Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases and is therefore one of the leading causes of cancer deaths worldwide. Afatinib is an oral receptor tyrosine kinase inhibitor (TKI) with antineoplastic activity which binds to and inhibits human epidermal growth factor receptors (EGFR).
In September 2013, the European Medicines Agency (EMA) licensed afatinib for the treatment of EGFR TKI-naïve adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) with activating EGFR mutations. In July 2013, the US Food and Drug Administration (FDA) approved afatinib as first-line treatment of patients with metastatic NSCLC whose tumours have EGFR mutations.
Two phase III studies (the LUX-Lung 3 and LUX-lung 6 trial) examined the efficacy and safety of afatinib as first-line therapy of EGFR TKI-naïve patients with advanced or metastatic NSCLC with activating EGFR mutations. The trials compared treatment of patients either with afatinib or double-agent chemotherapy. For patients treated with afatinib, median PFS was extended by 4.2 months (HR 0.58, p=0.001) and 5.4 months respectively (HR 0.28, p<0.0001). Secondary endpoints including objective response rate and duration of response favoured patients treated with afatinib. Quality of life was also assessed, showing a significantly delayed time to deterioration for cough and dyspnoea in the afatinib group but conflicting results for pain. AEs were common in the afatinib and in the chemotherapy groups, but distinct differences in the toxicity profiles exist. Improvements in functional scales were observed for patients receiving afatinib compared with chemotherapy.
Afatinib is the third EGFR TKI agent (besides erlotinib and gefitinib) licensed for the therapy of advanced NSCLC with EGFR mutations in Europe. Therefore, head-to-head comparison of afatinib, erlotinib and gefitinib is of great interest.