#283 
 
Priority Zoonotic Animal Drug 
Designation and Review Process 
 
Guidance for Industry 
 
Draft Guidance 
 
This guidance document is being distributed for comment purposes only. 
 
Submit comments on this draft guidance by the date provided in the Federal Register notice 
announcing the availability of the draft guidance.  Submit electronic comments to 
https://www.regulations.gov.  Submit written comments to the Dockets Management Staff 
(HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD  
20852.  All comments should be identified with docket number Docket No. FDA-2023-D-3740. 
 
For further information regarding this document, contact Dr. Michelle Hyre, Center for 
Veterinary Medicine (HFV-133), Food and Drug Administration, 7500 Standish Place, Rockville 
MD 20855, 240-402-0593, email: michelle.hyre@fda.hhs.gov. 
 
Additional copies of this draft guidance document may be requested from the Policy and 
Regulations Staff (HFV-6), Center for Veterinary Medicine, Food and Drug Administration, 
7500 Standish Place, Rockville MD 20855, and may be viewed on the Internet at 
https://www.fda.gov/animal-veterinary, https://www.fda.gov/regulatory-information/search-fda-
guidance-documents, or http://www.regulations.gov. 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Veterinary Medicine (CVM) 
December 2023
 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
Table of Contents 
I. Introduction .......................................................................................................................... 1 
II. Priority Zoonotic Animal Drug .......................................................................................... 1 
III. Background  The CARES Act .......................................................................................... 1 
IV. Priority Zoonotic Animal Drug Designation ..................................................................... 2 
A. PZAD Eligibility Criteria .............................................................................................. 2 
B. Other considerations for PZAD designation ............................................................... 4 
V. Priority Zoonotic Animal Drug Designation Request Process ........................................ 5 
VI. Enhancements to Expedite the PZAD Review Process .................................................... 5 
A. Informal meetings between CVM and sponsors ......................................................... 6 
B. PZAD pre-review feedback ........................................................................................... 6 
C. PZAD post-review feedback.......................................................................................... 7 
D. PZAD stop-the-review-clock ......................................................................................... 7 
i  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
 
Priority Zoonotic Animal Drug Designation and Review Process 
 
Draft Guidance for Industry 
 
This draft guidance, when finalized, will represent 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 staff responsible for this guidance as listed on the title page. 
 
I.  Introduction  
This draft guidance is intended to assist sponsors pursuing Priority Zoonotic Animal Drug 
(PZAD) designation of a new animal drug.1 
 This draft guidance is intended to provide the following: 
  the definition of a PZAD, 
  eligibility criteria for PZAD designation,  
  the process for PZAD designation requests, and 
  the process for expedited development and review of PZADs. 
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.  Priority Zoonotic Animal Drug  
Under section 512A of the Federal Food, Drug, and Cosmetic Act (FD&C Act), a PZAD is 
defined as a new animal drug, that alone or in combination with one or more other animal drugs, 
has the potential to prevent or treat a zoonotic disease in animals, including a vector-borne 
disease, that has the potential to cause serious adverse health consequences for, or serious or life-
threatening diseases in, humans. 
III.  Background  The CARES Act 
The Coronavirus Aid, Relief, and Economic Security (CARES) Act,2 signed into law on March 
 
1 The scope of this guidance includes products such as intentional genomic alterations in animals and animal cells, 
tissues, and cell- and tissue-based products. 
2 https://www.congress.gov/116/bills/hr748/BILLS-116hr748enr.pdf 
1 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
 
27, 2020, added section 512A Priority zoonotic animal drugs to the FD&C Act, which provides 
for the designation of a new animal drug as a PZAD.3  Section 512A(a) of the FD&C Act directs 
FDA to: 
expedite the development and review of such new animal drug if preliminary clinical 
evidence indicates that the new animal drug, alone or in combination with 1 or more 
other animal drugs, has the potential to prevent or treat a zoonotic disease in animals, 
including a vector borne-disease, that has the potential to cause serious adverse health 
consequences for, or serious or life-threatening diseases in, humans.  
Section 512A of the FD&C Act identifies actions FDA may pursue for the expedited 
development and review of the new animal drug applications (NADA) for designated PZADs.  
These actions include the following: 
A)  taking steps to ensure that the design of clinical trials is as efficient as practicable, when 
scientifically appropriate, such as by utilizing novel trial designs or drug development 
tools (including biomarkers) that may reduce the number of animals needed for studies; 
B)  providing timely advice to, and interactive communication with, the sponsor (which may 
include meetings with the sponsor and review team) regarding the development of the 
new animal drug to ensure that the development program to gather the nonclinical and 
clinical data necessary for approval is as efficient as practicable; 
C) involving senior managers and review staff with experience in zoonotic or vector-borne 
disease to facilitate collaborative, cross-disciplinary review, including, as appropriate, 
across agency centers; and 
D) implementing additional administrative or process enhancements, as necessary, to 
facilitate an efficient review and development program.4 
IV.  Priority Zoonotic Animal Drug Designation  
A.  PZAD Eligibility Criteria 
As stated in section 512A(a) of the FD&C Act, among other things, a new animal drug 
must meet two substantive criteria to be designated as a PZAD:  
1.  The new animal drug is intended to prevent or treat a zoonotic disease in 
animals, including a vector-borne disease. 
The following are some examples of types of FDA-regulated animal drug products 
that may meet this criterion:   
 
3 The PZAD designation is not the same as Minor Use Minor Species (MUMS) designation. 
4 See section 512A(c)(2) of the FD&C Act. 
2 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
 
  drug products intended for use in an animal to prevent or treat a specific 
disease in that animal that has the potential to transfer to humans; 
  drug products intended for use in an animal that harbors the zoonotic 
disease-causing agent that can be transmitted to humans by direct contact 
with the animal or animals environment, or by ingestion of or exposure to 
animal products.  These drugs may reduce or eliminate the zoonotic disease-
causing agent in the animal or animals environment; 
  drug products intended for use in an animal that harbors a zoonotic disease-
causing agent that can be transmitted to humans by insects or other vector 
species.  These drugs may reduce (or eliminate) the vector population, or 
may reduce or eliminate the zoonotic disease-causing agent in the animal, 
and so reduce the likelihood of transmission of the zoonotic disease-causing 
agent from the animal to insects or other vector species;5 
  drug products intended for use in a vector species that harbors a zoonotic 
disease-causing agent.  These drugs may reduce (or eliminate) the vector 
population,6 reduce or eliminate the zoonotic disease-causing agent in the 
vector, or otherwise decrease the vectors ability to transmit the zoonotic 
disease-causing agent to humans. 
Note that for products proposed to treat or prevent vector-borne diseases, early 
discussion may be needed between CVM and other regulatory agencies (e.g., 
United States Environmental Protection Agency,7 United States Department of 
Agriculture) to determine which agency should regulate the product. 
2.  The zoonotic disease the new animal drug is intended to treat or prevent must 
have the potential to cause serious adverse health consequences for, or serious 
or life-threatening disease in, humans 
The zoonotic disease needs to be recognized as a disease that has the potential to 
cause serious or life-threatening disease in humans or has the potential to cause 
serious adverse health consequences for humans.  
CVM may consult with other FDA Centers or other agencies to determine if a 
particular proposed product meets this criterion. 
 
5 Note that this guidance excludes products EPA regulates, including genetic modifications in pest animals intended 
for use as a pesticide (such as for mosquito and rodent population control). 
6 See footnote 5. 
7 See footnote 5. 
3 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
 
B.  Other considerations for PZAD designation  
1.  For a new animal drug to be eligible for a PZAD designation, there must be at least 
preliminary clinical evidence to support its proposed indication.  (Section 512A(a) 
of the FD&C Act). 
2.  A sponsor may seek PZAD designation for a new animal drug that is used alone or 
that is used in combination with another new animal drug.  (Section 512A(a) of the 
FD&C Act). 
 
3.  Only pioneer new animal drug products that may be approved8 or conditionally 
approved9 are eligible for PZAD designation.  Generic new animal drugs are not 
eligible for PZAD designation.  
4.  The PZAD designation for a new animal drug product will be limited to the 
zoonotic disease indication, even if the product is previously approved for other 
uses or is currently being evaluated under the same Investigational New Animal 
Drug (INAD) file for other indications. 
5.  The indication for a new animal drug product designated as a PZAD should reflect 
the primary endpoint used to determine success in the effectiveness study(ies).  The 
indication will not include how the product may prevent or treat zoonotic diseases 
in humans or that the product may prevent or treat zoonotic disease in animals if the 
effectiveness study(ies) did not include a prevention or treatment of disease 
endpoint.   
6.  PZAD designations can be separately granted to multiple sponsors seeking approval 
of the same drug for the same or similar zoonotic disease indication(s). 
7.  If CVM designates the new animal drug as a PZAD, all subsequent submissions to 
that file that are related to that PZAD designation are afforded the expedited review 
process described in section VI. Enhancements to Expedite the PZAD Review 
Process below.  The expedited review process does not apply to any submissions 
made to the file prior to the PZAD designation. 
8.  A PZAD designation does not guarantee the product will be approved or 
conditionally approved as a new animal drug.  PZAD products are still subject to 
the requirements of the animal drug approval process. 
9.  A PZAD designation does not provide any marketing incentives (e.g., market 
exclusivity) for the new animal drug product.  
 
8 Sections 512(j) and 512(b)(1) of the FD&C Act. 
9 Section 571 of the FD&C Act. 
4 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
 
V.  Priority Zoonotic Animal Drug Designation Request Process 
A request for designation as a PZAD may be made concurrently with, or at any time after, the 
opening of an INAD file or the filing of an NADA.  CVM recommends that PZAD designation 
requests be submitted to the INAD file.  Prior to submission, the sponsor may request a 
meeting10 with CVMs Office of New Animal Drug Evaluation (ONADE) to discuss their 
proposed request for designation.  If a drug has multiple indications, only the indication(s) to be 
evaluated for PZAD designation should be included in the submission.  
In the submission, the sponsor should provide information about their proposed conditions of use 
(i.e., drug identification, indication, species class, and dosage regimen).  The submission should 
address how the new animal drug product meets the criteria for PZAD designation (see section 
IV.A. PZAD Eligibility Criteria) as follows:  
a.  Provide information on how the drug will be administered. 
b.  Provide the mechanism of action of the drug (if known). 
c.  Explain the potential for the new animal drug to prevent or treat a zoonotic disease in 
animals, including a vector-borne disease. 
d.  Describe the potential of the zoonotic disease to cause serious adverse health 
consequences for, or serious or life-threatening disease in, humans. 
CVM will issue a letter informing the sponsor whether the drug is designated as a PZAD within 
60 calendar days of the request.11 
VI.  Enhancements to Expedite the PZAD Review Process 
To fulfill the requirements of the CARES Act for expediting review of PZAD products, CVM 
aims to increase efficiency in the approval process and thereby reduce the overall time to 
approval.  CVM hopes to achieve this by providing the enhancements to the review process 
described below, including informal meetings, pre-review feedback upon request, and stopping 
the review clock under certain circumstances. 
CVMs evaluation process for PZADs will follow CVMs new animal drug evaluation phased-
review process outlined in GFI #132, Administrative Applications and the Phased Review 
Process.12  Review of PZAD product submissions will be subject to the applicable current 
Animal Drug User Fee Act (ADUFA) timelines, with the goal of streamlining the process for 
PZAD products as described below.  
 
10 See CVM Program Policy and Procedures Manual 1243.3024 Scheduling and Holding Meetings with Outside 
Parties (April 2023). 
11 See section 512A(c)(1) of the FD&C Act.  
12 https://www.fda.gov/media/70029/download  
5 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
 
A.  Informal meetings between CVM and sponsors 
Communication is a critical part of the review process that allows both CVM and sponsors 
to receive timely responses to their questions and allows sponsors to submit appropriate 
data to ensure efficient evaluation of submissions.  To increase communication, once a new 
animal drug product is designated as a PZAD, CVM will offer recurring informal meetings 
between the sponsor and the review team without a formal submission.  The goal of these 
meetings is for the sponsor to provide updates on drug development, discuss any changes to 
data submission timelines, and for CVM to address questions and other issues that may 
result in minor amendments to technical section submissions.  These meetings are not 
intended to replace presubmission conferences13 or other formal meetings.  CVM 
encourages the sponsor to contact their CVM project manager (PM) to discuss whether 
their product may be at the appropriate stage to begin scheduling regular informal 
meetings.  In general, the frequency of these meetings will depend on the stage of the 
sponsors drug development and the information planned for submission to CVM. 
B.  PZAD pre-review feedback 
Sponsors pursuing approval or conditional approval of a new animal drug product 
designated as a PZAD are eligible to receive pre-review feedback from CVM.  Pre-review 
feedback is intended to provide sponsors an opportunity to receive high-level informal 
feedback from CVM regarding possible deficiencies in draft submissions prior to the 
formal submission.  Possible items that may be addressed under the pre-review feedback 
option include: 
  confirming if information is appropriate for inclusion in a submission and 
identifying gaps that may need to be addressed; 
  answering specific questions regarding the appropriate level of detail to include in a 
submission; and 
  providing examples of data presentation (e.g., data formatting, file format). 
Under pre-review feedback, CVM will not review information or data for acceptability, nor 
will CVM answer specific questions on the overall development plan.  Sponsors should 
contact their CVM PM with questions regarding their overall development plan. 
To receive pre-review feedback from CVM, sponsors should submit a meeting request via 
eSubmitter14 and include a list of questions for CVM to address.  The meeting request 
should include sufficient supporting information to allow CVM to provide appropriate 
 
13 See 21 CFR part 514, which describes the procedures to be followed for requesting, conducting, and documenting 
presubmission conferences, or CVM Program Policy and Procedures Manual 1243.3024 Scheduling and Holding 
Meetings with Outside Parties (April 2023).  
14 For more information on eSubmitter, see CVM eSubmitter Program for Animal DrugsOffice of New Animal 
Drug Evaluation | FDA.  
6 
  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
recommendations and feedback.  In addition, the meeting request should also indicate if 
sponsors would like a teleconference to discuss their submission prior to receiving written 
feedback.  If a teleconference is requested, CVM will aim to hold it within approximately 
25 calendar days of the receipt of the meeting request. 
CVM will aim to send sponsors a summary of CVMs pre-review feedback within 
approximately 35 calendar days of receipt of the meeting request.  No memorandum of 
conference (MOC) or acknowledgement letter will be issued. 
Sponsors should contact their PM for questions regarding pre-review feedback and how to 
request pre-review feedback. 
C.  PZAD post-review feedback
Sponsors pursuing approval or conditional approval of a new animal drug product 
designated as a PZAD are eligible to receive post-review feedback from CVM if they wish 
to discuss a CVM response letter that they have received.  The goal of post-review 
feedback is to facilitate communication between the sponsor and CVM.  Post-review 
feedback allows the sponsor and CVM to informally discuss the comments in CVMs 
response letter (e.g., Technical Section Incomplete, protocol non-concurrence letter) with 
the goal of assisting the sponsor in preparing their resubmission.  After the sponsor 
receives CVMs response letter, the sponsor may request an informal meeting and provide 
a list of clarifying questions to be discussed.  CVMs response letter will include the 
contact information for requesting post-review feedback.  CVM will not provide an MOC 
or acknowledgment letter for the post-review feedback.   
D.  PZAD stop-the-review-clock
Under user fee performance goals timeframes, CVM uses a review clock system under 
which each major technical section submission that will support an approval has a 180-day 
review time.  Ordinarily, when CVM determines a technical section submission is 
incomplete, a letter is sent to the sponsor informing them of this determination and the 
submission is closed out and removed from the queue.  When the sponsor responds to the 
deficiencies noted in the incomplete letter, the 180-day clock starts anew.
The PZAD stop-the-review-clock is an optional process that CVM may initiate when 
additional information is needed to complete a technical section or accept a study.  The 
stop-the-review-clock process provides sponsors preliminary feedback regarding missing 
or unacceptable elements of the submission without closing out the submission and 
removing it from the queue, and provides sponsors with an opportunity to submit additional 
information to address CVM comments prior to completion of review of the P submission.  
When a sponsor submits this additional information, the review clock resumes.  The goal is 
to decrease the number of review cycles.  Stopping the review clock rather than closing out 
a submission and initiating a new review cycle when this additional information is 
submitted can shorten the total time to address that technical section in support of approval. 
7  Contains Nonbinding Recommendations 
Draft  Not for Implementation 
Sponsors are expected to submit high-quality submissions to facilitate review by CVM.  
The stop-the-review-clock process is intended to address scientific issues (e.g., need for 
additional data to support conclusions, justifications, alternate data presentations) to 
facilitate the expedited review of PZAD products; it is not intended to rehabilitate poor-
quality submissions (e.g., issues with organization, incomplete submissions, or unclear 
purpose of the submission). 
If CVM utilizes the stop-the-review-clock process for a submission, CVM will send a letter 
to the sponsor providing a list of comments to address.  The sponsor should respond to 
CVM within 2 weeks of the date of the letter.  The sponsor may either: (1) agree to submit 
an amendment with the requested information within 120 days of the date of the letter; or 
(2) request that the clock be restarted because the sponsor does not agree to submit
additional information.  The review clock will be restarted when the sponsor either declines
to submit the amendment or when the amendment is received by CVM.
8