The FDA has implemented a policy requiring distinguishable suffixes as part of the nonproprietary name of biologic medicines.1

For originator biologics, the FDA recommends using a “core name” that is designated by the United States Pharmacopeial Convention with a 4-letter suffix. For a biosimilar, the core name will be the same as the originator biologic, but with a different 4-letter suffix.1

This policy is designed to: 1) help accurately track adverse events; 2) facilitate appropriate targeting of remedial action, eg, to a specific product vs a whole class; 3) minimize risk of inadvertent substitution; and 4) promote accurate identification of products by patients and providers.1

References: 1. US Food and Drug Administration. Guidance for Industry: Nonproprietary Naming of Biological Products. Accessed January 10, 2019.