EGFR-directed monoclonal antibodies in non-small cell lung cancer.

Several monoclonal antibodies directed against the epidermal growth factor receptor (EGFR) have been evaluated in patients with non-small cell lung cancer (NSCLC). Cetuximab, a chimeric monoclonal antibody, has been studied in combination with first-line chemotherapy in phase II and two phase III trials in patients with advanced NSCLC. The phase III FLEX trial demonstrated an increase in survival for cisplatin/vinorelbine plus cetuximab compared to chemotherapy alone in patients with advanced EGFR-expressing NSCLC. Cetuximab added to carboplatin/paclitaxel failed to improve progression-free survival in the BMS099 phase III trial. However, a meta-analysis of four randomized trials confirmed a significant survival benefit for platinum-based chemotherapy plus cetuximab compared to chemotherapy alone. High EGFR expression of tumor cells was then shown to predict the benefit of cetuximab, whereas KRAS mutations and EGFR fluorescent in situ hybridization analysis were without predictive value. Matuzumab and panitumumab have also been studied in phase II trials. Necitumumab, a fully human monoclonal antibody, is currently evaluated in combination with chemotherapy in two phase III trials in patients with advanced NSCLC. Cetuximab is also studied in combination with chemoradiotherapy in patients with locally advanced NSCLC.