changes to the purple book: progress on transparency | Rothwell, Figg, Ernst & Manbeck, CP
The recently enacted Purple Book Continuity Act of 2019 came into effect on June 25, 2021. The FDA is to proactively update the information in the Purple Book every 30 days with an alphabetical list of authorized biologics, including the date of approval of the marketing application and the marketing / license status. In addition, there is now a potentially higher price tag for developers of benchmark biologic drugs to enter the patent dance under the BPCIA and enforce their patents against potential competing biosimilar manufacturers.
Prior to the enactment of HR 1520, the Purple Book Continuity Act of 2019, the FDA issued the Purple Book Reference Guide for Biologic Drugs under Section 351 (a) or 351 (k) of the Public Health Service Act (PHS) with information as to whether the biologic biologics have been determined by the FDA to be biosimilars (or interchangeable with) the reference biologic and the date a biologic was authorized to market under PHS section 351 (a) or 351 (k). The Purple Book also indicated the applicable exclusivity expiration date if the FDA evaluated the biologic for reference product exclusivity under section 351 (k) (7). The Purple Book has only been updated periodically by the FDA.
The recent enactment now adds a new layer of complexity for parties strategizing to enter the patent dance under the BPCIA. The sponsor of the reference product must provide the FDA with the expiration dates of all patents listed in the patent list sent to the applicant in subsection (k) in accordance with 42 USC § 262 (l) (3) and any additional listings in accordance with 42 USC § 262 (l) (7) within 30 days of providing such listings to the requester of paragraph (k). The FDA will then publish the patent expiration dates on the Purple Book searchable database in its recurring monthly updates.
The new regulations will likely ensure that the Purple Book list will be closely watched by parties seeking to develop their own biosimilar versions of licensed biologics. As a result, a benchmark product sponsor may choose to forgo claiming all or part of its patents in order to avoid publication of expiration dates in what would amount to an easily accessible compilation of the relevant patent heritage. This prospect could change the calculation of benchmark product sponsors in terms of the number and type of patents they claim. For example, a referral product sponsor may want to limit the number of patents claimed against a party in order to avoid revealing their hand to follow competitors who may implement a design strategy around. It remains to be seen whether the new regulations will impact the desire to exercise the best part of expansive portfolios against competitors, for example AbbVie’s recent challenge to Alvotech reported here.
As of the date of this article, the Purple Book lists patents and expiration dates relating to AbbVie’s Humira® product and Genentech’s Avastin® and Lucentis® products. Notably, most of the patents listed relate to manufacturing methods rather than formulations, processing methods and other aspects relevant to manufacturers of biosimilar products.
Despite the progress, there is still room to improve the new regulations from the point of view of public transparency. For example, the equivalent of the Purple Book for small molecule drugs, “the Orange Book,” requires applicants and NDA holders to provide the patent number and expiration date of any patent that claims the drug or the method of use of this drug and which is the subject of a patent infringement claim. could reasonably be asserted (21 US Code § 355 (b)). The recent changes to the Orange Book were made by the Orange Book Transparency Act of 2020. NDA holders are now required to notify the FDA of a patent invalidation within 14 days in order for the book to list. orange can be changed if necessary.
The trend, both for the Purple Book and the Orange Book, is towards greater public transparency. The major impetus for the new regulations is to increase the number of lower-cost drug options on the market, for example by shedding more light on the patent minefield that awaits some potential competitors trying to enter. the market. However, it may be several years before we see an impact, if any, on the number of generic drugs and biosimilars entering the market.