Purpose: To review the marketing authorization of biosimilars and provide a critical analysis of the pivotal trials supporting their approval by the European Medicines Agency (EMA).
Methods: EMA website to identify the biosimilars approved up to July 2019 and the European Public Assessment Report for information on pivotal trial design, duration, intervention and control, primary outcome, data on immunogenicity, and comparability margins.
Results: The EMA has approved 55 biosimilars (62% in 2017-2019) of 16 biologic products, used in several clinical indications. Some biosimilars were licensed as multiple products, with different commercial names, by the same or different companies. The comparability exercise and subsequent approval of 49/55 (89%) biosimilars were based on one or more pivotal phase III trials testing their clinical efficacy. In all, biosimilars were approved on the basis of 55 trials, mostly phase III (42/55, 76%) assessing clinical efficacy; these were mainly equivalence trials (31/55, 56%). The pivotal phase III trials assessed surrogate measures of clinical effect, and 71% reported immunogenicity data.
Conclusion: Analysis of the approval of biosimilars in Europe depicts a complex and heterogeneous scenario. The requirement for showing similarity in terms of clinical efficacy and safety provides a robust demonstration of comparable clinical outcomes but lays a burden on biosimilar manufacturers and may delay the introduction of the drugs. The development, licensing, and monitoring of biosimilars would benefit from new strategies to accelerate access to these drugs while reducing uncertainties about their use in practice.
Keywords: Biosimilar; Clinical trials; Comparability exercise; Drug regulation; European Medicines Agency.