Citations

Abstract Diffuse Large B Cell Lymphoma (DLBCL) is the most common form of B-cell Non-Hodgkin Lymphoma (NHL), representing a third of all new cases. DLBCL is further sub-divided into various molecular sub-types based on gene expression and co-occurring genetic alterations. Gene expression based- subtypes include the germinal center B-cell (GCB) and the activated B-cell type (ABC) subtypes, with the ABC sub-type having a poorer prognosis than the GCB sub-type. Interestingly, 30-40% of all DLBCL patients harbor mutations in key epigenetic regulators, EZH2, KMT2D, CREBBP, EP300, and mutations in histone proteins themselves. Through an unbiased cell-based phenotypic screen, we discovered that inhibition of lysine demethylases, specifically KDM4C and KDM4A, represents a vulnerability across 15 different DLBCL cell lines including germinal center B-cell (GCB) and activated B-cell (ABC) type lines, with a GI50 value between 75nM to ~200nM, while sparing leukemia lines. Consistently, treatment of xenograft-based animal models of DLBCL with a low dose of KDM4A/KDM4C inhibitor delivered intra-peritoneally three times a week, results in a drastic reduction of tumor burden. Both KDM4A and KDM4C catalyze the removal of histone H3 K9 di- and tri-methylation (H3K9me2/3) and H3K36 di- and tri-methylation (H3K36me2/3). H3K9me2/3 is associated with promoter and enhancer repression, while H3K36me2/3 is present in gene bodies during transcription but also functions as a chromatin repressor Consistently, we have identified key enhancers, including those associated with IKZF1, that are "decommissioned" after inhibition of KDM4A/KDM4C. Repressed enhancer activity, through loss of H3K27 acetylation and H3K4me1, and gain of H3K9me2/3, results in a rapid transcriptional downregulation of IKZF1 and its partners including IKZF3. Given the role of IKZF1 in the transcriptional regulation of key B Cell Receptor (BCR) signaling components, we show that KDM4A/KDM4C inhibition leads to a downregulation of SYK, a proximal BCR-signaling component, which likely precedes DLBCL cell apoptosis. In addition, we observed an activation of extra-lineage transcription factors such as CEBPA and CEBPB, which are normally repressed by IKZF1 in the lymphoid lineage. A concomitant downregulation of the B-cell gene expression program and an upregulation of the myeloid (CD14+ monocytic) gene expression program is also observed, implying a "trans-differentiation" of DLBCL cells into the monocyte lineage. This lineage-switch correlates with an increased population of CD14+ expressing cells. Finally, using DLBCL patient data sets, we can show that over-expression of either KDM4A or KDM4C is associated with poor prognosis in DLBCL patients. In summary, we have discovered that KDM4A/KDM4C inhibition results in an increase of repressive histone modifications at several intra-genic "enhancers" of genes that are responsible for the survival and proliferation of DLBCL cells. The elucidation of this unique epigenetic mechanism provides a strong rationale for the development of novel targeted therapies against both multiple subtypes of DLBCL. Figure. Figure. Disclosures Shipp: Bayer: Research Funding; AstraZeneca: Honoraria; Merck: Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Abstract 880 Pulmonary marginal zone lymphoma is a distinct subgroup of B-cell non-Hodgkin's lymphomas originating from the bronchial-associated lymphoid tissue (BALT) and characterized by an indolent clinical course. Here we present the data of the IELSG-28 study of the International Extranodal Lymphoma Study Group (IELSG) on primary pulmonary lymphoma patients. Clinical records and histological material of 186 patients diagnosed with pulmonary marginal zone lymphoma from December 1986 to June 2009 were collected. The pathology was reviewed centrally and the diagnosis was confirmed in 180 (96%) patients. The median age at diagnosis was 62 (30 – 88). The majority of the patients (149/180) had localized disease at diagnosis with a good performance status (0–1) and low prognostic index (IPI 0–2). Eighty-one patients (45%) received local treatment, including surgery (74%) or radiotherapy (4%). Ninety-nine patients with advanced stage disease or incomplete surgical resection received an additional systemic treatment. Most of these patients (66; 66%) received an alkylating containing regimen, 22 (22%) patients were treated with an anthracycline containing regimen and 29 (29%) received the anti-CD20 monoclonal antibody in combination with chemotherapy. With a median follow up of 67 (range 1–256) months, 47/180 patients (26%) experienced disease progression. (median time to progression 30 months, range 0–109). Progression free survival analysis showed a trend in favour of patients treated with immuno-chemotherapy versus those receiving chemotherapy alone (HR 0.53–95%CI: 0.21, 1.33), while no difference in terms of OS and PFS was observed between patients receiving systemic anthracycline or alkylating containing regimens. In twenty five cases a specific PCR-assay was carried out for detecting the presence of Achromobacter (Alcaligenes) xylosoxidans. The presence of Achromobacter was detected in 50% of patients. Our results confirm that local therapy (surgery or radiotherapy) is the treatment of choice for patients with localized disease. Chemotherapy has to be considered in case of relapse, incomplete surgical excision or advanced disease. In this setting, alkylating containing regimens plus rituximab is the most effective option. Further studies are ongoing to confirm the relevance of infection/colonization with Achromobacter (Alcaligenes) xylosoxidans for pathogenesis of BALT lymphoma. Disclosures: No relevant conflicts of interest to declare.

Abstract Introduction: The impact of genomic alterations, such as mutations in ASXL1, on the risk of disease progression and leukemic transformation in patients with myelofibrosis (MF) is well established. Further, emerging data suggests that the number and type of mutations may impact response to therapies such as ruxolitinib or imetelstat. Allogeneic hematopoietic stem cell transplant (allo-HSCT) remains the only potentially curative treatment for MF patients. However, the impact of somatic mutations on overall survival (OS) and relapse-free survival (RFS) is poorly understood. Using next-generation sequencing of pre-transplant blood and bone marrow samples from a well clinically-annotated cohort of MF patients who underwent allo-HSCT, we sought to determine the impact of mutational burden on outcomes. Methods: A multicenter retrospective analysis of a cohort of 84 patients was carried out. This included 52 patients treated on the MPD-RC 101 prospective study (NCT00572897), 18 patients treated at Prince Margaret Hospital, and 14 patients treated at Memorial Sloan Kettering Cancer Center. Patient and transplant characteristics are displayed in Table 1. DNA was extracted from pre-transplant bone marrow aspirate samples or peripheral blood samples. High-throughput sequencing of a panel of genes was performed. Average coverage of 829x (standard deviation of ±130) was obtained. Mutect was utilized to call single point variants (comparing our samples to a pool of normal samples) and PINDEL was used to call short insertions and deletions. We excluded all mutations present in at least one database of known non-somatic variants (DBSNP and 1000 genomes) and absent from COSMIC. Univariate Cox regression and Kaplan-Meier graphics were used to investigate the association of patient, transplant, and disease characteristics with OS and RFS. Results: JAK2V617F was the most frequent mutation detected in 41(48.8%) patients (Table 2). Eighteen patients (21.4%) had triple negative disease (negative for JAK2, MPL, and CALR mutations). Univariate analysis included the following: patient characteristics (age, gender), transplant characteristics (related vs. unrelated donor, matched vs. mismatched donor and myeloablative vs. reduced intensity conditioning) and disease characteristics (DIPSS and presence of mutations). Decreased OS was associated with unrelated donor status (HR 2.09, 95% CI: 1.03-4.23, p=0.04), reduced intensity conditioning (HR 4.21, 95% CI: 1.01-17.59, p=0.049), triple negative disease (HR 2.09, 95% CI: 1.02-4.30, p=0.04), and presence of U2AF1 (HR 2.53, 95% CI: 1.10-5.81, p=0.03) or SUZ12 mutations (HR 3.92, 95% CI: 1.19-12.21, p=0.02). Decreased RFS was associated with unrelated donor status (HR 2.27, 95% CI: 1.16-4.45, p=0.02), and the presence of SUZ12 mutation (HR 6.97, 95% CI: 2.37-20.49, p<0.001). A descriptive decrease in RFS in patients with U2AF1 (HR 2.15, 95% CI: 0.94-4.88, p=0.07) was observed but did not reach statistical significance. Importantly, mutations previously reported to be associated with reduced OS and RFS in the non-transplant setting, such as ASXL1, EZH2, IDH1/2, and SRSF2, were not associated with poorer outcomes in this analysis in transplanted patients. In an exploratory multivariate analysis including donor type (related vs. unrelated) and presence of U2AF1 and SUZ12 mutations, there was a significantly reduced OS and RFS in patients who harbor these mutations regardless of donor type (OS: HR 5.30, 95% CI: 2.08-13.47, p<0.001; RFS: HR 5.49, 95% CI: 2.27-13.30, p<0.001). In patients without the above mutations, having an unrelated donor was associated with worse OS (HR 2.55, 95% CI: 1.09-5.96, p=0.03) and RFS (HR 2.61, 95% CI: 1.17-5.83, p=0.02, Figure 1). Conclusions: Our analysis demonstrates that mutations previously associated with poor prognosis in MF, such as ASXL1, do not appear to confer a worsened prognosis in patients undergoing allo-HSCT, suggesting transplant may be able to overcome the impact of these mutations. However, mutations in SUZ12 and U2AF1 are associated with reduced OS in univariate and multivariate analysis (together with donor type). Further studies with larger cohorts of patients are indicated to validate these findings, and to elucidate the impact of these mutations on disease biology. Disclosures Rampal: Incye and CTI: Consultancy. Mascarenhas:Janssen: Research Funding; CTi Biopharma: Research Funding; Promedior: Research Funding; Merk: Research Funding; Incyte: Research Funding. Mesa:Galena: Consultancy; Gilead: Research Funding; Promedior: Research Funding; Incyte: Research Funding; CTI Biopharma: Research Funding; Celgene: Research Funding; Ariad: Consultancy; Novartis: Consultancy. Gupta:Novartis: Consultancy, Honoraria, Research Funding; Incyte Corporation: Consultancy, Research Funding.

This prospective cohort study aimed to improve hospital outcomes through geographic location of hospitalist patients and conducting daily multidisciplinary team rounds—Goal-directed Achievements through Geographic Location (GAGL). Patients were admitted to a geographic (GAGL) study unit where daily multidisciplinary rounds took place among nursing, case management, a hospitalist, pharmacy, physical and occupational therapy, respiratory therapy, and nutrition services. A total of 985 (56.4%) patients were admitted to the GAGL study unit and 760 patients (43.6%) were admitted to non-GAGL units. Patients admitted to the GAGL study unit had a shorter average length of stay (3.64 days vs 4.35 days, P = .0001) and a lower number of risk events (91 [9.2%] vs 93 [12.2%], P = .038). There was no significant difference in 30-day readmissions, avoidable day events, or code blue team activations. GAGL provides a framework for hospital organizations to improve provider communication, hospital efficiency, and patient safety.

Abstract A number of efforts are underway to better understand the role of genetic variation in successful aging and longevity. However, to date, only two genes have been consistently associated with longevity in humans: APOE and FOXO3, with the APOE ɛ2 allele also protective against dementia. Recently, using an exome-wide SNP array approach, a missense variant CLEC3B c.316G&gt;A (rs13963 p.S106G) was reported to associate with longevity in two independent cohorts of Japanese and Chinese participants. Interestingly, CLEC3B p.S106G is more frequent in Caucasian populations. Herein, we examined the frequency of CLEC3B p.S106G in a Caucasian series of 1,483 neurologically healthy individuals with a specific subset &gt;80 years of age. Although our findings do not support an association between CLEC3B p.S106G and aging without neurological disease (p = .89), we confirmed the association between the APOE ε2 allele and better survival without neurological disease (p = .001). Further assessment of healthy aged cohorts that retain intact neurological function will be critical to understand the etiology of neurodegenerative disease and the role of age at risk.

Background. We examined the 10-year experience of Mayo Clinic's kidney paired donation (KPD).We aimed to determine the benefits for the recipients of enrolled ABO/HLA compatible pairs and determine the factors associated with prolonged KPD waiting time. Methods. We performed a retrospective study of 332 kidney transplants facilitated by the Mayo 3-site KPD program from September 2007 to June 2018. Results. The median (interquartile range) time from KPD entry to transplantation was 89 days (42-187 days). The factors independently associated with receiving a transplant >3 months after KPD entry included recipient blood type O and calculated panel reactive antibodies ≥98%. Fifty-four ABO/HLA compatible pairs participated in KPD for the following reasons: cytomegalovirus mismatch (18.5% [10/54]), Epstein-Barr virus (EBV) mismatch (EBV) (9.3% [5/54]), age/size mismatch (51.9% [28/54]), or altruistic reasons (20.3% [11/54]). Cytomegalovirus and EBV mismatch were avoided in 90% (9/10) and 100% (5/5) of cases. Recipients who entered KPD for age/size mismatch and altruistic reasons received kidneys from donors with lower Living Kidney Donor Profile Index scores than their actual donor (median [interquartile range] 31.5 [12.3-47]; P < 0.001 and 26 (-1 to 46); P = 0.01 points lower, respectively). Median time to transplant from KPD entry for compatible pair recipients was 70 days (41-163 days), and 44.4% (24/54) of these transplants were preemptive. All chains/swaps incorporating compatible pairs included ABO/HLA incompatible pairs. Conclusions. KPD should be considered for all living donor/recipient pairs because the recipients of these pairs can derive personal benefit from KPD while increasing the donor pool for difficult to match pairs.

AbstractBackgroundThe development of phenotypic biomarkers to aid the selection of treatment for patients with castrate‐resistant prostate cancer (CRPC) is an important priority. Plasma exosomes have excellent potential as real‐time biomarkers to characterize the tumor because they are easily accessible in the blood and contain DNA, RNA, and protein from the parent cell. This study aims to investigate the characteristics of putative prostate‐specific plasma extracellular vesicle (EV) markers and their relationship with clinical outcomes.Methods and PatientsWe investigated plasma EVs in a total of 89 patients with prostate cancer (PCa) at different stages of disease progression. EVs were isolated using both precipitation and ultracentrifugation methods; physical characterization was performed using dynamic light scattering, acetylcholinesterase (AChE) activity, and velocity gradients. An immunocapture method was developed for the evaluation of prostate‐specific membrane antigen (PSMA)‐positive exosomes. Exosomal messenger RNA (mRNA) was quantified using droplet digital polymerase chain reaction for the expression of KLK3 and androgen receptor splice variant 7 (AR‐V7) genes, which code prostate‐specific antigen (PSA) and AR‐V7, respectively. Serum sex steroids were measured using liquid chromatography‐tandem mass spectroscopy.ResultsIsolated exosomes from patients with CRPC had a smaller hydrodynamic size than those isolated from localized patients with PCa, while AChE activity showed no difference. Moreover, no differences were observed after initiation of androgen deprivation therapy in serial patient samples. Velocity gradients identified that PSMA‐positive exosomes occupied a specific fraction of isolated EVs. A total of 35 patients with CRPC had mRNA analyzed from isolated plasma exosomes. Detectable exosomal KLK3 corresponded with higher concomitant serum PSA measurements, as expected (mean, 112.6 vs 26.61 ng/mL; P = .065). Furthermore, detectable levels of AR‐V7 mRNA were associated with a shorter time to progression (median, 16.0 vs 28.0 months; P = .0499). Furthermore, detectable exosomal AR‐V7 was significantly associated with testosterone levels below the lower limit of quantification (<0.1 nM).ConclusionsOur results suggest that exosomal AR‐V7 is correlated with lower sex steroid levels in CRPC patients with a poorer prognosis. PSMA immunocapture does not appear sufficient to isolate PCa‐specific exosomes.

Abstract Presumably, reduced-intensity/nonmyeloablative conditioning (RIC/NMA) for allogeneic hematopoietic cell transplantation (alloHCT) results in reduced infections compared with myeloablative conditioning (MAC) regimens; however, published evidence is limited. In this Center for International Blood and Marrow Transplant Research study, 1755 patients (aged ≥40 years) with acute myeloid leukemia in first complete remission were evaluated for infections occurring within 100 days after T-cell replete alloHCT. Patients receiving RIC/NMA (n = 777) compared with those receiving MAC (n = 978) were older and underwent transplantation more recently; however, the groups were similar regarding Karnofsky performance score, HCT–comorbidity index, and cytogenetic risk. One or more infections occurred in 1045 (59.5%) patients (MAC, 595 [61%]; RIC/NMA, 450 [58%]; P = .21) by day 100. The median time to initial infection after MAC conditioning occurred earlier (MAC, 15 days [range, &lt;1-99 days]; RIC/NMA, 21 days [range, &lt;1-100 days]; P &lt; .001). Patients receiving MAC were more likely to experience at least 1 bacterial infection by day 100 (MAC, 46% [95% confidence interval (CI), 43-49]; RIC/NMA, 37% [95% CI, 34-41]; P = .0004), whereas at least a single viral infection was more prevalent in the RIC/NMA cohort (MAC, 34% [95% CI, 31-37]; RIC/NMA, 39% [95% CI, 36-42]; P = .046). MAC remained a risk factor for bacterial infections in multivariable analysis (relative risk, 1.44; 95% CI, 1.23-1.67; P &lt; .0001). Moreover, the rate of any infection per patient-days at risk in the first 100 days (infection density) after alloHCT was greater for the MAC cohort (1.21; 95% CI, 1.11-1.32; P &lt; .0001). RIC/NMA was associated with reduced infections, especially bacterial infections, in the first 100 days after alloHCT.