In December 2020, the United States signed into law the Consolidated Appropriations Act, 2021, which contains provisions affecting the transparency of patent information relating to US Food and Drug Administration (FDA)-licensed biologics1.

Under the Biologics Price Competition and Innovation Act (BPCIA), biologics license holders in the United States and companies seeking approval of a biosimilar engage in a statutorily-prescribed exchange of information about the patents to be litigated, which is often referred to as the “patent dance.” One of the first steps in the patent dance is a disclosure by the license holder to the biosimilar applicant of “a list of patents for which the [license holder] believes a claim of patent infringement could reasonably be asserted” pursuant to section (l)(3)(A) of the BPCIA.

Previously, the list of patents provided by the license holder remained confidential. The new law requires biologics license holders to provide the list of patents, and their expiry dates, to the FDA within 30 days of the disclosure to biosimilar applicants. The disclosed patents will be made publicly available by the FDA in a searchable online database called the Purple Book beginning in June 2021. This is a step toward the Orange Book model, which requires identification of patents that may be asserted against non-biological generics manufacturers.

What impact will the new law have on biologics license holders and biosimilar manufacturers?

  1. The new requirements will have little impact on a first biosimilar applicant for a particular biologic. That first applicant will, as before, enter the patent dance only with information obtained from its own freedom to operate patent searches.
  2. For second or later biosimilar applicants, the disclosures reduce the risk that the applicant will have unknown patents asserted against them in the patent dance.
  3. A biologics license holder can still assert patents against a second or later biosimilar applicant that were not asserted against the first applicant. Such patents would not be disclosed in the Purple Book and could lead to a nasty surprise for the biosimilar applicant if appropriate freedom to operate searches were not carried out.
  4. Biologics license holders can expect more Patent Trial and Appeal Board (PTAB) challenges against patents disclosed in the Purple Book.

The greater transparency of the Purple Book disclosures is a win for biosimilar manufacturers seeking approval in the United States. Over time, these disclosures will guide biosimilar launch strategies and potential design-around options in process development, particularly for products where manufacturing processes overlap.



H.R.133 - Consolidated Appropriations Act, 2021, Subtitle C, Section 325: “Biological product patent transparency” (full text available at