On September 11, 2025, the U.S. Food and Drug Administration (FDA) issued new guidance for the development of therapeutic protein biosimilars, focusing on comparative analytical assessment and quality-related considerations. This guidance is crucial for sponsors and manufacturers navigating the regulatory landscape for biosimilar approval under section 351(k) of the Public Health Service Act (PHS Act) [1] .

I. Abbreviated Licensure Pathway.

Section 351(k) of the PHS Act provides an abbreviated pathway for biosimilars, requiring sponsors to demonstrate that their product is “highly similar” to an FDA-licensed reference product, with no clinically meaningful differences in safety, purity, or potency. The PHA defines a “reference product” as the single biological product licensed under se

See Full Page