Non-Proprietary Naming of Biologics and Biosimilars: FDA Finalizes Guidance

In a departure from the way the WHO and Europe name biologics, the US Food and Drug Administration (FDA) on Thursday finalized long-awaited guidance on how biosimilars and their biologic reference products’ names should include a four-letter, FDA-designated meaningless suffix attached at the end of the nonproprietary name.

The decision to finalize this guidance follows not only several tweaks (including one that has companies submit 10 suffixes to FDA for consideration as part of the naming of biologics, which is included in the final guidance) but large opposition to the idea of using meaningless rather than meaningful suffixes that could make it easier to distinguish the manufacturers of the products.

For example, the first biosimilar approved by FDA was for Sandoz’s Zarxio, which includes a non-proprietary name with a meaningful suffix (Sndz for Sandoz): filgrastim-sndz.

But FDA has said it will change Zarxio’s nonproprietary name from filgrastim-sndz to “filgrastim-bflm." And Amgen's Neupogen (filgrastim) would be changed to "filgrastim-jcwp."

Final Guidance Details

As part of plans to facilitate better pharmacovigilance for the originator biologics and their biosimilar counterparts, FDA says: “The nonproprietary name designated for each originator biological product, related biological product, and biosimilar product will be a proper name that is a combination of the core name and a distinguishing suffix that is devoid of meaning and composed of four lowercase letters.”

And the random suffixes will not just be for biosimilars but for newly licensed and previously licensed originator biological products, related biological products and biosimilars.
“Nonproprietary names that include distinguishing suffixes can serve as a key element to identify specific products in spontaneous adverse event reporting and to reinforce accurate product identification in billing and claims records used for active pharmacovigilance,” FDA explains. “Other product-specific identifiers, such as proprietary names or NDCs, may not be available or could change over time.”

The distinguishing suffixes should also help to minimize “inadvertent substitution,” FDA says, particularly for biosimilars that have not been determined to be interchangeable.
“FDA is continuing to consider the appropriate suffix format for interchangeable products,” FDA says. Draft guidance on interchangeability is due to be released sometime later this year.
As far as submitting the 10 suffixes for consideration (which one could argue runs counter to the idea that the suffixes are random), FDA suggests the proposed suffix be:

• unique
• devoid of meaning
• four lowercase letters of which at least three are distinct
• nonproprietary
• attached to the core name with a hyphen
• free of legal barriers that would restrict its usage

And according to FDA, the proposed suffix should not:

• be false or misleading, such as by making misrepresentations with respect to safety or efficacy
• include numerals and other symbols aside from the hyphen attaching the suffix to the core name
• include abbreviations commonly used in clinical practice in a manner that may lead the suffix to be misinterpreted as another element on the prescription or order
• contain or suggest any drug substance name or core name
• look similar to or be capable of being mistaken for the name of a currently marketed product (e.g., should not increase the risk of confusion or medical errors with the product and/or other products in the clinical setting)
• look similar to or otherwise connote the name of the license holder
• be too similar to any other FDA-designated nonproprietary name suffix

But these suffix rules do not necessarily apply to all related biologics.

FDA notes that in some instances it has designated a proper name that includes an identifier attached as a prefix to distinguish the products from previously licensed biologics. For example, with ado-trastuzumab emtansine, FDA includes a unique prefix, which it says was necessary to minimize certain medication errors and to facilitate pharmacovigilance.

“FDA determined that a unique proper name including a prefix was necessary for ado-trastuzumab emtansine to distinguish the product from trastuzumab, a previously licensed biological product submitted in a different BLA,” the guidance says. “FDA may continue such practices on a limited basis, where appropriate, when the Agency determines that the designation of a prefix, in addition to a suffix as contemplated by this guidance, is necessary to ensure patient safety.”

Nonproprietary Naming of Biological Products Guidance for Industry