NSCLC patients who have failed first line TKI treatment (defined radiological documentation of disease progression during treatment for advanced or metastatic NSCLC with an approved EGFR-TKI e.g. gefitinib, afatinib or erlotinib) and are screened for the AURA3 study and determined to be lacking the T790M mutation as determined using the AURA3 designated central laboratory using the cobas® EGFR Mutation Test (Roche Molecular Systems). Only sites that are participating in the AURA3 study, and patients who had the T790M mutation tested for AURA3 screening (and determined not to have the T790M mutation) will be included.