New Chemical Entity 
Exclusivity Determinations 
for Certain Fixed-
Combination Drug Products  
 
Guidance for Industry 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
     October 2014 
Procedural 
   
New Chemical Entity 
Exclusivity Determinations 
for Certain Fixed-
Combination Drug Products 
 
Guidance for Industry 
 
 
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  
Phone: 855-543-3784 or 301-796-3400; Fax: 301-431-6353 
druginfo@fda.hhs.gov  
http://www.fda.gov/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/default.htm 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
     October 2014 
Procedural 
  Contains Nonbinding Recommendations 
 
TABLE OF CONTENTS 
 
 
 
I.  INTRODUCTION............................................................................................................. 1 
II.  BACKGROUND ............................................................................................................... 2 
III.  STATUTORY AND REGULATORY FRAMEWORK ............................................... 2 
IV.  FDAS HISTORICAL INTERPRETATION OF THE 5-YEAR NCE 
EXCLUSIVITY PROVISIONS ....................................................................................... 5 
V.  REVISED AGENCY INTERPRETATION OF THE 5-YEAR NCE EXCLUSIVITY 
PROVISIONS .................................................................................................................... 7 
  Contains Nonbinding Recommendations 
 
New Chemical Entity Exclusivity  
Determinations for Certain Fixed-Combination Drug Products  
 
1
Guidance for Industry  
 
 
This guidance represents the Food and Drug Administrations (FDAs) current thinking on this topic.  It 
does not create or confer any rights for or on any person and does not operate to bind FDA or the public.  
You can use an alternative approach if the approach satisfies the requirements of the applicable statutes 
and regulations.  If you want to discuss an alternative approach, contact the FDA staff responsible for 
implementing this guidance.  If you cannot identify the appropriate FDA staff, call the appropriate 
number listed on the title page of this guidance.  
 
 
 
I.  INTRODUCTION  
 
The Food and Drug Administration (FDA or the Agency) is issuing this guidance to set forth a 
change in the Agencys interpretation of the 5-year new chemical entity (NCE) exclusivity 
provisions as they apply to certain fixed-combination drug products (fixed-combinations).  
Historically, FDA has interpreted these provisions such that a fixed-combination was ineligible 
for 5-year NCE exclusivity if it contained a previously approved active moiety, even if the 
product also contained a new active moiety (i.e., an active moiety that the Agency had not 
previously approved).  The Agency recognizes that fixed-combinations have become 
increasingly prevalent in certain therapeutic areas (including cancer, cardiovascular, and 
infectious disease) and that these products play an important role in optimizing adherence to 
dosing regimens and improving patient outcomes.  As further discussed below, we are therefore 
revising our historical interpretation of the 5-year NCE exclusivity provisions to further 
incentivize the development of certain fixed-combination products. 
 
FDA intends to apply the new interpretation from the date of this guidances publication.  
Therefore, the new interpretation will not apply to fixed-combination drug products that were 
approved prior to the publication of this guidance document. 
 
FDAs guidance documents, including this guidance, 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. 
  
 
                                                 
1 This guidance has been prepared by the Office of Regulatory Policy in the Center for Drug Evaluation and 
Research (CDER) at the Food and Drug Administration.  
  1  Contains Nonbinding Recommendations 
 
II.  BACKGROUND 
 
Fixed-combinations are becoming increasingly important from patient and public health 
perspectives.  Combination therapy is emerging as the standard of care in certain disease settings, 
such as cancer, cardiovascular disease, and infectious disease (for example, in human 
immunodeficiency virus (HIV) infections/acquired immunodeficiency syndrome (AIDS)).  In 
recognition of the importance of such combination therapies, FDA has encouraged the 
development of these therapies through various policies and initiatives.  For example, FDA 
recently finalized its guidance for industry titled Codevelopment of Two or More New 
Investigational Drugs for Use in Combination (Codevelopment Guidance).2  In the 
Codevelopment Guidance, FDA explained the potential therapeutic benefits of combination 
therapies, including improvement in treatment response, lower risk of developing resistance, and 
lower rates of adverse events.3  We have concluded that interpreting the applicable statutory and 
regulatory provisions to permit broader availability of 5-year NCE exclusivity for certain fixed-
combinations would further incentivize the development of these important products. 
 
Under the Agencys historical interpretation of the applicable statutory and regulatory 
provisions, the presence of a previously approved active moiety in a fixed-combination generally 
rendered the drug product ineligible for 5-year NCE exclusivity.  This outcome arose out of the 
Agencys interpretation of the word drug in certain provisions of the Federal Food, Drug, and 
Cosmetic Act (FD&C Act) and the term new chemical entity in the Agencys implementing 
regulations to mean drug product. 4  As explained in detail in section III, FDA intends to instead 
interpret drug in the relevant provisions to mean drug substance or active ingredient.  This will 
allow a drug substance that meets the definition of new chemical entity5 to be eligible for 5-year 
NCE exclusivity, even when it is approved in a fixed-combination with another drug substance 
that contains a previously approved active moiety.  Accordingly, under the Agencys new 
interpretation, a drug substance would be eligible for 5-year NCE exclusivity, provided that it 
meets the definition of a new chemical entity, regardless of whether that drug substance is 
approved in a single-ingredient drug product, in a fixed-combination with another drug substance 
that contains no other previously approved active moiety, or in a fixed-combination with another 
drug substance that contains a previously approved active moiety.  
 
III.  STATUTORY AND REGULATORY FRAMEWORK 
 
Section 505(b) through (d) of the FD&C Act (21 U.S.C. 355(b) through (d)) establishes the 
approval requirements for new drug applications (NDAs).  Applications submitted under section 
505(b)(1) are supported entirely by investigations either conducted by the applicant or to which 
the applicant has a right of reference.  The Drug Price Competition and Patent Term Restoration 
                                                 
2  See FDA guidance for industry, Codevelopment of Two or More New Investigational Drugs for Use in 
Combination, available at:  
http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm236669.pdf. 
3  Id. at 2.  
4  See section 505(c)(3)(E)(ii) and (j)(5)(F)(ii) of the FD&C Act; 21 CFR 314.108(a). 
5  21 CFR 314.108(a). 
  2  Contains Nonbinding Recommendations 
 
Act of 1984 (Pub. L. No. 98-417) (the Hatch-Waxman Amendments) amended the FD&C Act 
and added section 505(b)(2) and (j) of the FD&C Act.  Section 505(b)(2) provides an alternative 
pathway for approval of an NDA, under which some or all of the safety and efficacy 
investigations relied on for approval were not conducted by or for the applicant and for which the 
applicant has not obtained a right of reference (a 505(b)(2) application).  Section 505(j) 
establishes the abbreviated new drug application (ANDA) approval process, which provides a 
more streamlined route for generic drugs to be approved and brought to market. 
 
In addition to establishing the drug approval pathways in section 505(b)(2) and (j) of the FD&C 
Act, the Hatch-Waxman Amendments authorized periods of exclusivity intended to provide 
incentives for pharmaceutical innovation by protecting certain drugs approved in an NDA from 
competition for certain periods.  The 5-year NCE exclusivity provision states:  
 
If an application submitted under subsection (b) of this section for a drug, no 
active ingredient (including any ester or salt of the active ingredient) of which has 
been approved in any other application under subsection (b) of this section, is 
approved . . . no application may be submitted under this subsection which refers 
to the drug for which the subsection (b) application was submitted before the 
expiration of five years from the date of the approval of the application under 
subsection (b) of this section . . . .6 
 
Thus, the statute includes clauses describing both eligibility for 5-year NCE exclusivity 
(eligibility clause) and the parameters of this exclusivity once it attaches (bar clause).  Under the 
eligibility clause, a drug is eligible for 5-year NCE exclusivity if it is a drug, no active 
ingredient (including any ester or salt of the active ingredient) of which has been approved in any 
other [505(b)] application.  The bar clause prevents the submission of any ANDA or 505(b)(2) 
application that refers to the drug for which the [505(b)] application was submitted.  This bar 
on submission lasts for five years from the date of the approval of the [505(b)] application.7 
Five-year NCE exclusivity does not block the submission, review, or approval of a 505(b)(1) 
NDA.  
 
In 1989, FDA published a proposed rule (Proposed Rule) interpreting and implementing the 5-
year NCE exclusivity statutory provisions, along with other provisions of the Hatch-Waxman 
Amendments.8  In 1994, FDA finalized the rule (Final Rule) without substantive changes to the 
exclusivity-related provisions of the Proposed Rule.9  The regulations, as finalized, describe 5-
year NCE exclusivity as follows:  
                                                 
6  Section 505(j)(5)(F)(ii) of the FD&C Act; see also section 505(c)(3)(E)(ii) of the FD&C Act. 
7  Id.  A 505(b)(2) application or an ANDA may be submitted after the expiration of 4 years from the date of 
approval if the 505(b)(2) application or ANDA contains a certification of patent invalidity or noninfringement to a 
patent listed for the listed drug referenced. This certification is also referred to as a paragraph IV certification. 
Section 505(j)(2)(A)(vii)(IV) of the FD&C Act; see 21 CFR 314.108(b)(2) and (3); see also section 505(c)(3)(E)(ii) 
and (j)(5)(F)(ii) of the FD&C Act. 
8  FDA, Abbreviated New Drug Application Regulations, Proposed Rule, 54 FR 28872 (July 10, 1989). 
9  FDA, Abbreviated New Drug Applications; Patent and Exclusivity Provisions, Final Rule, 59 FR 50338 (Oct. 3, 
1994).  
  3  Contains Nonbinding Recommendations 
 
 
If a drug product that contains a new chemical entity was approved . . . in an 
application submitted under section 505(b) of the act, no person may submit a 
505(b)(2) application or abbreviated new drug application under section 505(j) of 
the act for a drug product that contains the same active moiety as in the new 
chemical entity for a period of 5 years from the date of approval of the first 
approved new drug application . . . .10 
 
Thus, under 21 CFR 314.108(b)(2), if a drug product contains a new chemical entity, then the 
Agency is precluded from accepting any ANDA or 505(b)(2) application for a drug product that 
contains the same active moiety as in the new chemical entity until the 5-year NCE exclusivity 
period has expired.  
 
This provision includes several terms of art, two of which are defined in 21 CFR 314.108:  
 
  New chemical entity (NCE) is a drug that contains no active moiety that has been 
approved by FDA in any other application submitted under section 505(b) of the act.11  
  
  Active moiety is the molecule or ion, excluding those appended portions of the molecule 
that cause the drug to be an ester, salt . . . , or other noncovalent derivative . . . of the 
molecule, responsible for the physiological or pharmacological action of the drug 
substance.12  
 
In defining these terms, the regulation interprets the statutory phrase active ingredient in the 
eligibility clause to refer to an active moiety.13  Other terms of art incorporated into this 
provision of the regulations are defined in 21 CFR parts 210 and 314:  
 
  Drug product, in part, means a finished dosage form, for example, tablet, capsule, or 
solution, that contains a drug substance. . . .14  
 
  Drug substance is an active ingredient that is intended to furnish pharmacological 
activity or other direct effect . . . but does not include intermediates use [sic] in the 
synthesis of such ingredient.15  
 
  An active ingredient is any component that is intended to furnish pharmacological 
activity or other direct effect . . . includ[ing] those components that may undergo 
                                                 
10  21 CFR 314.108(b)(2) (emphasis added). 
11  21 CFR 314.108(a). 
12  Id. 
13  59 FR 50338 at 50358 (The agency has concluded that the term active ingredient, as used in the phrase active 
ingredient (including any salt or ester of the active ingredient), means active moiety.). 
14  21 CFR 314.3(b). 
15  Id. 
  4  Contains Nonbinding Recommendations 
 
chemical change in the manufacture of the drug product and be present in the drug 
product in a modified form intended to furnish the specified activity or effect.16  
 
The preamble to the Proposed Rule further states that [t]he Agency notes that the term drug is 
used throughout section 505 of the act.  FDA interprets the term drug to mean drug product 
unless otherwise specified.17 
 
IV.  FDAS HISTORICAL INTERPRETATION OF THE 5-YEAR NCE 
EXCLUSIVITY PROVISIONS 
 
The FD&C Act defines the term drug broadly and delegates to FDA the task of determining how 
to apply the definition in particular statutory provisions.18  Drug can mean a finished drug 
product (articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of 
disease in man or intended to affect the structure or function of the body of man)19 or the 
components of a finished drug product (articles intended for use as a [drug] component).20  
Therefore, FDA has recognized, and courts have accepted, that drug can be interpreted, among 
other possible meanings, to mean either drug product or drug substance.21 
 
Historically, FDA has interpreted the term drug in the eligibility clause of the 5-year NCE 
exclusivity statutory provisions to mean drug product, not drug substance.  In 1988, in an 
informal letter to industry that predated the issuance of FDAs implementing regulations, the 
Agency stated that it considers a drug product eligible for the five-year period [of NCE 
exclusivity] if it contains no active moiety that was previously approved by the Agency and a 
drug product will . . . not be considered a new chemical entity entitled to five years of 
exclusivity if it contains a previously approved active moiety . . . .22  
 
After issuing the Final Rule, FDA continued to interpret the term drug to mean drug product in 
the eligibility clause, such that a new chemical entity that is eligible for 5-year NCE exclusivity 
                                                 
16  21 CFR 210.3(b)(7). 
17  54 FR 28872 at 28877. 
18  See, e.g., Pharmanex v. Shalala, 221 F.3d 1151, 1156 (10th Cir. 2000) ([T]he term drug is defined in [section 
201(g) of the FD&C Act (21 U.S.C. 321(g))] to include both finished drug products as well as individual 
constituents.  Thus, the definition of new drug is largely colored by the ambiguity that attends the broad term 
drug.).  See also United States v. Sullivan, 332 U.S. 689, 694 (1948) ([FDA] is given rather broad discretion [in 
administering the FD&C Act].).  
19  Section 201(g)(1)(B) and (C) of the FD&C Act. 
20  Section 201(g)(1)(D) of the FD&C Act.  
21  See, e.g., United States v. Generix Drug Corp., 460 U.S. 453, 459 (1983) (holding that section 201(g)(1) of the 
FD&C Act is plainly broad enough to include both active ingredient and drug product); Pfizer, Inc. v. FDA, 
753 F. Supp. 171, 176 (D. Md. 1990) (stating that the definition of drug covers both a finished drug product and 
its active and inactive ingredient or ingredients.). 
22  Letter from Carl C. Peck, M.D., Director, Center for Drug Evaluation and Research, to all NDA or ANDA 
Holders and Applicants, at p. 2 (April 28, 1988) (Peck Letter) (emphasis added), available at 
http://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm075014.pdf. 
  5  Contains Nonbinding Recommendations 
 
is a drug product that contains no active moiety that has been [previously] approved by 
FDA.23  As the preamble to the Proposed Rule states, a drug product will thus not be 
considered a new chemical entity entitled to 5 years of exclusivity if it contains a previously 
approved active moiety . . . .24  Under this interpretation of the statute and regulations, if an 
active moiety that has never been previously approved is approved in an application for a fixed-
combination that also includes one or more active moieties that have been previously approved, 
that fixed-combination would not be eligible for 5-year NCE exclusivity, because it would not be 
considered a drug [product] no [active moiety] of which has been approved in any other 
application under [section 505(b)].25 
 
At the same time, the Agency interpreted the term drug in the bar clause to mean drug 
substance.26  As explained in the Proposed Rule, after a drug product becomes eligible for 5-year 
NCE exclusivity, certain drug products subsequently developed that contain the same active 
moiety would also benefit from the original products 5-year NCE exclusivity until the 
exclusivity period for the original product has expired.27  Under this interpretation (known as the 
umbrella policy), 5-year NCE exclusivity does not attach only to the first approved drug product 
that was eligible for 5-year NCE exclusivity, but also to other products containing the same 
active moiety.  FDA explained its reasoning for this interpretation as follows:  
 
[T]he agency interprets [5-year NCE exclusivity] to cover any subsequent 
approval of an application or supplemental application for a different ester, salt, or 
other noncovalent derivative, or a different dosage form, strength, route of 
administration, or new use of a drug with the same active moiety.  Any 
modification to the product will be protected for the period of exclusivity 
remaining on the original application, unless the change occurs after or toward the 
end of the initial 5 years of exclusivity and independently qualifies for exclusivity 
under another exclusivity provision.28  
 
Accordingly, under the umbrella policy, 5-year NCE exclusivity will apply not just to the first 
approved drug product containing no previously approved active moiety, but, with some 
exceptions, would also apply to any other drug product developed that contains the same new 
active moiety as in the first drug product and that is approved during the 5-year period.  Such a 
                                                 
23  21 CFR 314.108(a). 
24  54 FR 28872 at 28898. 
25  See section 505(c)(3)(E)(ii) and (j)(5)(F)(ii) of the FD&C Act.  The preamble to the Proposed Rule contains 
similar language in the context of a 10-year exclusivity provision (54 FR 28872 at 28898) (A drug product is 
entitled to 10 years of exclusivity only if it does not contain an active moiety that has been part of a drug product 
previously approved under section 505(b) of the act either as a single ingredient or as one ingredient of a 
combination drug product.). 
26  This guidance does not address the Agencys interpretation and implementation of the bar clause. 
27  54 FR 28872 at 28898-28899. 
28  Id.  
  6  Contains Nonbinding Recommendations 
 
subsequent drug product will be protected for the balance of the 5-year period, which runs from 
the date of approval of the first approved drug product. 
 
V.  REVISED AGENCY INTERPRETATION OF THE 5-YEAR NCE EXCLUSIVITY 
PROVISIONS  
 
The field of fixed-combination therapy has evolved significantly since the Agency promulgated 
its 5-year NCE exclusivity regulations.  Fixed-combinations have become increasingly common 
in a diverse set of therapeutic areas, ranging from HIV to cardiovascular disease to cancer.  The 
available data on fixed-combination approvals supports this proposition.  In the nearly 20 years 
since FDA finalized the regulations on exclusivity, the Agency has approved 19 NDAs for fixed-
combinations containing at least one new active moiety.  More than half of these NDAs have 
gained approval within the last 7 years.  As discussed in section II, in recent years, FDA has 
adopted policies aimed at encouraging the development of fixed-combinations because, among 
other things, such combinations have been shown to improve treatment response, lower the risk 
of developing resistance, and lower the rates of adverse events.  
 
In 2013, the Agency was petitioned to revise its current interpretation of the 5-year NCE 
exclusivity provisions with respect to certain fixed-combinations.29  The petitioners made several 
contentions in support of their conclusion that FDAs current interpretation of the 5-year NCE 
exclusivity provisions discourages the development of new active moieties in fixed-combinations 
with previously approved active moieties.  Among other things, the petitioners stated that FDAs 
historical interpretation might encourage an applicant to submit an NDA for a single-entity 
product before it submits an NDA for a fixed-combination to secure 5-year NCE exclusivity for 
the single entity and protect the later-approved fixed-combination with that exclusivity under the 
umbrella policy.  This might lead to suboptimal drug development strategies, especially in light 
of the increasing importance of fixed-combinations.  In addition, the petitioners stressed that 
timing the order of approval to preserve exclusivity may not be available in some situations, such 
as for a new active moiety that may not be effective or safe unless it is marketed in a fixed-
combination.  
 
In light of the increasing importance of fixed-combination products to treat serious diseases and 
conditions, and considering the factors discussed above, FDA has concluded that a new 
interpretation of 5-year NCE exclusivity for fixed-combination products would be beneficial to 
                                                 
29  Hogan Lovells, on behalf of Gilead Sciences, Inc., submitted a citizen petition dated January 8, 2013, requesting 
5-year NCE exclusivity for cobicistat and elvitegravir, the new active moieties in the fixed-combination Stribild 
(cobicistat; elvitegravir; emtricitabine; tenofovir disoproxil fumarate) (NDA 203100) (FDA-2013-P-0058), in spite 
of the fact that the Stribild drug product also contained certain previously approved active moieties.  Buchanan 
Ingersoll & Rooney PC, on behalf of Ferring Pharmaceuticals, Inc., submitted a citizen petition dated January 29, 
2013, requesting 5-year NCE exclusivity for picosulfate, the new active moiety in the fixed-combination Prepopik 
(citric acid; magnesium oxide; sodium picosulfate) (NDA 202535) (FDA-2013-P-0119), in spite of the fact that 
Prepopik also contained certain previously approved active moieties.  Ropes & Gray LLP, on behalf of Bayer 
HealthCare Pharmaceuticals Inc., submitted a citizen petition dated April 19, 2013, requesting 5-year NCE 
exclusivity for dienogest, the new active moiety in the fixed-combination Natazia (estradiol valerate; dienogest) 
(NDA 022252) (FDA-2013-P-0471), in spite of the fact that Natazia also contained a previously approved active 
moiety. 
  7  Contains Nonbinding Recommendations 
 
the public health.  Accordingly, FDA is changing its interpretation of the 5-year NCE exclusivity 
provisions to align the exclusivity incentives more closely with FDAs public health goals.  
Under the revised interpretation, the term drug in the eligibility clause of the statutory 
provisions, and in the regulatory definition of new chemical entity, refers to drug substance, not 
drug product.30  Accordingly, a 5-year NCE exclusivity determination will be made for each 
drug substance in a drug product, not for the drug product as a whole.  As a result, an application 
for a fixed-combination submitted under section 505(b) of the FD&C Act will be eligible for 5-
year NCE exclusivity if it contains a drug substance, no active moiety of which has been 
approved in any other application under section 505(b).31  For example, a fixed-combination 
drug product that contains a drug substance with a single, new active moiety would be eligible 
for 5-year NCE exclusivity, even if the fixed-combination also contained a drug substance with a 
previously approved active moiety.  
 
As explained in section IV, this is a permissible construction of the 5-year exclusivity statutory 
provisions and implementing regulations because of the inherent ambiguity in the term drug.  
The Agency is issuing this guidance to implement the new interpretation described above, which 
is effective on the date the guidance is published.32 
                                                 
30  Section 505(c)(3)(E)(ii) and (j)(5)(F)(ii) of the FD&C Act; 21 CFR 314.108(a). 
31  This change in interpretation generally will not affect 5-year NCE exclusivity determinations for single-entity 
drug products.  Such products typically contain a single drug substance that contains a single active moiety.  In such 
cases, where the drug substance contains a previously approved active moiety, so does the drug product. 
32  Because this interpretation represented a change in the Agencys historical interpretation of the relevant 
authorities that was of more than a minor nature, we solicited public comments on the draft version of this 
guidance, published on February 24, 2014 (section 701(h)(1)(C) of the FD&C Act (21 U.S.C. 371(h)(1)(C)); 21 
CFR 10.115).  We have carefully reviewed and considered the comments that we received before publishing this 
guidance.  
  8