Biosimilars: Implications for health-system pharmacists.

Purpose: An update on scientific and regulatory challenges in the rapidly evolving field of biosimilar product development is presented.

Summary: The U.S. market for biosimilar products (i.e., highly similar "follow-on" versions of approved biological drugs) is expected to expand with establishment of an expedited-approval pathway for biosimilars similar to that implemented in European Union countries eight years ago. In 2012, the Food and Drug Administration (FDA) published draft guidance clarifying the requirements of the biosimilars approval pathway; although no biosimilar has yet been approved via that pathway, FDA is engaged in ongoing meetings with a number of potential applicants. Due to molecular differences between innovator products and biosimilar versions, biosimilars are highly sensitive to manufacturing changes that can potentially have important safety and efficacy implications. Establishing the interchangeability of biosimilar and innovator drugs may be difficult at first, and it is possible that some biosimilars might not carry all the same indications for which the reference drug is approved. Pharmaceutical cost savings attained through the use of biosimilars are expected to average 20-30%. With several top-selling biologicals likely to lose patent exclusivity by 2020, health systems should prepare for the availability of new biosimilars by addressing formulary management and therapeutic interchange issues, pharmacovigilance and patient safety concerns, and related financial and operational issues.

Conclusion: Over the coming years, biosimilars will present opportunities for health care organizations to manage the growth of pharmaceutical expenditures. Pharmacists can play a key role in preparing health systems for projected rapid expansion in the use of biosimilars and associated medication-use policy challenges.