Postmarketing all-case surveillance trends and contribution to safety measures of drugs approved in Japan: a cross-sectional survey in 1999–2019

Background Postmarketing all-case surveillance (PACS) is a safety monitoring activity predominantly conducted for drugs with few domestic clinical trials, orphan drugs, or anticancer drugs that potentially cause serious adverse events. Aim This study comprehensively analyzed drugs in Japan requiring PACS as an approval condition and those implementing PACS-results-based safety measures. Method We included drugs approved in Japan between 1999 and 2019. Results During the 20-year survey, 1871 drugs were approved in Japan, including 277 (14.8%) requiring PACS as an approval prerequisite. The drug number requiring PACS for approval and its ratio to the total approved-drug number is increasing annually. In 2018, the number and percentage of PACS-requiring drugs reached a 37-drug maximum (32.5%). Additionally, among the 277 PACS-requiring drugs, upon examining the results of 87 drugs for which reexamination results had already been obtained, all 87 drugs (31.4%) were found to be in Category 1 which means there is no need to revise drug-approval conditions, indicating that their usefulness is consistent with approval. Furthermore, measures such as revising the package insert and providing information to medical institutions were adopted for 53 drugs, 14 of which had PACS-results-based safety measures. Conclusion PACS implementation for drug approval will potentially continue increasing. Normally, PACS is not conducted overseas, as it is a safety-monitoring activity exclusive to Japan, and the burden on institutions, such as medical sites and pharmaceutical companies, is heavy. Thus, ensuring a balance between the obtained effect and this burden is imperative.