In September 2014, the FDA published the first edition of the Purple Book: Lists of Licensed Biological Products with Reference Product Exclusivity and Biosimilarity or Interchangeability Evaluations (“Purple Book”), the biological equivalent of the pharmaceutical Orange Book. See FDA Releases a Purple Book for Biosimilars. The Purple Book has now been updated to include Sandoz, Inc.’s (“Sandoz”), Zarxio® (filgrastim), the United State’s first biosimilar approved under the Biologics Price Competition and Innovation Act (“BPCIA”). See FDA Approves First Biosimilar: Sandoz’s Zarxio®.

Zarxio® is now listed on the Center for Drug Evaluation and Research (“CDER”) portion of the Purple Book[1]  under “BLA STN 125553.” The “product (proper) name” is listed as filgrastim-sndz with a date of licensure of March 6, 2015. Expectedly, Zarxio® is categorized as “B,” biosimilar, instead of “I,” interchangeable, because only biosimilar status was sought in its application. No information regarding “Reference Product Exclusivity Expiration Date” has been provided. Further, Zarxio® is listed on the CDER portion of the Purple Book immediately after its reference product, Amgen Inc.’s (“Amgen”) Neupogen®.

The FDA does not note nor otherwise announce the changes made to the Purple Book, so it is not clear whether Zarxio® was first added in the March 17, 2015, update or in the list’s latest April 15, 2015, update.

Despite its approval, Zarxio® is not yet available in the United States, likely due to the ongoing litigation between Amgen and Sandoz. The District Court of the Northern District of California’s denial of Amgen’s motion for a preliminary injunction and partial summary judgment is now on appeal to the Federal Circuit. See Dancing Not Required: District Court Denies Amgen’s Bid for Preliminary Injunction, Finds BPCIA “Patent Dance” Optional.

K&L Gates will continue to monitor this litigation to see what further developments may arise.

Notes:
[1] The Purple Book is split into two parts: products approved by the Center for Drug Evaluation and Research (“CDER”) and products approved by the Center for Biologics Evaluation and Research (“CBER”).