The FDA recently issued a final rule regarding the definition of “biological product,” amending its previous definition.  The statutory definition of “biological product” included “protein (except any chemically synthesized polypeptide),” but this past December Congress removed the parenthetical excluding “any chemically synthesized polypeptide.”  Now, the FDA has announced that it interprets the word “protein” to mean “any alpha amino acid polymer with a specific defined sequence that is greater than 40 amino acids in size.”  The FDA states that this new interpretation “will reduce regulatory uncertainty” by adopting a “‘bright-line’ approach” that “will reduce the amount of time spent by FDA staff and industry” in determining whether a product is a biological product.