The history of developing anticancer Drugs and their evaluation guidelines in Japan

: The cancer therapies currently available do not yet offer fully satisfactory treatments, even in 21st century, and efforts and progress are being made daily in the area of drug development. Anticancer drugs, which play the leading role in cancer therapy, are being developed dynamically around the world, and Japan is not an exception. Looking back on the history of developing anticancer drugs, cytotoxic drugs were the mainstream of drug development until the end of the 20th century. In the 21st century, they have been replaced by molecularly targeted drugs, and thus the development of cytotoxic drugs has been declining rapidly. There were various approaches to the development of anticancer drugs and clinical trial endpoints until the 1980s. In 1991, the "Guidelines for Clinical Evaluation Methods of Anti-Cancer Drugs in Japan" was issued. From 2000 onwards, there was vigorous discussion on the clinical trial endpoints of anticancer drugs in the United States. In conjunction with this discussion, the "Guidelines for Clinical Evaluation Methods of Anti-Cancer Drugs in Japan" was revised in 2005. The revised guidelines required survival data at the time of filing a new drug application (NDA) as a general rule. Around 2005, a bridging strategy was promoted as the "International Conference on Harmonization E5" was promulgated among Japan, the U.S. and EU, resulting in an outflow of clinical trials to overseas, with more non-Japanese survival data generated outside of Japan used for NDAs than Japanese data. Subsequently, the "Guideline for Basic Principles on Global Clinical Trials" was issued in 2007, which promoted the change in the mainstream approach from a bridging strategy to a pivotal, global study involving Japan. Thus, an era of full-fledged globalization in clinical trials began. We believe Japan will need systems to enhance the motivation for anticancer drug development, such as an expedited program or pediatric program, from now on. We hope that the enhancement of these systems will contribute to shortening the period required for approving an anticancer drug and reducing developmental costs. Furthermore, we expect Japan to be creating breakthrough anticancer drugs in the near future.