Qualified Infectious 
Disease Product 
Designation 
Questions and Answers 
Guidance for Industry 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
May 2021 
Procedural 
 
  Qualified Infectious 
Disease Product 
Designation 
Questions and Answers 
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 
https://www.fda.gov/drugs/guidance-compliance-regulatory-information/guidances-drugs  
 
 
 
 
 
 
 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Drug Evaluation and Research (CDER) 
 
May 2021 
Procedural 
  TABLE OF CONTENTS 
 
I.  INTRODUCTION ...................................................................................................... 1 
II.  BACKGROUND ........................................................................................................ 1 
III.  QIDP DESIGNATION ............................................................................................... 2 
IV.  QUESTIONS AND ANSWERS ................................................................................. 2 
V.  GAIN EXCLUSIVITY ............................................................................................... 7 
VI.  QUALIFYING PATHOGENS ................................................................................... 8  Contains Nonbinding Recommendations 
 
Qualified Infectious Disease Product Designation 
Questions and Answers 
Guidance for Industry1 
 
 
 
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 provides information to sponsors about FDAs implementation of Title VIII of the 
Food and Drug Administration Safety and Innovation Act (FDASIA),2 titled Generating 
Antibiotic Incentives Now (GAIN).  The GAIN provisions create incentives for the development 
of antibacterial and antifungal drug products that treat serious or life-threatening infections.  The 
purpose of this guidance is to provide sponsors a resource for information on FDAs policies and 
procedures related to the designation of a qualified infectious disease product (QIDP) under 
GAIN. 
 
The contents of this document do not have the force and effect of law and are not meant to bind the 
public in any way, unless specifically incorporated into a contract.  This document is intended only to 
provide clarity to the public regarding existing requirements under the law.  FDA guidance 
documents, including this guidance, 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.  BACKGROUND 
 
GAIN offers incentives for certain antibacterial and antifungal products, most notably a 5-year 
exclusivity extension for certain applications of drug products that have been designated as a 
QIDP and approved under section 505 of the Federal Food, Drug, and Cosmetic Act (FD&C 
Act).  This 5-year exclusivity extension is added to any exclusivity for which the application 
qualifies upon approval (see section V of this guidance).  Additionally, section 524A of the 
FD&C Act (21 U.S.C. 360n-1) requires FDA to give priority review to the first application 
 
1 This guidance has been prepared by the Office of Antimicrobial Products in the Center for Drug Evaluation and 
Research at the Food and Drug Administration. 
 
2 Section 801 of FDASIA created the GAIN provisions under section 505E of the FD&C Act (21 U.S.C. 355f).  See 
Pub. L. 112-144, 126 Stat. 993 (2012). 
  1  Contains Nonbinding Recommendations 
 
submitted for approval for a QIDP (see Q10).  A QIDP will also receive fast track designation at 
the sponsors request (21 U.S.C. 356(b)(1)).  This guidance provides responses to common 
questions about QIDP designation and the review of new drug applications (NDAs) for QIDP-
designated products and are grouped by topic area. 
 
 
III.  QIDP DESIGNATION 
 
Section 505E(g) of the FD&C Act provides for the designation by FDA of certain 
antimicrobial products as QIDPs.  A QIDP is defined in section 505E(g) as an 
antibacterial or antifungal drug for human use intended to treat serious or life-threatening 
infections, including those caused by   
 
(1) an antibacterial or antifungal resistant pathogen, including novel or emerging 
infectious pathogens; or 
 
(2) qualifying pathogens listed by the Secretary under section 505E(f) of the 
FD&C Act 
 
The Agency has codified the list of qualifying pathogens in 21 CFR 317.2. 
 
For a drug product to be designated a QIDP, the sponsor is required to demonstrate that the drug 
is an antibacterial or antifungal drug for human use intended to treat serious or life-threatening 
infections.3  In its designation request, a sponsor requesting a QIDP designation may also 
include documentation that the product is intended to treat an antibacterial or antifungal 
resistant pathogen, including novel or emerging infectious pathogens or a qualifying pathogen 
included in 21 CFR 317.2; however, such documentation is not required.4 
 
 
IV.  QUESTIONS AND ANSWERS 
 
Q1.  For purposes of QIDP designation, what is an antibacterial or antifungal drug 
intended to treat serious or life-threatening infections? 
 
For the purpose of QIDP designation, FDA generally intends to consider a drug product to be an 
antibacterial or antifungal drug intended to treat serious or life-threatening infections if the 
sponsor can provide information to show that the drug product directly inhibits replication of, or 
kills, bacteria or fungi relevant to the proposed indication at concentrations that are likely to be 
 
3 See section 505E(g) of the FD&C Act. 
 
4 The fact that a product is intended to treat infections caused by a pathogen on the qualifying pathogens list is 
neither necessary nor sufficient to satisfy the standards for QIDP designation.  For QIDP designation, the sponsor is 
required to demonstrate that the drug is an antibacterial or antifungal drug for human use intended to treat serious 
or life-threatening infections. See section 505E(g) of the FD&C Act. 
 
  2  Contains Nonbinding Recommendations 
 
attainable in humans to achieve the intended therapeutic effect.5  For purposes of QIDP 
designation, FDA generally does not intend to consider a drug product to be an antibacterial or 
antifungal drug intended to treat serious or life-threatening infections if the drug product only 
inhibits replication of, or kills, bacteria or fungi at concentrations that are infeasible to study in 
human subjects because of anticipated toxicity. 
 
Q2.  Does a QIDP designation apply to any product containing the drug substance, or 
does it apply only to a specific sponsors drug product in the context of its specific proposed 
use? 
 
FDA generally considers the QIDP designation as applying to a specific drug product6 from a 
specific sponsor for a specific use for which it is being studied.7,8  The designation is granted 
only to the sponsor making the request,9 rather than applying to a drug substance in general or 
beyond the specified indications. 
 
Q3.  GAIN defines QIDP as an antibacterial or antifungal drug for human use intended 
to treat serious or life-threatening infections.  Could an antibacterial or antifungal drug 
intended to prevent or diagnose a serious or life-threatening infection be eligible for QIDP 
designation? 
 
In the context of other programs under the FD&C Act intended to expedite the development of 
drugs and biologics to address unmet medical needs, FDA has determined that a product is 
intended to treat a serious or life-threatening disease or condition if it is intended to have an 
effect on a serious condition or a serious aspect of the [serious or life-threatening] condition, 
including diagnosing, preventing, and treating a serious aspect of the condition.10  At the time of 
 
5 See question 7 for examples of types of information FDA considers appropriate to support a designation request. 
 
6 As defined in 21 CFR 314.3, Drug product is a finished dosage form, e.g., tablet, capsule, or solution, that 
contains a drug substance, generally, but not necessarily, in association with one or more other ingredients. 
 
7 See section 505E(d) and 505E(g) of the FD&C Act. 
 
8 Typically, sponsors submit a request for QIDP designation for a single drug product containing a single active 
ingredient.  However, FDA is aware of sponsors developing fixed-combination and co-packaged drugs for the 
treatment of serious or life-threatening infections.  A single QIDP designation request should be submitted to FDA 
for a fixed-combination or a co-packaged drug intended for submission in a single NDA, and that drug will 
generally be evaluated as a whole for purposes of QIDP designation. 
 
9 However, a QIDP designation granted to a requesting sponsor continues to apply to a sponsors successor in 
interest, e.g., if ownership of an IND is transferred following receipt of QIDP designation. 
 
10 A guidance on Fast Track Drug Development Programs (issued Nov. 1998) explained that the agency considers 
drugs intended to diagnose or prevent a serious or life-threatening disease or condition as treating a serious or life-
threatening disease or condition.  This language was carried through two revisions of the stand-alone guidance, 
which was ultimately replaced by a guidance on numerous expedited programs in 2014, with the 2014 guidance 
reflecting the same interpretation of treat as the stand-alone guidance.  See the guidance for industry Expedited 
Programs for Serious ConditionsDrugs and Biologics (May 2014).  We update guidances periodically.  To make 
sure you have the most recent version of a guidance, check the FDA guidance web page at 
https://www.fda.gov/regulatory-information/search-fda-guidance-documents. 
 
  3  Contains Nonbinding Recommendations 
 
GAINs enactment, Congress was aware of FDAs long-standing interpretation of the phrase 
serious and life-threatening. Thus, FDA interprets the phrase intended to treat a serious or 
life-threatening infection in the context of QIDPs in a manner similar to these other programs.  
Accordingly, FDA generally intends to consider a drug to be intended to treat a serious or life-
threatening infection if it is intended to diagnose, prevent, or treat such an infection. 
 
Q4.  Are biological products or devices eligible for QIDP designation? 
 
No.  The provisions of GAIN refer only to human drugs that are the subject of applications under 
section 505 of the FD&C Act, and therefore QIDPs must be human drugs whose applications are 
submitted pursuant to section 505(b) of the FD&C Act.11  Accordingly, biological products that 
are approved for marketing pursuant to section 351 of the Public Health Service Act (42 U.S.C. 
262) or devices that are cleared pursuant to section 510 of the FD&C Act (21 U.S.C. 360) or 
approved pursuant to section 515 of the FD&C Act (21 U.S.C. 360e) are not eligible for QIDP 
designation. 
 
Q5.  When can a sponsor make a request for QIDP designation? 
 
A sponsor may request a QIDP designation at any time before submitting a marketing 
application under section 505(b) for that sponsors drug product, as described in Q2, above.12 
 
If a sponsor requests QIDP designation for a new indication for the sponsors approved drug 
product, the sponsor should submit that request to the investigational new drug (IND) application 
for that drug product.  The marketing application for the new indication would then be submitted 
as an efficacy supplement.13 
 
If the proposed indication for the drug product changes before submission of a marketing 
application, the sponsor should request a new designation for that new indication. In addition, 
because QIDP designation also applies to a specific drug product, the sponsor should request a 
new designation when a significant change in the drug product is made during development, 
such as a change in dosage form. When a sponsor is uncertain whether a change necessitates a 
new QIDP designation request, FDA recommends the sponsor seek additional advice from the 
appropriate review division. 
 
Q6.  How does a sponsor request QIDP designation? 
 
A request for QIDP designation should be submitted either to an IND or as pre-IND 
correspondence.14  The cover letter should include the following text in bold font at the top of the 
 
11 Applications for combination products submitted under section 505(b) of the FD&C Act may qualify for QIDP 
designation. 
 
12 See section 505E(d)(1) of the FD&C Act. 
 
13 See 21 CFR 314.70. 
 
14 Information regarding the CDER pre-IND consultation program for the Office of Antimicrobial Products is 
available at https://www.fda.gov/drugs/investigational-new-drug-ind-application/pre-ind-consultation-program. 
  4  Contains Nonbinding Recommendations 
 
page: Request for Qualified Infectious Disease Product Designation.  Requests for multiple 
indications can be combined in a single submission or made separately.  The sponsor should 
clearly identify in the cover letter each indication for which it is requesting QIDP designation.   
When requests for multiple indications are combined in a single submission, FDA recommends 
that sponsors provide in the submission a separate rationale for each indication for which QIDP 
designation is requested. Requests should reflect how a sponsor anticipates the indication or 
indications would be described in the products labeling. 
 
Q7.  What information should a QIDP designation request contain? 
 
A QIDP designation request should contain a discussion of the information that supports the 
activity of the drug as an antibacterial or antifungal drug (see Q1).  Information to support the 
activity of the drug may include, for example: 
 
  In vitro data, including any available data on mechanism of action 
  Data from animal models of infection 
  Available human data from phase 1, phase 2, or phase 3 studies  
 
A QIDP designation request should also contain the specific serious or life-threatening infection 
or infections for which the sponsor intends (or has begun) to develop the drug and the rationale 
or suitability for developing the drug for the proposed serious or life-threatening infection or 
infections.  Sponsors may wish to refer to the definition of serious that the Agency has used in 
the context of other programs intended to encourage the development of drugs to treat serious 
and life-threatening diseases or conditions:  Whether a disease is serious is a matter of clinical 
judgment, based on its impact on such factors as survival, day-to-day functioning, or the 
likelihood that the disease, if left untreated, will progress from a less severe condition to a more 
serious one.15 
 
In addition, this request may (but is not required to) include information to demonstrate that the 
product is an antibacterial or antifungal drug that has the capacity to treat serious or life-
threatening infections caused by either of the following: 
 
  Resistant pathogens, including novel or emerging pathogens 
  Qualifying pathogens listed in 21 CFR 317.2 (see section VI) 
 
Q8.  When should a sponsor expect to hear from FDA about its QIDP designation 
request? 
 
 
15 See the guidance for industry Expedited Programs for Serious ConditionsDrugs and Biologics, which cites the 
definition used in the preamble to the proposed rule, New Drug, Antibiotic, and Biological Drug Product 
Regulations; Accelerated Approval, 57 FR 13234 at 13235 (April 15, 1992) and 21 CFR 312, subpart I. 
 
  5  Contains Nonbinding Recommendations 
 
FDA will respond to a QIDP designation request within 60 calendar days of submission.16  For 
the purposes of QIDP designation, FDA considers the date of submission to be the date FDA 
receives the request. 
 
Q9.  Is fast track designation granted automatically with the QIDP designation or must a 
sponsor specifically request fast track designation? 
 
Although a product designated as a QIDP is eligible for fast track designation,17 the sponsor 
must specifically request fast track designation.18  If fast track has not previously been granted 
for the indication that is being considered for QIDP designation, the sponsor can request fast 
track designation in the same letter with the QIDP designation request submitted to the sponsors 
IND.  If fast track designation has already been granted for this indication of the sponsors 
proposed drug, the sponsor need not make an additional request.  The sponsor may also request 
fast track designation at any time after the QIDP designation.  Although a sponsor may request 
QIDP designation before submitting an IND, a request for fast track designation may be made 
concurrently with, or any time after, submission of an IND.19 
 
Q10.  Is priority review designation automatically given to any application or efficacy 
supplement submitted for a QIDP? 
 
No.  FDA automatically gives priority review designation to the first application or efficacy 
supplement submitted for a specific drug product and indication for which QIDP designation was 
granted.20,21  A subsequent original application or efficacy supplement from the same sponsor for 
the same product and same indication will receive priority review designation only if it otherwise 
meets the criteria for priority review. A subsequent efficacy supplement for a new indication will 
 
16 See section 505E(d)(1) of the FD&C Act. 
 
17 See section 524A of the FD&C Act. 
 
18 See section 506(b)(1) of the FD&C Act. 
 
19 See section 506(a)(2) of the FD&C Act; see also the guidance for industry Expedited Programs for Serious 
ConditionsDrugs and Biologics, p. 28. 
 
20 Certain applications for QIDPs may qualify to receive a tropical disease priority review voucher (PRV) under 
section 524 of the FD&C Act, a rare pediatric disease PRV under section 529, or a material threat medical 
countermeasure PRV under section 565A.  For an applicant to receive a PRV, the application must be deemed 
(under section 524 or section 529) or determined (under section 565A) by the Agency to be eligible for priority 
review.  See sections 524, 529, or 565A of the FD&C Act.  In determining whether an application for a QIDP that 
receives priority review pursuant to section 524A is also eligible for priority review within the meaning of sections 
524, 529, or 565A of the FD&C Act, the Agency will determine whether the application satisfies the criteria for 
eligibility for a priority review designation (i.e., whether the drug treats a serious condition and, if approved, would 
provide a significant improvement in safety or effectiveness).  See section 101(b) of the Prescription Drug User Fee 
Amendments of 2012.  For more information on the priority review designation, see the guidance for industry 
Expedited Programs for Serious ConditionsDrugs and Biologics; see also the Manual of Policies and Procedures 
6020.3 Rev. 2. 
 
21 See section 524A of the FD&C Act, as amended by section 3101(a)(2)(N) of the 21st Century Cures Act. 
 
  6  Contains Nonbinding Recommendations 
 
automatically receive priority review if the sponsor received QIDP designation for the same drug 
product for the new indication before submitting the supplement. 
 
 
V.  GAIN EXCLUSIVITY 
 
Subject to the specified statutory limitations, a drug that is designated as a QIDP and is approved 
for the use for which the QIDP designation was granted will receive a 5-year extension to any 
exclusivity for which the application qualifies upon approval.  Section 505E of the FD&C Act 
lists the following limitations under which the 5-year GAIN exclusivity extension is not 
available: 
 
(c) LIMITATIONSSubsection (a) does not apply to the approval of 
(1) a supplement to an application under section 505(b) for any qualified infectious 
disease product for which an extension described in subsection (a) is in effect or has 
expired; 
(2) a subsequent application filed with respect to a product approved under section 505 
for a change that results in a new indication, route of administration, dosing schedule, 
dosage form, delivery system, delivery device, or strength; or  
(3) a product that does not meet the definition of a qualified infectious disease product 
under subsection (g) based upon its approved uses. 
 
Q11.  When is an efficacy supplement to an approved NDA eligible for the 5-year GAIN 
exclusivity extension? 
 
An efficacy supplement22 to an approved NDA may be eligible for the 5-year GAIN exclusivity 
extension if the following conditions apply:23 
 
  The application that is being supplemented has not previously received the 5-year GAIN 
exclusivity extension 
 
  The supplement is for an indication for which the product has received a QIDP 
designation prior to submission of the supplement 
 
  The supplement qualifies for 3-year exclusivity24 and/or orphan drug exclusivity,25 as 
applicable 
 
 
22 See 21 CFR 314.3(b) for definition of an efficacy supplement. 
 
23 Section 505E(a) and (c) of the FD&C Act. 
 
24Section 505(c)(3)(E)(iv) and 505(j)(5)(F)(iv) of the FD&C Act. 
 
25 Section 527 of the FD&C Act. 
 
  7  Contains Nonbinding Recommendations 
 
Q12.  Can a subsequent application for a previously approved product be eligible for the 
5-year GAIN exclusivity extension? 
 
Under section 505E(c)(2) of the FD&C Act, a subsequent application for a previously approved 
product is not eligible for the 5-year GAIN exclusivity extension if the applicant (or its 
predecessor in interest) previously received approval and received the 5-year exclusivity 
extension pursuant to section 505E(a), and the subsequent application is seeking approval for a 
change that results in a new indication, route of administration, dosing schedule, dosage form, 
delivery system, delivery device, or strength.26 
 
 
VI.  QUALIFYING PATHOGENS 
 
Section 505E(f) of the FD&C Act instructs the Secretary (and thus FDA, by delegation) to 
establish and maintain a list of qualifying pathogens and make public the methodology for 
developing the list.  A qualifying pathogen is defined in section 505E(f) as:  
 
a pathogen identified and listed by the Secretary ... that has the potential to pose a serious 
threat to public health, such as  
(A) resistant gram-positive pathogens, including methicillin-resistant Staphylococcus 
aureus, vancomycin-resistant enterococcus; 
(B) multi-drug resistant gram-negative bacteria, including Acinetobacter, Klebsiella, 
Pseudomonas, and E. coli species; 
(C) multi-drug resistant tuberculosis; and 
(D) Clostridium difficile. 
 
Q13.  Where can I find the list of qualifying pathogens mentioned in GAIN? 
 
The list of qualifying pathogens can be found in 21 CFR 317.2.  The final rule, Establishing a 
List of Qualifying Pathogens Under the Food and Drug Administration Safety and Innovation 
Act, was published on June 5, 2014.27  The final rule describes the factors FDA considered and 
the methodology used for developing the list. 
 
Q14.  Must a product be intended for the treatment of an infection caused by a qualifying 
pathogen to be eligible for QIDP designation? 
 
No.  The statutory standard for inclusion on FDAs list of qualifying pathogens is different from 
the statutory standard for QIDP designation.  QIDP designation, by definition, requires that the 
drug in question be an antibacterial or antifungal drug intended to treat a serious or life-
threatening infection.28  Qualifying pathogen is defined according to a different statutory 
standard; the term means a pathogen identified and listed by the Secretary...that has the 
 
26 Section 505E(c)(2) of the FD&C Act. 
 
27 79 FR 32464. 
 
28 See section 505E(g) of the FD&C Act. 
 
  8  Contains Nonbinding Recommendations 
 
potential to pose a serious threat to public health (emphasis added).29  That is, a drug intended 
to treat a serious or life-threatening bacterial or fungal infection caused by a pathogen that is not 
included on the list of qualifying pathogens may be eligible for designation as a QIDP; however, 
a drug that is intended to treat an infection caused by a pathogen on the list may not always be 
eligible for QIDP designation if it is not intended to treat a serious or life-threatening infection. 
 
29 See section 505E(f) of the FD&C Act. 
  9