What are biosimilars?

A biosimilar is a drug that is highly similar to an already approved biologic

A biosimilar is a biological medicine that is highly similar to another biological medicine already approved (European Medicines Agency definition).1 Because of this required similarity, there are no clinically meaningful differences in terms of efficacy, safety or exposure between a biosimilar and the reference biologic.1


  • Biological medicines are large, complex compounds grown in or derived from natural living cell lines1
  • Biologic drugs have multiple levels of structure (primary, secondary, tertiary, quaternary) and post-translational modifications2
  • Due to the variability of the biological system and manufacturing process, biological medicines may show a certain degree of variation, even between batches of the same product1
  • Although immunogenicity could be a potential concern for all biologics, experience shows that harmful immunogenicity is unlikely to occur after a change to the manufacturing process of a biologic or after switching between highly similar biologics1,3
  • Biological medicines are used to treat a wide range of diseases and medical conditions, including serious conditions such as rheumatoid arthritis and psoriasis, and life-threatening conditions such as cancer4

Biosimilars offer affordable therapies to a large number of patients. As similar versions of biologic drugs already approved, they make state-of-the-art therapies affordable and accessible to a larger and increasing number of patients.1 Cumulative savings for health systems in the EU and the US could exceed 50 billion euros over the next five years, freeing up resources within health systems for future innovations.5

How are biosimilars developed? Learn here

1. European Medicines Agency (EMA). Biosimilars in the EU: Information guide for healthcare professionals. 2017. Available at:
http://www.ema.europa.eu/docs/en_GB/document_library/Leaflet/2017/05/WC500226648.pdf (accessed in December 2020). 2. Abraham J. Semin Oncol 2013; 40:S5–S24. 3. Kurki P et al. BioDrugs 2017; 31:83–91. 4. Waller CF. Commun Oncol 2012; 9:198–205.
 5. IMS Institute 2016. Delivering on the potential of biosimilar medicines. Available at: https://www.medicinesforeurope.com/wp-content/uploads/2016/03/IMS-Institute-Biosimilar-Report-March-2016-FINAL.pdf (accessed in December 2020).