Biosimilars: the science of extrapolation

Blood. 2014 Nov 20;124(22):3191-6. doi: 10.1182/blood-2014-06-583617. Epub 2014 Oct 8.


Despite the establishment of a specific approval pathway, the issuance of detailed scientific guidelines for the development of similar biological medicinal products (so-called "biosimilars") and the approval of several biosimilars in the European Union, acceptance of biosimilars in the medical community continues to be low. This is especially true in therapeutic indications for which no specific clinical trials with the biosimilar have been performed and that have been licensed based on extrapolation of efficacy and safety data from other indications. This article addresses the concerns frequently raised in the medical community about the use of biosimilars in such extrapolated indications and explains the underlying scientific and regulatory decision making including some real-life examples from recently licensed biosimilars.

MeSH terms

  • Antibodies, Monoclonal / pharmacology
  • Antibodies, Monoclonal / therapeutic use
  • Biosimilar Pharmaceuticals / chemical synthesis
  • Biosimilar Pharmaceuticals / pharmacology*
  • Biosimilar Pharmaceuticals / therapeutic use*
  • Data Interpretation, Statistical*
  • Drug Design
  • Drug Evaluation, Preclinical / statistics & numerical data
  • Epoetin Alfa
  • Erythropoietin / pharmacology
  • Erythropoietin / therapeutic use
  • Filgrastim
  • Granulocyte Colony-Stimulating Factor / pharmacology
  • Granulocyte Colony-Stimulating Factor / therapeutic use
  • Humans
  • Infliximab
  • Patient Safety
  • Recombinant Proteins / pharmacology
  • Recombinant Proteins / therapeutic use
  • Treatment Outcome


  • Antibodies, Monoclonal
  • Biosimilar Pharmaceuticals
  • Recombinant Proteins
  • Erythropoietin
  • Granulocyte Colony-Stimulating Factor
  • Epoetin Alfa
  • Infliximab
  • Filgrastim