Thompson Examines Strategic Implications of FDA's 2025 Biosimilar Draft Guidance

01.27.2026

Stinson LLP attorney Theodore Thompson authored an article in The Legal Intelligencer analyzing the U.S. Food and Drug Administration's (FDA) October 2025 draft guidance on demonstrating biosimilarity to a reference product. In the article, Thompson focuses on strategic considerations for biosimilar developers and their counsel.

Thompson explains that the draft guidance reframes how sponsors should approach their evidentiary strategy for interchangeable biosimilar license applications (BLAs). He writes that sponsors should consider emphasizing a "totality of evidence" framework rather than default reliance on comparative efficacy studies. Thompson notes that the FDA's increased willingness to consider comparative analytical assessments, pharmacokinetic data and immunogenicity evidence elevates the importance of early development data and careful documentation.

"The guidance reinforces a familiar but increasingly important theme: regulatory success depends not just on meeting scientific standards, but on strategic planning, clear justification of evidence and thoughtful engagement with regulators," Thompson writes. He emphasizes that sponsors and their attorneys must assess early whether reference product characteristics and available data support a streamlined approach.

Thompson also examines how the guidance may shift regulatory risk allocation. While reduced reliance on traditional clinical trials may shorten development timelines and lower overall BLA costs, he cautions that sponsors must be prepared to defend the sufficiency of analytical and nonclinical data during FDA review and post-market scrutiny. He further highlights the importance of proactive engagement with the FDA when development programs fall outside the conditions outlined in the draft guidance.

Thompson focuses his practice on advising clients on FDA, HIPAA and False Claims Act compliance, including regulatory strategy for drugs and medical devices. He works closely with clients to translate complex regulatory requirements into practical, commercially viable pathways to market.

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