Second and third-generation epidermal growth factor receptor tyrosine kinase inhibitors in advanced nonsmall cell lung cancer

Purpose of review The first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, are effective as first-line treatment of advanced nonsmall cell lung cancer (NSCLC) harboring activating EGFR mutations (deletions in exon 19 and exon 21 L858R mutation). EGFR T790M resistance mutation (EGFR(T790M)) ultimately emerged in most of these patients. The second and third-generation EGFR-TKIs were designed to have more potent inhibition of EGFR and to overcome EGFR(T790M). This review describes the recent developments of these novel EGFR-TKIs. Recent findings The second-generation EGFR-TKIs, afatinib and dacomitinib, irreversibly bind to the tyrosine kinase of EGFR and other ErbB-family members. Afatinib has been approved as first-line treatment of advanced NSCLC harboring activating EGFR mutations. Dacomitinib is under development. Third-generation EGFR-TKIs, AZD9291, CO-1686, and HM61713, inhibit both EGFR activating and resistance mutations, while sparing wild-type EGFR. In early-phase studies, these drugs demonstrated promising response rates against tumors with acquired EGFR(T790M). Summary Second-generation EGFR-TKI, afatinib, is available as first-line treatment of advanced NSCLC harboring activating EGFR mutations. Third-generation EGFR-TKIs are under development for tumors harboring acquired EGFR(T790M).