Biosimilars, which are affordable alternatives to biologic medicines, face delays in market entry due to the current patent litigation framework under the Biologic Price Competition and Innovation Act. Currently, biosimilar manufacturers can only initiate patent litigation to attempt to clear weak and invalid patents after submitting their Biologic License Application to the Food and Drug Administration (FDA), which happens after completing extensive, and costly clinical trials. By contrast, generic drug manufacturers can start litigation earlier due to shorter development times and less stringent clinical requirements, allowing them to launch immediately after the primary patent expires. We propose allowing biosimilars to begin patent litigation at the start of phase 3 clinical trials, the final stage of biosimilar development, where the product and manufacturing process and product profile are largely finalized. This change would enable biosimilar firms to resolve patent issues well before the brand biologic's primary patent expiration date, potentially reducing market entry delays by about 1.8 years. This article examines the issues surrounding initiation of biosimilar litigation and suggests litigation reforms to expedite biosimilar market availability.
Keywords: biologic; biosimilar; drug spending; medicare; patents.
© The Author(s) 2025. Published by Oxford University Press on behalf of Duke University School of Law, Harvard Law School, Oxford University Press, and Stanford Law School.