In the United States, certain biosimilar products may be categorized by FDA as “interchangeable” biosimilars. This means that they may be substituted at the pharmacy without the intervention of the prescriber, much like how generic drugs are routinely substituted for brand name drugs, subject to state or national pharmacy laws.1
To be designated as an interchangeable biosimilar, FDA must find that the product meets additional requirements beyond the already rigorous requirements for biosimilarity, as outlined by law. The criteria used by FDA to evaluate interchangeability is as follows:2
As of August 2022, FDA has approved three interchangeable biosimilars.3 The approval of additional interchangeable biosimilars in the United States is expected over the next few years.