EGFR Inhibitors in Lung Cancer
November 01, 2005
Targeted therapies inhibiting the epidermal growth factor receptor(EGFR) have been introduced in the treatment of patients with advancednon–small-cell lung cancer (NSCLC). Many inhibitors of theEGFR have been developed, targeting either the extracellular receptordomain with antibodies or the intracellular tyrosine kinase bindingdomain with small molecules. The tyrosine kinase inhibitor (TKI)gefitinib (Iressa) was the first targeted drug to be registered for thetreatment of NSCLC after failure of chemotherapy. Given concurrentlytogether with platinum combination chemotherapy both TKIs gefitiniband erlotinib (Tarceva) failed to increase activity. Sequential targetedtherapy after chemotherapy is currently being investigated further. Studieswith the monoclonal antibody cetuximab (Erbitux) combined withchemotherapy are ongoing. Side effects of the small molecules aremainly skin rash and diarrhea, whereas the antibodies do not give diarrhea.Selection of patients, based on molecular markers and patientcharacteristics, has become an important issue for the further developmentof these drugs, given there is activity in a relatively small group ofpatients with NSCLC. Newer drugs inhibiting more than one receptorpathway are being investigated in order to find activity in a broadergroup of patients.