[Front-line drug discovery system for cancer]

Research and development of anticancer drugs targeting causative molecules of tumorigenesis have been actively promoted since discovery of human oncogenes in the 1980s. Innovative molecular-targeted drugs such as Trastuzumab and Imatinib are typical fruits of the efforts over the past decade. In the anticancer drug market at present, a family of these molecular-targeted drugs has come to outperform conventional chemotherapeutic agents such as DNA acting agents, tubulin binders, and antimetabolites. Methodology developments and achievements of genomics research including completion of the human genome sequencing in 2003 are drastically changing the drug discovery system for cancer. Cancer medicine now enters an era of personalized medicine in which characteristics of a cancer and the individual constitution of a patient are reflected in the therapeutic treatment. Utilization of biomarkers is an important issue for this personalized medicine. It is strongly pointed out that the action of a drug on its target should be validated at the early phase of clinical trials in view of the proof of concept(POC) in order to increase the success rate of drug discovery. In this article, the current state and the future of dramatically-evolving anticancer drug discovery are reviewed.