Insulin-like growth factor receptor type I as a target for cancer therapy.

In recent years, improvements in the understanding of oncogenesis has permitted the identification of new molecular targets for cancer therapy. Among all the different approaches, inhibition of tyrosine kinase receptor activity using small molecules or biomolecules for controlling cancer growth has been successful and has brought new therapeutic opportunities to the medical community. After more than 20 years of extensive work, insulin-like growth factor receptor I (IGF-IR) is becoming an attractive target for drug development. Owing to its close homology to insulin receptor, IGF-IR is of interest for antibody design while its specificity allows us to discriminate between the two receptors. Major efforts from a large number of pharmaceutical companies are invested in evaluating the efficacy of such molecules in humans. Discovery of biomarkers associated with efficacy and patient selection are the main challenges that we will have to deal with in order to target the appropriate patient population that will most benefit from anti-IGF-IR monoclonal antibodies and combined treatments. This review will provide an overview of the current knowledge on IGF-IR and ongoing clinical trials.