Development of Orphan Drugs in Japan: Characteristics of Orphan Drugs Developed in Japan *

Since 1993, some support measures to promote development of orphan drugs have been introduced. This support system was modeled after the United States system, but the contents were slightly different. The annual average numbers of orphan drug designations in Japan is about one half of those in the United States. The proportion of approved orphan drugs to designated drugs in Japan was 2.0 times of that in the United States. In the United States, 77% of applicants were smaller companies, but in Japan only 3% of applicants were venture companies. In Japan more drugs were introduced from overseas than developed in the country. Looking at the designated orphan drugs, drugs with less chance of failure which required less money for development tend to have been developed in Japan. Most of the applicants were larger companies. It seems important to view the support measures from the point of view of fostering venture companies.