TOPIC SERIES: BIOSIMILAR DRUGS

Two key challenges will face the United States healthcare system in the coming decade: a spiraling up of healthcare costs and patent expirations of many established biologic agents that are increasingly being used as the standard of care in the management of many chronic diseases, including autoimmune diseases such as rheumatoid arthritis (RA).1 To create market competition beyond patent expiration while lowering healthcare costs, the Biologics Price Competition and Innovation Act (BPCIA) of 2009 provided an abbreviated pathway to regulatory approval of biosimilars, which are copies of brand-name biologics manufactured according to the stringent standards set by the US Food and Drug Administration (FDA).2-4

Biosimilars must demonstrate no clinically meaningful differences in safety, purity, and potency compared with the reference biologic agent.5-7 Although the European Union has brought 19 biosimilar products to market since 2005,8 the FDA has been slow in providing the regulatory guidance needed for submitting applications for biosimilar approval, even though the Patient Protection and Affordable Care Act ,an amendment to the BPCIA that gave the FDA authority to approve biosimilars, was signed into law in 2010.9 

The first biosimilar, filgrastim-sndz (Zarxio) was approved in the United States in March 2015.10 Several other biosimilars will join the queue for FDA approval. Among them is CT-P13, a biosimiliar of infliximab. Under the trade name of Remsima, it is the first antitumor necrosis factor biosimilar approved by the European Medicines Agency for the treatment of RA.11, 12 The approval occurred in September 2013.

As the pathway for regulatory approval is refined, a key challenge for the FDA is naming biosimilars to ensure their safe use and foster acceptance by all key stakeholders. This challenge is sparking intense debate across the United States because a lot is at stake, with implications for drug interchangeability substitution, pharmacovigilance,  physician prescriptions, and potential patient biases.13-16

The debate appears evenly split between opponents and proponents of a naming convention that adopts the World Health Organization (WHO) International Nonproprietary Names (INN) system, which is the global standard for naming pharmaceutical products. The INN system names the active ingredient such that the branded drug and the generic version share the same name.8,17 The INN system has been proposed for the naming of biosimilars; however, in recognition of the complexity of biologic agents, the WHO recommended adding a 4-letter code, or “biological qualifier,” to the INN to establish a more robust system for distinguishing biosimilars from other biologics.8,18