Pediatric-Specific Drug Loss Issue in Japan: Comparison of Pediatric Development Status Between Japan and the United States.

Background: The lack of label information for the pediatric population has been a global issue, leading to the introduction of several countermeasures by major health authorities. Despite various efforts by Japanese health authorities, some drugs are approved only for adults in Japan, while the United States (US) label includes information on pediatric usage for the same drugs. This suggests a potential for pediatric-specific drug loss in Japan, where overall drug loss has recently become a major concern.

Methods: In this study, we compared the pediatric usage status between Japan and the US, focusing on the indications approved in both countries.

Results: Of the 404 indications, 70 (17.3%) and 102 (25.2%) included pediatric usage in Japan and the US, respectively. The proportion of indications, including pediatric usage, was significantly higher in the US than in Japan (χ² test, p < 0.001). Multivariate analysis of indications for pediatric usage in the US demonstrated that simultaneous development with adults (odds ratio (OR), 24.9; 95% confidence interval (CI), 6.79-91.1) and Japan-first development (OR, 31.5; 95% CI, 2.59-384) were significantly affecting the inclusion of pediatric usage in Japan.

Conclusions: Our results suggest that there was pediatric-specific drug loss in Japan compared to that in the US. The multivariate analysis demonstrated that US-first development and non-simultaneous development had a negative impact on the inclusion of pediatric usage in Japan; however, pediatric assessment request was not a significant factor. Further frameworks to promote pediatric drug development should be introduced in Japan to address pediatric-specific drug loss issues.