On 29 October 2025, the FDA announced proposed measures to make it faster and less costly to develop biosimilars, by simplifying biosimilarity studies, reducing unnecessary clinical trials and facilitating pharmacy level substitution.
In a new draft guidance, entitled “Scientific Considerations in Demonstrating Biosimilarity to a Reference Product: Updated Recommendations for Assessing the Need for Comparative Efficacy Studies”, the FDA recommends that biosimilar sponsors consider a streamlined approach in which a clinical efficacy study (CES) may not be necessary to support a demonstration of biosimilarity. The FDA suggests that this approach should be considered when:
- the reference product and biosimilar are manufactured from clonal cell lines, are highly purified and can be well characterised analytically;
- the relationship between quality attributes and clinical efficacy is generally understood for the reference product and can be evaluated by assays included in the comparative analytical assessment; and
- a human pharmacokinetic similarity study is feasible and clinically relevant.
In these circumstances, the adequacy of data from a comparative analytical assessment, pharmacokinetic similarity data, and immunogenicity assessment to support a demonstration of biosimilarity would be evaluated based on the totality of the evidence submitted in the biologics licence application (BLA).
The draft guidance is open for comment for 60 days and is expected to be published in its final form in 3 to 6 months.
In a separate initiative announced at the same time, the FDA also intends to make it easier for biosimilars to be developed as interchangeable with reference products by not requiring switching studies.
The FDA’s announcements follow similar initiatives in other regions, including the European Medicines Agency’s April 2025 reflection paper considering the possible waiver of comparative efficacy study requirements for biosimilars and India’s revised draft biosimilar guidelines in May 2025.