Citations

452 Background: CC pts with biliary stents or catheters often present with fever and/or jaundice requiring urgent treatment for which there is no uniform guideline. We aimed to develop an expert panel consensus on this topic using the modified RAND/UCLA Delphi process to rate treatment appropriateness. Methods: We recruited 13 physician experts from relevant specialty, geography, and practice settings. Patient scenarios were developed based on a literature review, and therapies were rated by the experts before and after a face-to-face discussion. The appropriateness of various therapies was rated on a 1-9 scale and classified as appropriate, inappropriate, or uncertain. Scenarios with > 2 ratings of 1-3 (inappropriate) and > 2 ratings of 7-9 (appropriate) were considered to have disagreement and were not assigned an appropriateness rating. Results: Panelists were from all US regions (92%) and the UK (8%); had practiced for a mean 16.5 years (4-33 years) and reported seeing an average of 120 unique CC patients a year (0-900 pts). Panelists rated 288 clinical scenarios. Experts decided that ongoing treatment with chemotherapy did not influence decision-making. Disagreement decreased from 37.5% before the meeting to 10.4% after. Consensus statements are summarized in table 1. Conclusions: The Delphi process produced consensus guidelines to fill an unmet need in urgent management of ascending cholangitis in pts with CC. Studies of the impact of these guidelines on cost of care and pt outcomes are warranted. (Support: The Cholangiocarcinoma Foundation)[Table: see text]

Abstract Mutations in the EGFR gene or transcript fusion involving EML4-ALK result in oncogenic activation of these oncogenes driving lung adenocarcinoma growth in tumors carrying such an alteration. For lung adenocarcinoma with these genetic changes, small-molecule tyrosine kinase inhibitors have been highly effective at reducing tumor burden and improve the outcome of the patients. Unfortunately, drug resistance eventually develops in these tumors and challenges remain in controlling lung cancer recurrence after targeted therapy. To overcome recurrence, we initiated a prove-of-principle study to evaluate the feasibility of an integrated strategy utilizing genomic profiles of the tumor and patient-specific tumor xenografts derived (PDX) from biopsies for ex vivo evaluation of antitumor drugs to help guide personalized treatment of lung cancer in patients who have developed resistance to targeted therapy drugs. Our study has three main objectives. 1) Use tumor biopsies obtained at the time of recurrence for oncogene mutation and RNAseq analyses to identify molecular changes in oncogenes and gene pathways that can be potentially targeted. 2) Evaluate drug efficacy and optimize personalized therapy for each patient using PDX models. 3) Assess clinical feasibility and our experience using integrated approaches for lung cancer patients who failed targeted therapy. This study was approved by the Mayo Clinic Institutional Review Board (IRB) and utilizes both clinical and research biopsies. A dedicated nurse study coordinator reviews clinical patient list and history on weekly basis and informs the study team of each potential candidate patient. A total of 30 patients having ALK positive lung cancers have been identified and followed up from nearly 500 potentially ALK positive cases between April 2014 to Sept. 2015. Most patients were never smokers but six were former smokers and two were current smokers. Age at diagnoses ranged from 27-78 years (median = 61). Seven patients (23%) were 45 years or younger at the time of diagnosis. A total of 22 patients are currently being treated with crizotinib while eight are on ceritinib or alectinib. For each biopsy, tumor tissues are obtained using a 20 gauge needle, transferred on ice in preserving media and implanted within one hour into 6-8 week old NOD/SCID mice. Many patients have been on treatment for 2-3 years with stable disease so they do not require biopsy. Using a similar strategy, we also obtained biopsies from patients with EGFR gene mutations in their tumors and have progressed while on targeted therapy. A total of seven cases have been implanted. We will report our experiences in patient selection, clinical follow up, patient consent, PDX development, time from biopsy to tumor establishment, and the results of molecular analyses. Our study enabled us to gain new insights regarding the molecular changes associated with recurring tumors after they have failed targeted therapy as well as clinical experiences on how to utilize state-of-the art approaches and comprehensive genomic information to further improve cancer patient care upon disease progression. Acknowledgements: This work is supported in part by the Hillsberg Award from the National Foundation for Cancer Research and by the Biomarker Discovery Program at the Mayo Clinic Center for Individualized Medicine. Citation Format: Jin Jen, Aaron Mansfield, Patrick W. Eiken, Shawn Stoddard, Karlyn Pierson, Xiaonan Hou, Hong Zheng Ren, Julian Molina, Joanne Yi, Ping Yang. Integrated Approaches to Treating Lung Adenocarcinoma Resistant to Targeted Therapy. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B34.

Abstract Background. We previously reported an alternative ESR1 somatic gain-of-function chromosomal translocation event in a patient presenting with aggressive, endocrine therapy resistant estrogen receptor (ER) positive disease, producing an in-frame fusion gene consisting of N-terminal ESR1 and the C-terminus of the Hippo pathway coactivator YAP1 (ESR1-YAP1). We recently identified another ESR1 fusion through RNA sequencing (RNA-seq) in advanced stage ER+ disease from a chest wall recurrence in a male patient that was refractory to multiple lines of treatment. Two examples of fusions discovered in primary breast cancer samples include ESR1 fused in-frame to C-terminal sequences from NOP2 (ESR1-NOP2), identified in a resistant cohort from a RNA-seq screen focused on 81 primary breast cancers from aromatase inhibitor clinical trials, and a second ESR1 fusion, fused in-frame to the entire coding sequence of POLH (ESR1-POLH), that was identified from RNA-seq analysis of 728 Cancer Genome Atlas breast samples. This current study extends our previous characterization of ESR1-YAP1 by comparing functional and pharmacological properties of these three additional ESR1 gene fusion events of both early stage and advanced breast cancers. Methods. In vitro and in vivo experiments were conducted to test ESR1 fusions to induce therapeutic resistance, and metastasis. The transcriptional and binding properties of each fusion was also examined. Pharmacological inhibition with Palbociclib, a cyclin-dependent kinase 4/6 inhibitor, was utilized to assess drug sensitivity in ESR1 fusion containing breast cancer cells and in a patient derived xenograft (PDX) model expressing ESR1-YAP1 (WHIM18). Results. The YAP1 and PCDH11x fusions conferred estrogen-independent and fulvestrant-resistant growth. Immunohistochemistry revealed significantly higher numbers of ER+ cells in lungs of mice xenografted with T47D cells expressing the YAP1 and PCDH11x fusions compared to YFP control, NOP2 and POLH fusions. Results from ChIP-seq and microarray studies suggest that these two fusions promote proliferation and metastasis through genomic action by binding estrogen response elements (ERE) and subsequent gene activation. We thereby define these fusions as “canonical” fusions compared to “non-canonical” NOP2 and POLH fusions, which demonstrated dramatically decreased genomic binding ability. The non-canonical fusions induced genes associated with basal-like breast cancer and promoted HER2, EGFR, and MAPK gene expression signatures in contrast to genes associated with cell cycle/proliferation induced by canonical fusions. The proliferative ability of canonical fusion-containing ER+ cells was inhibited by Palbociclib in a dose-dependent manner. In vivo WHIM18 tumors in mice fed with Palbociclib-containing chow demonstrated significantly reduced tumor volume, growth rate, and weight compared to tumors in mice on control chow. Conclusions. In-frame ERE activating canonical fusions occur in end-stage drug resistant advanced breast cancer and can be added to ESR1 point mutations as a class of recurrent somatic mutation that may cause acquired resistance. Growth induced by these fusions can be antagonized by Palbociclib and is potentially clinically helpful. Citation Format: Lei JT, Shao J, Zhang J, Iglesia M, Cao J, Chan DW, He X, Kosaka Y, Schmidt C, Matsunuma R, Haricharan S, Crowder R, Hoog J, Phommaly C, Goncalves R, Ramalho S, Lai W-C, Hampton O, Rogers A, Tobias E, Parikh P, Davies S, Ma C, Suman V, Hunt K, Watson M, Hoadley KA, Thompson A, Chen X, Perou CM, Creighton CJ, Maher C, Ellis MJ. Recurrent functionally diverse in-frame ESR1 gene fusions drive endocrine resistance in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD2-03.

259 Background: Belinostat is a novel histone deactylase inhibitor which demonstrates preclinical activity in HCC. We report the results of a phase I/II study on belinostat in patients (pts) with unresectable HCC. Methods: Major eligibility criteria included histologically confirmed HCC not amenable to curative treatment; PS ≤ 2; adequate organ function; prior systemic therapy was allowed. In the phase I portion, belinostat was given i.v. on D1-5 every 3 weeks with dose levels of 600, 900, 1200 and 1400 mg/m2/day. In the phase II portion, belinostat was tested at the MTD. Primary endpoint was PFS and secondary endpoints were RR according to RECIST and OS. CT assessment was done every 8 weeks. Results: Phase I portion: a total of 18 pts were accrued; no DLTs were observed at 1400mg/m2/day for 5 days, and this dose was selected for phase II development. Phase II portion: 42 pts were accrued; Median age = 57.5 years; 41 had Child’s A function, and 24 pt had ECOG 0. Sixteen (38%) had previous systemic therapy, and 21 (50%) had previous transarterial therapy. Median follow-up was 20.0 months. The PR and SD rate was 2.4% (1/42) and 45.2% (19/42). Median PFS was 2.64 months (95%C.I. 1.55-3.17) and OS was 6.60 months (95%C.I. 4.53-11.60). Grade 3 or higher toxicities (>5% rate) were abdominal pain (9.5%), (9.5%) hyperbilirubinemia (9.5%), raised ALT (9.5%); anemia (7.1%) and vomiting (7.1%). Conclusions: Belinostat demonstrates disease stabilization in a predominantly pretreated population of pts with unresectable HCC with an acceptable safety profile. Further randomized studies are warranted.Supported in part by N01-CM-62205.

Abstract Background Thyroid carcinoma, which is rare in pediatric patients (age 0–18 years) but more common in adolescent and young adult (AYA) patients (age 15–39 years), carries the potential for morbidity and mortality. Methods Hybrid-capture-based comprehensive genomic profiling (CGP) was performed prospectively on 512 consecutively submitted thyroid carcinomas, including 58 from pediatric and AYA (PAYA) patients, to identify genomic alterations (GAs), including base substitutions, insertions/deletions, copy number alterations, and rearrangements. This PAYA data series includes 41 patients with papillary thyroid carcinoma (PTC), 3 with anaplastic thyroid carcinoma (ATC), and 14 with medullary thyroid carcinoma (MTC). Results GAs were detected in 93% (54/58) of PAYA cases, with a mean of 1.4 GAs per case. In addition to BRAF V600E mutations, detected in 46% (19/41) of PAYA PTC cases and in 1 of 3 AYA ATC cases, oncogenic fusions involving RET, NTRK1, NTRK3, and ALK were detected in 37% (15/41) of PAYA PTC and 33% (1/3) of AYA ATC cases. Ninety-three percent (13/14) of MTC patients harbored RET alterations, including 3 novel insertions/deletions in exons 6 and 11. Two of these MTC patients with novel alterations in RET experienced clinical benefit from vandetanib treatment. Conclusion CGP identified diverse clinically relevant GAs in PAYA patients with thyroid carcinoma, including 83% (34/41) of PTC cases harboring activating kinase mutations or activating kinase rearrangements. These genomic observations and index cases exhibiting clinical benefit from targeted therapy suggest that young patients with advanced thyroid carcinoma can benefit from CGP and rationally matched targeted therapy.

Triggering receptor expressed on myeloid cells 2 (TREM2) is an innate immune receptor expressed in microglia in the brain. A soluble form of TREM2 (sTREM2) derived from proteolytic cleavage of the cell surface receptor is increased in the preclinical stages of AD and positively correlates with the amounts of total and phosphorylated tau in the cerebrospinal fluid. However, the physiological and pathological functions of sTREM2 remain unknown. Here, we show that sTREM2 promotes microglial survival in a PI3K/Akt-dependent manner and stimulates the production of inflammatory cytokines depending on NF-κB. Variants of sTREM2 carrying AD risk-associated mutations were less potent in both suppressing apoptosis and triggering inflammatory responses. Importantly, sTREM2 delivered to the hippocampi of both wild-type and Trem2-knockout mice elevated the expression of inflammatory cytokines and induced morphological changes of microglia. Collectively, these data indicate that sTREM2 triggers microglial activation inducing inflammatory responses and promoting survival. This study has implications for the pathogenesis of AD and provides insights into targeting sTREM2 pathway for AD therapy.