PMS73 - BRIGHT FUTURE FOR THE USE OF BIOSIMILAR INFLIXIMAB: EVIDENCE-BASED ANALYSIS USING HEALTHCARE CLAIM DATABASE

Abstract

Generic small molecule drugs have shown the tendency to sharply alter the market with the launch of generic drugs. In this study, we investigated whether this tendency is also present in biosimilars, which is considered not biologically equivalent. Data from HIRA (Health Insurance Review and Assessment Services) between 2012 and 2016 was used to evaluate prescription volume of infliximab. The dataset included approximately 3% of nationwide patient population. We used the differences of drug prices between the original biologic and its biosimilars to classify medications because medications in the dataset were coded according to only the active ingredients. The base price was set as the upper limit of the reimbursement price of biosimilar. The trends of prescribed infliximab and its biosimilar uses were analyzed by the number of patients, prescriptions and the type of medical institution in SAS 9.4. Our analysis showed that the total use of infliximab had gradually increased since biosimilar infliximab was approved for reimbursement in 2012. As the biosimilar entered into the drug market, the proportion of the original infliximab use was decreased. In contrast, the use of the biosimilars has increased the market share of infliximab. In the 4th quarter of 2016, more patients were prescribed with biosimilar infliximab (from 3.70 to 52.04%) compared to the original infliximab (from 96.30 to 47.96%). A similar pattern was observed with the number of prescriptions for biosimilar infliximab. There were no statistical significant correlation between the type of medical institution and the biosimilar use. The use of biosimilars and biologics has increased with the proportion of biosimilars being used more compared to biologics ever since biosimilars entered into the drug market. Further studies based on larger data sets are needed to analyze the various factors that affect the market share of biosimilars.