On March 6, 2015, the U.S. Food and Drug Administration (FDA) approved the first biosimilar product under the Biologics Price Competition and Innovation Act (BPCIA), which created an abbreviated licensure pathway for biological products that can demonstrate that they are “highly similar” to an already-approved biological product.  Sandoz Inc.’s Zarxio (filgrastim-sndz) is biosimilar to Amgen Inc.’s Neupogen and is approved for the same indications for patients with cancer and other conditions.  In order to obtain this approval, Sandoz demonstrated that there are no clinically meaningful differences in terms of safety and effectiveness between Zarxio and Neupogen.  However, the products are not interchangeable, and Zarxio may not be substituted for Neupogen without involvement of the prescriber.

Zarxio’s approval was based on structural and functional characterization, animal study data, human pharmacokinetic and pharmacodynamics data, clinical immunogenicity data and other clinical safety and effectiveness data that demonstrates Zarxio is biosimilar to Neupogen.  The biosimilar product must have the same mechanism(s) of action, route(s) of administration, dosage form(s) and strength(s), indication(s) and condition(s) of use that have been approved for the reference product.  The abbreviated licensure pathway under the BPCIA is the first to permit reliance on existing scientific knowledge about the safety and effectiveness of a reference biological product enabling approval of a product based on abbreviated product-specific and clinical data.

FDA has not yet determined a comprehensive naming policy for biosimilar and biological products; therefore, the nonproprietary name for this product, “filgrastim-sndz” is a placeholder.  FDA intends to issue guidance on biosimilar naming in the future.  Significantly, FDA appears also to have decided two contentious issues: it will not require disclosure of the biosimilar application to the pioneer, thus short-circuiting the patent exchange procedures and first wave of infringement litigation; and it will allow biosimilar applicants to provide 180 days advanced notice of commercial marketing prior to biosimilar licensing.