Introducing biosimilar competition for cell and gene therapy products.

This article provides an early analysis of the potential for creating future biosimilar competition for cell and gene therapies (CGTs) to lower prices and improve patient access, building on a unique set of interviews with relevant experts. Our discussion addressed regulatory, manufacturing, intellectual property, and market size challenges. Due to CGTs' complexity, meeting the regulatory requirement of 'high similarity with no clinically meaningful differences' will be difficult. Gene therapies are likely better candidates for biosimilar development than cell therapies. Biosimilarity should be met when gene therapy biosimilars contain the same genetic sequence as a reference product, and the variability in the vector meets the high similarity standard. Manufacturing challenges, including the lack of standardized platforms, high production costs, and complexity, pose significant obstacles. It may also be important to demonstrate biosimilarity within the manufacturing process. Intellectual property barriers, specifically patenting, trade secrecy, and regulatory exclusivity, could hinder biosimilars' ability to gain market share, although recent Supreme Court decisions limiting the breadth of patent claims could ease barriers to future CGT competition, including from biosimilars. Finally, inadequate market sizes might create hurdles, especially for curative treatments, as patient pools shrink following treatment by the reference CGT.