What’s in a name?

A critical part of medication safety is being able to evaluate a patient’s response to a specific medicine, as well as being able to monitor the patient for adverse events. An important way this can be achieved is by tracking the use of a prescribed medicine, identifying any side effects that occur, and accurately capturing the name of the medication in a patient’s medical record. This allows the adverse event to be tracked back to a specific medicine. This practice is also known as pharmacovigilance.1

Pharmacovigilance is particularly important for biologics, including biosimilars. When it comes to biologic medicines, no two are identical the way a generic drug is an exact copy of its reference product. Biosimilars are highly similar to their reference products, though they may bear some minor differences that are not deemed clinically meaningful.2,3 However, since biologics are extremely sensitive to manufacturing and handling conditions, it is important that they bear distinguishable names – this allows doctors, pharmacists, and patients to tell them apart and allows for accurate identification of the product in a patient’s medical records.3, 4, 5

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.5

FDA Naming Policy for Biologic Medicines

In January 2017, the FDA issued its final naming policy for biologic medicines calling for distinguishable names for all biological products, so that all biological products bear an international nonproprietary name (INN) that includes a core name and a unique suffix.

This unique suffix reflects FDA’s thinking that there is a need to clearly identify biological products to improve pharmacovigilance, and, for the purposes of safe use, to clearly differentiate among biological products.5

The Suffix and Patient Safety

The proper use of the suffix with the core name to capture the full name of a biologic medicine facilitates accuracy in the medical record. For evaluating the effect of a drug among patient populations as a whole, a distinguishable suffix allows adverse event data to be immediately associated with a given drug name. Furthermore, a distinguishable suffix allows for tracking and tracing of these agents via post-marketing surveillance, which is crucial should adverse events necessitate identifying the origin of the drug. 1, 6

The extreme complexity and large molecular size of biologic medicines mean that even minor differences between two highly similar biologics can cause unexpected reactions in patients, including unwanted immune responses. Additionally, biologics are extremely sensitive to any changes in the manufacturing process, which has the potential to change how the medicine behaves in the body. 1, 2, 3

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

Examples of FDA Approach to Naming of Biologics

Core Name - Suffix Date of FDA Approval Product Information
Emicizumab – kxwh November 2017 7 Prescribing Information
FDA information
Vestronidase alfa – vjbk November 2017 8 Prescribing Information
FDA information
Ibalizumab – uiyk March 2018 9 Prescribing Information
FDA information
Tildrakizumab – asmn March 2018 10 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. US 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 November 23, 2016.
  4. 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 November 23, 2016.
  5. 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 February, 2018.
  6. Niederwieser D, Schmitz S. Biosimilar agents in oncology/haematology: from approval to practice. Eur J Haematol. 2011;86:277-288. U.S. Food and Drug Administration. Biosimilar Product Information. December 2017. Available at: https://www.fda.gov/Drugs/DevelopmentApprovalProcess/HowDrugsareDevelopedandApproved/ApprovalApplications/TherapeuticBiologicApplications/Biosimilars/
  7. U.S. Food and Drug Administration. FDA approves emicizumab-kxwh. November 2017. Available at: https://www.fda.gov/Drugs/InformationOnDrugs/ApprovedDrugs/ucm585650.htm. Accessed April 2018.
  8. U.S. Food and Drug Administration. FDA approves treatment. November 2017. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm585308.htm. Accessed April 2018.
  9. Healio. FDA approves Trogarzo. March 2018. Available at: https://www.healio.com/infectious-disease/hiv-aids/news/online/%7B2bd8c257-c4e2-41f8-af53-b4c12f992038%7D/fda-approves-trogarzo-for-mdr-hiv. Accessed April 2018.
  10. Pharmacy Times. FDA Approves Treatment. March 2018. Available at: http://www.pharmacytimes.com/news/fda-approves-treatment-for-moderatetosevere-psoriasis. Accessed April 2018.