Targeted therapies and non-small cell lung cancer: methodological and conceptual challenge for clinical trials

Targeted therapies are emerging as important drugs in the treatment of advanced non-small cell lung cancer (NSCLC). Within the past months, there have been considerable contributions to this topic. The results of several important clinical trials have been published. Furthermore, laboratory results have significantly contributed to clear out some molecular mechanisms regulating sensitivity or resistance to these drugs and to provide rational basis for further clinical studies.

A great part of recently published research on targeted agents in NSCLC regards EGFR inhibitors. Following the demonstration of activity of gefitinib in patients pretreated with chemotherapy, four large randomized trials testing the addition of gefitinib or erlotinib to first-line chemotherapy have been conducted, but failed to show any advantage. Interestingly, erlotinib has shown efficacy compared with placebo in pretreated patients. Mutations in the EGFR gene have shown a strong predictive role for sensitivity to EGFR inhibitors. A number of other targeted agents are currently under investigation: most of the phase II trials maintain a traditional methodology, with response rate as primary measure of activity.

Recent advances will lead to a rapid expansion of further studies aimed to define the best way to use targeted agents in NSCLC. Several methodological issues are still open. The proper selection of patients, the choice of the best study design and the most appropriate end-point for early clinical trials, and the correct modality to integrate these drugs with traditional chemotherapy represent the most challenging points that research is called to answer in the near future.