Japan's Pharmaceutical Regulatory Reform to Overcome Drug Loss Issue

In recent years, there has been a significant increase in "drug loss"-the absence of drugs on the Japanese market that are already approved in countries outside of Japan-primarily due to the lack of their development in Japan. There were 86 drugs approved in Europe and the United States for which development had not yet begun in Japan. Of these, 48 (56%) were what can be termed 'venture-developed' drugs, 40 (47%) were orphan drugs, and 32 (37%) were for pediatric use. The lack of availability of these drugs in Japan is a significant issue.In an attempt to address this drug loss issue, the Japanese Ministry of Health, Labour and Welfare (MHLW) decided to focus on and review Japan's pharmaceutical regulations, which were considered an important factor in the drug loss issue. The MHLW held a series of meetings to discuss possible changes in its policies and methods as potential solutions to the drug loss problem. MHLW issued several notifications and related Question and Answer (Q&A) communications about those discussions. Furthermore, MHLW made revisions to the Pharmaceutical and Medical Device Act that were enacted in May 2025.This manuscript summarizes the major outcomes of these activities, particularly the issues related to clinical trials and the orphan designation system, in terms of how they relate to the future of pharmaceutical regulation in Japan.