Today, the US Food and Drug Administration (FDA) released its long-awaited guidance establishing a naming convention for biologicals, including related and biosimilar products.
With the passage of the Affordable Care Act in 2010, the US created a new pathway for biosimilar products to come to market, similar to the pathway in place for generic drugs.
This pathway allows companies to get biosimilars to market more quickly and cheaply by relying on clinical evidence generated by the original manufacturer. While generic drugs are reviewed for their bioequivalence to an original product, biosimilars must demonstrate they behave similarly in terms of safety and efficacy, despite being chemically different from their reference product.
In April 2015, after a three-year delay, FDA finalized three guidance documents clarifying its expectations for biosimilar products, answering specific questions about how the agency interprets the Biologics Price Competition and Innovation Act (BPCI) and giving industry insight into quality and scientific considerations for biosimilar product development.
Since the creation of the biosimilar pathway, one of the biggest debates about these new products has focused on how they would be named.
For chemical drugs, both branded drugs their generic versions share the same nonproprietary name, but use different trade names to distinguish themselves. However, because biosimilar products are not chemically identical to the original product, regulators have struggled to determine how these products should be named.
Industry and patient groups have claimed having identical nonproprietary names could create confusion and make postmarket surveillance difficult. Others have argued the focus on how these products are named is a distraction and likely to have little real world impact.
However, the general trend among regulators has been to establish some way of distinguishing biological products from their biosimilars using a "biological qualifier" such as a three- or four-letter code.
After a lengthy wait, FDA has finally released a draft guidance reflecting the agency's current thinking on biological nonproprietary naming.
In the guidance, the agency says biologics and their related biosimilars will share the same nonproprietary name, referred to as "proper name" in the guidance, but will have a four lowercase letter suffix to differentiate different similar products.
FDA says it will assign a unique suffix for each biologic product. In addition, the new naming convention will apply to new and previously-licensed products under the Public Health Service Act.
The agency says these suffixes will be devoid of meaning, and gives the example of a fictional reference product "replicamab-cznm" and related biosimilar "replicamab-hixf."
In a post to FDA Voice, the agency argues the proposed naming convention will:
- "help prevent inadvertent substitution (which could lead to medication errors) of biological products that are not determined to be interchangeable by the FDA."
- "support 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."
For products that have demonstrated interchangeability, FDA is asking for more feedback on whether to use the same suffix as their reference product, or if they should be given a unique suffix.
Regardless, the agency says: "the Purple Book will identify biological products determined by FDA to be biosimilar to or interchangeable with a reference product."
As such, the agency is asking for feedback on the challenges or benefits of interchangeable products sharing a suffix, and what the impact of this distinction would be for pharmacovigilance efforts.
The agency notes the proposed naming convention is similar to the World Health Organization's (WHO) biological qualifier proposal, and asks how the WHO-generated qualifiers should be considered when FDA is designating a product's suffix.
FDA also released a proposed rule alongside its draft guidance to designate the proper names of six already approved biological products.
The products include filgrastim, pegfilgrastim, infliximab and epoetin alfa, each of which is a reference product for "an approved or publicly disclosed section 351(k) application," a related biological product, tbo-filgrastim, and a biosimilar, filgrastim-sndz.
The document proposes assigning a suffix to each of the six products, or replacing the product's previous suffix (or prefix, in the case of tbo-filgrastim).
For example, Amgen's Neupogen (filgrastim) would be changed to "filgrastim-jcwp," while Sandoz' Zarxio (filgrastim-sndz) would be renamed "filgrastim-bflm." For the biosimilar Granix (tbo-filgrastim), FDA has proposed removing the prefix "tbo" and a adding a new suffix, making its proper name "filgrastim-vkzt".
The agency says it believes changing the names and of these products will help "avoid confusion regarding these products relationships to one another." Additionally, by using only suffixes, related or similar products can be "grouped together in electronic databases," while remaining distinguishable.
The agency says it also is considering alternative names for these specific products that would still use a four letter suffix, but where the suffix is based on the product license holder's name, such as "amgn" for Amgen, or "jnsn" for Janssen.
Draft Guidance, Proposed Rule, FDA Voice