a trend toward significanceP =0.057
33 Finally, a retrospective analysis evaluated the value of EGFR gene copy number assessed with fluorescence in situ hybridization (FISH), as a predictor of outcome in 557 evaluable patients; although a positive FISH does not qualify as a predictor of outcome with statistical significance, a trend toward significance was observed for both PFS (interaction P =0.057) and OS (interaction P =0.066), and the addition of necitumumab in the FISH-positive population resulted in an HR equal to 0.71 for PFS (95% CI=0.52–0.97) and 0.70 for OS (95% CI=0.52–0.96). 34 Safety profile The different trials involving necitumumab allowed the investigators to collect meaningful data about its safety profile and the drug-related adverse events.