On September 9, 2014, the U.S. Food and Drug Administration (“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 Purple Book is the biological equivalent of the pharmaceutical Orange Book, and seeks to aid regulatory agents, generic manufacturers, and physicians by arming them with information related to biological products such as biosimilars including, for example, providing information regarding the interchangeability of products.
The publication of the Purple Book comes several years after the enactment of the Biologics Price Competition and Innovation Act (“BPCIA”) in 2010, which established an expedited pathway for FDA approval of biosimilars. Since the enactment of the BPCIA, many organizations have supported the creation of an Orange Book equivalent for biological products. The Purple Book takes a significant step toward this goal, and will list those biological products that have been “licensed” or approved by FDA under section 351(k) of the Public Health Service Act (“PHSA”). Notably, FDA’s release of the Purple Book comes a little over a month after the filing of the first biosimilar application under section 351(k) and points to FDA providing further clarity regarding biosimilars in the coming months, such as the naming of biosimilars.1
Purple Book Contents
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”). The Purple Book’s lists include the following information: the date a biological product was licensed under section 351(a) of the PHSA, whether FDA evaluated the biological product for reference product exclusivity under section 351(k)(7) of the PHSA, whether a biological product licensed under section 351(k) of the PHSA has been determined by FDA to be biosimilar or interchangeable with a reference biological product, and biosimilarity or interchangeability evaluations. Notably, the Purple Book will organize biosimilars licensed under section 351(k) deemed to be biosimilar or interchangeable under the reference product to which biosimilarity or interchangeability was demonstrated.
As the approval process under section 351(k) is still in its infancy, the lists in the Purple Book are incomplete and will require updating as biological products are licensed under 351(k). For example, currently, the CBER list does not include reference product exclusivity information or expiry date of first licensure information. FDA has addressed this missing information in the Purple Book background by stating that, although FDA has not determined the date of first licensure for all section 351(a) biological products included in the Purple Book lists, it does not mean that those biological products on the list are not eligible for exclusivity. FDA further stated that determinations of date of first licensure and when any remaining reference product exclusivity will expire for biological products submitted under section 351(a) will generally be made for regulatory necessity and/or at the request of the section 351(a) license holder.
Additionally, as FDA has yet to approve any biosimilar under section 351(k), it is unclear how it will identify “Interchangeable Biological Product Exclusivity” under section 351(k)(6) of the PHSA. Therefore, it is likely that as the field of biosimilars grows and exclusivity is granted, the Purple Book will be updated over time to accommodate these changes.
[1] FDA Accepts First Biosimilar Application Filed under Section 351(k) of the Public Health Service Act, K&L Gates Legal Insight, July 28, 2014
