Optimizing chemotherapy and targeted agent combinations in NSCLC.

Abstract

Chemotherapy extends life and provides symptom palliation for patients with advanced non-small cell lung cancer (NSCLC). Numerous trials have been conducted that evaluate a variety of doublet regimens, but the majority of trials have found equal efficacy among the treatment arms. Indeed, a plateau appears to have been reached with respect to survival associated with traditional cytotoxic drug regimens. It was initially hoped that the addition of novel targeted agents to conventional chemotherapy would produce significant survival benefits for patients with advanced NSCLC; however, most trials have failed to show such a benefit. There is no survival benefit associated with adding erlotinib or gefitinib to a chemotherapy regimen, although there is a significant improvement in survival associated with erlotinib monotherapy in the second- and third-line advanced disease setting. In contrast, the results of E4599 clearly demonstrate that the addition of bevacizumab to paclitaxel-carboplatin chemotherapy extends survival in a select group of patients with non-squamous cell NSCLC. E4599 also represents a rational approach to drug development that could be modeled in other trials, namely, the use of a large, well designed, randomized trial prior to beginning a traditional phase II approach. This strategy can lead to the identification of subgroups most likely to benefit, as well as those that might experience increased toxicity, such as patients with squamous cell carcinoma treated with bevacizumab. Another approach to optimizing targeted therapy involves selecting a chemotherapy regimen with the greatest potential for synergy based on preclinical modeling. Because docetaxel has been shown to prolong survival in second-line treatment, a number of novel agents have been combined with docetaxel in order to improve efficacy. Alternatively, investigators have sought to combine novel agents with either carboplatin-paclitaxel or cisplatin-gemcitabine in first-line treatment. A number of trials are underway that combine these agents with inhibitors of the epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and the proteasome, as well as COX2 inhibitors, and novel immunomodulators.