Nonproprietary Naming  
of Biological Products 
 
Guidance for Industry 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
Center for Biologics Evaluation and Research (CBER) 
 
 
January 2017 
Labeling 
 
 
OMB control number XXXX-XXXX 
Expiration Date:  xx/xx/xxxx 
 
The information collection provisions in this guidance regarding submission of proposed 
suffixes are under OMB review and are not for current implementation. 
See additional PRA statement in section VII of this guidance. 
 
 
   
Nonproprietary Naming  
of Biological Products 
 
Guidance for Industry 
 
 
Additional copies are available from: 
 
Office of Communications, Division of Drug Information  
Center for Drug Evaluation and Research 
Food and Drug Administration 
10001 New Hampshire Ave., Hillandale Bldg., 4th Floor  
Silver Spring, MD 20993-0002 
Phone: 855-543-3784 or 301-796-3400; Fax: 301-431-6353 
Email: druginfo@fda.hhs.gov  
http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm 
 
and/or 
 
Office of Communication, Outreach and Development  
Center for Biologics Evaluation and Research 
 Food and Drug Administration 
10903 New Hampshire Ave., Bldg. 71, Room 3128 
Silver Spring, MD 20993-0002 
Phone: 800-835-4709 or 240-402-8010 
Email: ocod@fda.hhs.gov 
http://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guidances/default.htm    
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
Center for Biologics Evaluation and Research (CBER) 
 
January 2017 
Labeling 
 
 
  Contains Nonbinding Recommendations 
TABLE OF CONTENTS 
 
 
I.  INTRODUCTION............................................................................................................. 1 
II.  SCOPE ............................................................................................................................... 2 
III.  BACKGROUND ............................................................................................................... 3 
A.  The Biologics Price Competition and Innovation Act of 2009 ................................................... 3 
B.  Evaluation of the Appropriate Naming Convention ................................................................... 3 
IV.  CONSIDERATIONS FOR NONPROPRIETARY NAMING OF ORIGINATOR 
BIOLOGICAL PRODUCTS, RELATED BIOLOGICAL PRODUCTS, AND 
BIOSIMILAR PRODUCTS ......................................................................................................... 4 
A.  Enhancing Biological Product Pharmacovigilance ..................................................................... 4 
B.  Ensuring Safe Use for Biological Products .................................................................................. 5 
C.  Advancing Appropriate Practices and Perceptions Regarding Biological Products ............... 6 
D.  Prospective and Retrospective Application of Naming Convention .......................................... 7 
V.  FRAMEWORK FOR DESIGNATING THE PROPER NAME OF A 
BIOLOGICAL PRODUCT.......................................................................................................... 7 
A.  Prospective Naming of Biological Products Submitted Under Section 351(a)  
of the PHS Act ......................................................................................................................................... 9 
B.  Retrospective Naming of Biological Products Licensed Under Section 351(a)  
of the PHS Act ......................................................................................................................................... 9 
C.  Naming of Biosimilar Products Submitted Under Section 351(k) of the PHS Act .................. 9 
VI.  PROPOSING A SUFFIX FOR THE PROPER NAME OF AN ORIGINATOR 
BIOLOGICAL PRODUCT, A RELATED BIOLOGICAL PRODUCT, OR A 
BIOSIMILAR PRODUCT ......................................................................................................... 10 
VII.  PAPERWORK REDUCTION ACT OF 1995 .............................................................. 11 
GLOSSARY................................................................................................................................. 12 
i  Contains Nonbinding Recommendations 
Nonproprietary Naming of Biological Products 
 
1
Guidance for Industry  
 
 
This guidance represents the current thinking of the Food and Drug Administration (FDA or Agency) on 
this topic.  It does not establish any rights for any person and is not binding on FDA or the public.  You 
can use an alternative approach if it satisfies the requirements of the applicable statutes and regulations.  
To discuss an alternative approach, contact the FDA office responsible for this guidance as listed on the 
title page.  
 
 
 
I.  INTRODUCTION  
 
This guidance describes FDAs current thinking on the need for biological products licensed 
under the Public Health Service Act (PHS Act) to bear a nonproprietary name2 that includes an 
FDA-designated suffix.  Under this naming convention, the nonproprietary name designated for 
each originator biological product, related biological product, and biosimilar product will be a 
proper name that is a combination of the core name and a distinguishing suffix that is devoid of 
meaning and composed of four lowercase letters.3  The suffix format described in this guidance 
is applicable to originator biological products, related biological products, and biosimilar 
products previously licensed and newly licensed under section 351(a) or 351(k) of the PHS Act.  
FDA is continuing to consider the appropriate suffix format for interchangeable products.   
 
This naming convention will facilitate pharmacovigilance for originator biological products, 
related biological products, and biosimilar products containing related drug substances when 
other means to track a specific dispensed product are not readily accessible or available, as 
described in section IV.A of this guidance.  Distinguishable nonproprietary names will also 
facilitate accurate identification of these biological products by health care practitioners and 
patients.  Further, distinguishing suffixes should help minimize inadvertent substitution of any 
such products that have not been determined to be interchangeable.  Application of the naming 
convention to biological products licensed under the PHS Act should (1) encourage routine use 
of designated suffixes in ordering, prescribing, dispensing, recordkeeping, and 
pharmacovigilance practices and (2) avoid inaccurate perceptions of the safety and effectiveness 
of biological products based on their licensure pathway, as described in detail in this guidance.  
                                                 
1 This guidance has been prepared by the Office of Medical Policy in the Center for Drug Evaluation and Research 
in cooperation with the Center for Biologics Evaluation and Research at the Food and Drug Administration. 
  
2 See the Glossary for definitions and usage of specific terms used throughout this guidance. 
 
3 The nonproprietary name designated by FDA in the license for a biological product licensed under the PHS Act is 
its proper name (section 351(a)(1)(B)(i) of the PHS Act (42 U.S.C. 262(a)(1)(B)(i)) and  600.3(k) (21 CFR 
600.3(k)). 
 
  1  Contains Nonbinding Recommendations 
 
This guidance provides information to industry, the health care community, other regulatory 
agencies, and the public on FDAs rationale for this naming convention.  It is also intended to 
assist applicants and license holders in proposing the suffix to be incorporated in the 
nonproprietary name (referred to throughout this guidance as the proper name) for an originator 
biological product, a related biological product, or a biosimilar product. 
 
In general, FDAs guidance documents do not establish legally enforceable responsibilities.  
Instead, guidances describe the Agencys current thinking on a topic and should be viewed only 
as recommendations, unless specific regulatory or statutory requirements are cited.  The use of 
the word should in Agency guidances means that something is suggested or recommended, but 
not required.  
 
 
II.  SCOPE 
 
This guidance describes FDAs approach to designating the proper name for originator and 
related biological products licensed under section 351(a) of the PHS Act and for biosimilar 
products licensed under section 351(k) of the PHS Act.  FDA intends to apply a naming 
convention to interchangeable products that will feature a core name and a suffix included in the 
proper name; however, FDA is continuing to consider the appropriate format of the suffix for 
these products.  FDA intends to apply the naming convention discussed in this guidance to both 
newly licensed and previously licensed biological products.  As discussed further in section V of 
this guidance, the revised proper name of biological products previously licensed under the PHS 
Act generally would include the products original proper name serving as the core name plus 
the distinguishing suffix attached with a hyphen.  FDA is continuing to consider the process for 
implementation of this naming convention for previously licensed products but, in the near term, 
intends to assign distinguishing suffixes to a limited group of these products4 and also will 
accept submissions of prior approval labeling supplements that include proposed suffixes. 
 
This guidance also will apply to those biological products that are approved under the Federal 
Food, Drug, and Cosmetic Act (FD&C Act) on or before March 23, 2020, when such products 
are deemed to be licensed under section 351 of the PHS Act on March 23, 2020 (section 
7002(e)(2) through (e)(4) of the Biologics Price Competition and Innovation Act of 2009 (BPCI 
Act)). 5  FDA intends to provide additional guidance regarding administrative issues associated 
with the transition (including the process for implementing the naming convention described in 
this guidance).   
 
                                                 
4 The Agency published a proposed rule in the Federal Register of August 28, 2015 (80 FR 52224) (Designation of 
Official Names and Proper Names for Certain Biological Products).   
 
5 See the draft guidance for industry Implementation of the Deemed to be a License Provision of the Biologics 
Price Competition and Innovation Act of 2009.  When final, this guidance will represent FDAs current thinking on 
this topic.  For the most recent version of a guidance, check the FDA Drugs guidance Web page at 
http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm. 
  2  Contains Nonbinding Recommendations 
For the purposes of this document, unless otherwise specified, references to biological products 
include biological products licensed under the PHS Act, such as therapeutic protein products, 
vaccines, allergenic products, and blood derivatives, and do not include certain biological 
products that also meet the definition of a device in section 201(h) of the FD&C Act (21 U.S.C. 
321(h)), such as in vitro reagents (e.g., antibody to hepatitis B surface antigen, blood grouping 
reagents, hepatitis C virus encoded antigen) and blood donor screening tests (e.g., HIV and 
hepatitis C).  Also, for the purposes of this document, unless otherwise specified, references to 
biological products do not include products for which a proper name is provided in the 
regulations (e.g., 21 CFR part 640) or to certain categories of biological products for which there 
are well-established, robust identification and tracking systems to ensure safe dispensing 
practices and optimal pharmacovigilance (e.g., ISBT 128 for cord blood products and blood 
components).  
 
 
III.  BACKGROUND 
 
A.  The Biologics Price Competition and Innovation Act of 2009 
 
With the passage of the BPCI Act,6 which established an abbreviated licensure pathway for 
products demonstrated to be biosimilar to or interchangeable with an FDA-licensed reference 
product, a growing number of biological products will be entering the marketplace. 
 
Section 351(k) of the PHS Act (42 U.S.C. 262(k)), added by the BPCI Act, sets forth the 
requirements for an application for a proposed biosimilar product and an application or a 
supplement for a proposed interchangeable product.  Section 351(i) defines biosimilarity to mean 
that the biological product is highly similar to the reference product notwithstanding minor 
differences in clinically inactive components and that there are no clinically meaningful 
differences between the biological product and the reference product in terms of the safety, 
purity, and potency of the product (see section 351(i)(2) of the PHS Act).  To meet the 
additional standard of interchangeability, an applicant must provide sufficient information to 
demonstrate biosimilarity and also to demonstrate that the biological product can be expected to 
produce the same clinical result as the reference product in any given patient and, if the 
biological product is administered more than once to an individual, the risk in terms of safety or 
diminished efficacy of alternating or switching between the use of the biological product and the 
reference product is not greater than the risk of using the reference product without such 
alternation or switch (see section 351(k)(4) of the PHS Act).  Interchangeable products may be 
substituted for the reference product without the intervention of the prescribing health care 
provider (see section 351(i)(3) of the PHS Act).   
 
B.  Evaluation of the Appropriate Naming Convention 
 
The proper name of a biological product reflects certain scientific characteristics of the product, 
such as chemical structure and pharmacological properties.  This name is different from a 
                                                 
6 Sections 7001 through 7003 of the Patient Protection and Affordable Care Act (Public Law 111-148).   
 
  3  Contains Nonbinding Recommendations 
proprietary name, which generally is trademarked and registered for private use.  For biological 
products licensed under the PHS Act, FDA designates the proper name in the license for use 
upon each package of the biological product (see section 351(a)(1)(B)(i) of the PHS Act and 
21 CFR 600.3(k)).  Among other things, the proper name of a biological product helps health 
care providers identify the products drug substance and distinguish biological products from one 
another.   
 
As part of FDAs implementation of the BPCI Act, the Agency requested public comment on its 
development of a framework for safe use and optimal pharmacovigilance for biosimilar products 
and interchangeable products that is informed by current experience and industry best practices, 
including the role of a products proper name.   
 
FDA has evaluated comments received on the approaches to naming biosimilar products and 
interchangeable products.7  In light of the issues considered for biosimilar products and 
interchangeable products, FDA also evaluated its approach to designating proper names for 
biological products licensed under section 351(a) of the PHS Act.   
 
In implementing the BPCI Act, FDA has carefully considered the appropriate naming convention 
to maximize the success of biosimilar products and interchangeable products and to help ensure 
the safety of patients receiving biological products licensed under the PHS Act.   
 
 
IV.  CONSIDERATIONS FOR NONPROPRIETARY NAMING OF ORIGINATOR 
BIOLOGICAL PRODUCTS, RELATED BIOLOGICAL PRODUCTS, AND 
BIOSIMILAR PRODUCTS 
 
This section discusses the main considerations that led FDA to adopt the naming convention 
described in section V of this guidance.   
 
A.  Enhancing Biological Product Pharmacovigilance 
 
The Agency considers appropriate pharmacovigilance fundamentally important for biological 
products.  Although safety of biological products is rigorously assessed before approval, safety 
issues that are specific to a manufacturer may arise after approval with any marketed product.  
To help ensure patient safety and allow the Agency and the manufacturer to swiftly identify and 
address a problem, FDA aims to track adverse events to a specific manufacturer (and as 
appropriate, to a lot or manufacturing site for a particular biological product) and allow 
surveillance systems to detect safety signals throughout the life cycle of a product.  Identifying a 
biological products manufacturer can help target remedial action (including recall) to avoid 
implicating a broader set of products for which no such problem exists.   
                                                 
7 See, for example, notices that published in the Federal Register, Approval Pathway for Biosimilar and 
Interchangeable Biological Products; Public Hearing; Request for Comments (75 FR 61497, October 5, 2010); 
Draft Guidances Relating to the Development of Biosimilar Products; Public Hearing; Request for Comments 
(77 FR 12853, March 2, 2012); Nonproprietary Naming of Biological Products; Draft Guidance for Industry; 
Availability (80 FR 52296, August 28, 2015); and other public dockets established by FDA. 
 
  4  Contains Nonbinding Recommendations 
 
Pharmacovigilance systems, both active and passive, vary in their use of identifiers to 
differentiate among biological products.  These identifiers may include the proprietary name, 
proper name, manufacturer, national drug code (NDC) number, lot number, and billing codes.  
However, many active pharmacovigilance systems, which generally identify adverse events by 
querying privately held electronic health care data such as administrative and billing data, have 
limited ability to track to its manufacturer a biological product that shares the same proper name 
with other biological products.  Other product identifiers, such as NDC numbers, are not 
routinely recorded in billing and patient records in many clinical settings in which biological 
products are dispensed and administered, and therefore the utility of these alternative identifiers 
in active pharmacovigilance is limited.  Similarly, proprietary names and NDC numbers are 
often not included in adverse event reports.  As a result, the use of alternative identifiers, 
including distinct proprietary names or NDC numbers, is insufficient to address concerns 
regarding pharmacovigilance.   
 
Nonproprietary names that include distinguishing suffixes can serve as a key element to identify 
specific products in spontaneous adverse event reporting and to reinforce accurate product 
identification in billing and claims records used for active pharmacovigilance.  Other product-
specific identifiers, such as proprietary names or NDCs, may not be available or could change 
over time.  A distinguishing suffix will also support the tracking of product-specific events over 
time, thereby enhancing the accurate attribution of product-specific adverse event reports.8   
 
The Agencys approach to nonproprietary naming of biological products will provide another 
critical tool for accurately identifying and facilitating pharmacovigilance for originator biological 
products, related biological products, and biosimilar products.  
 
B.  Ensuring Safe Use for Biological Products 
 
Biological products generally consist of large, complex molecules and raise unique safety 
concerns related to immunogenicity.  FDA believes the nonproprietary naming convention for 
originator biological products, related biological products, or biosimilar products should help 
prevent inadvertent substitution.  Inadvertent substitution may lead to unintended alternating or 
switching of biological products that are not determined by FDA to be interchangeable with each 
other.  This naming convention should facilitate safe use and help to protect the safety of 
patients.   
 
Related biological products may be licensed for different indications.  Biosimilar products may 
be licensed for fewer than all indications for which the reference product is licensed.  Likewise, 
related biological products and biosimilar products may be licensed for fewer than all routes of 
administration and may be packaged in different delivery systems than those approved for the  
 
                                                 
8See the draft guidance for industry Postmarketing Safety Reporting for Human Drugs and Biological Products 
Including Vaccines.  When final, this guidance will represent FDAs current thinking on this topic.   
 
  5  Contains Nonbinding Recommendations 
originator biological product.  If originator biological products, related biological products, and 
biosimilar products all share the same proper name, inadvertent substitution may lead to 
medication errors.  For example, a patient could inadvertently receive a product with a different 
delivery system or route of administration than was prescribed, which may lead to confusion 
among patients and result in dosing errors.   
 
Confusion may also arise among health care providers who, based on their experience with 
small-molecule drugs and generic versions of those drugs, may incorrectly assume that FDA has 
determined biological products with the same proper name to be interchangeable.  Information 
on alternating or switching between a proposed product and its reference product is required to 
support a demonstration of interchangeability, but is not required to support a demonstration of 
biosimilarity (see section 351(k)(4) of the PHS Act).  Applications for related biological products 
are not required to include any comparative data to any other biological product in support of 
licensure (see section 351(a) of the PHS Act).  Although many biological products may have 
proprietary names, many health care systems mainly use proper names instead of proprietary 
names for ordering, prescribing, and dispensing products. 
 
The naming convention discussed in this guidance will also facilitate use of the Purple Book9 for 
biological products.  The Purple Book enables a user to readily see all licensed biological 
products and identify whether a biological product licensed under section 351(k) of the PHS Act 
has been determined by FDA to be biosimilar to or interchangeable with a reference product (a 
previously licensed biological product).  Biosimilar products and interchangeable products 
licensed under section 351(k) of the PHS Act will be listed under the reference product to which 
biosimilarity or interchangeability was demonstrated. 
 
C.  Advancing Appropriate Practices and Perceptions Regarding Biological 
Products 
 
With the introduction of more biological products, FDA believes it is important to encourage 
routine use of designated suffixes in ordering, prescribing, dispensing, recordkeeping, and 
pharmacovigilance practices for biological products, irrespective of their licensure pathway and 
date of licensure.  The designated suffix will provide a consistent, readily available and 
recognizable mechanism for patients and health care professionals, including providers and 
pharmacists, to correctly identify these products.  FDA believes it is likely that FDA-designated 
suffixes will be used routinely when identifying, describing, and recording use of biological 
products if such suffixes are present in the proper names of all biological products licensed under 
the PHS Act. 
 
                                                 
9 FDA published the Purple Book: Lists of Licensed Biological Products With Reference Product Exclusivity and 
Biosimilarity or Interchangeability Evaluations in September 2014, which is publicly available at 
http://www.fda.gov/drugs/developmentapprovalprocess/howdrugsaredevelopedandapproved/approvalapplications/th
erapeuticbiologicapplications/biosimilars/ucm411418.htm.  The Purple Book is updated periodically to reflect FDA 
licensure of a biological product under section 351(a) or section 351(k) of the PHS Act and/or to reflect a 
determination regarding date of first licensure for a biological product licensed under section 351(a) of the PHS Act. 
  6  Contains Nonbinding Recommendations 
The inclusion of an FDA-designated suffix in the nonproprietary name of biological products 
licensed under section 351(a) or 351(k) of the PHS Act should have the added benefit of helping 
to avoid inaccurate perceptions of the safety and effectiveness of biological products based on 
their licensure pathway.  The safety and effectiveness of biological products is rigorously 
assessed before approval.  Through FDAs implementation of the BPCI Acts standards for 
biosimilarity and interchangeability, FDA can ensure that the products it determines to be 
biosimilar to or interchangeable with a reference product can be relied upon by providers and 
patients to be safe and effective.  Applying this naming convention only for products licensed 
under section 351(k) of the PHS Actbut not for the reference product licensed under 351(a) of 
the PHS Actcould adversely affect health care provider and patient perceptions of these new 
products.  Specifically, such an approach could be misinterpreted as indicating that biosimilar 
products differ from their reference products in a clinically meaningful way or are inferior to 
their reference products for their approved conditions of use.     
 
D.  Prospective and Retrospective Application of Naming Convention 
 
FDAs current thinking is that a proper name that includes a distinguishing suffix is warranted 
for both newly licensed and previously licensed originator biological products, related biological 
products, and biosimilar products.  As with prospective application of the naming convention, 
retrospective application will help (1) prevent a patient from receiving a product different from 
what was intended to be prescribed; (2) facilitate manufacturer-specific pharmacovigilance by 
providing a means of determining which biological product is dispensed to patients; 
(3) encourage routine use of FDA-designated suffixes in ordering, prescribing, dispensing, and 
recordkeeping practices for these products; and (4) advance accurate perceptions of these 
biological products. 
 
 
V.  FRAMEWORK FOR DESIGNATING THE PROPER NAME OF A 
BIOLOGICAL PRODUCT 
 
FDAs naming convention for biological products licensed under the PHS Act will be a proper 
name consisting of a core name10 and an FDA-designated suffix.  Proper names designated by 
FDA for originator biological products, related biological products, and biosimilar products will 
include a combination of a core name and a distinguishing suffix.     
 
For originator biological products, FDA intends to use a core name that is the adopted name 
designated by the USAN Council11 for the relevant biological substance when available.  If the 
biological product is a related biological product, a biosimilar product, or an interchangeable 
                                                 
10 Two examples of a core name are filgrastim and epoetin alfa.  The proper name for all biological products will 
include a distinguishing suffix composed of four lowercase letters attached to the core name with a hyphen. 
 
11 The United States Pharmacopeial Convention, 2016, Guiding Principles for Coining United States Adopted 
Names for Drugs (2016 USP Dictionary of USAN and International Drug Names at 
http://www.uspusan.com/usan/pub/index1.html).   
 
  7  Contains Nonbinding Recommendations 
product, the core name will be the same as the core name identified in the proper name of the 
relevant previously licensed product.12  A distinguishing suffix that is devoid of meaning and 
composed of four lowercase letters will be attached with a hyphen to the core name of each 
originator biological product, related biological product, or biosimilar product.13  Use of a shared 
core name will indicate a relationship among products.  The placement of the identifier as a 
suffix, rather than a prefix, should result in biological products with the same core name being 
grouped together in electronic databases to help health care providers locate and identify these 
products.14  
 
To illustrate, the proper names for products sharing the core name replicamab may be displayed 
as follows: 
 
replicamab-cznm 
replicamab-hjxf  
 
To illustrate, the proper names for products sharing the core name putonastim alfa may be 
displayed as follows: 
 
putonastim alfa-jnzt 
putonastim alfa-kngx 
 
In designating proper names for related biological products, the Agency has in some instances 
designated a proper name that includes an identifier attached as a prefix to distinguish the 
products from previously licensed biological products; for example, ado-trastuzumab emtansine.  
In this case, designation of a proper name that includes a unique prefix was necessary to 
minimize certain medication errors and to facilitate pharmacovigilance.  FDA determined that a 
unique proper name including a prefix was necessary for ado-trastuzumab emtansine to 
distinguish the product from trastuzumab, a previously licensed biological product submitted in a 
different BLA.15  FDA may continue such practices on a limited basis, where appropriate, when 
the Agency determines that the designation of a prefix, in addition to a suffix as contemplated by 
this guidance, is necessary to ensure patient safety.  
                                                 
12 FDA will work with stakeholders that play a role in national drug naming and listing to help ensure that the 
suffixes added to the core name of biological products are recorded appropriately in drug listing systems. 
 
13 FDA determined that a hyphen should separate the shared core name from the suffix.  A hyphen is a common 
punctuation mark used in writing and electronic systems; it is a readily recognized mark.  Another punctuation mark, 
such as an underscore, may not be normally used in handwriting and may not be readily seen in handwriting, 
electronic systems, or both.  
 
14 The license holder and all distributors of a biological product should use the proper name designated by FDA in 
the license for that product. 
 
15 As described in the BLA submission for ado-trastuzumab emtansine, medication errors involving administration 
of the wrong drug (trastuzumab emtansine versus trastuzumab) during clinical trials resulted in serious adverse 
events.   
 
  8  Contains Nonbinding Recommendations 
 
 
A.  Prospective Naming of Biological Products Submitted Under Section 351(a) 
of the PHS Act 
 
An applicant should propose a suffix composed of four lowercase letters for use as the 
distinguishing identifier included in the proper name designated by FDA at the time of licensure 
(see section VI of this guidance).  Such submissions can be made during the investigational new 
drug application (IND) phase16 or at the time of BLA submission.  An applicant should submit 
up to 10 proposed suffixes, as described in this section, in the order of the applicants preference.  
We recommend including any supporting analyses of the proposed suffixes for FDAs 
consideration based on the factors described in this guidance.   
 
B.  Retrospective Naming of Biological Products Licensed Under Section 351(a) 
of the PHS Act 
 
A BLA holder may propose a suffix, as described in this guidance, for use in the proper name of 
currently licensed biological products held by the company by submitting a prior-approval 
labeling supplement to its BLA  (see section VI of this guidance).  As part of that labeling 
supplement, a BLA holder should submit up to 10 proposed suffixes, as described in this section, 
in the order of the applicants preference.  We recommend including any supporting analyses of 
the proposed suffixes for FDAs consideration based on the factors described in this guidance. 
 
C.  Naming of Biosimilar Products Submitted Under Section 351(k) of the PHS 
Act 
 
An applicant for a proposed biosimilar product submitted under section 351(k) of the PHS Act 
should propose a suffix composed of four lowercase letters for use as the distinguishing identifier 
included in the proper name designated by FDA at the time of licensure (see section VI of this 
guidance).  Such submissions can be made during the investigational new drug application (IND) 
phase17 or at the time of BLA submission.  An applicant should submit up to 10 proposed 
suffixes, as described in this section, in the order of the applicants preference.  We recommend 
including any supporting analyses of the proposed suffixes for FDAs consideration based on the 
factors described in this guidance.   
 
 
                                                 
16 A request for FDA review of a proposed suffix submitted during the investigational new drug application (IND) 
phase should be submitted no earlier than at the request for a pre-biologics license application (pre-BLA) meeting 
for biological products to be submitted under section 351(a) of the PHS Act. 
  
17 A request for FDA review of a proposed suffix submitted during the investigational new drug application (IND) 
phase should be submitted no earlier than at the request for a biosimilar biological product development (BPD) 
type 4 meeting for biological products to be submitted under section 351(k) of the PHS Act. 
  9  Contains Nonbinding Recommendations 
VI.  PROPOSING A SUFFIX FOR THE PROPER NAME OF AN ORIGINATOR 
BIOLOGICAL PRODUCT, A RELATED BIOLOGICAL PRODUCT, OR A 
BIOSIMILAR PRODUCT 
 
The proposed suffix should: 
 
  Be unique  
 
  Be devoid of meaning 
 
  Be four lowercase letters of which at least three are distinct 
 
  Be nonproprietary 
 
  Be attached to the core name with a hyphen 
 
  Be free of legal barriers that would restrict its usage 
 
The proposed suffix should not: 
 
  Be false or misleading, such as by making misrepresentations with respect to safety or 
efficacy 
 
  Include numerals and other symbols aside from the hyphen attaching the suffix to the 
core name 
 
  Include abbreviations commonly used in clinical practice in a manner that may lead the 
suffix to be misinterpreted as another element on the prescription or order 
 
  Contain or suggest any drug substance name or core name  
 
  Look similar to or be capable of being mistaken for the name of a currently marketed 
product (e.g., should not increase the risk of confusion or medical errors with the product 
and/or other products in the clinical setting) 
 
  Look similar to or otherwise connote the name of the license holder 
 
  Be too similar to any other FDA-designated nonproprietary name suffix 
 
FDA encourages applicants to conduct due diligence on their proposed suffixes to ensure that no 
other restrictions apply to use of the proposed suffix in this context.  Any supporting information 
can be provided to FDA with the submission of the proposed suffix(es). 
 
The final determination on the acceptability of a proposed suffix is based on FDAs review of all 
information and analyses described in this guidance, along with any information submitted by 
the sponsor.   
  10  Contains Nonbinding Recommendations 
 
FDA will evaluate proposed suffixes against the factors described in this section and may 
consider other factors if they impact the utility of the suffix in meeting the goals of the naming 
convention articulated in this guidance.  Upon completion of the Agencys evaluation, FDA will 
notify applicants if a proposed suffix is acceptable or if all of the proposed suffixes are 
determined to be unacceptable.  If all of the proposed suffixes are determined to be unacceptable, 
applicants may submit additional proposed suffixes for FDAs consideration.  If an applicant 
does not submit a suffix that FDA finds acceptable or does not propose suffix candidates within 
an appropriate time frame to allow sufficient time for FDA review, FDA may elect to assign a 
four-letter suffix for inclusion in the proper name designated in the license at the time FDA 
approves the application.   
 
 
VII.  PAPERWORK REDUCTION ACT OF 1995  
 
This guidance contains information collection provisions that are subject to review by the Office 
of Management and Budget (OMB) under the Paperwork Reduction Act of 1995 
(44 U.S.C. 3501-3520).  Specifically, the guidance recommends that applicants and application 
holders submit up to 10 proposed suffixes, in the order of the applicants preference.  FDA also 
recommends including any supporting analyses for FDAs consideration, demonstrating that the 
proposed suffixes meet the factors described in the final guidance.  
 
FDA estimates that the time required to complete this information collection will average 
420 hours per response, including the time to review instructions, search existing data sources, 
gather the data needed, and complete and review the information collection.  Send comments 
regarding this burden estimate or suggestions for reducing this burden to:   
 
Office of Medical Policy, Center for Drug Evaluation and Research, Food and Drug 
Administration, 10903 New Hampshire Avenue, Bldg. 51, rm. 6337, Silver Spring, MD  
20993-0002 
 
This guidance also refers to previously approved collections of information found in FDA 
regulations.  The collections of information related to the submission of a BLA under section 
351(k) of the PHS Act have been approved under OMB control number 0910-0719, and the 
collections of information in 21 CFR part 601 have been approved under OMB control number 
0910-0338. 
 
An Agency may not conduct or sponsor, and a person is not required to respond to, a collection 
of information unless it displays a currently valid OMB control number.  The information 
collection provisions in this guidance, including resulting proposed modifications to the 
information collections approved under OMB control number 0910-0338, have been submitted 
to OMB for review as required by section 3507(d) of the Paperwork Reduction Act of 1995 and 
are not for current implementation.  Before implementing the information collection 
provisions contained in this guidance, we will publish a notice in the Federal Register 
announcing OMB's decision to approve, modify, or disapprove those information collection 
provisions. 
  11  Contains Nonbinding Recommendations 
GLOSSARY 
 
Biosimilar Product means a biological product submitted in a 351(k) application that has been 
shown to be highly similar to the reference product notwithstanding minor differences in 
clinically inactive components, and for which there are no clinically meaningful differences 
between the biological product and the reference product in terms of the safety, purity, and 
potency of the product (see section 351(i)(2) of the PHS Act). 
 
Core Name means the component shared among an originator biological product and any related 
biological product, biosimilar product, or interchangeable product as part of the proper names of 
those products.  Two examples of a core name are filgrastim and epoetin alfa.   
 
Interchangeable Product means a biological product that has been shown to meet the standards 
described in section 351(k)(4) of the PHS Act and may be substituted for the reference product 
without the intervention of the health care provider who prescribed the reference product (see 
section 351(i)(3) of the PHS Act). 
 
Nonproprietary Name means a name unprotected by trademark rights that is in the public 
domain.  It may be used by the public at large, both lay and professional. 
 
Originator Biological Product means a biological product submitted in a BLA under section 
351(a) of the PHS Act (i.e., a stand-alone BLA) that is not a related biological product.  
 
Proper Name means the nonproprietary name designated by FDA in the license for a biological 
product licensed under the PHS Act.18   
 
Proprietary Name means the trademark or brand name. 
 
Reference Product means the single biological product licensed under section 351(a) of the 
PHS Act against which a biological product is evaluated in a 351(k) application 
(section 351(i)(4) of the PHS Act). 
 
Related Biological Product means a biological product submitted in a BLA under section 
351(a) of the PHS Act (i.e., a stand-alone BLA) for which there is a previously licensed 
biological product submitted in a different section 351(a) BLA that contains a drug substance for 
which certain nomenclature conventions (e.g., United States Adopted Names (USAN) Guiding 
Principles19) would be expected to provide for use of the same drug substance name.20  
                                                 
18 Section 351(a)(1)(B)(i) of the PHS Act (42 U.S.C. 262(a)(1)(B)(i) and  600.3(k)( 21 CFR 600.3(k)). 
 
19 The United States Pharmacopeial Convention, 2016, Guiding Principles for Coining United States Adopted 
Names for Drugs (2016 USP Dictionary of USAN and International Drug Names at 
http://www.uspusan.com/usan/pub/index1.html).  
 
20 FDAs description of a biological product as a related biological product in this guidance is separate from any 
determination FDA may make about whether a related biological product is eligible for a period of exclusivity under 
section 351(k)(7) of the PHS Act. 
 
  12