日本・米国・英国における小児用医薬品の開発推進策と承認状況

Pediatric drug development is challenging due to various difficulties in clinical evaluation and inadequate economic return over development cost. The legislative measures have been taken in several countries, including the European Union（EU）and the United States（US）, to advance drug development in pediatrics because of its importance in disease management. We compared legislation related to promotion of pediatric drug development in the US, the United Kingdom（UK）and Japan. Next, we set the US, a pioneer in addressing off-label use in children, as the standard against which to compare the approval status of pediatric indications in Japan and the UK. According to the drug labels, we identified 72 products approved for pediatric indications in the US between January 2016 and April 2020 which were also approved for adults or children in both Japan and the UK. We calculated the percentage of products with pediatric indications and analyzed the development status of products without pediatric indications. In the UK, 83％（60/72）of products had pediatric indications. Of the 12 products without pediatric indications, four were investigated in clinical trials or planned to be developed for pediatric use. In contrast, the percentage of products with pediatric indications in Japan was 44％（32/72）, and of the 40 products without pediatric indications, only two were in development for pediatric use. All of the products reviewed by the Evaluation Committee on Unapproved or Off-labeled Drugs with High Medical Needs of the Japanese Ministry of Health, Labour and Welfare were indicated for pediatric patients. In contrast, only about half（9/19）of the drugs with orphan drug designation had pediatric indications. With reference to the regulatory frameworks in the US and UK, the＂Designation of Pharmaceuticals for Specific Use＂, established in the 2019 revision of the Pharmaceuticals and Medical Devices Law（PMDL）, may offer the better means to promote pediatric drug development in Japan.