Economic Impact of Biosimilars in Spain (2020-2023): A Retrospective Analysis and Lessons Learned

OBJECTIVES: As the use of biological medicines grows, biosimilars become increasingly important in reducing healthcare spending. Rationalisation of pharmaceutical expenditure comprehends savings generated by biosimilars, with lower prices than original biologicals. We update and compare results from previous research with those observed in real life (2020-2023).

METHODS: We develop a budget impact model and estimate retrospectively savings generated through the use of biosimilars in Spain between 2020-2023 using the payer perspective. Thus, we compare a hypothetical scenario without biosimilars (retaining prices from original products) with the current scenario, with biosimilars and lower prices due to competition.

We use Real-World data from Spanish official sources to populate the model (original and biosimilar consumption, public prices, and commercial discounts). We perform the analysis using the payer perspective (Spanish NHS). Therefore, we only consider pharmaceutical spending.

RESULTS: We obtain aggregated savings of € 5,804M, greater than estimations made in the prospective analysis published in 2020, due to higher penetration rates observed for most active principles, and greater price reductions (public prices and commercial discounts). More than half of total savings were generated by the use of biosimilars with several years in the market indicated for chronic diseases.

CONCLUSIONS: The introduction of biosimilars has generated significant savings in Spain (2020-2023). Although price difference between originals and biosimilars is greater during the early years of competition, initial savings achieved through lower market entry price of biosimilars were continued by public price reductions and higher commercial discounts for biosimilars.

To our knowledge, we present the first BIA based on official data from the fourth largest European pharmaceutical market, considering all active substances exposed to biosimilar competition, and actual prices. Our analysis has allowed us to validate and improve our methodology, which could serve as a reference method for the BIA of biosimilar medicines.