What’s in a name?

Robust medication safety involves ensuring patients receive the medication they were prescribed, the ability to evaluate a patient’s response to a specific medicine, and the capability to monitor the patient for adverse events. It is important to be able to track the use of a prescribed medicine, identify any side effects that may occur, and accurately capture the medication in a patient’s medical record. This helps promote traceability of adverse events that might occur back to a specific medicine—a practice known as pharmacovigilance.1 A biologic’s distinguishable nonproprietary name can help support pharmacovigilance.

Pharmacovigilance is particularly important for biologics, including biosimilar and interchangeable products. These medicines involve complex manufacturing processes and thus require more distinct regulatory requirements.

Biosimilars, although highly similar to their reference products, are not identical to their reference products or to each other.2,3 The same holds true for interchangeable biosimilars. While a biosimilar designated as an interchangeable product can be expected to produce the same clinical result as the reference product in any given patient, the assessment made to support approval generally only establishes a comparison between the interchangeable biosimilar and the reference product, not between two different interchangeable products.4, Importantly, interchangeable products can be substituted for the reference product by a pharmacist without the intervention of the prescriber, per state pharmacy laws.4, For these reasons, it is imperative that the ability exists to clearly identify one product from another and to identify which was administered to the patient.

Distinguishable names allow prescribers, pharmacists, and patients to more readily identify, track, and document all of the biologic, biosimilar, and interchangeable products their patients receive.3, 4, 5, 7

Using the biological products naming convention developed by the U.S. Food and Drug Administration (FDA) is an important part of patient care and safety.6

FDA Naming Policy for Biologic Medicines

FDA issued guidance in January 2017 and March 2019 establishing a policy for distinguishable names for biologics.

Specifically, FDA intends to assign a distinguishable nonproprietary name to all new biological products (i.e., new originator products, new biosimilar products, and new interchangeable biosimilars). The distinguishable name will consist of a “core name” plus a unique suffix.

FDA is still assessing, however, its naming policy for vaccine products.

The use of a unique four-letter suffix reflects the need to clearly identify biological products to improve pharmacovigilance and promote safe use.6,7

The Suffix and Patient Safety

The proper use of the suffix along with the core name, to capture the full name of a biologic medicine, facilitates accurate dispensing of these products, clear identification in medical records, and helps adverse event data to be more rapidly associated with a specific medicine. Furthermore, a unique suffix promotes tracking and tracing of these medicines via post-marketing surveillance, which is crucial should adverse events necessitate identifying the medicine involved. 1, 8

Capturing the drug core name and unique suffix in all patient records when prescribing or dispensing biologics, including biosimilars and interchangeable products, promotes good patient care, adds an important layer of patient safety, and supports unique product identification and manufacturer accountability. 1

Examples of FDA Approach to Naming of Biologics

Core Name - Suffix Date of FDA Approval Product Information
Vestronidase alfa – vjbk November 2017 9 Prescribing Information
FDA Information
Tildrakizumab – asmn March 2018 10 Prescribing Information
FDA Information
Cemiplimab – rwlc September 2018 11 Prescribing Information
FDA Information
PrabotulinumtoxinA – xvfs February 2019 12 Prescribing Information
FDA Information

Additional Resources

To learn more about biosimilars and interchangeable products, please visit the following FDA resources:


  1. Mellstedt H, Niederwieser D, Ludwig H. The challenge of biosimilars. Ann Oncol. 2008;19:411-419.
  2. Camacho LH, Frost CP, Abella E, Morrow PK, Whittaker S. Biosimilars 101: considerations for U.S. oncologists in clinical practice. Cancer Medicine. 2014;3:889-899.
  3. U.S. Department of Health and Human Services. Scientific considerations in demonstrating biosimilarity to a reference product. Guidance for industry. http://www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation/guidances/ucm291128.pdf. Accessed April 11, 2019.
  4. U.S. Food and Drug Administration. Considerations in Demonstrating Interchangeability with a Reference Product. Draft Guidance for Industry. January 2017. https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM537135.pdf. Accessed April 11, 2019.
  5. Lybecker KM. The biologics revolution in the production of drugs. https://www.fraserinstitute.org/studies/biologics-revolution-in-the-production-of-drugs. Fraser Institute. Accessed April 11, 2019.
  6. U.S. Food and Drug Administration. Guidance for Industry: Nonproprietary naming of biological products. January 2017. Available at: http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM459987.pdf. Accessed April 11, 2019.
  7. U.S. Food and Drug Administration. Draft Guidance for Industry: Nonproprietary naming of biological products: Update. March 2019. Available at: https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM632806.pdf. Accessed April 11, 2019.
  8. Niederwieser D, Schmitz S. Biosimilar agents in oncology/haematology: from approval to practice. Eur J Haematol. 2011;86:277-288.
  9. U.S. Food and Drug Administration. FDA approves treatment. November 2017. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm585308.htm. Accessed April 11, 2019.
  10. Pharmacy Times. FDA Approves Treatment. March 2018. Available at: http://www.pharmacytimes.com/news/fda-approves-treatment-for-moderatetosevere-psoriasis. Accessed April 11, 2019.
  11. U.S. Food and Drug Administration. FDA approves first treatment for advanced form of the second most common skin cancer. September 2018. Available at: https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm622044.htm. Accessed April 11, 2019.
  12. Dermatology Advisor. Aesthetic-Only Neurotoxin Jeuveau Gets FDA Approval. February 2019 https://www.dermatologyadvisor.com/home/topics/aesthetic-medicine/aesthetic-only-neurotoxin-jeuveau-gets-fda-approval/. Accessed April 11, 2019.