MYD88 L265P mutation. Patients with WM seen at Mayo Clinic, Rochester, USA and University Hospital of Reims, France, between 01/01/1996 and December 31, 2017 were included; 50 (4.3%) of 1147 patients transformed to a high‐grade lymphoma, with median time‐to‐transformation of 4.5 (range 0‐21) years in the transformed cohort. The MYD88 L265P mutation status was known in 435/1147 (38%) patients (406 with non‐transformed WM and 29 patients in transformed cohort). On multivariate analysis, MYD88 WT status alone was an independent predictor of transformation (odds ratio, 7[95%CI: 2.1‐23]; P = .003). Additionally, the MYD88 WT status was independently associated with shorter time‐to‐transformation (HR 7.9 [95%CI: 2.3‐27; P = .001]), with a 5‐year transformation rate of 16% for MYD88 WT vs 2.8% with MYD88 L265P mutated patients. Patients with transformation demonstrated a significant increase in risk of death compared to patients who did not transform (HR 5.075; 95%CI: 3.8‐6.8; P < .001). In conclusion, the MYD88 WT status is an independent predictor of transformation and associated with a shorter time‐to‐transformation. Additionally, transformation conferred an inferior overall survival in patients with WM.

Abstract Background. Recent clinical trials based on immunotherapies targeting the PD-1/PD-L1 pathway have shown striking durable responses in a subset of patients with solid cancers. The Programmed death 1 (PD-1) protein is a key immune checkpoint inhibitor expressed by activated T cells. Its ligand, PD-L1, was reported highly expressed by tumor cells in some diffuse large B-cell lymphomas (DLBCL) of non-Germinal Center phenotype. We recently reported on the French multicenter GOELAMS075 trial that pre-treatment soluble PD-L1 (sPD-L1) in plasma was elevated in DLBCL patients compared to controls, and that elevated sPD-L1 was associated with inferior overall survival (OS), independent of the International Prognostic Index (IPI) and other clinical factors (Rossille et al., Leukemia 2014). Here, we replicate and extend these findings in two independent studies from Australia and the US. Methods. The protein expression of sPD-L1 was evaluated using a commercial ELISA kit. The French discovery cohort consisted of 288 adults with newly diagnosed aggressive DLBCL, age 18 to 60 years, and treated with R-CHOP or high dose chemotherapy plus rituximab followed by autologous stem cell support (clinicaltrials.gov: NCT00561379); there were also 60 controls. The Australian study consisted of 51 DLBCL patients age 18 to 71 years, all stages, treated with R-CHOP14, along with 57 controls. The US study was an observational cohort from the Iowa/Mayo Lymphoma SPORE and consisted of 225 DLBCLs, age 19 to 92 years, all stages, treated with immunochemotherapy, along with 98 controls. Plasma samples were collected pre-treatment using EDTA tubes for the Australian and the US cohorts, BDª P100 tubes for the French cohort. sPD-L1 expression was measured in Rennes, France (French & US samples) and in Brisbane, Australia (Australian samples).The Kaplan-Meier method and Cox regression were used to model the association of sPD-L1 with OS. The 95th percentile of the sPD-L1 levels in each matched control group was used as the cutoff point to define elevated sPD-L1 levels. Results. Replicating the French findings, sPD-L1 levels were significantly higher for DLBCL patients compared to controls in both the US (P<0.0001) and Australian (P<0.0001) studies (Figure 1). The odds ratios for elevated sPD-L1 among patients compared to controls were 10.7 (95% CI 3.3-22.0), 8.9 (95% CI 3.1-25.3) and 12.6 (95% CI 2.7-28.0) for the French, US and Australian studies, respectively. In the French cohort, elevated sPD-L1 levels were associated with inferior OS (Hazard Ratio (HR)=2.05; 95% CI 1.18-3.57), and this was replicated in the US cohort (HR=1.71; 95% CI 0.97-3.01) (Figure 2). Due to the similarity of the results, we next pooled the French and US cohorts to increase power for multivariate and subset analyses. The median age at diagnosis of the 513 patients was 54 years; 29% were more than 60 years old; 69% of the patients had stage III-IV disease; 56% were IPI intermediate-risk and 9% were IPI high-risk patients. The median follow-up was 48 months (range, 0.5-126) overall, and 66 months for the patients still alive; there were 102 deaths. Using a cutpoint of 1729 pg/mL from the combined studies, patients with elevated sPD-L1 had inferior OS compared to patients without elevated sPD-L1, with 3-year OS rates estimated at 78% (95% CI 71.8-84.9) vs. 87.8% (95%CI 84.5-91.4) (P<0.01). In multivariate analysis, elevated sPD-L1 (HR=1.75; 95%CI 1.16-2.64), age (HR=1.03; 95%CI 1.02-1.05), high-risk IPI score (HR=3.71; 95%CI 1.91-7.21) and ALC ² 1 G/L (HR=2.19; 95%CI 1.44-3.33) were all significant at P<0.01. In analyses stratified by IPI, the 3-year OS rates among high-risk patients (IPI 4-5) was 40.9% (95% CI 23.6-71.0) for elevated sPD-L1 vs. 82.1% (95% CI 69.1-97.6) for not elevated sPD-L1 (P<0.01). There was no association of sPD-L1 with 3-year OS among low risk (IPI 0-1) or intermediate-risk (IPI 2-3) patients. Conclusion. We confirmed that sPD-L1 levels are higher in pre-treatment plasma samples of newly diagnosed DLBCL patients compared to controls, and that elevated levels of sPD-L1 are associated with inferior OS in DLBCL patients treated with immunochemotherapy, and this is independent of IPI and other clinical factors. Among high risk patients, we identified a subgroup with less than 50% survival. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

Abstract Background: EBV+ DLBCL not otherwise specified (EBV+ DLBCL NOS) is defined by the 2016 WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues as EBV+ DLBCL in patients without a history of known immunosuppression. Among Asian patients, adverse outcomes have been associated with EBV+ vs EBV- DLBCL, and circulating EBV has been found in the majority of patients. Outcome studies of unselected North American patients are few and non-confirmatory. No formal assessment of immunosuppression status has been incorporated into these analyses, leading to the variable inclusion of patients with a history of immunocompromised states. We sought to determine the prevalence, presenting clinical and pathology characteristics, and outcomes of DLBCL by EBV and immunosuppression status in an unselected prospective cohort study of North American patients. Methods: From 2002-2012, we enrolled consecutive, newly diagnosed patients with lymphoma who were ≥ 18 years and HIV negative into the Molecular Epidemiology Resource (MER). Clinical, laboratory, and treatment data were abstracted from medical records. All DLBCL patients with available tissue microarrays (TMAs), excluding primary mediastinal DLBCL and post-transplant lymphoproliferative disorders, were included. Medical records were reviewed using a standard protocol to classify patients as immunocompromised based on a documented history of primary immunodeficiency or iatrogenic immunosuppression. DLBCL cell of origin was classified as germinal center (GCB) vs non-GCB using the Hans algorithm. CD30 was determined using immunohistochemistry; positivity cutoff was 20% of neoplastic cells. EBV testing was performed by in-situ hybridization for EBV encoded small RNAs (EBERs), and scored by an expert hematopathologist. Event free survival (EFS) was defined as time from diagnosis until recurrence, retreatment, or death due to any cause. Associations with EFS and Overall Survival (OS) were obtained using the methods of Kaplan-Meier (KM). Hazard Ratios (HRs) and 95% confidence intervals (CIs) were estimated from Cox regression models. Results: 1,100 patients with DLBCL were enrolled into the MER; 362 had TMAs available for this analysis. Median age was 63 years (range 20-89) and 59% were male. 89.5% of patients were treated with immunochemotherapy. 16 cases (4.4%) were EBV+, and 39 cases (10.8%) were considered immunocompromised. EBV positivity was more common in immunocompromised vs immunocompetent patients, with a trend towards significance (10.3% vs 3.7%; P = 0.08). The non-GCB subtype was more frequent in EBV+ vs EBV- DLBCL (62.5% vs 34.1%; P < 0.01), but similar between immunocompromised vs immunocompetent patients (48.7% vs 33.7%; P = 0.10). CD30 positivity was also more frequent in EBV+ vs. EBV- DLBCL (25.0% vs 8.1%; P < 0.01), but similar between immunocompromised vs immunocompetent patients (12.8% vs 8.4%, respectively; P = 0.45). With a median follow-up of 59 months (range 0.7-155.2) there were 151 events and 119 deaths. KM curves by EBV and immunosuppression status are shown in the figure. There was no association of EBV positivity with EFS (HR = 0.76; 95% CI 0.34-1.72) or OS (HR = 0.99; 95% CI 0.43-2.25). A history of immunosuppression was not associated with EFS (HR = 1.17; 95% CI 0.72-1.89) or OS (HR = 1.02; 95% CI 0.58-1.78). In the subset of immunocompetent patients, there was no association of EBV positivity with EFS (HR = 0.54; 95% CI 0.17-1.70) or OS (HR = 0.71; 95% CI 0.23-2.25). Similar results were obtained after adjustment for the International Prognostic Index. Circulating viral DNA was detected in 2/5 EBV+ and 4/49 EBV- DLBCL patients. Conclusions: The prevalence of EBV+ DLBCL NOS is <5% among patients in a large North American cohort, similar to other western populations. There was no evidence of an association of EBV or immunosuppression status with EFS or OS, with low power for detecting associations with EBV. Circulating viral DNA was infrequent among either EBV+ or EBV- DLBCL patients. While immunosuppression has been previously shown to be a risk factor for DLBCL, it was not found to be associated with EFS or OS. Overall, these results suggest divergent outcomes among EBV+ DLBCL patients between western and non-western populations, underscoring differences in host factors or circulating viral strains. Disclosures Ansell: BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding.

Abstract B-cell receptor (BCR) signaling pathway components represent promising treatment targets in multiple B-cell tumors including diffuse large B-cell lymphoma (DLBCL). BCR signaling activates proximal pathway components such as the spleen tyrosine kinase (SYK) and downstream effectors including PI3K/AKT and NF-κB. In recent studies, we characterized distinct SYK/PI3K/AKT-dependent viability pathways in BCR DLBCL cell lines and primary tumors with high- or low-baseline NF-κB activity and defined additional SYK/PI3K/AKT-dependent processes essential for BCR DLBCLs with low- or high-baseline NF-κB (Chen et al Cancer Cell 2013; 23:826-838). For example, SYK/PI3K/AKT-dependent cholesterol biosynthesis was identified as a feed-forward mechanism of preserving the integrity of BCRs in lipid rafts in all BCR-dependent DLBCLs. In the current study, we sought to identify biomarkers of intact BCR signaling in DLBCLs with low or high baseline NF-κB. We found highly significant transcriptional upregulation of CXCR4 in all BCR-dependent DLBCLs treated with a chemical SYK inhibitor (R406). These results were of particular interest because BCR signaling inhibits stromal cell-derived factor (SDF)-1α chemotaxis and promotes intermobilization of the SDF-1α receptor, CXCR4. To expand on our findings, we analyzed CXCR4 transcript abundance in a large panel of cell lines including BCR-dependent/ low NF-κB (GC type) and BCR-dependent/ high NF-κB (ABC type) and BCR-independent/ OxPhos DLBCLs. CXCR4 transcript abundance was significantly and selectively upregulated in all BCR-dependent DLBCL lines assessed by qRT-PCR following chemical SYK inhibition. Consistent with the qRT-PCR results, SYK blockade also selectively upregulated cell surface CXCR4 expression in all BCR-dependent DLBCLs. Similar results were obtained following SYK knockdown with multiple independent shRNAs; CXCR4 transcript abundance was significantly and selectively upregulated in all BCR-dependent/ low NF-κB (GCB) DLBCLs and BCR-dependent/ high NF-κB (ABC) DLBCLs but was not altered in BCR-independent/ OxPhos tumors. Following SYK blockade, we also observed significant CXCR4 induction (by qRT-PCR) in multiple primary BCR-dependent DLBCLs (NF-κB low and NF-κB high) and unchanged CXCR4 levels in primary BCR-independent tumors. These data confirm that the observations regarding SYK blockade and CXCR4 induction in BCR-dependent DLBCL cell lines translated to primary tumors. Our recent studies indicate that all BCR-dependent DLBCLs exhibit SYK/PI3K/AKT signaling and modulation of FOXO1 regardless of baseline NF-κB levels. Given the recent identification of CXCR4 as a FOXO1 target, we asked whether modulation of CXCR4 in DLBCLs was via a PI3K/AKT pathway. In BCR-dependent DLBCLs with low or high baseline NF-κB, chemical PI3K inhibition (LY294002) phenocopied chemical SYK blockade (R406) with highly significant transcriptional upregulation of CXCR4. Moreover, in BCR-dependent DLBCL cell lines, enforced expression of a constitutively active form of AKT (myrAKT) abrogated CXCR4 upregulation resulting from SYK blockade. These data indicate that in BCR-dependent DLBCLs, CXCR4 is modulated by a SYK/PI3K/AKT-dependent pathway. To assess the functional significance of CXCR4 upregulation in BCR-dependent DLBCLs, we performed a transwell chemotaxis assay and evaluated migration toward a SDF-1α gradient. Following chemical SYK inhibition, all BCR-dependent DLBCLs exhibited significantly increased migration toward the CXCR4 ligand, SDF-1α, whereas the BCR-independent/ OxPhos DLBCLs were unaffected. The enhanced SDF-1α dependent migration was abrogated when the chemotaxis assay was performed in the presence of the specific CXCR4 inhibitor, AMD3100, confirming the specificity of the observed effect. Therefore, in BCR-dependent DLBCLs with low or high baseline NF-kB, SYK/PI3K inhibition is associated with significant and functionally relevant upregulation of CXCR4. For these reasons, CXCR4 may serve as a robust biomarker to assess the integrity of the BCR pathway and evaluate the efficacy of BCR inhibition in DLBCL. Disclosures: Off Label Use: R406 is not get approved, but is being evaluated in DLBCL and CLL.

Abstract Background: Vitamin D insufficiency (VDI) has been associated with inferior outcomes in patients with follicular lymphoma (FL) treated with chemotherapy and an anti-CD20 monoclonal antibody (immunochemotherapy; IC), but whether this association holds for other FL treatment strategies is not known. Furthermore, the subset of FL patients who experience clinical failure (progression, treatment failure) within 12 months of diagnosis have an inferior outcome compared to those achieving event-free status at 12 months (EFS12). We tested the hypothesis that VDI is predictive of early clinical failure (failure to achieve EFS12), overall survival (OS), and lymphoma-specific survival (LSS) among FL patients overall and in subgroups who were initially observed, treated with IC, rituximab monotherapy, or other therapies. Methods: We evaluated this hypothesis in a prospective cohort study of 642 newly diagnosed patients with grade 1-3a FL enrolled from 2002-2012 in the Molecular Epidemiology Resource of the Iowa/Mayo Lymphoma SPORE. Serum 25-hydroxyvitamin D [25(OH)D] was measured by liquid chromatography-tandem mass spectroscopy, and VDI was defined as serum total 25(OH)D <20 ng/mL (per Institute of Medicine criteria) determined within 120 days of diagnosis. We used logistic regression to estimate Odds Ratios (ORs) and 95% confidence intervals (CIs) and Cox regression to estimate hazard ratios (HRs) and 95% CIs. We adjusted for FLIPI, body mass index, and month of blood draw; for the full cohort, we additionally adjusted for treatment. Results: The mean age at diagnosis was 60 years (range 23-93); 19% of patients had VDI. The median follow-up period was 59 months (range 1-144), with 297 events and 78 deaths (42 due to lymphoma). Treatment included IC (N=252), observation (N=218), rituximab monotherapy (N=76), or other (N=96). OS and EFS curves are shown in figures 1 and 2. In the full cohort, VDI was associated with inferior EFS12 (OR=2.05; 95% CI 1.18-3.54), OS (HR=2.35; 95% CI 1.37-4.02), and LSS (HR=2.97; 95% CI 1.52-5.80). In the IC subset, VDI was associated with inferior EFS12 (OR=3.00; 95% CI 1.26-7.13), OS (HR=2.86; 95% CI 1.39-5.85), and LSS (HR=2.96; 95% CI 1.29-6.79). VDI was associated with inferior OS in patients who were observed (HR=2.25; 95% CI 1.20-6.76) or received other therapies (HR=3.06; 95% CI 1.01-9.24). VDI was positively but not statistically significantly associated with inferior EFS12 in the patients who were observed (OR=1.71; 95% CI 0.70-4.17) or received other therapies (OR=2.31; 95% CI 0.41-13.07), with low power for these associations; LSS could not be estimated due to lack of deaths. There were too few events (N=10) and deaths (N=5) in the R-monotherapy group for analysis. Conclusions: We confirm previous findings that vitamin D insufficiency is associated with adverse long-term prognosis among patients with FL treated with IC, and extend these findings to patients who are initially observed or treated with other therapies. For the first time, we observed an association of vitamin D insufficiency with early clinical failure, suggesting a potentially modifiable factor to address in this subset of patients with poor outcomes. Whether treating VDI improves outcomes in FL warrants assessment. Disclosures Ansell: BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Nowakowski:Celgene: Research Funding; Morphosys: Research Funding; Bayer: Consultancy, Research Funding.