Natsuko Kameyama, Ayana Ide, Hideki Maeda
Japan's approach to IMI has broadly aligned with international standards, particularly regarding special population-related IMI, while several operational issues remain. Strengthening additional pharmacovigilance activities for selected older patients, explicitly including long-term use as an example of IMI in Japanese RMP guidance, and defining IMI based on the need for additional activities might help enhance RMP management and support future regulatory refinement.
INTRODUCTION: More than 10 years have passed since Japan introduced risk management plans (RMPs), yet research focusing on important missing information (IMI) remains limited. This study aimed to characterize IMI, particularly in special populations.
METHODS: Based on publicly available information from the Pharmaceuticals and Medical Devices Agency, we analyzed 330 eligible RMPs as of May 2023 and summarized the number and classification of IMI items and associated activities.
RESULTS: Among 330 RMPs, 101 (30.6%) included 199 IMI items. Additional pharmacovigilance activities, additional risk minimization activities, and documentation in the package insert were identified for 69.3%, 25.1%, and 56.3% of the items, respectively. Special populations accounted for 62.8% of all IMI items, and their categorization aligned with International Council for Harmonisation guideline E2E. Additional pharmacovigilance activities were specified in the RMP for 64.0% of special population-related items, whereas the rate was significantly lower for older patients than for other special population categories (33.3%, p = 0.028). For long-term use (44 items, 22.1%), additional pharmacovigilance activities were specified in the RMP more frequently than other IMI categories (84.1%, p = 0.016), whereas additional risk minimization activities and documentation in the package insert were less frequent [11.4% (p = 0.018) and 13.6% (p < 0.001), respectively].
CONCLUSION: Japan's approach to IMI has broadly aligned with international standards, particularly regarding special population-related IMI, while several operational issues remain. Strengthening additional pharmacovigilance activities for selected older patients, explicitly including long-term use as an example of IMI in Japanese RMP guidance, and defining IMI based on the need for additional activities might help enhance RMP management and support future regulatory refinement.