Keeping our fingers crossed on 2^nd generation EGFR TKIs: is better good enough?

It has been almost a decade since the first generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has been approved for use in non-small cell lung cancer (NSCLC). When EGFR TKIs (gefitinib, erlotinib) were approved, it was based on response rates (gefitinib) or significant improvement in overall survival when compared to placebo (erlotinib) in 2^nd line or 3^rd line treatment in an unselected NSCLC patient population regardless of histology, gender, or smoking status (1,2).