The FDA has proposed to amend its regulation that defines “biological product” to incorporate changes made by the Biologics Price Competition and Innovation Act of 2009 (BPCI Act), and to provide its interpretation of the statutory terms “protein” and “chemically synthesized polypeptide.” Under that interpretation, the term protein would mean any alpha amino acid polymer with a specific, defined sequence that is greater than 40 amino acids in size. 

A chemically synthesized polypeptide would mean any alpha amino acid polymer that is made entirely by chemical synthesis and is greater than 40 amino acids but less than 100 amino acids in size. Formalizing these interpretations would reduce regulatory uncertainty over whether some products are regulated as drugs or biological products. This reduced uncertainty, under the “bright-line” approach described in the proposed rule, would allow both the FDA and private industry to avoid spending hours and resources on case-by-case determinations for each product.