Citations

Background and Aims In cholestatic liver diseases, ductular reactive (DR) cells extend into the hepatic parenchyma and promote inflammation and fibrosis. We have previously observed that multidrug‐resistant 2 (Mdr2−/− ) double knockout (DKO) mice lacking tumor necrosis factor–related apoptosis‐inducing ligand receptor (Tr−/− ) display a more extensive ductular reaction and hepatic fibrosis compared to Mdr2−/− mice. This observation suggests that the magnitude of the DR‐cell population may be regulated by apoptosis. Approach and Results To examine this concept, we cultured epithelial cell adhesion molecule–positive reactive cholangioids (ERCs) obtained from wild‐type (WT), Tr−/− , Mdr2−/− and DKO mice. Single‐cell transcriptomics and immunostaining of both WT and DKO ERCs confirmed their DR‐cell phenotype. Moreover, DKO ERCs displayed a unique translational cluster with expression of chemokines, indicating a reactive state. Incubation with the myeloid cell leukemia 1 (MCL1) inhibitor S63845, a proapoptotic BH3‐mimetic therapy, significantly decreased DKO and Mdr2−/− ERC viability compared to WT. Intravenous administration of S63845 significantly reduced the DR‐cell population and markers of inflammation and liver fibrosis in Mdr2−/− and DKO mice. Furthermore, DKO mice treated with S63845 displayed a significant decrease in hepatic B lymphocytes compared to untreated mice as assessed by high‐definition mass cytometry by time‐of‐flight. Coculture of bone marrow–derived macrophages with ERCs from DKO mouse livers up‐regulated expression of the B cell–directed chemokine (C‐C motif) ligand 5. Finally, DR cells were noted to be primed for apoptosis with Bcl‐2 homologous antagonist/killer activation in vitro and in vivo in primary sclerosing cholangitis liver specimens. Conclusions DR cells appear to play a key role in recruiting immune cells to the liver to actively create an inflammatory and profibrogenic microenvironment. Pharmacologic targeting of MCL1 in a mouse model of chronic cholestasis reduces DR‐cell and B‐cell populations and hepatic fibrosis.

30 Background: BM in patients (pts) with CRPC are associated with shorter overall survival (OS) and higher costs. BRI zoledronic acid and denosumab are frequently used to prevent skeletal-related events (SRE) in pts with CRPC and BM. AA is the most common 1st line therapy for men with metastatic CRPC. We aimed to assess the impact of BRI on OS and time to first SRE (ttSRE) of pts receiving 1st line treatment AA for CRPC with BM. Methods: A retrospective cohort of pts starting AA as 1st line therapy for CRPC with BM between 2013-2016 was identified through 8 hospitals’ IRB approved registries. Pts were classified by use of concomitant BRI and subgrouped by volume of disease (per E3805 definition) at AA start. Kaplan-Meier method and Cox models were used to assess OS and ttSRE with hazard ratio (HR) estimates (95% CI). Results: Of the 745 pts included (543 deaths), 529 (71.0%) had AA alone and 216 (29.0%) AA+BRI. Median follow-up was 23.5 months. Pts receiving concomitant BRI showed a significantly longer OS and a 35% reduced risk of death compared to AA alone (HR=0.65; 95% CI, 0.54-0.79; P<.0001). The OS benefit with BRI was greater for the subgroup with high volume disease (HV) (HR=0.51; 95% CI, 0.38-0.68; P<.0001). The cohort with AA+BRI had a significantly shorter ttSRE (HR=1.27; 95% CI; 1.0-1.60; P=.0439) and, notably, the risk of first SRE was more than doubled for the subgroup with LV (HR=2.29; 95% CI, 1.57-3.35; P<.0001). On MVA, BRI vs. no BRI, prior local therapy (PLT) vs. no PLT, LV vs. HV, baseline VAS pain ≤3 vs. >5, PS 0 vs. ≥1, and PSA are independently associated with longer OS. Conclusions: The addition of BRI to 1st line AA for CRPC men with BM was associated with improved OS, particularly in HV, and worsened ttSRE, more evident in LV. These data suggest a potentially different impact of concomitant BRI on HV vs. LV, which could affect clinical decision making.[Table: see text]

149 Background: Patients with metastatic hormone-sensitive prostate cancer (mHSPC) have a variable response to ADT and some benefit from the addition of docetaxel or an androgen signaling pathway inhibitor. We found that loss of the epigenetic regulator KDM5D is associated with more aggressive prostate cancer (PC). We sought to determine whether MYBL2 which is regulated by KDM5D mediates this effect. MYBL2 is a transcription factor which controls key genes (e.g. FOXM1) and increases cell cycle progression and survival. Methods: AR expressing hormone-sensitive cell lines, LNCaP and LAPC4 were used. Motif analysis and CHiPseq of LNCaP with and without siKDM5D was performed and impact of modulation of KDM5D and MYBL2 in both cells on cell survival was assessed. Gene expression profiling (GEP) data assessed MYBL2’s association with KDM5D levels in localized disease (publicly available data) and mHSPC (Decipher whole Affymetrix platform on CHAARTED samples). Results: Silencing KDM5D increased H3K4me3 and increased MYBL2 expression. GEP showed a strong negative correlation between KDM5D and MYBL2 in patients with localized PC (-0.66; TCGA) but not from primary prostate cancer tissue with mHSPC (-0.03; CHAARTED). Cells with low KDM5D and high MYBL2 were androgen independent and more resistant to docetaxel. In TCGA, patients with high MYBL2 had a higher rate of relapse from localized disease. In patients with metastatic disease (CHAARTED) low MYBL2 was associated with a better overall survival (OS) on multivariable analysis when treated with ADT or ADT + docetaxel. Conclusions: Low MYBL2 is associated with a longer OS with ADT alone and ADT and docetaxel independent of clinical variables. Patients with high MYBL2 expression had better OS with ADT plus docetaxel compared with patients with high MYBL2 treated with ADT alone.[Table: see text]

746 Background: Pelareorep is a proprietary formulation of live, replication-competent, naturally occurring Reovirus Type 3 Dearing strain. A randomized phase II trial of pelareorep in combination with carboplatin and paclitaxel in first-line treatment of metastatic PDAC (NCT01280058) was performed. Although pelareorep did not improve the primary endpoint of progression-free survival compared to carboplatin and paclitaxel alone, impressive durable responses were seen in the pelareorep arm in some patients (pts). Further, prior studies have noted the immunomodulatory carcinoembryonic antigen-related cell adhesion molecule (CEACAM6/CD66c) as a receptor for specific viral subtypes. We thus speculated that altered CEACAM6 levels may be predictive for pelareorep sensitivity. Methods: Pre-treatment tissue biopsies were collected prior enrolment for all 73 pts on study. Evaluable pts with transcriptomic data was available for only 31 pts. RNA was purified from FFPE tissue and gene expression analysis was performed using SensationPlus FFPE Amplification and WT labelling kit and the Human Transcriptome Array 2.0. CEACAM6 protein expression was determined by immunohistochemistry. Differential gene expression and survival analysis using were performed in R/Bioconductor. Appropriate corrections for multiplicity were performed. Results: When comparing extraordinary responders in the pelareorep treated arm to those with poor outcomes, low levels of CEACAM6 mRNA expression were associated with prolonged PFS in pelareorep-treated pts (adjusted p = 0.05). This effect was not seen in non-pelareorep treated pts. The luminal, but not the cytoplasmic immunohistochemistry score, was highly correlated with mRNA expression levels of CEACAM6, p = 0.001. Modulation of CEACAM6 in vitro and in vivo are underway. Conclusions: CEACAM6 may be a candidate biomarker of sensitivity to pelareorep and, in theory, could improve viral trafficking of this compound in tumor cells. Clinical trial information: NCT01280058 . [Table: see text]

713 Background: AbGn-107 is an ADC directed against AG-7 antigen, a Lewis A-like glycol-epitope expressed in 24-61% of gastric (G), colorectal (CRC), pancreatic (PDA), and biliary (BIL) cancers. Based on promising antitumor activity of AbGn-107 in both in vitro and in vivo preclinical studies, we performed a Phase Ia trial in pts with the aforementioned GI malignancies. Methods: Standard 3+3 dose escalation was used. Key eligibility criteria: locally adv or metastatic G, CRC, PDA, or BIL cancer, previously treated, ECOG PS 0-1; positive AG-7 expression was not required. Two dosing intervals were tested: AbGn-107 administered i.v. Q4 weeks (at doses ranging from 0.1-1.2 mg/kg) and Q2 weeks (at doses from 0.8-1.0 mg/kg). DLTs were based on grade 3/4 hematologic and non-heme AEs occurring during the initial 4-week rx window. Pts were treated until dz progression or unacceptable toxicity, with tumor assessments Q8 weeks. 1o objectives: safety and MTD; 2o objectives: PK, immunogenicity, and efficacy defined by ORR (RECIST 1.1). Results: 35 patients were enrolled across 6 dose levels (median age 61.5 yo (range 40 – 81); G (0)/CRC (12)/PDA (20)/BIL (3); median # lines of prior rx = 3 (range 1-7). Safety: 5 pts experienced Grade 3 or 4 neutropenia, all at higher dose levels, with 1 episode of febrile neutropenia. Other frequent drug-related AEs, mostly grade 1/2, inc. fatigue (29%), nausea (20%), and diarrhea (14%). DLTs include grade 4 CK elevation (n = 1) at 0.8 mg/kg Q4W and grade 3 arthralgias (n = 1) at 1.2 mg/kg Q4W. MTD was not reached at either 1.2 mg/kg Q4W or 0.8 mg/kg Q2W; the 1.0 mg/kg Q2W cohort will complete enrollment in Oct 2019. Efficacy: Median duration of treatment = 56 days (range, 8 – 225 days); best response observed to date is stable dz lasting > 6 months at 0.8 mg/kg Q4W and Q2W cohorts (n = 1 each). Conclusions: Overall, AbGn-107 appears well-tolerated with encouraging prelim signs of efficacy (prolonged dz control) in non-biomarker selected pts with advanced GI cancers. Pre-screening for high AG-7 expression is underway for subjects with G, CRC, PDA, and BIL cancers for the cohort expansion phase of this study, which will be open across multiple sites in U.S. and Taiwan. Clinical trial information: NCT02908451.

AbstractIntroductionAlthough some members of families with autosomal dominant Alzheimer's disease mutations learn their mutation status, most do not. How knowledge of mutation status affects clinical disease progression is unknown. This study quantifies the influence of mutation awareness on clinical symptoms, cognition, and biomarkers.MethodsMutation carriers and non‐carriers from the Dominantly Inherited Alzheimer Network (DIAN) were stratified based on knowledge of mutation status. Rates of change on standard clinical, cognitive, and neuroimaging outcomes were examined.ResultsMutation knowledge had no associations with cognitive decline, clinical progression, amyloid deposition, hippocampal volume, or depression in either carriers or non‐carriers. Carriers who learned their status mid‐study had slightly higher levels of depression and lower cognitive scores.DiscussionKnowledge of mutation status does not affect rates of change on any measured outcome. Learning of status mid‐study may confer short‐term changes in cognitive functioning, or changes in cognition may influence the determination of mutation status.

Soft tissue tumors with GLI1 gene fusions or amplifications have been recently described as a unique pathologic entity with an established risk of malignancy. We herein expand these findings by investigating a cohort of 11 head and neck lesions with GLI1 alterations, including 8 from the tongue, for their clinicopathologic and molecular features. The tumors commonly affected males in their 30s (male:female ratio 2.7:1; range: 1 to 65). Tumors showed a multinodular growth pattern, nested architecture separated by a delicate, arborizing vascular network, monotonous round to ovoid nuclei, and clear cytoplasm. Tumor protrusion into vascular spaces was common. Genetic alterations were investigated by fluorescence in situ hybridization and/or targeted RNA sequencing. Seven tumors harbored GLI1 fusions with the following partners: ACTB (n=4), PTCH1 (n=2), or MALAT1 (n=1). The remaining 4 cases showed coamplifications of GLI1 with CDK4 and MDM2 genes. Tumors were commonly positive for S100 protein and CD56. CDK4, MDM2, and STAT6 were positive in GLI1 -amplified tumors. Two of 6 patients with available follow-up (1 each with GLI1 amplification and PTCH1-GLI1 fusion) developed distant metastases. Both tumors showed a high mitotic index and tumor necrosis. The head and neck region, particularly tongue, is a common location for GLI1 -related mesenchymal tumors. Although a morphologic overlap was noted with the previously reported “pericytoma with t(7,12) translocation,” often occurring in the tongue, our findings expand the original findings, to include a more variable immunophenotype, propensity for late distant metastases, and alternative mechanisms of GLI1 oncogenic activation, such as various GLI1 fusion partners or GLI1 coamplifications with MDM2 and CDK4 genes.

Alcoholic hepatitis (AH) is a severe inflammatory liver disease that develops in some heavy drinkers. The immune system in patients with AH is hyperactive and yet dysfunctional. Here, we investigated whether this immune‐dysregulated state is related to the alcoholic impact on immune checkpoints (ICPs). We used multiplex immunoassays and enzyme‐linked immunosorbent assay to quantify plasma levels of 18 soluble ICPs (sICPs) from 81 patients with AH, 65 heavy drinkers without liver diseases (HDCs), and 39 healthy controls (HCs) at baseline, 33 patients with AH and 32 HDCs at 6‐month follow‐up, and 18 patients with AH and 29 HDCs at 12‐month follow‐up. We demonstrated that baseline levels of 6 sICPs (soluble T‐cell immunoglobulin and mucin domain 3 [sTIM‐3], soluble cluster of differentiation [sCD]27, sCD40, soluble Toll‐like receptor‐2 [sTLR‐2], soluble herpesvirus entry mediator [sHVEM], and soluble lymphotoxin‐like inducible protein that competes with glycoprotein D for herpes virus entry on T cells [sLIGHT]) were up‐regulated, while 11 sICPs (soluble B‐ and T‐lymphocyte attenuator [sBTLA], sCD160, soluble cytotoxic T‐lymphocyte‐associated protein 4 [sCTLA‐4], soluble lymphocyte‐activation gene 3 [sLAG‐3], soluble programmed death 1 [sPD‐1], sPD ligand 1 [sPD‐L1], sCD28, soluble glucocorticoid‐induced tumor necrosis factor receptor‐related protein [sGITR], sGITR ligand [sGITRL], sCD80, and inducible T‐cell costimulator [sICOS]) were down‐regulated in patients with AH compared to HDCs. The up‐regulated sICPs except sLIGHT and down‐regulated sCD80, sCD160, sCTLA‐4, and sLAG‐3 correlated positively or negatively with AH disease severity, bacterial translocation, and inflammatory factors. At follow‐up, abstinent patients with AH still had higher levels of several sICPs compared to HDCs. We also compared expression of 10 membrane‐bound ICPs (mICPs) on peripheral blood mononuclear cells (PBMCs) from patients with AH and HCs by flow cytometry and found that several mICPs were dysregulated on blood cells from patients with AH. The function and regulation of sICPs and mICPs were studied using PBMCs from patients with AH and HCs. Recombinant sHVEM affected tumor necrosis factor (TNF)‐α and interferon‐γ production by T cells from patients with AH and HCs. Conclusion: Both sICPs and mICPs were dysregulated in patients with AH, and alcohol abstinence did not fully reverse these abnormalities. The HVEM axis plays a role in regulating T‐cell function in patients with AH.

Background: Mechanical injury in the conduction system requiring permanent pacemaker (PPM) associated with transcatheter aortic valve replacement (TAVR) procedure is a common complication. The objective of this study was to use ambulatory monitor BodyGuardian to assess late occurrence of atrioventricular block (AVB) after TAVR. Methods: This prospective study evaluated 365 patients who underwent TAVR at Mayo Clinic, Rochester, Minnesota between June 2016 and August 2017. Patients who received PPM for bradycardia after TAVR before discharge were considered as the PPM group. Those not requiring PPM received a BodyGuardian system (BodyGuardian group) for 30 days of continuous monitoring. Primary end point was Mobitz II or third-degree atrioventricular block (II/III AVB) at 30-day follow-up. Results: Of 365 patients, 74 who had a PPM or an implantable cardioverter-defibrillator before TAVR and 94 who were enrolled in other studies were excluded. Of 197 patients enrolled in the study, 70 (35.5%) received PPM and 127 had BodyGuardian before the hospital dismissal. Eleven of 127 (8.6%) BodyGuardian group required PPM within 30 days after TAVR for late occurrence of symptomatic bradycardia. In total, 33 of 197 (16.7%) patients developed II/III AVB (24 before and 9 after discharge). Thirty-four patients had preexisting right bundle branch block. Of them, 16 (47%) developed II/III AVB. Of 53 patients who developed new left bundle branch block after TAVR, 14% progressed to II/III AVB within 30 days. Conclusions: In patients without a standard post-TAVR pacing indication, yet a potential risk to develop AVB, a strategy of 30-day monitoring identifies additional patients who require permanent pacing.