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G. Mi



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    P2.03b - Poster Session with Presenters Present (ID 465)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Advanced NSCLC
    • Presentations: 1
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      P2.03b-035 - EGFR FISH as Potential Predictor of Necitumumab Benefit with Chemotherapy in Squamous NSCLC: Subgroup Analyses from SQUIRE (ID 5708)

      14:30 - 14:30  |  Author(s): G. Mi

      • Abstract

      Background:
      Necitumumab (Neci) is a monoclonal antibody directed against the human epidermal growth factor receptor (EGFR). In the SQUIRE trial (NCT00981058), the addition of Neci to gemcitabine plus cisplatin (Gem-Cis) in squamous cell lung cancer resulted in a significant advantage in terms of overall survival (OS), but the expression of EGFR assessed by immunohistochemistry was not able to robustly predict the benefit from Neci. In a post-hoc analysis of SQUIRE, EGFR gene copy number gain determined by fluorescence in situ hybridization (FISH) showed a trend towards improved OS (HR=0.70) and progression-free survival (PFS) (HR=0.71) with the addition of Neci. We present the analysis of granular EGFR-FISH data from SQUIRE to examine the potential predictive role of high polysomy (HP) vs gene amplification (GA) as both were included in the “FISH-positive” category.

      Methods:
      Suitable specimens from SQUIRE patients underwent FISH analysis. Probe hybridization was performed in a central laboratory and each sample was analyzed using the Colorado EGFR scoring criteria. FISH was considered positive in cases of HP (≥40% cells with ≥4 EGFR copies) or GA (EGFR/CEP7 ≥2 or ≥10% cells with ≥15 EGFR copies). The correlation of granular FISH parameters with clinical outcomes was assessed.

      Results:
      FISH analysis was available for 557 patients (out of 1093); 208 patients (37.3%) were FISH+, including 167 (30.0%) with HP and 41 (7.4%) with GA. The outcome data for HP and GA are reported below:

      HIGH POLYSOMY GENE AMPLIFICATION
      Neci+Gem-Cis (N=89) Gem-Cis (N=78) Neci+Gem-Cis (N=22) Gem-Cis (N=19)
      Median OS in months (95% CI) 12.58 (11.04-16.00) 9.53 (7.16-12.48) 14.78 (10.02-31.51) 7.62 (4.99-16.10)
      Hazard ratio within subgroup (interaction model) 0.77 (0.55-1.08) p = 0.133 0.45 (0.21-0.93) p = 0.033
      Interaction p value 0.189
      Median PFS in months(95% CI) 6.08 (5.59-7.59) 5.13 (4.24-5.72) 7.36 (4.27-11.40) 5.55 (2.79-8.34)
      Hazard ratio within subgroup (interaction model) 0.70 (0.50-0.99) p = 0.044 0.69 (0.33-1.45) p = 0.334
      Interaction p value 0.980


      Conclusion:
      The OS benefit from the addition of Neci to Gem-Cis appeared to be more pronounced in the small subset of patients with GA when compared to HP, but the same trend was not observed for PFS. The potential predictive value of different EGFR FISH parameters should be evaluated in future studies.