On October 13, 2026, the FDA announced the availability of a final guidance for industry entitled “Postapproval Manufacturing Changes to Biosimilar and Interchangeable Biosimilar Products: Questions and Answers,” finalizing a previously issued draft guidance of the same title issued on July 23, 2024. The FDA issued the guidance pursuant to the 2022 reauthorization of the Biosimilar User Fee Act (BsUFA III) for fiscal years 2023 through 2027. As with the draft, the final guidance is “intended to inform applicants of the nature and type of information, for different reporting categories, that applicants should provide to support manufacturing changes to licensed biosimilar and licensed interchangeable biosimilar products” licensed under section 351(k) of the Public Health Service Act. The FDA states that the recommendations are “intended to be consistent with the principles outlined in” ICH Q5E, Comparability of Biotechnological/Biological Products Subject to Changes in Their Manufacturing Process (June 2005).
According to the notice, the FDA considered the comments received on the draft and made three substantive changes in finalizing the guidance: “(1) further aligning recommendations in the guidance with the principles in ICH Q5E; (2) clarifying recommendations for leveraging comparative analytical assessment data from an original 351(k) biologics license application (351(k) BLA); and (3) clarifying edits to Q&A 4 on the nature and type of information that FDA recommends to support approval of a supplement for a dosage form or a strength that has not previously been licensed under the 351(k) BLA.” The FDA also made editorial changes for clarity.
The final guidance also supersedes the FDA’s prior treatment of the topic in its biosimilar development Q&A guidance. The FDA explained that postapproval manufacturing changes had been addressed in Q&A I.20 of “Questions and Answers on Biosimilar Development and the BPCI Act,” but that the Agency declined to extend that Q&A to interchangeable biosimilars at the time because it “had limited experience regarding manufacturing changes for licensed interchangeable biosimilar products.” Having “since determined that the principles that apply to manufacturing changes for biosimilar products are relevant to interchangeable biosimilar products,” the FDA is concurrently withdrawing Q&A I.20 from that guidance.
As with all FDA guidance, the document is non-binding and reflects the Agency’s current thinking, and comments may be submitted to the docket at any time.
Stay tuned to Big Molecule Watch for further developments in FDA biosimilar regulatory policy.