Be Careful What You Wish For? FDA’s Biosimilars Naming Guidance Proposes New Identifiers For All Biologic Products

Yesterday, the Food and Drug Administration (FDA) released much anticipated guidance on how they plan to address nonproprietary naming of biologics and biosimilars. In it, FDA proposed that all biologics—both reference products and biosimilars—will share a core drug substance name and also a new “FDA-designated suffix” that is unique for each product. While brand-biologic manufacturers pressed FDA to ensure biosimilars carry unique names, the agency’s proposal in fact places a large burden on these manufacturers and prescribers to adopt the new naming model. 

In March, FDA approved the first biosimilar product, Zarxio—Sandoz Inc.’s copy of Neupogen (filgrastim). At the time, FDA referred to Sandoz’s biosimilar as “filgratism-sndz,” which seemed to suggest that FDA was headed towards a unique-naming scheme for biosimilars. However, it turns out the agency only partially showed their hand. Their draft guidance reveals the agency wants all biologics, including the reference product, to be renamed under a four-letter suffix scheme.

Janet Woodcock, the Director of the Center for Drug Evaluation and Research (CDER) and Karen Midthun, Director of the Center for Biologics Evaluation and Research (CBER) published an overview of their agency’s plan and how how the naming would work. “This suffix would be composed of four lowercase letters, and not carry any meaning,” they write. “For example, the nonproprietary name of a reference product could be replicamab-cznm, and a biosimilar to that product could be replicamab-hixf.”

In the time leading up to this guidance, most of the commentary surrounding the “naming” issue focused primarily on the biosimilar product. In broad terms, the biosimilar industry and insurers argued that FDA should assign a biosimilar the same nonproprietary name as the reference product on which it was based in order to facilitate substitution by providers and pharmacists. Brand manufacturers argued that because biologics are inherently complex and impossible to replicate in the way small-compound drugs can, biosimilars should carry different nonproprietary names. Specialists who often prescribe biologics also called for unique naming for biosimilar products, arguing this was necessary to clarify that biosimilars are not identical to reference products and may not be approved for all the same conditions as the reference, as well as to prevent confusion regarding adverse event reporting.

Interestingly, neither side seemed to be lobbying for a change in the naming scheme for all biologics, including reference products. Gillian Woollett, Senior Vice President at Avalere Health, notes that the immediate impact of the proposed guidance and accompanying regulation on the originator products is actually much greater than the impact on biosimilars. It is unclear how manufacturers will retroactively change the names for their products, and the implementation of FDA’s proposal could result in substantial disruption along the supply chain as data systems have to accommodate multiple names for the same product, some concurrent. This has never happened before. We expect this issue to feature prominently in the comments FDA receives.

“[W]e must also consider what we need to do to address previously approved biological products that have nonproprietary names without a suffix,” the FDA Directors acknowledged. “Applying the naming convention to these products would encourage routine use of designated suffixes in ordering, prescribing, dispensing, and recordkeeping practices and avoid inaccurate perceptions of the safety and effectiveness of biological products based on their licensure pathway.” FDA is seeking comment on the best approach to implement this naming convention for previously licensed products.

FDA is also issuing a proposed rule to designate nonproprietary names that contain a suffix for six previously licensed biological products. Each of the six products is either a reference product for an approved or publicly disclosed biosimilar product application or a biological product that is either biosimilar to or related to one of these reference products. For example, Johnson & Johnson’s arthritis treatment Remicade (infliximib) would be have to be changed to infliximab-hjmt, according to the proposed rule.

Woodcock and Midthun note that FDA’s aim with the proposed naming convention is to address two issues, both of which were put forth by the brand industry as reasons to apply unique names to biosimilars. 

First, FDA wants to help prevent inadvertent substitution of biological products that are not determined to be “interchangeable” by the FDA. The agency has not yet issued guidance on how they will determine whether biosimilar products rise to the level of “interchangeability,” but FDA is getting a jump start on the naming issue. The agency is soliciting feedback about whether the nonproprietary name for interchangeable products should include a distinct suffix, or should share the same suffix as its reference product. The FDA will presumably also need to address currently marketed biologic products that share nonproprietary names as these may also be in danger of now being presumed to  be interchangeable if nonproprietary names are to become the basis of interchangeability.

Second, FDA is seeking to facilitate “safety monitoring of all biological products after they are on the market, by making it easier to accurately track usage of biological products in all settings of care, such as outpatient, hospital, and pharmacy settings.” Peter Pitts, President at the Center for Medicine in the Public Interest agreed that FDA’s proposal is an important one. “FDA has come out in favor of patient safety with the ability to track adverse events back to the manufacturer,” he noted.

View FDA’s draft guidance that explains FDA’s proposal on nonproprietary naming of biologicals (comments close in 60 days). View FDA’s proposed rule for renaming existing biologics (comments close in 75 days).