Temporal trends in the prescription of biosimilars and the status of switching from original biologics to biosimilars at individual and institutional levels in Japan
As of November 2024, only 13.6% of somatropin prescriptions were biosimilars, indicating limited adoption despite their availability.
Where it sits
this study against the rest of the hgh (somatropin) corpusSummary and findings
This study analyzed the prescription trends of biologics in Japan, focusing on the switching from original biologics to biosimilars. The data was derived from the JMDC claims database from January 2005 to November 2024. The findings indicate that the proportion of biosimilar prescriptions for somatropin was 13.6% as of November 2024.
Abstract
<h4>Purpose</h4> 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. <h4>Methods</h4> Using the JMDC claims database from January 2005 to November 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. <h4>Results</h4> Temporal trends in the proportions of original biologics and biosimilars varied widely. In November 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. <h4>Conclusion</h4> 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.
Background
This paper addresses the trends in the prescription of biologics, particularly focusing on the transition from original biologics to biosimilars in Japan. Prior knowledge indicates that biosimilars can offer cost-effective alternatives to original biologics, but their adoption rates vary. Understanding these trends is crucial for healthcare policy and practice, especially in promoting biosimilar use.
Methods
The study utilized the JMDC claims database, analyzing data from January 2005 to November 2024. It identified patients who received prescriptions for 17 biologics, assessing monthly trends in the proportions of original biologics versus biosimilars. The study measured both individual-level switching behaviors and institutional-level prescribing patterns.
Results
The proportion of biosimilar prescriptions for somatropin was 13.6% in November 2024. The proportion of patients switching from original biologics to biosimilars ranged from 1.2% to 14.0%. Variability was noted in the adoption of biosimilars across different types of medical institutions.
Interpretation
The findings suggest that while biosimilars are available, their adoption, particularly for somatropin, remains limited. The low switching rates may indicate barriers to biosimilar acceptance among patients and providers. The institutional differences in prescribing practices highlight the need for targeted strategies to promote biosimilar use in various healthcare settings.
Key findings
- 13.6% biosimilar prescriptions for somatropin in November 2024.
- 92.5% biosimilar prescriptions for filgrastim in November 2024.
- Proportion of patients switching from original biologics to biosimilars was low at 1.2–14.0%.
- University-related hospitals were more likely to introduce biosimilars than public hospitals.
- Not reported in abstract.
Limitations
- Reliance on claims data may not capture all prescribing behaviors.
- Limited to the Japanese healthcare context, affecting generalizability.
- Low switching rates suggest potential barriers to biosimilar adoption.