In September 2023, the FDA released draft guidance detailing the proposed changes in biosimilar and interchangeable labeling, replacing the 2018 Guidance. The FDA identified four significant changes:

• Labeling for interchangeable biosimilar products
• Product identification when the reference product labeling describes a clinical study conducted with a non-US-approved biological product
• Pediatric use statements
• Incorporating relevant immunogenicity data and information from the reference product labeling into the biosimilar or interchangeable biosimilar product labeling

Although four major changes have been identified, this post will focus only on the proposed labeling change for biosimilars.  The proposed labeling changes include where and how within the labeling to use proprietary names, generic names, and molecule names. They also include a recommendation to require a uniform biosimilarity statement in the label that does not distinguish between biosimilar and interchangeable products. Although the Purple Book identifies a product as biosimilar or interchangeable according to the FDA approval requirements, state pharmacy practice laws use the Purple Book assignments as guidance for drug substitution laws and regulations, like they do with the FDA Orange Book in state laws and regulations governing the substitution of non-biological drug products.

The current inclusion of the Purple Book biosimilar or interchangeable assignment in the labeling introduced an additional level of detail in the product label that is not provided in small molecule prescription drug labels.  It allowed healthcare professionals to utilize the label itself, instead of the FDA Purple Book, to determine the biosimilar and interchangeable status for a product. The same healthcare professionals currently utilize the FDA Orange Book codes to determine the therapeutic equivalence rating for small molecules instead of product labels.

The draft guidance will more closely align with the current labeling practice for small molecules. Therapeutic equivalence ratings (A- and B- ratings) for non-biological drugs are absent from labeling and instead found in the FDA Orange Book. The proposed guidance recommends all biosimilars, including interchangeable products, use the same statement of biosimilarity in the product label, with the expectation that users will utilize the FDA Purple Book to determine whether a product is simply biosimilar, or whether it has interchangeable identification. This eliminates the risk of using outdated product labeling to determine FDA Purple Book codes.

The FDA requests comments on this draft guidance in order to increase clarity and understanding before it officially rolls out. These comments are due by November 17, 2023. The change to the biosimilarity statement in the label will more closely align with small molecule labels in that substitutability cannot be determined simply by reviewing the product’s labeling. Pharmacists, prescribers, and pharmacy system developers will need to rely on the FDA Purple Book to determine the interchangeability designation for specific products, similar to the FDA Orange Book for small molecule therapeutic equivalence. What impacts do you see with the proposed guidance on FDA labeling statements for biosimilars and interchangeable biosimilars?

Sources

Labeling for Biosimilar and Interchangeable Biosimilar Products | FDA

Posted: October 2023