Significant differences in drug lag in clinical development among various strategies used for regulatory submissions in Japan.

Although the number of global clinical trials (GCTs) conducted in multiple countries including Japan has increased recently, it is not clear how much these GCTs help in reducing the lag in drug development (LDD: difference between the submission dates for new drug applications (NDAs) in the United States and Japan). We examined the effects of various clinical development strategies on LDD because the development period depends on what types of clinical trials were conducted for the Japanese NDA. Although various drug development strategies are available, deciding early on an appropriate strategy is a key to minimizing the LDD in Japan. The inclusion of GCTs in the clinical development strategy is also important; simultaneously, the smaller sample size of the Japanese population should be taken into consideration. Furthermore, reinforcement of Japan's capability to lead drug development may also be important in providing innovative drugs to Japanese patients without any significant LDD.