Epidermal growth factor inhibitors

PURPOSE: Tyrosine kinases are implicated in the normal cellular proliferation and in malignant transformation. Among the tyrosine kinase receptors, one of best described is the Epidermal Growth Factor Receptor (EGFR), which is widely expressed in particular in epithelial cells and in many human carcinomas. CURRENT KNOWLEDGE AND KEY POINTS: Compounds have been developed that target either the extracellular ligand-binding region of EGFR (Cetuximab) or the intracellular tyrosine kinase ATP-binding (Iressa), Tarceva. Phase I studies showed that these molecules have a favorable pharmacokinetic and pharmacodynamic profile, with excellent tolerance and easy administration. Phase II and III studies are currently testing their efficacy. FUTURE PROSPECTS AND PROJECTS: Preliminary results show interesting activity in different tumors, alone or in combination with either chemotherapy or radiotherapy. If these results are confirmed in larger trials including a high number of patients, these agents might be very useful in combination with chemotherapy, radiotherapy or other biological targeting agents such as cellular cycle inhibitors or antiangiogenics.