FDA approves first biosimilar drug


Zarxio was approved based on its similarity to Neupogen

On March 6, FDA approved the first biosimilar product for U.S. patients, filgrastim-sndz (Zarxio—Sandoz). Approval was based on its similarity to filgrastim (Neupogen—Amgen), which has been used to prevent infections during chemotherapy and bone marrow transplants since 1991. 


“Physicians and patients can be confident that Zarxio should behave the same as Neupogen from a safety and efficacy standpoint,” said John Jenkins, MD, Director of the Office of New Drugs, Center for Drug Evaluation and Research at FDA, during a call with reporters. 



Biological products are generally derived from living organisms. They can come from many sources, including humans, animals, microorganisms, or yeast. The approval of Zarxio is in accordance with a unanimous FDA advisory panel vote earlier this year to recommend that the agency approve a biosimilar version of Neupogen. Biosimilar drugs have been available in Europe and other countries for several years. 


On the basis of structural and functional characterization, animal study data, human pharmacokinetic and pharmacodynamics data, clinical immunogenicity data, and other clinical safety and effectiveness data, FDA found no clinically meaningful differences between Zarxio and Neupogen, according to Jenkins. 


“We didn’t see differences that suggest a prescriber would have to choose one or the other based on concerns of safety or efficacy,” said Johnson. 


Lower cost


A choice could have to do with price, however. Zarxio was approved under the first application using the 351(k) biosimilar pathway, which was part of the Biologics Price Competition and Innovation Act of 2009 (BPCI Act) defined by the Affordable Care Act nearly 5 years ago. 


Jenkins said that one of the goals of the BPCI Act was to make more products available, and therefore create lower price points through competition. 


“Biological products tend to have very high prices, so with competition, one of the goals is to hopefully see lower prices” so that patients who need these products have better access to them, said Jenkins.


Avalere Health, the health care advisory company, issued comments after the announcement and said that the economic impact of biosimilar products in the United States will depend on many factors, including the methods by which substitution is allowed, physician views and adoption of new products, relative pricing decisions, and the posture of government programs.


Biosimilar vs. ‘interchangeable’


Jenkins made clear that biosimilar products are not “interchangeable” products, as determined by FDA—meaning they can’t be substituted at the pharmacy counter without the intervention of the health care provider.


However, the practice of pharmacy-level substitution is driven by state laws and overseen by state boards of pharmacy, according to Leah Christl, PhD, Associate Director for Therapeutic Biologics in the Office of New Drugs at the Center for Drug Evaluation and Research at FDA. 


During the question-and-answer session of the call, Christl confirmed that if a state’s law allowed for it, a pharmacist could call the prescriber and ask if he or she would consider prescribing Zarxio instead of Neupogen. 


What’s in a name?


The question of naming has been central to the discussion on biosimilar drugs. FDA said it has not yet decided on a naming approach. For the approval of Zarxio, FDA designated “filgrastim-sndz” as a placeholder nonproprietary name for the drug.


Jenkins said the provision of a placeholder nonproprietary name for Zarxio should not be viewed as reflective of the agency’s decision on a comprehensive naming policy for biosimilar and other biological products. While FDA has not yet issued draft guidance on how current and future biological products marketed in the United States should be named, the agency intends to do so in the near future. 


In June 2014, APhA, the National Association of Chain Drug Stores, and the National Community Pharmacists Association sent a joint letter to the World Health Organization in support of assigning the same individual nonproprietary name to a biosimilar product that is assigned to the reference biologic counterpart.


FDA has publicly disclosed that it has received four other biosimilar applications and expects more. All should generally follow the 10-month review clock. The agency also intends to issue draft guidance on biosimilar labeling this year.