Regulatory review time for approval of oncology drugs in Japan between 2001 and 2014. Considerations of changes, factors that affect review time, and difference with the United States.

In this study, we comprehensively and historically studied the review time of oncology drugs approved by the regulatory authorities in Japan with publicly available information. A total of 120 applications of oncology drugs were approved in Japan between April 2001 and July 2014. The review time peaked with 732.0 days (24.4 months) in 2005, and showed a tendency to decline gradually each year thereafter. After 2012, a significant reduction of the review time was seen in comparison to the median of 13-year median time. In addition, we compared the review time with that in the United States. The median review time lag with the United States was significantly peaked in 2005. After 2005, the review time lag with the FDA has decreased, but lag did not significantly reduce by 2014. We also examined factors influencing the review time in Japan with multiple regression analysis. It was found that the factors related to a use of overseas data and expedited program for accelerating the reviews influenced the direction of shortening the review time. We consider that regulatory authorities in Japan need to keep making efforts to reduce the review time further and eliminate the review time lag with the United States.