On June 25, 2021, the Biological Product Patent Transparency (BPPT) amendments to 42 U.S.C. 262(k) of the Biologics Price Competition and Innovation Act (BPCIA) will take effect. Those amendments make publication of the FDA “Purple Book” mandatory; require that the Purple Book include additional information—including patent lists provided by a reference product sponsor (RPS) to a biosimilar applicant pursuant to 42 U.S.C. 262(l)(3)(A) or (l)(7)—and require that FDA update the Purple Book every 30 days.

What Will Change

The Purple Book is an electronic reference that to date has been published voluntarily by FDA, and that lists certain information for biologics license applications (BLAs), including the BLA applicant’s name and BLA number, the date on which the biological product was licensed by FDA, and whether the product has been determined to be biosimilar to or interchangeable with a reference product.

Under the BPPT amendments, which will appear at 42 U.S.C. 262(k)(9), publication of the Purple Book will be mandatory, and the Purple Book must provide:

  • For each reference product, a list of patents that have been included on an RPS’s 42 U.S.C. 262(l)(3)(A) or (l)(7) list (which lists set forth patents owned or licensed exclusively by the RPS, and for which the RPS “believes a claim of patent infringement could reasonably be asserted” against a biosimilar applicant); and
  • Each reference product exclusivity period and each first interchangeable exclusivity period “for which FDA has determined such biological product to be eligible and for which such period has not concluded.”

42 U.S.C. 262(k)(9)(A)(iii)-(iv).

Although the BPPT amendments require the publication of those two additional categories of information, they do not impose any obligation to generate new information specifically for the Purple Book. As to patents, the amendments require only that an RPS disclose those (l)(3)(A) or (l)(7) patent lists that the RPS has provided to biosimilar applicants as part of the BPCIA’s “patent dance”—and the patent dance is not mandatory. As to exclusivities, the amendments do not impose an obligation upon FDA to determine, prospectively, all exclusivity periods for all reference and interchangeable products; rather, FDA is required to list in the Purple Book only those exclusivity periods for which FDA “has determined a biological product to be eligible.”

The BPPT amendments additionally require removal from the Purple Book of any biological product for which a BLA has been revoked or suspended “for reasons of safety, purity, or potency.” 42 U.S.C. 262(k)(9)(B).

Submitting (l)(3)(A) and (l)(7) Lists to FDA

The BPPT amendments require that an RPS provide a (l)(3)(A) or (l)(7) patent list to FDA no later than 30 days after such a list has been provided by the RPS to a biosimilar applicant. 42 U.S.C. 262(k)(9)(A)(iii). FDA has instructed RPSs to submit those lists (along with a cover letter) to FDA via its Electronic Submissions Gateway, in the form of an Excel spreadsheet having the following fields:

  • Reference product BLA number
  • Applicant name
  • Proprietary name
  • Proper name
  • Patent number
  • Patent expiration date An email copy of the cover letter and spreadsheet should also be sent to [email protected]. Id.

For subsequent patent lists, FDA advises RPSs to “[o]nly include additional patents and their corresponding expiration dates in an update submission. Applicants do not need to duplicate information already submitted in an initial list or previous update submission.” Id.

As to when patent listings will start appearing in the Purple Book, FDA indicates that it “will begin publishing patent lists in the Purple Book not later than 180 days after the date of enactment (June 25, 2021), or when FDA has received any such lists from reference product sponsors, whichever is later. FDA subsequently will revise the list on a monthly basis to include any additional initial lists and any updates from subsequent or supplemental lists.” Id.

Christopher Loh has extensive experience counseling clients and litigating matters involving biotechnology and life sciences, including in the areas of antibody biosimilars, targeted cancer therapies, diabetes treatments and siRNA technologies. Christopher has a B.S. in Molecular Biochemistry and Biophysics and in Economics from Yale University.


    Information contained in the Venable BiologicsHQ database relates to FDA-approved drug products listed in the CDER Purple Book or on the FDA website ( Information relating to FDA licensed products, FDA-approved indications, and aBLA and 505(b)(2) applications is obtained from public sources including the U.S. FDA website ( Information relating to litigations is given only for cases active from January 31, 2010 onward. Information relating to foreign biosimilar / biologics follow-on products approved in Australia, Canada, the E.U., Japan and South Korea is from public sources. Statistics graphics are compiled from information contained in the Venable BiologicsHQ database.


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