New targeted treatments in lung cancer--overview of clinical trials

Abstract

Combination chemotherapy has been established as the cornerstone of systemic treatment for advanced lung cancer in the last ten to fifteen years. However, improvements with new drug combinations in recent years have been rather small and a general outcome plateau has been reached with one-year survival rates of about 40% and two-year survival rates of less than 15%. Survival over three to four years is still a rare event in this disease, and more and more efforts are being made to develop innovative systemic treatment strategies with mechanisms of action different from conventional cytotoxic drugs. These molecular targeted agents have made a strong move forward in the management of this disease since Gefitinib--a small molecule EGF-receptor tyrosine kinase inhibitor--was registered in 2003 by the FDA and a number of further countries for the third-line treatment of non-small-cell lung cancer. Since then, every month findings have been reported about new cellular targets on lung-cancer cells and, consequently, new agents aiming at these molecular targets are being developed, preclinically. Some of these agents have already been tested in the clinics within phase-I, phase-II and some even within randomised phase-III trials. In this review we will try to summarise the current knowledge and data on the clinical activity of these new drugs in lung cancer and to give a perspective on the future for these new treatment principles. The most promising strategies have been aiming at the EGF-receptor family, serum-VEGF and the VEGF-receptor family (VEGF-1 and -2, respectively). Results from pivotal registration trials are expected within the next one or two years for a number of these new drugs, and the standards of care for advanced lung cancer may change dramatically, comparable to what we have seen in other solid tumours such as metastasised breast and colon cancer.