Biosimilars for Immune-Mediated Chronic Diseases in Primary Care: What a Practicing Physician Needs to Know

Am J Med Sci. 2018 May;355(5):411-417. doi: 10.1016/j.amjms.2017.12.014. Epub 2017 Dec 29.


The introduction of biologics has revolutionized the treatment of immune-mediated diseases, but high cost and limited patient access remain hurdles, and some physicians are concerned that biosimilars are not similar enough. The purpose of this narrative review is to describe biosimilar safety, efficacy, nomenclature, extrapolation and interchangeability. In the United States, the Biologics Price Competition and Innovation Act created an abbreviated pathway for licensing of a biologic that is biosimilar to another licensed product (i.e., the reference product). This approval pathway differs from that of generic small-molecule drugs because biologics are too complex to be perfectly duplicated, and follows a process designed to demonstrate that any differences between the biosimilar and its reference product have no significant impact on safety and efficacy. The US approval process requires extensive analytical assessments, animal studies and clinical trials, assuring that biosimilar products provide clinical results similar to those of the reference product.

Keywords: Biologic; Biosimilar; Immunology; Rheumatology.

Publication types

  • Review

MeSH terms

  • Animals
  • Autoimmune Diseases / drug therapy*
  • Biosimilar Pharmaceuticals / adverse effects
  • Biosimilar Pharmaceuticals / economics
  • Biosimilar Pharmaceuticals / therapeutic use*
  • Chronic Disease
  • Drug Approval
  • Drug Costs
  • Drugs, Generic
  • Humans
  • Physicians, Primary Care
  • Primary Health Care / methods*
  • Small Molecule Libraries / adverse effects
  • Small Molecule Libraries / economics
  • Small Molecule Libraries / therapeutic use*
  • United States


  • Biosimilar Pharmaceuticals
  • Drugs, Generic
  • Small Molecule Libraries