4 September 2019 - As defined by the European Commission, the term interchangeability refers to “the possibility of exchanging one medicine for another that is expected to have the same clinical effect.”

In the context of biosimilars the term interchangeability has caused confusion. Likely due to specific regulatory requirements in the United States, physicians sometimes interpret interchangeability as the potential for a biologic to be substituted by a biosimilar at the pharmacy level, without the involvement of a physician. 

However, interchangeability between a biological reference medicine and a corresponding biosimilar medicine should not be defined by its practical application; whether physician‐driven switch or pharmacist‐driven substitution. Interchangeability, ie, the possibility of safely and effectively changing a reference medicine by its biosimilar, or vice‐versa, in a given patient, should be rather recognised as a scientific concept. In this paper, we review the evidence supporting the assertion that interchangeability is inherent to biosimilarity.

Read Br J Clin Pharmacol article