Targeted therapies in the treatment of non-small cell lung cancer

New targeted treatments offer an important opening towards the improvement of the results in the treatment of lung cancer. Currently two types of therapeutic targets are developed successfully in the treatment of advanced non-small cell lung cancer: tumour angiogenesis and growth factor receptors. Therapeutic drugs are small molecules inhibitors and the monoclonal antibodies. Bevacizumab is a monoclonal antibody against vascular endothelial growth factor receptor, VEGF, an important molecule in tumour angiogenesis. The combination of bevacizumab with first line chemotherapy increases the median survival of advanced NSCLC with a few weeks. At this moment no biomarker predicting efficacy that can help in the selection of patients is unfortunately available for this expensive treatment, although it is important to select patients based on specific contra-indications. The epidermal growth factor receptor (EGFR or HER1) is activated in NSCLC by several mechanisms. The small molecules erlotinib and gefitinib are targeting the intracellular kinase domain of the EGF receptor, thus inhibiting the signal transduction cascade. Erlotinib is currently registered and reimbursed in Belgium. The concomitant use of these small molecules with chemotherapy is ineffective in non-selected NSCLC patients. On the other hand, these molecules have great activity in patients with tumours having a constitutionally activated EGFR. Changes in the kinase domain of the receptor give rise to extremely high response rates and unexpectedly improved survival duration in patients with NSCLC. Currently studies are exploring whether erlotinib should be employed in the first line treatment of NSCLC. The FIELT study is a translational academic and multicentre phase II study in Belgium and Luxemburg addressing this issue. Specific mechanisms of resistance for these agents are gradually discovered and the new drugs being able to overcome these resistances are at the horizon.