Table 1.
Classification of drugs examined
| Number of drugs (%) | ||
|---|---|---|
| Ultra-orphan drugs n = 43 | Orphan drugs other than ultra-orphan drugs n = 88 | |
| Therapeutic category | ||
| Metabolic drug | 16 (37%) | 12 (14%) |
| Anticancer drug | 11 (26%) | 33 (38%) |
| Biological drug | 8 (19%) | 7 (8%) |
| Cardiovascular drugs | - | 10 (11%) |
| Central nervous system drugs | 1 (2%) | 6 (7%) |
| Sensory organ agents | - | 5 (6%) |
| Hormones | 1 (2%) | 4 (4%) |
| Peripheral nervous system drugs | 1 (2%) | 3 (3%) |
| Digestive organ agents | 1 (2%) | 2 (2%) |
| Others | 4 (10%) | 6 (7%) |
| Drugs with new ingredients | ||
| 31 (72%) | 50 (57%) | |
| Approved in other countries outside Japan | ||
| 36 (84%) | 63 (72%) | |
Classification of therapeutic category, drugs with new ingredients and drugs that had already been approved in countries outside Japan of the 43 ultra-orphan drugs and 88 orphan drugs other than ultra-orphan drugs approved in Japan in the period from January 2001 to December 2014. The classification of drug’s therapeutic category was based on the standard commodity numbers used in Japan