인플릭시맵 바이오시밀러 도입 이후 TNF-α 억제제 사용 변화 및 지출 영향 분석

Impact of an Infliximab Biosimilar on Utilization and Expenditure of TNF-α inhibitors in South Korea

Tumor necrosis factor α (TNF-α) inhibitor, biologics for immunosuppression, is widely used for various kinds of autoimmune disease and it has contributed to improving patients’ prognosis. With the expiration of its patent, biosimilars have emerged since September 2012 in South Korea. The competitive cost of biosimilars can lead to significant impact on national health insurance finance. Thus, we aimed to estimate budget impact of the introduction of infliximab biosimilar. Overall trends of utilization and expenditure among TNF-α inhibitors were presented using the National Health Insurance Service-National Sample Cohort database, between May 2011 and December 2013. We conducted segmented regression of interrupted time series analysis to evaluate impact of biosimilar introduction. Utilization and expenditure of TNF-α inhibitor had generally increased during study period. Both quantitative usage and drug expenditure of infliximab biosimilar have significantly increased, while those of etanercept have decreased, since the introduction of infliximab biosimilar. The estimated expenditure savings due to the introduction of infliximab biosimilar was about 52 billion won, which greatly contributed to the reduction of the price of the infliximab original rather than the reduction from the use of infliximab biosimilar. In conclusion, the introduction of biosimilar presented substantial savings of expenditure. Further study will be needed to assess comprehensive impact of other biosimilars introduction.