Biosimilar Uptake in Spain from 2016 to 2023: Analysis Based on Official Data Collection.

Even though the use of biosimilar medicines is increasing across European countries, detailed and regularly published official data on biosimilar uptake are not publicly available except in Italy and Portugal. The main objective of this study was to provide a nationwide assessment of biosimilar consumption and uptake patterns in Spain between 2016 and 2023. Data were provided by the Ministry of Health and included the defined daily dose (DDD) of biosimilars (N = 17) dispensed through both community pharmacies and public hospitals, biosimilar market share, and information on the registration status of both the bio-originator and biosimilars of each active principle. Data were analysed using non-parametric tests and bootstrap analysis with 10,000 replications, considering market share, time since market entry, number of competitors, and indication type (acute vs. chronic). The results show that biosimilar penetration increased from 9% in 2016 to 47% in 2023. In 2023, the biosimilar market share was substantially higher in the hospital setting (68%) compared to community pharmacies (34%). Biosimilars indicated for acute conditions achieved significantly higher market shares than those used for chronic conditions (p < 0.05). A positive correlation was observed between market share and the number of competitors, which was statistically significant only in the hospital setting (p = 0.007), while no significant association was found in the community pharmacy setting. Additionally, no correlation was identified between biosimilar market penetration and the time elapsed since the introduction of the first biosimilar. Other factors, such as prices, tendering, interchangeability, patients' characteristics, etc., may also influence biosimilar use. We suggest further analysis of policies aimed at promoting biosimilar adoption in Spain.