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K.J. O'Byrne

Moderator of

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    ORAL 32 - EGFR WT and MT Targeting (ID 144)

    • Event: WCLC 2015
    • Type: Oral Session
    • Track: Treatment of Advanced Diseases - NSCLC
    • Presentations: 8
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      ORAL32.01 - Tumor Genomic Analysis from LUX-Lung 8: A Phase III Trial of Afatinib versus Erlotinib in Squamous Cell Carcinoma of the Lung (ID 1401)

      16:45 - 18:15  |  Author(s): J. Soria, E. Felip, M. Cobo, S. Lu, V. Georgoulias, A. Ardizzoni, S. Gadgeel, N. Gibson, C. Ittrich, V.K. Chand, G. Goss

      • Abstract
      • Presentation
      • Slides

      Background:
      Overexpression of EGFR and other ErbB receptors, and/or dysregulation of their downstream pathways are implicated in the pathogenesis of squamous cell carcinoma (SCC) of the lung, generating interest in exploring EGFR/ErbB-targeted agents in this setting. Recent analyses from the global LUX-Lung 8 trial (n=795) in patients with SCC of the lung demonstrated that second-line afatinib (an irreversible ErbB family blocker) conferred overall survival (OS; median 7.9 vs 6.8 months; HR [95% CI] 0.81 [0.69‒0.95]; p=0.008) and progression-free survival (PFS; median 2.6 vs 1.9 months; HR [95% CI] 0.81 [0.69‒0.96]; p=0.010) benefit over erlotinib (a reversible EGFR inhibitor). To assess biomarkers for efficacy for these agents in SCC we conducted an exploratory analysis using archival tumor tissue collected at time of study entry.

      Methods:
      Among all randomized patients, samples were retrospectively enriched for those from patients with PFS >2 months and appropriate controls (PFS ≤2 months; Figure 1) and were selected for analysis using the Foundation Medicine (FM) FoundationOne™ next-generation sequencing (NGS) platform (n=433); 300 cancer-related genes were analyzed for copy number alterations (CNAs), rearrangements and single nucleotide variants (SVs). Preliminary results from the 238 samples analyzable so far (~30% of the randomized patients), focusing on genomic alterations of EGFR and their potential association to survival endpoints PFS and OS, are presented.

      Results:
      Fourteen EGFR SVs (5.8%) were detected of which 10 were novel with unknown clinical significance (Figure 1). Figure 1 Four had been previously reported; 2 (E114K [afatinib arm], Q1021* [erlotinib arm]) occurred in the non-kinase domains and 2 (L861Q [afatinib arm], L858R [erlotinib arm]) in the kinase domain. The frequency of EGFR CNAs (n=15 [6.3%]; afatinib: 9; erlotinib: 6) was also low. At the time of these ongoing analyses, these low frequencies of EGFR mutations/amplifications were deemed not to be associated with the observed improvements in PFS and OS. Genomic alterations aggregated across two key gene groups (ErbB and FGF families) and their association with survival outcomes will be presented.



      Conclusion:
      The frequency of EGFR genomic aberrations in the samples tested was low. Based on this analysis of a subgroup of patients, PFS and OS improvements conferred by afatinib in LUX-Lung 8 were not driven by the presence of activating EGFR mutations or amplifications and may be related to afatinib’s ability to inactivate multiple aberrant signaling cascades associated with, and downstream of, ErbB receptors.

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      ORAL32.02 - Long-Term Survivors with EGFR Wild-Type Advanced NSCLC Treated with Second-Line Erlotinib: Subgroup Analysis from WILT Study (ID 1661)

      16:45 - 18:15  |  Author(s): J. De Castro, R. Bernabe, M.A. Sala, J. Puente, S. Vazquez, M. Majem, M.R. Garcia-Campelo, A. Paredes, R. Lopez, R. Girones, P. Diz, J. Gomez-Codina, A. Triguboff, A. Terrancle, R. Gordo

      • Abstract
      • Presentation
      • Slides

      Background:
      The overwhelming majority of advanced NSCLC p worldwide is wild-type (WT) EGFR. The results reported so far are difficult to interpret due to the heterogeneous nature of this large group of p. There is a variation in terms of efficacy considering known prognostic factors; however, other characteristics, as yet undefined, might further explain this variability. In the clinical setting, prolonged second-line treatment with Erlotinib (E) has been identified in a small group of p with WT EGFR leading to a long-term survival. The role of E in this special subset needs to be further determined in order to identify who might be most likely to benefit.

      Methods:
      WILT is a multicentre, open-label, observational study. WT EGFR (if rarely unknown, both squamous tumour and current/former smoking status as mandatory criteria) advanced NSCLC p treated with second-line E (150mg/d, until unacceptable toxicity/progressive disease) were included. Using a prognostic index model, the aim of this study is to identify subgroups of p with specific clinical and laboratory parameters that are likely to derive clinically meaningful and statistically significant benefit from E. Here we present the results of patients’ subgroups with long-term E treatment in second-line setting (PFS≥6 months and PFS≥9 months).

      Results:
      355 p were included in the study and preliminary reported data showed an overall median PFS of 2.3 months, finding 40% of p with a median PFS>2.5 months. Baseline subgroups characteristics of 52 p (14.6%) with a PFS≥6 months and 30 p (8.5%) with a PFS≥9 months are shown in Table 1. Efficacy data in PFS≥6 months subgroup: Median PFS of 10.8 months (95% CI: 9.2-12.3). Objective Response Rate of 21.6% and Disease Control Rate of 82.4%. Main related grade≥3 toxicities were rash (1.9%) and diarrhoea (3.8%). Efficacy data in PFS≥9 months subgroup: Median PFS of 13.5 months (95% CI: 12-15). Objective Response Rate of 17.2% and Disease Control Rate of 82.8%. Main related grade≥3 toxicities were rash (3.3%) and diarrhoea (6.7%). Table1: Patient characteristics

      SLP ≥6 months (N=52) SLP ≥9 months (N=30)
      Median age ( years) 65 67
      Male/Female (%) 69/31 67/33
      ECOG 0/1/2 (%) 21/62/17 23/64/13
      Histology (%) Adenocarcinoma/Squamous 48/39 43/50
      Stage (%) IV 75 67
      EGFR status (%) WT Unknown* 85 15 80 20
      Smoking status (%) Current/Never/Former 19/17/64 17/16/67
      Metastases (%) Yes Lung/Bone/CNS/Pleura/Liver 83 44/21/14/12/9 77 39/22/9/13/13
      Prior platinum-based doublet (%) Yes 94 93
      Prior Maintenance Treatment (%) Yes 27 17
      Best response to first-line (%) CR+PR/SD 48/31 40/37
      Weight loss during first-line (%) Yes 22 23
      Anaemia (%) Yes 69 63
      *Unknown: Squamous and current/former smokers

      Conclusion:
      Global efficacy results of E, in terms of PFS, match with previously reported data for second-line setting. A long-term survivors group has been identified, whom the administration of E resulted in an extraordinary prolonged response. Highlighting the heterogeneity of this subgroup, it was not possible the identification of standardized prognostic factors. Potentially molecular variables for long-term survival with E in WT EGFR NSCLC could play a role in the determination of different evolutions.

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      ORAL32.03 - Efficacy and Safety of Necitumumab Continuation Therapy in Phase 3 SQUIRE Study (ID 1391)

      16:45 - 18:15  |  Author(s): T. Ciuleanu, M.A. Socinski, C. Obasaju, A.V. Luft, A. Szczesna, W. Szafrański, R. Ramlau, B. Bálint, A. Kazarnowicz, O. Molinier, H. Depenbrock, S. Nanda, P. Paterson, L. Paz-Ares, N. Thatcher

      • Abstract
      • Presentation
      • Slides

      Background:
      The SQUIRE study demonstrated that the addition of necitumumab (N) to gemcitabine-cisplatin (GC) improved survival in patients with stage IV sq-NSCLC. This retrospective analysis compares efficacy and safety outcomes for patients who received single-agent N as continuation therapy after completion of chemotherapy treatment (CT) in GC+N arm to the continuation therapy-eligible population of the GC arm.

      Methods:
      Patients were randomized 1:1 to GC (G=1250 mg/m² iv, days 1 and 8; C=75 mg/m² iv, day 1) plus N (800 mg iv, days 1 and 8), or GC alone every 21 days up to 6 cycles. Patients in GC+N with no progression continued on N alone until progressive disease. In this analysis, we consider patients in GC+N arm who were alive and progression-free before the start of N single-agent therapy (GC+N arm continuation therapy patients) and patients in GC arm who were alive, progression-free after completion of CT and did not discontinue treatment due to adverse event (AE) (GC arm non-progressor patients). This analysis included patients in both arms who received ≥4 cycles of CT. Overall survival (OS) and progression-free survival (PFS) were measured from the date of randomization, with parameters estimated using the Kaplan-Meier method. Hazard ratios and 95% CIs between subgroups were estimated from stratified Cox proportional hazards models. OS and PFS for post-induction period were measured from the completion of CT + 21 days. Selected treatment-emergent AEs (TEAEs) for patients in each arm are presented in the table.

      Results:
      261 patients were progression-free, received ≥4 cycles of CT, and received ≥1 dose of N alone in GC+N arm. 215 pts in GC arm completed ≥4 cycles of CT, were progression-free, and did not discontinue due to AE. Patient baseline characteristics and exposure to CT were well balanced between GC+N and GC arms. Median OS from randomization in GC+N vs GC was 15.9 vs 15.0 months; HR 0.85 (95% CI, 0.69, 1.05). Median OS for post-induction period in GC+N vs GC was 11.5 vs 10.9 months; HR 0.84 (95% CI, 0.68; 1.04). Median PFS from randomization in GC+N vs GC was 7.4 vs 6.9 months; HR 0.86 (95% CI, 0.70, 1.06). Median PFS from post-induction period in GC+N vs GC was 3.2 vs 2.3 months; HR 0.85 (95% CI, 0.70, 1.04). Selected TEAEs (Overall):

      GC+N Continuation PatientsN = 261, % GC Non-ProgressorsN = 215, %
      Category Any Grade Grade ≥3 Any Grade Grade ≥3
      Neutropenia 55.9 34.1 57.7 33.0
      Anemia 46.7 10.0 49.3 8.8
      Thrombocytopenia 26.1 9.6 29.3 12.6
      Hypomagnesemia 42.1 14.9 18.6 0.9
      Conjunctivitis 11.9 0.8 3.3 0
      Rash 87.4 8.8 10.2 0.5
      Arterial thromboembolic event 5.7 3.1 0.5 0
      Venous thromboembolic event 9.2 3.8 4.2 0.9


      Conclusion:
      There was a consistent treatment effect in favor of GC+N continuation patients as compared to GC non-progressors with no unexpected increases in AEs.

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      ORAL32.04 - Discussant for ORAL32.01, ORAL32.02, ORAL32.03 (ID 3369)

      16:45 - 18:15  |  Author(s): Y. Wu

      • Abstract
      • Presentation

      Abstract not provided

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      ORAL32.05 - EGFR IHC and FISH Correlative Analyses (SQUIRE Trial): Necitumumab + Gemcitabine-Cisplatin vs Gemcitabine-Cisplatin in 1st-Line Squamous NSCLC (ID 2651)

      16:45 - 18:15  |  Author(s): F.R. Hirsch, T.A. Boyle, N. Thatcher, L. Paz-Ares, M. Varella-Garcia, A.A. Kowalewski, R.R. Hozak, G. Mi, S.A. Melemed, C.W. Caldwell, R. Kurek, M.A. Socinski

      • Abstract
      • Presentation
      • Slides

      Background:
      SQUIRE, a randomized phase III study, demonstrated that the addition of necitumumab (N) (a second-generation, recombinant, human immunoglobulin G1 EGFR antibody) to gemcitabine-cisplatin (GC) improved overall survival (OS) in patients with stage IV squamous non-small cell lung cancer (NSCLC). Analyses of the relationship between efficacy and epidermal growth factor receptor (EGFR) protein expression using the immunohistochemistry (IHC) H-score=200 cut-point were previously reported (Thatcher et al. Lancet Onc, 2015; doi: 10.1016/S1470-2045(15)00021-2). Here we report additional exploratory analyses of the relationship with EGFR protein, as well as analyses of EGFR gene copy number.

      Methods:
      SQUIRE included mandatory tissue collection from archived tumor. EGFR protein expression was assessed by IHC in a central lab, using the Dako EGFR PharmDx kit. Analyses of the relationships between efficacy outcomes with EGFR across the range of protein levels were performed, using methodologies including subpopulation treatment effect pattern plot (STEPP) with a sliding window target size of 200 patients. An exploratory assessment of EGFR gene copy number gain was performed in tissue sections using fluorescence in situ hybridization (FISH) (J Clin Pathol; 2009;62(11):970-7). Efficacy outcomes were estimated using the Kaplan-Meier method and hazard ratios estimated using an un-stratified Cox model. .

      Results:
      A total of 982 patients (89.8% of the ITT) had evaluable IHC assay results. The large majority of these patients (95.2%) had tumor samples expressing EGFR protein; only 4.8% had tumors without detectable EGFR protein (H-score=0). The STEPP analyses showed no consistent trend or obvious cut-point for the relationship between either OS or PFS with EGFR protein across the range of IHC values when comparing treatment arms. Archived tumor tissue with evaluable results for exploratory EGFR FISH analysis was available for 51.0% of patients (557 of 1093 ITT patients). Of these patients, 208 patients (37.3%) had increased EGFR gene copy number (FISH positive). A trend for greater necitumumab benefit was observed in EGFR FISH positive patients. Treatment HR (95% CI) for FISH positive and negative patients were 0.70 (0.52, 0.96) and 1.02 (0.80, 1.29) for OS, and 0.71 (0.52, 0.97) and 1.04 (0.82, 1.33) for PFS. However, the interaction of EGFR gene copy number gain with treatment was not statistically significant for either OS or PFS (p=0.066 and 0.057, respectively).

      Conclusion:
      The analysis of EGFR protein expression did not identify consistent trends related to efficacy outcomes across the range of IHC values. EGFR gene copy number gain showed a trend for a more favorable HR, but did not appear to be strongly predictive. However, both markers showed some evidence of potential trends that will be investigated further in future trials.

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      ORAL32.06 - Intercalating and Maintenance Use of Gefitinib plus Chemotherapy versus Chemotherapy Alone in Selected Advanced NSCLC: A Phase III Study (ID 2108)

      16:45 - 18:15  |  Author(s): H. Jian, W. Li, Z. Ma, J. Huang, J. Feng, Y. Song, B. Gao, H. Zhu, M. Tao, C. Bai, S. Ma, H. Pan, S. Qin, D. Hua, Y. Yu, S. Lu

      • Abstract
      • Presentation
      • Slides

      Background:
      This study investigated whether intercalating and maintenance use of gefitinib with chemotherapy improves clinical outcomes versus chemotherapy alone in selected, chemotherapy-naive patients with advanced non-small cell lung cancer (NSCLC) after receiving two cycles of gemcitabine plus carboplatin with stable disease.

      Methods:
      We undertook an open-label, randomized, phase III trial at 14 centres in China. Non-smoking patients with previously untreated stage IIIB/IV lung adenocarcinoma with EGFR mutation status unknown (tissue not available) firstly received two cycles of gemcitabine (1,250 mg/m2 days 1 and 8) plus carboplatin (AUC=5, day 1). The patients with stable disease and Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (1:1) to receive either gefitinib (250mg/d) on days 15 to 25 with a 4-week cycle of gemcitabine and carboplatin or a 4-week cycle of gemcitabine and carboplatin alone. A maximum of four cycles of chemotherapy was allowed in both arms after which time patients continued to receive gefitinib or observation until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and safety. The trial is registered at ClinicalTrials.gov, number NCT01404260, and has completed enrolment; patients are still in follow-up.

      Results:
      From June 2011 to August 2014, 219 patients with stable disease were randomized to intercalating and maintenance use of gefitinib with chemotherapy (n=109) or chemotherapy alone (n=110). The number of PFS events is 84 cases for the gefitinib plus chemotherapy group and 93 cases for the chemotherapy alone group. PFS was significantly longer in the patients receiving gefitinib and chemotherapy than in those receiving chemotherapy alone (median 10.0 vs 4.4 months, respectively; hazard ratio 0.475, 95% CI 0.349-0.646; p<0.0001). The median follow-up duration for OS is 24.5 months; OS of maturity 34.7% was not statistically different between these two arms (32.2 vs 32.5 months, respectively; hazard ratio 1.01, 95% CI 0.64-1.58; p=0.97). The addition of gefitinib to chemotherapy was well tolerated, with no increase in haematologic toxicity and no treatment-related interstitial lung disease.

      Conclusion:
      Intercalating and maintenance use of gefitinib with gemcitabine/carboplatin led to a significant improvement in PFS versus gemcitabine/carboplatin alone for Chinese nonsmoking patients with advanced pulmonary adenocarcinoma (EGFR mutation status unknown) who had previously achieved stable disease after receiving two cycles of gemcitabine/carboplatin; immature OS was not statistically different.

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      ORAL32.07 - Randomized Phase II Trial of Sequential Gefitinib and Pemetrexed/Cisplatin Chemotherapy for Stage IIIB/IV Lung Adenocarcinoma in Never Smokers (ID 1332)

      16:45 - 18:15  |  Author(s): J.S. Lee, Y.J. Lee, H.Y. Kim, B. Nam, G.K. Lee, H.T. Kim, S.J. Yoon, J. Han

      • Abstract
      • Presentation
      • Slides

      Background:
      While concurrent administration of EGFR-TKI and chemotherapy failed to improve the survival outcome, preclinical and clinical data suggested that sequential administration of EGFR-TKI within a chemotherapy cycle might improve the clinical outcome by avoiding the putative antagonism of TKI-induced G1 arrest of the cell cycle phase-dependent activity of chemotherapy. This study was designed to evaluate this idea with gefitinib and Pemetrexed/Cisplatin (Pem/Cis), the best known regimen for lung adenocarcinoma (ADC), in never-smokers with chemo-naive ADC of the lung.

      Methods:
      Eligible patients (pts) were never-smokers with chemo-naive stage IIIB/IV ADC, performance status of 0-2 and adequate organ functions, who were randomized after stratification by the EGFR mutation status (positive vs. negative/unknown) to receive either gefitinib (G) 250 mg/day or placebo (P) on days 5-18 of a 3-weekly cycle of chemotherapy, which consisted of Pem 500 mg/m[2] and cisplatin(Cis) 75mg/m[2] given iv on day 1, every 3 weeks for a maximum of 9 cycles. Responding patients continued to receive either G or P every day until PD or unacceptable toxicity. After documentation of PD, pts who had been on P arm were crossed over to receive G. The primary endpoint was progression-free survival (PFS).

      Results:
      Between 06/2012 and 12/2014, 76 pts (M/F: 9/67) with median age of 58.0 years (range 32-75) were enrolled; 72 pts had stage IV and 4 had IIIB tumors. EGFR mutation was (+) in 29, (-) in 43, and unknown in 4. As of 03/17/2015, while randomization code is not broken yet, 53 pts are off treatment (48 due to PD, 2 deaths, 2 patient’s refusal, and 1 due to intercurrent brain tumor) and 19 pts are known dead (17 due to PD and 2 due to other causes). Overall, more pts with EGFR mt(+) tumor received 6 cycles of therapy than those with EGFR mt(-) tumor [28/29 (97%) vs. 32/43 (73%)] and completed 9 cycles of therapy as planned [19/29 (66%) vs. 14/43 (33%)]. The treatment was well tolerated with less G-associated skin toxicities, due to intermittent administration schedule of G per protocol. The most common G3/4 adverse events were: anemia (17.1%), neutropenia (15.8%), vomiting (5.3%), thrombocytopenia (3.9%), and peripheral neuropathy (3.9%). There was no unexpected safety issue except for more Cis-associated peripheral neuropathy which became more noticeable as the treatment continued beyond 6 cycles of therapy. Median PFS was 8.2 months (mos) for the entire group, and 10.6 mos and 6.6 mos for EGFR mt(+) and mt(-) groups, respectively. Overall median survival has not been reached yet with an estimated 2-year survival rate of 56.3%.

      Conclusion:
      First-line sequential administration of G with Pem/Cis chemotherapy was well tolerated with no undue side effects or any compromise in efficacy parameters. Detailed data will be presented to see whether this strategy warrants further investigation in a certain subset of pts with advanced NSCLC.

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      ORAL32.08 - Discussant for ORAL32.05, ORAL32.06, ORAL32.07 (ID 3370)

      16:45 - 18:15  |  Author(s): D.R. Gandara

      • Abstract
      • Presentation

      Abstract not provided

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Author of

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    HOD 02 - Highlights of the Previous Day: Biology, Pathology, Molecular Testing, Prevention, Tobacco Control, Screening and Early Detection (ID 241)

    • Event: WCLC 2015
    • Type: Highlights of the Day
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      HOD02.01 - Biology, Pathology, Molecular Testing (ID 3395)

      07:00 - 08:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation

      Abstract not provided

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    MINI 05 - EGFR Mutant Lung Cancer 1 (ID 103)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Treatment of Advanced Diseases - NSCLC
    • Presentations: 1
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      MINI05.08 - Comparison of the Efficacy of Dacomitinib v Erlotinib for NSCLC Pts with Del 19/L858R (ID 775)

      16:45 - 18:15  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation
      • Slides

      Background:
      To date there have been limited randomized comparisons of EGFR tyrosine kinase inhibitors (TKI) in EGFR mutant NSCLC. Dacomitinib is a potent, irreversible EGFR inhibitor that demonstrated robust activity in a phase 2 study for patients with common activating EGFR mutations. Additionally, preclinical data suggests greater activity in patients with common EGFR activating mutations in exon 19 or 21. ARCHER 1009 (NCT01360554) and A7471028 (NCT00769067) each compared the clinical activity of dacomitinib (D) versus erlotinib (E) in advanced NSCLC including patients with common activating EGFR mutations; pooled results are presented.

      Methods:
      Patients (pts) with locally advanced/metastatic NSCLC were randomized following progression with 1 or 2 prior chemotherapy regimens to treatment with dacomitinib (D) (45 mg PO QD) or erlotinib (E) (150 mg PO QD). The Phase 2 study (A7471028) was open label while the Phase 3 ARCHER 1009 study was double-blind and double dummy. Archived tumor tissue, ECOG performance status (PS) of 0-2, adequate organ function and informed consent were required. Results of the two studies were previously reported individually. Analyses were performed by pooling patients with common EGFR activating mutations from both studies to compare efficacy of D versus E.

      Results:
      121 patients with any EGFR mutation were enrolled into the two studies with 1 patient randomized but not treated; 101 (53 on D) pts had activating mutations in exon 19 or 21. For patients with exon19/21 mutations, the median PFS was 14.6 months (95%CI 9.0–18.2) for D and 9.6 months (95%CI 7.4–12.7) for E and unstratified HR 0.717 (95%CI 0.458–1.124) with 1-sided p=0.073. The median OS was 26.6 months (95%CI 21.6–41.5) for D and 23.2 months (95%CI 16.0–31.8) for E and unstratified HR 0.737 (95%CI 0.431–1.259) with 1-sided p=0.132. The corresponding pooled analyses were conducted separately in exon 19 and exon 21. The adverse-event profile did not differ between the activating mutation subset and the overall population. Figure 1



      Conclusion:
      Dacomitinib may be associated with an improved PFS and OS compared to Erlotinib in patients with exon 19/21 EGFR mutations. A prospective P3 study comparing D to another EGFR TKI in 1L EGFR mutated NSCLC is ongoing to verify these observations (NCT01774721).

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    MINI 08 - Prognostic/Predictive Biomarkers (ID 106)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 2
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      MINI08.08 - VEGF-Mediated Cell Survival in NSCLC: Implications for Epigenetic Targeting of VEGF Receptors as a Therapeutic Approach (ID 2721)

      16:45 - 18:15  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation
      • Slides

      Background:
      We have recently shown that VEGF, at least in part, is an autocrine growth factor for NSCLC cells, mediating its survival effects via VEGFR2 (KDR) in addition to the more novel receptor, Neuropilin-1 (Barr et al., Mol Cancer, 2015). In this study, we evaluated the potential therapeutic utility of histone deacetylase (HDAC) inhibitors in targeting the VEGF-VEGFR signalling axis in non-small cell lung cancer (NSCLC) cells.

      Methods:
      The effect of the HDAC inhibitor, Trichostatin-A (TSA) on modulating the expression of the VEGF receptors, VEGFR1, VEGFR2, NP1 and NP2, in A549 and SKMES-1 cells was examined and validated at the mRNA level and protein levels using RT-PCR and Western blot analysis. Gene expression was further validated by quantitative real-time PCR. To investigate the effect of TSA on the viability of NSCLC cells, these were treated with increasing concentrations of TSA (2.5 ng/ml-250 ng/ml) for 24h. Cell proliferation and apoptosis was measured by BrdU and Annexin V/PI (FACS), respectively. VEGF protein secretion in response to TSA was assessed in conditioned media from lung tumour cells by ELISA. To determine if the effects of TSA on VEGFR receptors were mediated through immediate to early responses, cells were pre-treated with cycloheximide (10 µg/ml) for 2 h followed by treatment with TSA (250 ng/ml) for 24 h. To confirm whether the observed effects of HDAC inhibition by TSA were due to increased histone hyperacetylation at the VEGFR1 and VEGFR2 gene promoters, chromatin immunoprecipitation (ChIP) analysis was carried out following treatment with TSA.

      Results:
      NP1 and NP2 mRNA levels were decreased in both A549 and SKMES-1 lung cancer cells in response to TSA and induced the expression of VEGFR1 and VEGFR2 at higher concentrations. TSA however, had no effect on VEGF mRNA expression. Critically, the effect of TSA was more marked at the protein level, with complete loss of Neuropilin-1 protein. HDAC inhibition resulted in a significant decrease in the viability of A549 and SKMES-1 cells in a dose-dependent fashion. While TSA induced significant apoptosis of both lung tumour cell lines, VEGF was unable to rescue cells from TSA-induced cell death. VEGF secretion was significantly decreased in both cell lines. Treatment with cycloheximide was unable to abrogate the TSA-mediated increase in the VEGF receptors examined, indicating that de novo protein synthesis is not required for these observed effects, but may be due to direct effects at the promoter level. Direct histone acetylation of histones H3 and H4 was observed, indicating an increase in histone hyperacetylation of VEGFR1 and VEGR2 promoters. A significant trend in the modulation of the VEGF receptors similar to that seen in response to TSA was shown when treated with Vorinostat (SAHA).

      Conclusion:
      Epigenetic targeting of the Neuropilin receptors may offer an effective treatment for NSCLC patients in the clinical setting. The possibility of novel targeted agents decreasing the levels, or function, of tumour VEGF receptors, in particular NP1, may lead to more successful treatments and prolonged overall survival in these patients.

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      MINI08.10 - Co-Occurrence of Driver Mutations of MAPK and PI3K Pathways in Non Small Cell Lung Cancer: A Report from Lung Cancer Genomics Ireland (LCGI) Study (ID 2627)

      16:45 - 18:15  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation
      • Slides

      Background:
      The mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways are frequently altered in human cancers. Targeting these pathways is an attractive therapeutic strategy in malignant disease. The frequency of single and dual pathway alterations varies substantially across various cancers. Co-occurrence of the MAPK and PI3K pathway aberrations is reported in 5-7% of melanomas, gastric and colorectal cancers, and is associated with a worse clinical outcome. In this report we aim to determine the co-occurrence of the MAPK and PI3K pathway mutations in a large cohort of surgically resected NSCLC tumors.

      Methods:
      We used the platform of Sequenom’s MassArray to perform genotyping for 548 somatic hotspot mutations in 49 genes including genes in the MAPK and PI3K pathways in surgically resected NSCLC tumors. MAPK pathway genes that were screened include: KRAS, HRAS, BRAF, RAF1, MAP3K1, MAP3K2, MAP3K3, MAP3K4, MAP3K5, MAP2K1, MAP2K2, MAP2K3, and PTPN11. PI3K pathway genes that were screened include: PIK3CA, PIK3R1, PIK3R2, PTEN, PDPK1, AKT1, AKT2, and MTOR. Fisher’s exact test was used to determine the statistical significance of association between the MAPK and PI3K pathway mutations. The strength of association was determined in the form of odds ratio.

      Results:
      NSCLC tumors from 356 patients (258 squamous cell, 98 adenocarcinomas) were tested using Sequenom’s MassArray. The frequency of mutations in the MAPK and PI3K pathways was 22.5% (n=80) and 22.8% (n=81) respectively. Among these patients, 38 patients had mutations in both pathways (i.e: 47.5% of patients with a MAPK pathway mutation also had a mutation in the PI3K pathway, and 46.9% of patients with a PI3K pathway mutation also had a mutation in the MAPK pathway, see table 1). Fisher’s exact test revealed that mutations in the MAPK and the PI3K pathways are mutually inclusive (p<0.0001, odds ratio=4.95, 95% CI 2.9-8.5) Table 1: The co-occurrence of MAPK and PI3K pathway mutations in NSCLC

      Pathway/no of patients PI3K WT PI3K MT
      MAPK WT 235 43
      MAPK MT 42 38


      Conclusion:
      38 (10.7%) of 356 NSCLC patients included in the LCGI study had hotspot somatic mutations in both the MAPK and PI3K pathways. Contrary to previous reports, we observed that activating mutations of the MAPK and PI3K pathways are mutually inclusive in NSCLC. These findings may have implications in designing clinical trials of targeted therapies in lung cancer.

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    MINI 13 - Genetic Alterations and Testing (ID 120)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      MINI13.08 - Targetable Genomic Aberrations in Squamous Cell Lung Cancer (SCC): A Report from the Lung Cancer Genomics Ireland (LCGI) Study (ID 766)

      10:45 - 12:15  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation
      • Slides

      Background:
      The prognosis of lung SCC continues to be poor with no molecularly targeted agents specifically developed for its treatment. LCGI aims to identify potential targetable oncogenes in lung SCC.

      Methods:
      The LCGI study is being carried out in 500 patients with surgically resected lung SCC, treated at St James’s University Hospital and Beaumont University Hospital, Dublin. We used the platform of Sequenom’s MassArray to perform genotyping for accustomed panel of 258 somatic hotspot mutations in 49 genes including genes in the MAPK and PI3K pathways. We also evaluated FGFR1 amplification by fluorescence in situ hybridization (FISH) and MET protein expression by immunohistochemistry (IHC).

      Results:
      Lung SCCs from 258 patients have been tested by Sequenom MassArray to date. Lung SCCs from 150 patients have been evaluated for MET protein expression and 89 for FGFR1 amplification. 163 (63.2%) patients were male. The median age of the cohort was 68. The majority of patients were either current (39.5%) or former (58.1%) smokers at the time of diagnosis. 138 (53.5%) were stage I, 87 (33.7%) were stage II, and 33 (12.8%) were stage III SCCs. At least one aberrant, potentially targetable oncogene was identified in the SCC of 101 (39.1%) patients (see Table). The presence of PIK3CA or KRAS mutations, or FGFR1 amplification did not have a statistically significant impact on median overall survival or recurrence-free survival. However, the presence of two or more aberrations in driver oncogenes in a tumor (patients, n=19) was associated with a worse median overall survival compared to patients with either a single driver aberration (p=0.04) or no aberrations (p<.01). Table: Frequency of driver mutations in LCGI compared to The Cancer Genome Atlas (TCGA) study

      Mutation LCGI (n=258) TCGA (n=178)
      FGFR1 amp (n=89) 13 % 16.8 %
      PIK3CA 15.1 % 10.1 %
      KRAS 6.5 % 0.6 %
      PTPN11 3.5 % 1.7 %
      STK11 3.1 % 1.7 %
      MYC 1.9 % 0.0 %
      NRAS 1.6 % 0.0 %
      BRAF 1.2 % 3.9 %
      HRAS 1.6 % 1.7 %
      CTNNB1 1.5 % 1.7 %
      FBXW7 1.5 % 3.4 %
      MET Overexpression (n=150) 1.3 % NA
      EGFR 0.9 % 2.8 %
      AKT1 0.4 % 0.6 %
      CDK4 0.4 % 0.0 %
      GNA11 0.4 % 0.6 %
      MAP2K1 0.4 % 0.6 %
      DDR2 0 % 1.1 %


      Conclusion:
      39.1% of lung SCC patients have an aberrant, potentially targetable driver oncogene in their tumor. The presence of two or more aberrant oncogenes is a poor prognostic factor in lung SCC. These findings can be used to guide clinical trials in lung SCC.

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    MINI 34 - RNA and miRNA (ID 162)

    • Event: WCLC 2015
    • Type: Mini Oral
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      MINI34.07 - A Novel microRNA Signature Associated with Cisplatin Resistance in NSCLC (ID 2709)

      18:30 - 20:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation
      • Slides

      Background:
      MicroRNAs (miRNAs) are an abundant class of small non-coding RNAs that range in size from 19 to 25 nucleotides. Alteration in miRNA expression can cause them to act as either tumour suppressor or oncogenes. They have also been shown to regulate a number of processes involved in tumour biology such as metastasis, invasion and angiogenesis. More recently, miRNAs have been linked to chemo- and radio-resistance in many solid tumours, including lung cancer.

      Methods:
      An isogenic model of cisplatin resistance was established by chronically exposing a panel of NSCLC cell lines (MOR, H460, A549, SKMES-1, H1299) to cisplatin for 12 months, generating cisplatin resistant (CisR) sublines from their corresponding age-matched parental (PT) cells. MicroRNA expression profiling was carried out using 7th generation miRCURY LNA™ microRNA arrays consisting of 1,919 miRNAs (Exiqon). MicroRNAs that were significantly increased in CisR sublines were inhibited using antagomirs (Exiqon), while those that were significantly decreased were over-expressed using pre-miRs (Ambion). Functional studies examining clonogenic survival ability, proliferation (BrdU) and apoptosis (Annexin V/PI) were subsequently carried out in the presence or absence of cisplatin. To examine the translational relevance of these microRNAs, their expression was further examined in a cohort of pre-treatment matched normal and tumour lung tissues from NSCLC patients of different histological subtypes. Validation of this miRNA signature is currently being investigated in serum samples from this same cohort of patients and normal controls.

      Results:
      MicroRNA profiling analysis identified ten miRNAs which were significantly altered between parental and corresponding cisplatin resistant lung cancer cell lines. Validation of these miRNAs by real-time PCR (qPCR) identified a specific 5-miR signature that was significantly altered in CisR cells relative to their parental counterparts. Modification of these microRNAs altered the response of resistant cells to the cytotoxic effects of cisplatin and decreased the clonogenic survival of CisR cells when treated with increasing doses of cisplatin (0.1µM-10μM). Significant differential expression was found between normal and tumour tissues across each histological subtype, highlighting the potential use of these microRNAs as markers of response to cisplatin therapy in NSCLC patients. Three miRNAs (miR-A, B, C) belonging to the same family were significantly altered in tumour lung tissue of adenocarcinoma and squamous cell histology compared to matched normal lung tissue. MicroRNA-D expression was significantly altered in squamous cell carcinomas while miR-E was differentially expressed in adenocarcinomas only. Data relating to the expression of this novel signature in the circulation of our NSCLC patient cohort and normal controls will be presented at WCLC 2015.

      Conclusion:
      We have identified and validated a novel miRNA signature associated with cisplatin resistance in a panel of cisplatin resistant cell lines and in patient lung tumours. Genetic manipulation of these specific miRNAs in vitro altered the cisplatin resistant cell response to the cytotoxic effects of cisplatin chemotherapy. The data obtained from this study may provide a basis for the potential development of a companion diagnostic for lung cancer patients who are most likely to benefit, or not, from cisplatin chemotherapy.

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    ORAL 37 - Novel Targets (ID 146)

    • Event: WCLC 2015
    • Type: Oral Session
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      ORAL37.02 - Protein Tyrosine Phosphatase Non Receptor 11 PTPN11/Shp2 as a Driver Oncogene and a Novel Therapeutic Target in Non-Small Cell Lung Cancer NSCLC (ID 1590)

      16:45 - 18:15  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      PTPN11/Shp2 somatic mutations occur in 25% of Juvenile myelomonocytic leukemias (JMML) and less commonly in adult solid tumors. PTPN11/Shp2 activates the mitogen-activated protein kinase (MAPK) and the phosphatidylinositide 3-kinase (PI3K) pathways. Accordingly, PTPN11/Shp2 mutations were shown to sensitize leukemia cells to MEK and PI3K inhibitors.

      Methods:
      We applied mass-spectrometry based genotyping (Sequenom Inc., Germany) to DNA extracted from tumor and matched normal tissue of 356 NSCLC patients (98 adenocarcinomas and 258 squamous cell (SCC)). PTPN11/Shp2 constructs with mutations (E76A, A72D) were generated and stably expressed in IL-3 dependent BaF3 cells and NSCLC cell lines (H1703, H157). The acquisition of MAPK and PI3K pathways activation was evaluated using western blotting and reverse phase protein array (RPPA). PTPN11/Shp2 phosphatase activity was measured in whole cell protein lysates using Shp2 assay kit (R&D Systems).

      Results:
      Somatic PTPN11/Shp2 hotspot mutations occurred in 3 (3.1%) and 9 (3.4%) of adenocarcinomas and SCCs, respectively. Mutant PTPN11/Shp2, compared to PTPN11/Shp2 wild type, promoted ten-fold IL-3 independent BaF3 cell survival. BaF3, H1703, and H157 cells expressing mutant PTPN11/Shp2 exhibited increased PTPN11/Shp2 phosphatase activity, phospho-ERK1/2, and phospho-AKT levels. Sequencing of NSCLC cell lines revealed that NSCLC H661 cell line has a PTPN11/Shp2 activating mutation (N58S). H661 had significantly higher PTPN11/Shp2 phosphatase activity when compared to PTPN11 wild-type H1703 and Calu3 NSCLC cells. Since the biological functions of PTPN11/Shp2 are mediated through its phosphatase domain, we stably expressed the inactivating PTPN11/Shp2 phosphatase domain mutation (C459S) in H661, H1703 and H157 cells resulting in catalytically inactive PTPN11/Shp2. This led to decreased phospho-ERK1/2 levels in all three cell lines. Importantly, the inactivation of PTPN11/Shp2 resulted in decreased phospho-AKT levels in H661 cells (PTPN11-mutated) and had no effect on phospho-AKT levels in the PTPN11/Shp2-wild type H1703 and H157 cells. Taken together, this data suggests that PTPN11/Shp2 activating mutations are oncogenic in NSCLC cells. Moreover, these findings reveal that PTPN11/Shp2 mutations may selectively activate the PI3K pathway in NSCLC cells. Parental H661 (PTPN11-mutated, KRAS and PIK3CA-wild type), parental H1703 (PTPN11, KRAS and PIK3CA-wild type) and parental H157 (KRAS-mutated, PTPN11 and PIK3CA-wild type) cells were treated with the novel MEK (BAY86-9766) and PI3K (BAY80-6946) inhibitors. IC50 values (table 1) suggest that PTPN11-mutated NSCLC cells have modest sensitivity to MEK inhibitors and profound sensitivity to PI3K inhibitors.

      Table 1 IC 50 valuse
      Cell Line BAY86-9766 (nM) BAY80-6946 (nM)
      H661 2880 ± 600 13 ± 4.7
      H157 1450 ± 520 < 50% inhibition @ 200
      H1704 < 50% inhibition @ 10000


      Conclusion:
      PTPN11/Shp2 demonstrates the in vitro features of a driver oncogene, and potentially represents a new target in NSCLC.

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    ORAL 42 - Drug Resistance (ID 160)

    • Event: WCLC 2015
    • Type: Oral Session
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 1
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      ORAL42.06 - Cancer Stem Cells: Targeting Aldehyde Dehydrogenase 1 (ALDH1) as a Novel Strategy in Cisplatin Resistant Non-Small Cell Lung Cancer? (ID 2724)

      18:30 - 20:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Presentation
      • Slides

      Background:
      Cisplatin is the backbone of chemotherapeutic treatment of lung cancer. Unfortunately the development of resistance has become a major challenge in the use of this cytotoxic drug. Understanding the mechanisms underlying this resistance phenotype may potentially result in the development of novel agents that may enhance the sensitivity of cisplatin chemotherapy in the clinical setting. The root of this resistance is hypothesized to be due to the presence of a rare cancer stem cell (CSC) population within the tumour that can reform a heterogenic tumour, resulting in recurrence and resistance following cisplatin chemotherapy.

      Methods:
      An isogenic model of cisplatin resistance was established by chronically exposing a panel of NSCLC cell lines (H460, SKMES, H1299) to cisplatin for 12months, thereby creating cisplatin resistant (CisR) sublines and their corresponding age-matched parental (PT) cells. To identify a CSC population within the resistant sublines, PT and CisR cell lines representing the three classifications of NSCLC were stained for ALDH1 using the Aldefluor kit (Stemcell Technologies). ALDH1 positive (+ve) and negative (-ve) subpopulations were isolated and their functional characteristics assessed. Proliferation and survival of ALDH1+ve fractions in response to cisplatin was assessed using BrdU and clonogenic survival assays relative to ALDH1-ve cells. ALDH1 subpopulations were examined for asymmetric division and expression of the human embryonic stem cell markers Nanog, Oct-4, Sox-2, Klf-4 and c-Myc and CD133. To confirm that this ALDH1+ve population is associated with cisplatin treatment, PT and CisR cells were chronically exposed to high dose cisplatin for 2 weeks and stained for ALDH1 and re-assessed for stemness qualities. Apoptosis and clonogenic survival of PT and CisR cells was assessed in response to selective inhibition of ALDH1 using diethylaminobenzaldehyde (DEAB) in combination with cisplatin. Xenograft studies in NOD/SCID mice are currently under investigation to examine the tumourigenic potential of isolated subpopulations of ALDH1.

      Results:
      A significant ALDH1+ve population was detected in CisR sublines, but not in their PT counterparts. Characterisation of the ALDH1+ve subpopulation confirmed enhanced expression of stemness markers, increased resistance and clonogenic survival in response to cisplatin compared to their ALDH1-ve counterparts, and the ability to asymmetrically divide. Chronic cisplatin treatment of the PT cell lines for 2 weeks increased resistance to cisplatin, increased stemness marker expression and induced the emergence of an ALDH1+ve population. Chronic high dose cisplatin treatment significantly expanded the ALDH1+ve population in the CisR cell lines. Importantly, inhibition of ALDH1 activity, with DEAB, decreased the mean cell viability, clonogenic survival capacity and increased cisplatin-induced apoptosis of the CisR cells when used in combination with cisplatin, an effect not seen in the PT cells.

      Conclusion:
      In this study, we have demonstrated the existence of a putative CSC population within our model of isogenic cisplatin resistant cell lines and suggest a role for ALDH1 inhibition as a potential therapeutic strategy in re-sensitizing chemoresistant lung cancer cells to the cytotoxic effects of cisplatin. Further studies will focus on re-purposing of FDA-approved ALDH1 inhibitor, Disulfiram (Antabuse), used in the treatment of chronic alcoholism as a potential combination therapy to prime chemoresistant cells to cisplatin.

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    P1.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 233)

    • Event: WCLC 2015
    • Type: Poster
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 3
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      P1.04-076 - CDCA3 Is a Novel Cell Cycle Regulator in Lung Cancer (ID 1630)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      Progression through the mammalian cell cycle relies upon coordination of a complex network of proteins. Following genomic insult, checkpoints during each stage of the cell cycle are engaged to halt cell cycle progression to allow faithful DNA repair. Failure to arrest cell cycle may lead to genomic instability and cancer development. However, the molecular basis for the loss of genome integrity during cancer development remains to be determined. Cell division cycle associated 3 (CDCA3) is a key regulator of the normal cell cycle. CDCA3 modulates this process by enabling cell entry into mitosis through degradation of the mitosis-inhibitory factor WEE1. CDCA3 itself is also degraded in G1 yet re-expressed in G2/M phase, to allow successful progression through the cell cycle. Here we describe for the first time a novel function for CDCA3 in maintaining effective cell cycle progression in lung cancer.

      Methods:
      To examine the role of CDCA3 in modulating the cell cycle of lung cancer cells, CDCA3 was depleted using an siRNA approach in A549, SKMES and H460 cell lines. CDCA3 depletion was assessed using Western blot analysis. Cell proliferation assays were performed on control and CDCA3 knockdown cells over a period of 96 h using the Promega CellTitre-Glo cell viability assay. Cell cycle progression was assessed on propidium iodide stained cells using a Beckman Coulter Gallios flow cytometer. To determine if CDCA3 expression is associated with lung cancer progression, a tissue microarray (TMA) with cores from 600 patients was stained with an anti-CDCA3 antibody. Correlation of CDCA3 staining with clinical data and patient prognosis is ongoing.

      Results:
      As a cell cycle related protein, we tested if CDCA3 is required for effective proliferation of a range of lung cancer cell lines. CDCA3 depletion reduced the proliferation of U2OS (osteosarcoma), A549, MOR (lung adenomcarcenoma) and SKMES cancer cells (squamous lung cancer). Interestingly, depletion of CDCA3 did not affect proliferation of H460 cells (large neuroendocrine lung cancer). We next tested the cell cycle progression and noted that knockdown of CDCA3 induced an increase of all cell lines in G1 arrest with the exception of H460 cells. To observe if CDCA3 expression is linked with disease progression, TMA staining of lung cancer biopsies was performed. Accordingly, elevated expression of CDCA3 was identified specifically in tumour cells. These data highlight the potential prognostic value of CDCA3 expression.

      Conclusion:
      Our data point to a potential role for CDCA3 in the progression of lung cancer. While the precise mechanism for CDCA3-dependent cell cycle regulation remains unknown, it is possible that elevated CDCA3 levels modulate tumour cell proliferation. Identifying the molecular basis may yield novel therapeutic avenues worth targeting during aberrant cell cycle in cancer.

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      P1.04-088 - Lung Cancer Cells Can Alter the Behaviour of Normal Bronchial Epithelial Cells Through Multiple Mechanisms (ID 1312)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      Lung cancer is one of the most heterogeneous of all solid cancers. This may in part be due to hi-jacking and additional bystander affects that are exerted on the normal lung cell population by the cancer cells. A number of pathways may be stimulated through soluble factors or effector filled vesicles such as exosomes secreted by cancer cells. The aim of this project was to evaluate the effects of non-small cell lung cancer (NSCLC) cells on an immortalised normal bronchial epithelial cell line.

      Methods:
      A normal bronchial epithelial cell line (HBEC4) was exposed to adenocarcinoma, large cell and squamous NSCLC cell lines and a number of phenotypic and genotypic characterisations were undertaken. These included cellular proliferation (BrdU ELISA), gene (RT-PCR) and miRNA expression screening (Nanostring). The effect of cancer exosome fractions was also determined.

      Results:
      Exposure to various subtypes of NSCLC significantly increased the cellular proliferation rate of the immortalised cell line in a number of models. Expression of a number of miRNAs were altered in the normal cells pre- and post exposure to the cancer cells. Various stem cell factor markers (KLF4, Oct, c-myc) were also significantly changed at the mRNA level. In addition, exosome fractions altered the behaviour of the normal cell line, likewise stimulating cell proliferation.

      Conclusion:
      Lung cancer cells may influence normal cell behaviour in both a direct and indirect manner using multiple mechanisms. Normal bronchial epithelial cells with stem like features may be induced to proliferate and behave in a malignant manner. This, akin to Hodgkin’s lymphoma, may contribute significantly to the composition of the tumour. Furthermore this observation may contribute to the heterogeneity of lung cancer tumours and affect treatment response. Ongoing studies are evaluating these effects in novel 2D and 3D culture systems.

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      P1.04-105 - The Development and Assessment of Advanced Cellular Models for the Study of Non-Small Cell Lung Cancer (ID 1335)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      The key mechanisms that underlie drug resistance in lung cancer have yet to be fully elucidated. A significant limiting factor is the lack of biologically relevant cellular models for basic laboratory research. To address these issues, many are now turning to three-dimensional (3D) based cellular assay systems that permit the formation of multicellular structures such as tumour spheroids. Depending on their size the internal microenvironment of these structures mimics closely that of those in vivo. In the majority of cases, spheroids with a diameter greater than 100µm exhibit an asymmetry in cellular proliferation and viability - proliferating tumour cells at the periphery; cell-cycle arrested cells at larger distances from the surface. Regions of necrosis associated with reduced oxygen tension and hypoxia have often been reported. This study compared drug resistant models of non-small cell lung cancer (NSCLC) in 3D culture with those in grown in two-dimensional (2D) culture. The behaviour of cells grown in these distinct geometric configurations was monitored and compared by measuring viability, proliferation and oxygen tensions.

      Methods:
      Happy Cell Advanced Suspension Medium[™] (ASM) was chosen to culture our 3D spheroids. This polymer-based formulation was selected for its ease of use, as well as its compliance with liquid handling, high content imaging and analysis (HCSA) and high throughput screening (HTS) systems. Isogenic NSCLC cell line models of cisplatin resistance were cultured in 2D and 3D cell culture systems. Cisplatin sensitive (Pt) and isogenic cisplatin resistant (CisR) NSCLC sub-types were studied. IC50 values were calculated and a positive control was selected. All cultures were grown in a range of cisplatin concentrations for 72 hours. Subsequently, viability and hypoxia assays were conducted in order to compare the response of Pt and CisR cells in both 2D and 3D culture systems. Morphological analysis was performed via high content analysis (HCA) and confocal microscopy.

      Results:
      At equivalent cisplatin concentrations 3D spheroids exhibit greater resistance compared with monolayers. Imaging experiments have shown that these 3D structures have a central necrotic core, a feature of the asymmetric growth patterns associated with 3D structures.

      Conclusion:
      Happy Cell ASM is a novel 3D culture medium for generating multicellular tumour spheroids and has potential for HTS and HCSA. When treated with cisplatin our spheroids exhibited resistance to therapy compared to 2D monolayer cultures. These results suggest that spheroids may provide a more accurate in vitro model to elucidate mechanisms of drug resistance and may aid the identification of novel targets to re-sensitise patient therapy.

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    P1.08 - Poster Session/ Thymoma, Mesothelioma and Other Thoracic Malignancies (ID 224)

    • Event: WCLC 2015
    • Type: Poster
    • Track: Thymoma, Mesothelioma and Other Thoracic Malignancies
    • Presentations: 1
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      P1.08-014 - The Small Molecule Inhibitor, LCRF004, Is Effective in Targeting the RON/MST1R Pathway in Malignant Pleural Mesothelioma (ID 1311)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      Malignant pleural mesothelioma (MPM) is an aggressive inflammatory cancer. We have previously identified RON as frequently activated in MPM patient samples and cell lines. RON is a member of the MET proto-oncogene family and is bound by macrophage stimulating protein (MSP). High positivity for total RON by IHC was an independent predictor of favourable prognosis. Additionally, elevated expression levels of MSP correlated with better survival. The aim of this study was to further examine the MSP-RON signalling axis in MPM using a RON inhibitor, LCRF004.

      Methods:
      MPM cell lines and a normal mesothelial cell line were screened for the expression of RON and MSP at the protein (Western) and mRNA (RT-PCR) level. Downstream mediators affected by MSP stimulation and LCRF004 were identified using a proteome profiler array. The effect of LCRF004 and MSP were examined using proliferation (BrdU ELISA), viability (High Content Analysis), migration (xCELLigence), apoptosis and cell cycle (HCA) assays. A xenograft study was also completed.

      Results:
      Treatment with LCRF004 resulted in a significant decrease in proliferation, viability and migration in vitro and reduced tumour growth in vivo (p<0.05, compared with vehicle control). In addition, LCRF004 significantly increased apoptosis. In terms of cell cycle, drug treatment decreased cells in 2n, whilst increasing cells in the G0/G1 phase. Experiments are on going to further characterise the mechanism of action of LCRF004.

      Conclusion:
      The in vivo and in vitro data generated in this study, indicates that the MSP-RON signalling axis is a potential target in MPM. Targeting the RTK domain of the RON receptor with a small molecule inhibitor is an effective interventional strategy in MPM.

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    P2.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 234)

    • Event: WCLC 2015
    • Type: Poster
    • Track: Biology, Pathology, and Molecular Testing
    • Presentations: 4
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      P2.04-057 - Targeting PIM Kinase in NSCLC (ID 933)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      PIM proteins belong to a family of serine/threonine kinases composed of 3 isoforms, PIM1, PIM2 and PIM3, that play a key role in cell cycle regulation, have potent anti-apoptotic activity and play a role in the homing and migration of metastatic cells. Furthermore, PIM kinases have also been shown to be activated in response to Akt pathway inhibition, indicating a role in adaptive responses to inhibition of this pathway potentially leading to treatment resistance. Thus, there is a strong rationale for combining PIM kinase inhibition with inhibition of the Akt pathway (i.e., inhibitors of EGFR, PI3K, Akt and mTOR). PIM kinase has been recognised as a therapeutic target particularly in haematological malignancies however the role of PIM kinases in solid tumours and NSCLC in particular are less well characterised. This study is the first to elucidate the expression of all 3 PIM isoforms in NSCLC cell lines and patient tumours as well as to examine the effect of Inflection Bioscience Ltd novel dual PI3K/PIM kinase (IBL-202) and triple PI3K/mTOR/PIM kinase (IBL-301) targeted therapies in-vitro and in-vivo.

      Methods:
      PIM 1/2/3 protein expression was quantified by western blot analysis in a panel of NSCLC cell lines and 40 matched normal/tumour tissues from NSCLC patients (20 adenocarcinoma and 20 squamous cell carcinoma). PIM kinase expression was correlated to patient clinicopathological characteristics and survival data. The effectiveness of IBL-202 and IBL-301 on proliferation and apoptosis in NSCLC cell lines were examined by BrdU and Annexin V/PI FACS analysis, respectively. A head-to-head in-vivo study of IBL-202 vs. IBL-301 in xenograft nude mice formed using H1975 cells is ongoing.

      Results:
      All 3 isoforms of PIM kinase are highly expressed across a panel of NSCLC cell lines. PIM kinase is expressed in ~ 90% of NSCLC tumour tissues across all stages of the disease. IBL-202 and IBL-301 induced apoptosis and decreased cell proliferation in NSCLC cell lines at micromolar concentrations in-vitro. The in-vivo study is ongoing and results will be presented.

      Conclusion:
      PIM kinase is a promising new therapeutic target for the treatment of NSCLC patients. Dual PI3K/PIM kinase (IBL-202) and triple PI3K/mTOR/PIM kinase (IBL-301) targeted therapies have demonstrated pro-apoptotic and anti-proliferative activity in-vitro and in-vivo and should be considered in the treatment of NSCLC patients.

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      P2.04-099 - Differential Regulation of DNA Repair Genes in Cisplatin Resistant Non-Small Cell Lung Cancer Cells (ID 2746)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      In the absence of specific treatable mutations, cisplatin-based doublet chemotherapy remains the gold standard treatment for NSCLC patients. However, its clinical efficacy is hindered in many patients due to both intrinsic and acquired resistance to this drug. Alterations in the DNA repair capacity of damaged cells is now recognised as an important factor in mediating this phenomenon. DNA repair is therefore a vital target to improving cancer therapy and overcoming resistance of tumour cells to DNA damaging agents currently used in the treatment of NSCLC patients.

      Methods:
      DNA Repair Pathway RT[2 ]Profiler Arrays were used to elucidate the key DNA repair genes implicated in cisplatin resistant NSCLC cells using cisplatin resistant (CisR) and corresponding parental (PT) H460 NSCLC cells previously established in our laboratory. The regulation of the trans-activation of p53 in response to DNA damage was studied by examining protein accumulation, post-translational modifications (p53[Ser15]) and whether depletion of the novel DNA repair protein, hSSB1, affects the regulation of p53 in response to cisplatin. The repair of cisplatin-induced double strand breaks (DSBs) was examined by immunofluorescence imaging of γH2AX foci. Expression of p53[Ser15] (phosphorylated & total) in addition to hSSB1 was also assessed by HCA and Western blot analysis.

      Results:
      We identified a number of critical DNA repair genes that were differentially regulated between parental and cisplatin resistant NSCLC cells, some of which are known to be implicated in the nucleotide and mismatch repair pathways. H2AX was shown to be a reliable and specific marker of DNA double strand DNA breaks induced by platinum agents such as cisplatin. Cisplatin induced the translocation of p53 from the cytoplasmic compartment of H460 PT cells to the nuclear compartment, while significant levels of p53 were retained within the cytoplasmic compartment of CisR cells. Using both HCS and Western blot analysis, hSSB1 protein was undetectable.

      Conclusion:
      To date, despite reports that differential expression of components of the various DNA repair pathways correlate with response to cisplatin, translation of such findings in the clinical setting are warranted. The identification of alterations in specific proteins and pathways that contribute to these unique DNA repair pathways in cisplatin resistant cancer cells may potentially lead to a renewed interest in the development of rational novel therapies for cisplatin resistant cancers, in particular, lung cancer.

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      P2.04-102 - Targeting Inflammatory Mediators to Overcome Intrinsic and Acquired Cisplatin Resistance in Non-Small Cell Lung Cancer (ID 1314)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      Cisplatin based doublet-chemotherapy is commonly used in non-small cell lung cancer (NSCLC) treatment with an initial objective response rate of 40-50%. However, intrinsic and acquired chemo-resistance constitutes a major clinical obstacle. The mechanisms of resistance have yet to be fully understood. We have previously demonstrated that NF-κB levels are elevated in cisplatin resistant cells (CisR) and that the use of an NF-κB inhibitor, DHMEQ, resulted in greater CisR cell death. The goal of this project is to elucidate the mechanistic links between NF-κB regulated pathways and the development of cisplatin resistant NSCLC.

      Methods:
      The expression of NF-κB mediators and immune regulators were assessed in an isogenic NSCLC cell line model of cisplatin resistance using qPCR arrays (252 genes). A number of targets were identified and validated using PCR. The effect of drug combinations (Cisplatin and DHMEQ) was also determined. Comet assays (DNA damage) were also performed to determine the effect of DHMEQ alone or in combination with irradiation (6 Gy).

      Results:
      Various chemokines and their receptors were elevated in cisplatin resistant (CisR) cells compared with cisplatin sensitive (PT). In addition, a number of key TLRs and regulators of the innate immune pathway were altered. DHMEQ enhanced cellular sensitivity to cisplatin in both PT and CisR cell lines (p<0.05). This drug also overcame the chemo-protective effect of a number of chemokines and enhanced irradiation induced DNA damage. An animal study will commence shortly using DHMEQ alone and in combination with cisplatin.

      Conclusion:
      Immune-modulators such as DHMEQ may be a novel viable option in addressing inflammatory mediated acquired and intrinsic NSCLC chemo-resistance. In addition, immune regulators identified in this project may provide innovative targets for immuno-oncology therapy.

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      P2.04-109 - Epithelial-To-Mesenchymal Transition (EMT) and Acquired Resistance to PI3K-mTOR Inhibition in NSCLC (ID 934)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      The PI3K-Akt-mTOR pathway regulates cell growth and proliferation and is often dysregulated in NSCLC, making it an attractive therapeutic target in this setting. GDC-0980 is a selective dual inhibitor of PI3K and mTOR, which is currently in Phase II clinical trials for solid tumours. As with all targeted therapies, acquired resistance to GDC-0980 is anticipated to be a major hurdle in the success of this drug. The aims of this project are to (i) elucidate the frequency of PIK3CA mutations in an Irish cohort of NSCLC patients and (ii) develop and characterise three cell line models of resistance to GDC-0980, each representing a different molecular subtype of NSCLC, in order to identify biomarkers of response/resistance to the drug that may dictate beneficial treatment strategies.

      Methods:
      DNA was extracted from 250 NSCLC patient tissue samples, and screened for 547 clinically relevant mutations in 46 genes using the Sequenom platform. H460, A549, and H1975 cells were cultured in GDC-0980 at IC50 concentrations over a period of several months, along with matched ‘parent’ cell lines. Development of resistance was assessed by monthly BrdU proliferation assays. Cell growth patterns were compared across the sensitive and resistant cell lines in real time using the xCELLigence platform. Cell lines were then interrogated for alterations in DNA (Sequenom), mRNA (SABiosciences arrays profiling expression of >150 genes), miRNA (Exiqon expression profiling of 2100 miRNAs) and protein (R&D Phospho Kinase array expression profiling of 43 kinases and 2 associated total proteins, PTMScan[®] Ubiquitin Remnant Motif (K-ε-GG) Kit from CST and Western blot analysis).

      Results:
      PIK3CA mutations occur in ~5% adenocarcinomas & 12% squamous cell carcinomas. H1975 cells (PIK3CA mutant and activated pAkt (Ser473/Thr308), pmTOR, pS6R) were most sensitive to GDC-0980, however they were the first to develop resistance to the drug. Results obtained from xCELLigence studies identified H1975 resistant (H1975R) cells as having the highest cell index out of all parent and resistant cell lines after 100 hours of cell growth, suggesting that these are the most aggressive cells. Initially a 33 miRNA signature was identified contrasting H1975P and H1975R. qPCR validation of miR-205 (a regulator of EMT) identified expression in H1975P cells but miR-205 was undetectable in H1975R cells. mRNA expression of Zeb1 & Zeb2 (direct targets of miR-205) were increased in H1975R cells compared to H1975P cells. 1,200 proteins were found to be differentially expressed between H1975P and H1975R cells. Increased expression of EMT proteins vimentin, desmin and filamin was detected in H1975R cells (p < 0.05, fold change >2). Vimentin overexpression in H1975R cells was confirmed by western blot analyis. Activation of EMT was identified as one potential mechanism of resistance to GDC-0980 in H1975R cells.

      Conclusion:
      The PI3K-mTOR pathway is frequently mutated in NSCLC, in particular squamous cell carcinoma, making it an ideal therapeutic target. Acquired resistance to GDC-0980 developed rapidly in NSCLC cell lines, (4-6 months) and correlates to the induction of EMT. Further elucidation of EMT regulation is under investigation and is crucial to the design of improved treatment protocols.

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    P2.08 - Poster Session/ Thymoma, Mesothelioma and Other Thoracic Malignancies (ID 225)

    • Event: WCLC 2015
    • Type: Poster
    • Track: Thymoma, Mesothelioma and Other Thoracic Malignancies
    • Presentations: 1
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      P2.08-006 - The JmjC Family of Lysine Demethylases Are Overexpressed and Potential Therapeutic Targets in Malignant Pleural Mesothelioma (ID 1753)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      Malignant pleural mesothelioma (MPM) is an aggressive rare cancer affecting the pleura and is predominatly associated with prior exposure to asbestos. Treatment options are limited, and most patients die within 24 months of diagnosis. The current standard of care for MPM patients is a combination of cisplatin and pemetrexed (or alternatively cisplatin and raltitrexed), yet most patients die within 24 months of diagnosis. There is therefore an urgent unmet need to identify new therapeutic options for the treatment of MPM. Asbestos fibres contain of transition metals and their ability to both adsorb and accumulate these metals was one of the first mechanisms suggested for explaining the toxic and particularly carcinogenic effects of asbestos. One of the transition metals in asbestos fibres is iron, and therefore asbestos fibres may cause an alteration of iron homeostasis in the tissue. In addition, asbestos fibres have also been shown to have high affinity for histones, and therefore may result in high accumulation of iron around chromatin. Lysine Demethylases (KDMs) containing a JmjC domain require both Fe2+ and 2-oxoglutarate as co-factors to regulate gene expression by “erasing or removing” methylation on histones in chromatin. Members of this family are frequently found to have aberrant expression in cancer and currently are actively pursued as candidate pharmaceutical therapeutic targets. Given that asbestos increases iron levels, this may result in aberrant KDM activity, and these KDMs could therefore be novel candidate targets in mesothelioma. We therefore examined the expression of several JmjC containing KDMs in MPM and assessed their potential for therapeutic intervention in mesothelioma using existing small molecule inhibitors.

      Methods:
      A panel of MPM cell lines were screened for expression of KDM4A-D, KDM5A/B and KDM6A/B by RT-PCR. mRNA levels were subsequently examined by RT-PCR in a cohort of snap-frozen patient samples isolated at surgery comprising benign, epithelial, biphasic, and sarcomatoid histologies. IHC was performed for KDM4A on a cohort of FFPE specimens. The effects of treatments with small molecule inhibitors targeting these proteins on both cellular health and gene expression were assessed.

      Results:
      The expression of the various KDMs was detectable across our panel of cell lines. In primary tumours the expression of these KDMs were significantly elevated in malignant MPM compared to benign pleura (p<0.05), and significant differences were also observed when samples were analysed across different histological subtypes. Treatment of mesothelioma cell lines with various small molecule inhibitors caused significant effects on cellular health and on the expression of a panel of genes.

      Conclusion:
      The expression of KDMs are significantly altered in MPM. Small molecule inhibitors directed against these KDMs show potential therapeutic efficacy with significant anti-proliferative effects. We continue to assess the effects of these compounds on gene expression and cellular health to confirm their potential utility as novel therapies for the treatment of MPM.

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    P3.08 - Poster Session/ Thymoma, Mesothelioma and Other Thoracic Malignancies (ID 226)

    • Event: WCLC 2015
    • Type: Poster
    • Track: Thymoma, Mesothelioma and Other Thoracic Malignancies
    • Presentations: 1
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      P3.08-008 - Tip60 (KAT5) May Be a Candidate for Therapeutic Targeting in Malignant Pleural Mesothelioma (ID 1760)

      09:30 - 17:00  |  Author(s): K.J. O'Byrne

      • Abstract
      • Slides

      Background:
      Malignant pleural mesothelioma (MPM) is a rare aggressive cancer of the pleura. The most well established risk factor for this disease is exposure to asbestos. The current standard of care for patients suffering from MPM is a combination of cisplatin and pemetrexed (or alternatively cisplatin and raltitrexed). Most patients however, die within 24 months of diagnosis. New therapies are therefore urgently required for this disease. KAT5 (also known as Tip60) is the catalytic subunit of the NuA4 histone acetyltransferase complex which is involved in transcriptional activation of select genes. This complex may be required for the activation of transcriptional programs associated with oncogene and proto-oncogene mediated growth induction, tumor suppressor mediated growth arrest and replicative senescence, apoptosis, and DNA repair. KAT5 has also been linked with the development of cisplatin resistance. KAT5 may therefore be a significant element in MPM with respect to responses to cisplatin based therapy and could represent a novel candidate target for intervention.

      Methods:
      KAT5 has 4 variant mRNAs. Primers were designed to distinguish between all variants, and a panel of MPM cell lines was screened for KAT5 expression by RT-PCR. Levels of KAT5 were subsequently examined in a cohort of snap-frozen patient samples isolated at surgery comprising benign, epithelial, biphasic, and sarcomatoid histologies by RT-PCR. The effects of a small molecule inhibitor of KAT5 (MG-149) on cellular proliferation were examined.

      Results:
      Semi-quantitative densitometric analysis showed that the expression of KAT5 is dramatically increased in MPM for all mRNA variants. When separated according to histological subtype, significant differences were also observed between the various histologies. A small molecule inhibitor of KAT5 exists and treatment of cells with this small molecule inhibitor (MG-149) resulted in a significant inhibition of cellular proliferation (p < 0.001) in the NCI-H226 cell line. We continue to assess this compound by other methodologies to confirm its potential utility in the treatment of MPM.

      Conclusion:
      KAT5, a lysine acetyltransferase associated with cisplatin resistance in cancer is significantly altered in MPM. A small molecule inhibitor of this protein shows significant anti-proliferative effects in MPM cell lines. Targeting this protein may have important future implications for the management of MPM.

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