Some interesting new regulatory tea leaves in the debate over biosimilar nomenclature.According to the USP, if Sandoz’s biosimilar (Zarxio – or filgrastim-sndz) meets the filgrastim monograph, it should carry the same nonproprietary name as Neupogen. But the FDA says it’s already determined the monograph does not apply. According to Dr. John Jenkins, director of FDA's Office of New Drugs the naming of this particular drug does not necessarily mean this will become the general policy for naming biosimilars.
An important point to remember is that the USP is not responsible for testing and enforcement of its standards, including comparing products to existing monographs. That’s an FDA responsibility.
While the FDA agrees that the USP has a role “regarding the nonproprietary names of drugs in certain circumstances,” they do not believe that the nonproprietary names FDA assigns for drugs and biologics are temporary until the USP reached a decision.
On March 18 (just under two weeks after the FDA approved Zarxio) USP issued a statement to the effect that it had “just begun a dialog with FDA regarding Zarxio and it is too early to comment further.”
So watch the regualtory fur fly and keep those tea leaves steeping.