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

<title>Abstract</title> <p><bold>Background</bold> 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 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. <bold>Methods</bold> In this study, we compared the pediatric usage status between Japan and the US, focusing on the indications approved in both countries. <bold>Results</bold> We found that the proportion of indications, including pediatric usage, was significantly higher in the US than in Japan. Multivariate analysis of indications for pediatric usage in the US demonstrated that US-first development and non-simultaneous development with adults had a negative impact on the inclusion of pediatric usage in Japan; however, the pediatric assessment request on the grounds of US legislation was not a significant factor. For pediatric indications approved solely in the US, most relied on multi-regional clinical trial data that included the US but excluded Japan. <bold>Conclusions</bold> Our results suggest that there was pediatric-specific drug loss in Japan compared to that in the US. Further frameworks to promote pediatric drug development should be introduced in Japan to address pediatric-specific drug loss issues.</p>