Purple Book: Lists of Licensed Biological Products with Reference Product Exclusivity and Biosimilarity or Interchangeability Evaluations

The “Purple Book” is not an actual book; it is a nickname applied to electronic lists of biological products licensed by FDA under the Public Health Service (PHS) Act, including any biosimilar and interchangeable biological products. Separate lists are maintained for biological products regulated by the Center for Drug Evaluation and Research (CDER) and the Center for Biologics Evaluation and Research (CBER).

“Purple Book” is a nod to “Orange Book,” the nickname for the FDA publication (Approved Drug Products with Therapeutic Equivalence Evaluations) that contains therapeutic equivalence evaluations for approved multisource prescription drug products. The original print version had a distinctive orange cover.

The Purple Book was made available on the FDA website in September 2014 and is updated periodically. The lists include the following information about biological products:

  • The date on which the product was licensed under section 351(a) of the PHS Act.
  • Whether FDA evaluated the product for reference product exclusivity.
  • Whether the product has been determined to be biosimilar to or interchangeable with a reference product (i.e., a previously licensed biological product).

To facilitate use of Purple Book information, biosimilar products and interchangeable products are grouped under the reference product to which biosimilarity or interchangeability was demonstrated.

The current Purple Book lists are available on the FDA website.