RESUMEN
PURPOSE: The aim of this study was to describe the implementation and uptake of biosimilar trastuzumab in Denmark compared with other European countries. METHODS: European data for usage of trastuzumab was supplied by IQVIA™, using the MIDAS® dataset. A comparison was performed based on market share estimated in sales volume. A separate comparison was undertaken between countries with a full two-fold switch between different biosimilars. Data was collected spanning the time from first registered sales of biosimilar trastuzumab until the 1st quarter of 2020. RESULTS: Denmark had the fastest and most thorough uptake of biosimilar trastuzumab compared with other EU countries. After 3 months, the market share of biosimilar trastuzumab had increased to 90% while the second fastest country had a 50% market share after 3 months. Only two other countries had undergone a full second switch between biosimilars, Hungary and Norway. All of the three countries made near complete switches between biosimilars while only Denmark had reduced the use of biooriginator below 10%. CONCLUSION: The implementation of biosimilar trastuzumab in Denmark was rapid and achieved high overall uptake compared with other EU countries. The switch from one biosimilar to another was also achieved quickly and thoroughly. We believe that the rapid dissemination of information and involvement of all stakeholders - administrators, pharmacies, prescribers, nurses, and patients - constitute the backbone of the Danish success. A similar strategy is recommend for biosimilar implementation in other countries.