According to the news article “薬事検討会 国際共同P３前に企業責任で複数人種での安全性確認を条件に「日本人P１データ不要」も一考 | ニュース | ミクスOnline (mixonline.jp)” released by MixOnline as of 08Aug2023, the study group operating under the Ministry of Health, Labour and Welfare discussed the necessity of conducting Japanese Phase 1 before Japan’s joining multi-regional clinical trials (MRCTs). Japanese Phase 1 trials were mandatory as of 2007, and a more flexible approach was introduced in 2014. However, there are still many cases where Japanese Phase 1 was required, and there is no clear understanding between the industry and the government regarding conditions where such a flexible approach is acceptable. This issue leads to delays in MRCTs in Japan and raises concerns about “drug loss” risks. Ei Narusawa (Professor at Kitasato University School of Pharmacy), a member of the study group, pointed out that verifying safety in the Japanese population should ideally be done in Phase 3 studies. He suggested, “If companies can thoroughly confirm that there is no difference in safety and PK profiles among different races before the initiation of Phase 3, it might be possible to propose a direction where Japanese Phase 1 is not necessarily required.” A PMDA’s executive officer said that though a definitive standard for deciding the necessity of these trials for the Japanese is complex, it’s feasible to outline the factors that should be considered when evaluating this necessity. Additionally, there were diverse suggestions to change the handling of orphan drugs and to clarify responses based on similar drugs, highlighting the necessity of defining the design of the regulatory framework.