The FDA adopted the INN system in naming filgrastrim-sndz, with “sndz” signifying the agents manufacturer, Sandoz. The problem here is that identifying a biosimilar by its manufacturer may inadvertently stimulate an unhealthy competition for market share rather than a focus on what is best for patients. To improve biosimilar naming, the FDA sought public comment on 2 consultation documents published in August 2015, the Draft Guidance19 and Proposed Rule,20 the latter of which recommended adding an arbitrary unique 4-letter lower-case suffix to the agent’s generic name., For example, products sharing the core name replicamab may be displayed as replicamab-cznm and replicamab-hixf to respectively designate the biologic and its biosimilar.15 The FDA also invited suggestions for other naming approaches.
The FDA’s goals in regard to biosimilars include prevention of inadvertent substitution that may lead to medication errors from biologic agents that are not determined to be interchangeable, improvement of traceability, and establishment of a system to monitor and report adverse events (AEs) associated with biosimilars. Although the FDA is attempting to develop a standardized naming system for biosimilars, conflicting opinions and unanswered questions persist.21, 22 The arguments for and against use of the INN system, with designation of suffixes, arbitrary or otherwise, are compelling. Hanging in the balance are decisions that may influence perceived drug safety and how widely biologics are prescribed by physicians, dispensed by pharmacists, and recommended by pharmaceutical benefit managers, who are responsible for steering patients to the right product at the best price.
Proponents of a 4-letter suffix argue that biosimilars are not generics and should not be treated as such when choosing naming conventions. They also stress that knowing exactly what drug a patient has been prescribed and being able to properly track and report AEs are important. They additionally argue that clinical trials may not detect rare AEs or AEs that may occur after prolonged biosimilar use, which may differ from the reference biologic.16,23,24
Opponents of a 4-letter suffix, including representatives in the US Congress, argue that different names may create unnecessary confusion for doctors and patients. The confusion may possibly trigger medical errors and impede appropriate drug substitution, including drug substitution as a cost-saving measure, a strategy that generic-drugs figure into.14,16,22,25