Insulin-like growth factor type I receptor: a new target in the treatment of non-small cell lung cancer patients
Despite the use of new drugs for the treatment of stage IV non-small cell lung cancer (NSCLC) patients, only a moderate overall survival benefit could be reached and the prognosis of this disease is still bad. Therefore, the intensive search for additional, especially targeted, drugs is still ongoing. In recent years evidence has been grown that the insulin-like growth factor type I receptor (IGF-IR) and its ligands play an important role in oncogenic transformation, growth and survival of malignant cells. Thus, strategies have been developed to block this receptor. The most promising concepts include anti-IGF-IR antibodies and anti-IGF-IR tyrosine kinase inhibitors. Currently, most data are available for the monoclonal antibody CP-751,871 (figitumumab). A recent phase II study (Karp et al., J Clin Oncol, 27: 2516, 2009) compared the efficacy and side effects of paclitaxel/carboplatin/CP-751,871 versus paclitaxel/carboplatin in untreated locally advanced or metastatic NSCLC patients. Although the combination of CP-751,871 20 mg/kg with paclitaxel/carboplatin was found to be safe and effective, the following phase III study had to be discontinued. Thus, additional studies are necessary to define the clinical impact of CP-751,871 in NSCLC patients. Other drugs targeting the IGF-IR are also currently under investigation.