FDA Announces Update to Nonproprietary Naming Convention for Biosimilar Products

March 15, 2019

On Thursday, March 7th, FDA published a revised draft guidance, updating its nonproprietary naming convention for biological products licensed under section 351 of the Public Health Service Act (PHS Act).  According to a recent statement from Scott Gottlieb, MD, FDA Commissioner, the Agency no longer has intentions to modify the proper names of biological products as set out in the 2017 guidance, “Nonproprietary Naming of Biological Products,” nor does it intend on applying the naming convention to the proper names of transition biological products.

Appropriate Naming Convention

A biological product’s proper name is the nonproprietary name designated by FDA in the license for a biological product listed under the PHS Act. It reflects certain scientific characteristics of the product such as chemical structure and pharmacological properties. A proprietary name differs from a proper name in that a proprietary name is a trademark or brand name.

On each package of a biological product, the FDA designates the proper name in the license for use. The proper name of a biological product can assist health care providers in identifying the product drug substance and in distinguishing biological products from one another.


According to section 351(i) of the PHS Act, a biosimilar product is that which “’is highly similar to the reference product notwithstanding minor differences in clinically inactive components’ and that ‘there are no clinically meaningful differences between the biological product and the reference product in terms of the safety, purity, and potency of the product.’”

In 2010, The Biologics Price Competition and Innovation Act of 2009 (BPCI Act) was enacted, establishing the pathway for products demonstrated to be biosimilar to or interchangeable with an FDA-licensed reference product. The BPCI Act added Section 351(k) to the PHS Act, which “sets forth the requirements for an application for a proposed biosimilar product and an application or a supplement for a proposed interchangeable product.”

In a 2015 draft guidance, FDA explained that nonproprietary names were not appropriate for all biological products. In that document, the Agency stated that a process to clearly identify biological products was necessary to improve pharmacovigilance and identified its intent to designate a nonproprietary name that included a suffix composed of four lowercase letters.

In 2017, the FDA finalized that draft detailing how the suffixes would be added. The guidance allowed the Agency to begin adding the suffixes to the names of newly appointed biological products, with the intention of going back and adding suffixes to the nonproprietary names of all previously approved biologics.

FDA Changes Course with 2019 Revised Draft Guidance

According to last week’s draft guidance, FDA no longer intends to modify the proper names of a biological product under the PHS Act. The Agency has determined that the pharmacovigilance and safe use goals of the naming convention can be applied at the time a biologic is licensed under 351 of the PHS Act., and “without applying it to licensed biological products that do not contain a suffix in their proper names.” Moreover, the Agency determined that the naming policy could still be applied to newly licensed biological products.

In his press release, Dr. Gottlieb stated that the updated naming convention will provide consistency among biologics and will ensure safety for health care providers as well as patients. Gottlieb explained that the four-letter suffix will be “applied to originator products going forward, as well as to any biosimilar and interchangeable products, so they can be appropriately distinguished from one another at the pharmacy level.” Having unique suffixes is a critical component for FDA to be able to track adverse events back to a specific biological product and manufacturer so appropriate action(s) can be taken to protect patients. The commissioner addressed that changing the names of approved products would impose substantial costs on the healthcare system and could counteract the goal of access and affordability for patients if those costs were to be passed along.


According to the updated draft guidance, vaccines fall under the scope of the naming convention. The revised document states that the FDA is reconsidering and reevaluating this approach to determine if the current identification system is sufficiently robust for ensuring pharmacovigilance so that proper names would not be required.

Suffix Format

The Agency believes that a distinguishing suffix is necessary to provide adequate pharmacovigilance, rather than a suffix shared with the reference product. A unique suffix will assist in tracking the biological product dispensement to patients and avoid the need “for changes to the nonproprietary name of a biological product that is first licensed as a biosimilar product and later determined to be an interchangeable product”. These changes could be a burden on Sponsors, the FDA, and the health care system, and could confuse health care practitioners or patients.

Applicants for a proposed interchangeable product submitted under section 351(k) of the PHS Act should submit up to ten proposed suffixes consisting of four lowercase letters in order of the applicant’s preference. Submissions can be made during the investigational new drug (IND) application phase, or at the time of BLA submission. The Agency recommends “including any supporting analyses of the proposed suffixes for FDA’s consideration based on the factors described in the Naming Guidance.”

Any applicant seeking a determination of interchangeability in a supplement to an approved 351(k) application will retain the product's nonproprietary name. The FDA-designated suffix will be retained as well, and additional proposed suffix requests are not required.

FDA is seeking comments on issues mentioned in the guidance, and based on the comments received, the Agency will revise the 2017 “Nonproprietary Naming of Biological Products” guidance, issuing a revised final version. The Agency is asking interested parties to submit written or electronic comments by May 7th, 2019.

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Are you in the process of developing a biosimilar or other FDA-regulated product?  We can help you obtain FDA approval.  For the last 35 years, we have been helping our clients achieve successful interactions with the FDA and have established a strong relationship with the Agency over the years.  We have the knowledge and experience you need to develop and submit a successful application.  Contact us today to learn more about our services and how we can help you.


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