PURPOSE: Scientific information in the drug labeling is expected to be the most up-to-date and consistent information across countries where medicine is approved. The objective of the present study is to investigate the consistency of safety-related information on product labeling for novel therapeutics concurrently approved in Japan and the US.
METHODS: Safety information at the time of initial approval of new drugs approved concurrently both in Japan and the US in the recent 7 years were identified and reviewed for concordance. Factors associated with the discordance were also investigated.
RESULTS: Despite the similar medical practices, population health, and regulation in Japan and the US, the level of concordance of safety information found in the drug labeling of 45 new active substances was low (20.4%). The development strategy of the drugs and having the same MAH were significantly associated with the concordance rate. The mean concordance rate among the 9 drugs with Black Box Warning in both countries was also low (32.9%).
CONCLUSIONS: We found a low level of concordance between Japan and the US even when related to clinically important information raised by Black Box Warnings. The low concordance rate highlighted the need for a greater transparency in decision-making processes about the safety information in a drug labeling by both industry and regulators to take appropriate countermeasures against the discordance.
