What is the difference between a generic and a biosimilar?

BioSimilars vs. Generic Drugs: What’s In a Word?

"How do biosimilars differ from so-called generic drugs? Generic drugs are essentially “copycat” versions of small molecule drugs – drugs that can be synthesized in the lab by following standardized, pre-defined procedures. Using well-established analytic techniques, the generic version of a small molecule drug can be demonstrated to be chemically and structurally identical to the innovator drug.


Biologic drugs, however, are much more complex than small molecule drugs. These drugs are proteins that must be produced by a living cell – they cannot be chemically synthesized in the lab by following a standard set of procedures. The cell makes these proteins by following a recipe provided by a short sequence of DNA – a gene – that is inserted into the cell. Here’s the catch: even if two different cells are provided the exact same recipe, the final product may be slightly different."