Molecular "Sameness" Is the Key Guiding Principle for Extrapolation to Multiple Indications.

Much has been made of biosimilars as a new regulatory concept, yet it is clear that misunderstandings are widespread, including the scientific justification for use in all indications of the reference product or "extrapolation." However, as this article shows, biosimilarity and extrapolation are not new concepts and most patients being treated with a branded biologic have already received a similar version of the original reference biologic based on changes in the manufacturing process.