On January 20, ASBM submitted formal comments to the U.S. Food and Drug Administration on the agency’s October 2025 draft guidance, Scientific Considerations in Demonstrating Biosimilarity to a Reference Product: Updated Recommendations for Assessing the Need for Comparative Efficacy Studies.
In the comments, ASBM supports FDA’s recognition that comparative analytical assessments (CAA) have become increasingly powerful and, in many cases, more sensitive than traditional comparative efficacy studies (CES) for detecting product differences. ASBM agrees that thoughtful, science-based streamlining – applied on a case-by-case basis – can be appropriate and consistent with a modern biosimilar development paradigm.
However, ASBM warns that reducing CES expectations cannot be viewed in isolation, particularly when paired with public messaging and policy initiatives that frame biosimilars as interchangeable generics. The comments emphasize that physician and patient confidence in biosimilars was built through a stepwise, totality-of-evidence framework integrating analytics, clinical pharmacology, immunogenicity, and targeted clinical data where appropriate – not analytics alone. From the comments:
“Alone, a science-based reduction in comparative efficacy study requirements may be reasonable in defined circumstances. In the current policy environment, however, CES reduction does not occur in isolation. It is unfolding alongside public statements by senior HHS and FDA leadership encouraging the public to ‘think of biosimilars as generics,’ proposals to eliminate the practical distinction between biosimilars and interchangeable biosimilars, and FDA support for legislative efforts such as the Biosimilar Red Tape Elimination Act. Together, these developments amount to a de facto ‘genericization’ of biosimilars that risks eroding physician and patient confidence in the U.S. biosimilar framework.”
ASBM urges FDA to clarify guardrails in the final guidance to avoid misinterpretation, reaffirm the continued role of clinical evidence where residual uncertainty exists, and clearly distinguish biosimilars from small-molecule generics. Preserving confidence, the comments argue, is essential to maintaining treatment stability, supporting responsible uptake, and realizing the savings biosimilars are intended to deliver.
Read ASBM’s comments here.
