ICHP Position Statement - Differentiating Nomenclature for Biosimilars

The Illinois Council of Health-System Pharmacists (ICHP) supports the position that biosimilar products be given the same root name following the standards for nonproprietary names established by the US Adopted Name Council and approved by the INN Expert Panel. Furthermore, ICHP supports the addition of suffixes (e.g., alpha, beta) to the INN name to distinguish among biosimilar products.


  1. “A biosimilar may not be exactly the same as the original biologic (reference) product because of differences in manufacturing.”1 The biosimilar product may have inactive ingredients, or have undergone a purification process different than the reference product.  Therefore, a biosimilar product should not be referred to using the same generic name as the reference product.2,3

  2. A unique generic name will facilitate effective tracking and tracing of biosimilars.  This is necessary since biosimilar products may have different safety profiles from each other and from the reference product.  An adverse effect may be molecule-specific, as opposed to a drug class effect.1

  3. A unique generic name is also necessary because biosimilar products may not be designated by the Food and Drug Administration (FDA) as interchangeable (that the biosimilar product has been tested and shown to produce the same clinical result as the reference product).1,2

  4. Some ways to differentiate among biosimilar products:
    A. Use a common root and a unique suffix.
    Example:  epoetin alpha, epoetin zeta, epoetin theta

    B. Refer to biosimilars by brand name.  This has been recommended by the World Health Organization and European Union.3

    Another way to distinguish among biosimilar products is to use a common root, a unique suffix, and a unique prefix.  The suffix and prefix designate unique molecular characteristics of the biosimilar product. However, ASHP has stated that “use of such prefixes is not recommended because it could introduce confusion and add unnecessary complexity to programming of information systems. In addition, substantial public health concerns already have arisen with Kadcyla as a result of this poor naming practice using prefixes.”4

  5. The FDA has not yet developed a standardized system on naming biosimilars, although it recognizes the importance of tracking individual biosimilar products.3,5  It has been recommended that the FDA consider three key factors when developing this nomenclature system:
    A.    Use a system that is systematic and predictable.
    B.    Consider structural relationships or classes when naming biosimilars
    C.    Assign unique, similar, or generic names to biosimilar products.5

Relevant Positions of ASHP on Biosimilar Products

  1. “ASHP supports legislation and regulation that would authorize the FDA to determine the interchangeability of biosimilars, thus permitting the substitution of biosimilars for the reference product without the intervention of the prescriber.  Further, ASHP opposes the implementation of any state laws regarding biosimilar interchangeability prior to finalization of FDA guidance.”6
  2. ASHP supports “a legislative and regulatory pathway for biosimilars in the U.S. and encourages the development of safe and effective biosimilar medications in order to make such medications more affordable and accessible to patients.”4
  3. ASHP has taken the position that “Grouping products by active ingredient that is conceptually equivalent provides a uniform, predictable, and effective way for healthcare professionals to identify drugs….the current U.S. standard nomenclature for naming clinical drug concepts, the National Library of Medicine’s RxNorm, uses common root names among other things to normalize group products that conceptually are equivalent.  This terminology is critical in supporting semantic interoperability among drug terminologies and pharmacy knowledge base systems, allowing computer systems to communicate drug-related information efficiently and unambiguously….ASHP recommends that it is essential that biosimilars be given the same root name following standards for nonproprietary names established by the US Adopted Name Council and approved by the INN Expert Panel….we do not oppose the addition of suffixes (e.g., alpha, beta) to the INN name….”4


1.    Casadevall N, Edwards IR, Felix T, Graze PR, Litten JB, Strober BE, et al.  Pharmacovigilance and biosimilars:  considerations, needs, and challenges.  Expert Opin Biol Ther 2013;13(7):1039-1047.
2.    Tkaczuk KHR, Jacobs IA.  Biosimilars in oncology:  from development to clinical practice.  Semin Oncol 2014;41:S3-S12.
3.    Niederwieser D, Schmitz S.  Biosimilar agents in oncology/haematology:  from approval to practice.  Eur J Haematol 2011;86:277-278.
4.    Topeleski CJ, Director ASHP Regulatory Affairs.   Letter to Federal Trade Commission, 2/27/2014.
5.    Choy E, Jacobs Ia.  Biosimilar safety considerations in clinical practice.  Semin Oncol 2014;41:S3-S14.
6.    Pawlicki KG.  Board of Directors Report on the Council on Pharmacy Management, ASHP House of Delegates 2014, June 1-3, 2014.

Approved 10/2015

Revised 1/2018