Treatment With BIBW 2992, Irreversible Inhibitor of EGFR and HER-2 in Non-small Cell Lung Cancer

Lung cancer is the main cause of cancer-related mortality worldwide, accounting for 1.6 million deaths in 2012. Non-small-cell lung cancer (NSCLC) histology comprises ap-proximately 85% of cases. At the time of diagnosis, 75% of the patients have locally advanced or metastatic disease, with a 5-year survival rate of less than 5%. Although treatment options for these patients remain limited, drugs targeting the epidermal growth factor receptor (EGFR) have proved to be a highly effective therapy in NSCLC patients harboring sensitizing EGFR mutations. Afatinib, a second-generation irreversible TKI, confers a theoretical advantage over re-versible TKIs in patients with acquired resistance. Through covalent binding to the kinase domain of EGFR, afatinib down regulates signaling from all homodimers and heter-odimers formed by ERBB receptor family members including EGFR, HER2 (ErbB2), HER3 (ErbB3) and HER4 (ErbB4). HER2 mutations in NSCLC are rare, being found in approximately 1-4% of lung adenocarcinomas. In contrast with reversible TKIs, the mechanisms of resistance to irreversible TKIs have not been fully elucidated, and identification of biomarkers that predict response to these drugs, particularly in patients progressing after first line therapy, is needed. In this study we assess the usefulness of plasma HGF concentrations as a predictor of response to afatinib in patients with advanced-stage lung adenocarcinoma.