Impact of Clinical Response on Different Approved Doses in Japan and the United States

The document from 2012 explored the differences in drug dosages approved in Japan and the United States, focusing on new molecular entities (NMEs) approved between 2003 and 2010. It found that 39 out of 139 products had different approved dose levels, with 13 showing a considerable difference. Only 2 of these 13 products were suggested to have different clinical responses between Japanese and non-Japanese populations. The study concluded that ethnic factors should be considered in dose-setting strategies and called for further investigation and collaboration to improve international drug development efficiency. Additionally, the study analyzed specific drugs and found that while some showed higher efficacy or similar parameters between populations, others had no dose-dependent response, indicating limitations in Japanese data for risk-benefit assessment and dose selection. The study also noted that different clinical responses were not the main reason for dose differences, suggesting that a broad therapeutic range should be established for the global population, except for drugs with a narrow therapeutic index. The study recognized its limitations, including the focus on products approved in both Japan and the U.S. and reliance on public domain data, and recommended further investigation and international harmonization discussions.