1) A tumor which harbors an Epidermal Growth Factor Receptor (EGFR) -mutation known to be associated with drug sensitivity (i.e., G719X, exon 19 deletion, L858R, L861Q) from previous tumor biopsy or surgery. A tumor which harbors exon 20 insertion or de novo T790M mutation is eligible for the treatment in the sequential arm 2) Objective clinical benefit from treatment with an Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR TKI) as defined by either