Earlier this year, two new laws were enacted that impact patent listings in the Orange Book (drugs) and Purple Book (biologics). The Orange Book Transparency Act primarily codifies current FDA practices, but adds a new requirement for delisting patents invalidated by the Patent Trial and Appeal Board of the USPTO. The Purple Book Continuing Act codifies a number of FDA's current Purple Book practices, and imposes a new requirement for publishing the reference product sponsor's "patent lists" exchanged in the so-called "patent dance" of BPCIA biosimilar litigation. 

The Orange Book Transparency Act

The Orange Book Transparency Act (Pub. Law. 116-290) codifies the practice of listing patents in the Orange Book that claim the drug at issue (drug substance or formulation patents) and/or that claim a method of using the drug for the indication(s) at issue. The Act provides the following time periods for submitting patent information to FDA, depending on when the patent is granted:

  • With the 505(b)(1) application
  • Within 30 days of approval of the 505(b)(1) application
  • Within 30 days of grant of the patent

The Act does not specify any stand-alone consequences for "late" listing or failing to list a patent.

The Act imposes a new requirement for delisting patents invalidated by the Patent Trial and Appeal Board of the USPTO (e.g., in an Inter Partes Review or Post Grant Review proceeding). The delisting requirement applies to "a final decision issued by the Patent Trial and Appeal Board ... or by a court, from which no appeal has been, or can be, taken," if the result of the decision is that the patent no longer meets the listing requirements (e.g., if all relevant claims were invalidated).

The Act requires the NDA holder to notify FDA in writing, within 14 days of the decision and to provide a copy of the decision to FDA. The Act requires FDA to delist the patent, but not before the expiration of any pending 180-day exclusivity period stemming from a paragraph (IV) certification against the patent.

The new delisting requirement "applies only with respect to a decision ... issued on or after the date of enactment of this Act," which was January 5, 2021.

The Purple Book Continuity Act

The Purple Book Continuity Act is part of the Omnibus Appropriations Bill enacted December 27, 2020, in Section 325 entitled "Biological Product Patent Transparency." Similar to the Orange Book Transparency Act, the Purple Book Continuity Act codifies current FDA Purple Book practices, but also imposes a new patent listing requirement.

In particular, the Act add a new paragraph (9) to 42 U.S.C. 262(k), entitled "PUBLIC LISTING." The provisions requires FDA to publish a list of approved biological products, their date of licensure and application number, their licensure and marketing status, and any regulatory exclusivity periods, and to update the list every 30 days.

The patent listing requirement comes under (9)(A)(iii), entitled "PATENT INFORMATION," which states:

Not later than 30 days after a list of patents under subsection (l)(3)(A), or a supplement to such list under subsection (l)(7), has been provided by the reference product sponsor to the subsection (k) applicant respecting a biological product included on the list published under this subparagraph, the reference product sponsor shall provide such list of patents (or supplement thereto) and their corresponding expiry dates to the Secretary, and the Secretary shall, in revisions made under clause (ii), include such information for such biological product. Within 30 days of providing any subsequent or supplemental list of patents to any subsequent subsection (k) applicant under subsection (l)(3)(A) or (l)(7), the reference product sponsor shall update the information provided to the Secretary under this clause with any additional patents from such subsequent or supplemental list and their corresponding expiry dates.

The effective date of these provisions of the Purple Book Continuity Act is June 25, 2021. FDA has provided initial guidance on how reference product sponsors can submit patent information on its Purple book FAQ page.

As enacted, the Purple Book Continuity Act is significantly more conservative than the Biological Patent Transparency Act that was introduced by Sen. Collins (R-Maine) in 2019. As discussed in this article, that Act would have imposed a forward-looking patent listing requirement similar to that of the Orange Book.

More Transparency But Not Consistency

While both the Orange Book Transparency Act and the Purple Book Continuing Act require FDA to publish patents relating to approved products, the acts maintained the different patent listing paradigms that apply to drugs versus biologics. While 505(b)(1) applicants must identify relevant patents up front, BLA holders need only identify patents if and when they are included on a "patent list" during the "patent dance" stage of biosimilar litigation under the BPCIA. While the Orange Book includes only drug product and method of use patents, the Purple Book could include method of manufacture patents, but only those that have been raised against a specific biosimilar applicant. Thus, competitors seeking to develop generic drug or biosimilar products will still need to undertake their own patent searches to identify potentially relevant patents that are not required to be listed.

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