Matsumoto Minako, Kumazawa Ryosuke, Ishii-Watabe Akiko, Horiguchi Itsuko, Mamiya Hiroaki, Shibata Hiroko, Saito Yoshiro, Adomi Motohiko, Taniguchi Yuta, Komiyama Jun, Sakai Ryoko, Iwagami Masao
Department of Preventive Medicine and Public Health, School of Medicine, Keio University, Tokyo, Japan.
Department of Public Health and Epidemiology, Meiji Pharmaceutical University, Tokyo, Japan.
Ther Innov Regul Sci. 2025 Aug 7. doi: 10.1007/s43441-025-00850-7.
To describe the temporal trends in the prescription of biologics in Japan, with additional analysis focusing on switching from original biologics to biosimilars at the individual and institutional levels.
Using the JMDC claims database from January 2005 to May 2024, we identified patients who received at least one prescription for 17 biologics (original biologics or biosimilars). We elucidated the monthly trends in the proportions of original biologics and biosimilars. We also estimated the proportion of patients receiving original biologics only, those receiving biosimilars only, and those switching from original biologics to biosimilars (and vice versa) during the study period. Finally, we estimated the proportion of medical institutions that started prescribing biosimilars during the study period based on the type of medical institution.
Temporal trends in the proportions of original biologics and biosimilars varied widely. In May 2024, the proportion of biosimilar prescriptions was 13.6% for somatropin and 92.5% for filgrastim. At the individual level, the proportion of patients switching from original biologics to biosimilars was low (1.2-14.0%), indicating that switches do not often occur within the same patient, while more recent new users of biologics start biosimilars. At the institutional level, university-related hospitals and clinics were more and less likely, respectively to introduce biosimilars than public and other types of hospitals.
Temporal trends in the prescription of biosimilars and switching patterns varied widely by the type of biologics. The type of medical institution should be considered when assessing and promoting the use of biosimilars. Further research and strategies to increase the use of biosimilars in clinics may be needed.
描述日本生物制剂处方的时间趋势，并在个体和机构层面上重点分析从原研生物制剂转换为生物类似药的情况。
利用2005年1月至2024年5月的JMDC索赔数据库，我们确定了接受过至少一种17种生物制剂（原研生物制剂或生物类似药）处方的患者。我们阐明了原研生物制剂和生物类似药比例的月度趋势。我们还估计了在研究期间仅接受原研生物制剂的患者比例、仅接受生物类似药的患者比例以及从原研生物制剂转换为生物类似药（反之亦然）的患者比例。最后，我们根据医疗机构类型估计了在研究期间开始处方生物类似药的医疗机构比例。
原研生物制剂和生物类似药的比例随时间变化差异很大。在2024年5月，生长激素的生物类似药处方比例为13.6%，非格司亭为92.5%。在个体层面，从原研生物制剂转换为生物类似药的患者比例较低（1.2 - 14.0%），这表明同一患者内转换情况不常发生，而生物制剂的新使用者更倾向于开始使用生物类似药。在机构层面，与大学相关的医院和诊所引入生物类似药的可能性分别低于公立和其他类型的医院。
生物类似药处方的时间趋势和转换模式因生物制剂类型而异。在评估和推广生物类似药的使用时应考虑医疗机构类型。可能需要进一步的研究和策略来增加临床中生物类似药的使用。
