The importance of World Health Organization international reference standards in the product life cycle of biosimilars

Technological advances in analytics, as well as scientific and regulatory knowledge and experience gained from biosimilar development/approvals over the last decade, enabled the World Health Organization (WHO) in 2022 to revise its guidelines on the evaluation of biosimilars. Among the revisions, there is more reliance on analytical and functional aspects to prove similarity (and likely fewer clinical requirements). WHO international reference standards for biosimilars provide additional confidence to regulators looking for evidence- and data-based regulatory convergence in scientific and technical measures of quality attributes. These standards serve as a benchmark for harmonizing the bioactivity or potency of biosimilars, ensuring their future sustainability. This article discusses the availability and role of WHO international reference standards throughout the product life cycle of biosimilars.