Guidance for Industry

Information Request and Discipline 

Review Letters Under the 

Prescription Drug User Fee Act

Comments and suggestions regarding this document should be submitted at anytime to Dockets 

Management Branch (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061, 

Rockville, MD 20852. All comments should be identified with the title of this guidance 

document.

Additional copies of this guidance document are available from the Office of Communication, 

Training and Manufacturers Assistance (HFM-40), 1401 Rockville Pike, Rockville, MD 20852-

1448, or by calling 1-800-835-4709 or 301-827-1800, or from the Internet at 

http://www.fda.gov/cber/guidelines.htm. 

For questions on the content of the document, contact (CDER) Dr. Sandra Kweder, 301-594-

5400 or (CBER) Robert A. Yetter, Ph.D., 301-827-0373.

U.S. Department of Health and Human Services

Food and Drug Administration

Center for Biologics Evaluation and Research (CBER)

Center for Drug Evaluation and Research (CDER)

November 2001
Guidance for Industry

Information Request and 

Discipline Review Letters Under 

the Prescription Drug User Fee Act

Additional copies of this guidance are available from

Office of Training and Communication

Division of Communications Management

Drug Information Branch, HFD-210

Center for Drug Evaluation and Research

Food and Drug Administration

5600 Fishers Lane, Rockville, MD 20857 

(Phone: 301-827-4573),

Internet: http://www.fda.gov/cder/guidance/index.htm

or

Office of Communication, Training, and

Manufacturers Assistance, HFM-40

Center for Biologics Evaluation and Research

Food and Drug Administration

1401 Rockville Pike, Rockville, MD 20852-1448

(Phone: 301-827-4573),

Internet: http://www.fda.gov/cber/guidelines.htm

Fax: 1-888-CBERFAX or 301-827-3844

Voice Information System: 800-835-4709 or 301-827-1800

U.S. Department of Health and Human Services

Food and Drug Administration

Center for Biologics Evaluation and Research (CBER)

Center for Drug Evaluation and Research (CDER)

November 2001
Table of Contents

I. INTRODUCTION ..............................................................................................................1

II. BACKGROUND.................................................................................................................1

III. EXPLANATION OF TERMS...........................................................................................2

IV. ISSUANCE AND USE OF INFORMATION REQUEST 

 AND DISCIPLINE REVIEW LETTERS.....................................................................3

A. General..........................................................................................................................3

B. Applicant Response and Effect on the User Fee Clock ............................................4
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GUIDANCE FOR INDUSTRY 1

Information Request and Discipline Review Letters Under the Prescription 

Drug User Fee Act

This guidance document represents the agency’s current thinking on information request and 

discipline review letters under the Prescription Drug User Fee Act. It does not create or 

confer any rights for or on any person and does not operate to bind FDA or the public. An 

alternative approach may be used if such approach satisfies the requirements of the applicable 

statutes and regulations.

I. INTRODUCTION

This guidance for industry explains how the Agency will issue and use information request 

(IR) letters and discipline review (DR) letters during the review of products in original human 

drug applications as defined in section 735(1) of the Federal Food, Drug, and Cosmetic Act 

(21 U.S.C. 379g(1)) (PDUFA products). This guidance does not apply to supplemental 

applications, resubmissions, or to applications for non-PDUFA products.

In a November 1997 letter to Congress regarding the reauthorization of the Prescription Drug 

User Fee Act (PDUFA) as part of the Food and Drug Administration Modernization Act of 

1997, the Secretary of Health and Human Services committed the Food and Drug 

Administration to certain user fee performance goals and additional procedures related to the 

review of PDUFA products. These include the goals of reviewing and acting on increasing 

percentages of applicants' original new drug applications (NDAs) or biologics license 

applications (BLAs), within 6 months for priority applications and within 10 months for 

standard applications for drugs and biologics. The term review and act on means the issuance 

of an action letter after the complete review of a filed application. In addition to the 

performance goals for application review, to help expedite the development of drugs and 

biologics, the Secretary specified that FDA intends to provide early Agency thoughts on 

possible deficiencies to applicants in a letter as each discipline finishes its initial review of its 

portion of the pending application (except when it results in the ability to issue an action 

letter).

II. BACKGROUND

Upon implementation of the Prescription Drug User Fee Act of 1992 (PDUFA 1), the Center 

for Biologics Evaluation and Research (CBER) and the Center for Drug Evaluation and 

Research (CDER) undertook to review and act on complete NDAs and BLAs within agreed 

 

1

 This guidance has been prepared by the Review Management Working Group comprising individuals in the 

Centers for Drug Evaluation and Research (CDER) and Biologics Evaluation and Research (CBER) at the Food 

and Drug Administration. 
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upon time frames. As part of this undertaking FDA instituted the use of two types of letters, 

action letters and IR letters. FDA issued an action letter (not approvable, approvable or 

approval letter) after a complete review of the application. If not an approval, the action letter 

contained a complete list of deficiencies in the application and completed the review cycle for 

the application. The next review cycle (resubmission) began when the agency receive a 

complete response to all deficiencies listed in the letter. CDER and CBER used IR letters to 

ask for information that would assist reviewers during the course of the review or to convey 

deficiencies identified in the application in advance of the issuance of an action letter. These 

IR letters did not stop the review clock, did not signal the completion of a review cycle, and 

were not used consistently across divisions or centers.

In discussions held to prepare for the reauthorization of PDUFA (PDUFA 2), industry 

proposed that applicants be notified of any deficiencies in an NDA or BLA as early as 

possible after a discipline review had been completed. It was agreed that deficiencies would 

be communicated in a specific type of letter. The company could then begin preparing a 

response to the deficiencies, thereby decreasing the response time to the Agency and 

potentially expediting availability of products to consumers. Although the enclosure to the 

PDUFA 2 goals letter signed by Secretary Shalala refers to these as IR letters, FDA finds that 

it will be less confusing if these letters are clearly identified as a unique type of letter, the DR 

letter. Consequently the Agency will continue to use an IR letter, if needed, to request 

information while a specific discipline review is in progress and institute the use of a DR 

letter to convey early thoughts on possible deficiencies in the discipline's section of the 

application when a discipline review is complete.

A discipline review refers to the review of sections of the NDA and BLA by staff with that 

expertise. These sections include, but are not limited to, the clinical section, the chemistry, 

manufacturing and controls section, the non-clinical pharmacology and toxicology section, 

and the human pharmacokinetics and bioavailability section. As part of their PDUFA 2 

commitments at the conclusion of a discipline review, CBER and CDER will send a discipline 

review letter to the applicant identifying deficiencies in that particular discipline's portion of 

an application as described in this document, unless the discipline review completes the 

review of the application.

III. EXPLANATION OF TERMS

An action letter is a letter to an applicant that is issued after the complete review of a filed 

application. If the letter is not an approval letter, it will set forth in detail the specific 

deficiencies and, where appropriate, the actions necessary to place the application in 

condition for approval. An action letter may contain additional or fewer deficiencies than 

were provided in previously issued DR letters, depending on the final review of the 

application and supervisory evaluation by Division and/or Office Directors. The issuance of 

an action letter completes the review cycle for a pending application. It is the benchmark by 

which the Agency's performance against the PDUFA application review goals is measured.

A DR letter is a letter used to convey early thoughts on possible deficiencies found by a 

discipline review team for its portion of the pending application at the conclusion of the 
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discipline review. FDA does not consider DR letters to be action letters because they do not 

represent a complete review of the submission and, therefore, do not stop the user fee review 

clock. In addition, a DR letter does not necessarily reflect input from upper supervisory levels 

(i.e., Division or Office Directors). A single DR letter may contain comments from multiple 

discipline reviews if it is more efficient to do so. FDA may review such information if it 

determines that such review would not adversely affect its ability to meet its PDUFA 

performance goal for that review cycle. FDA has no obligation to review information 

submitted in response to a DR letter during the review cycle in which the DR letter was 

issued. 

An IR letter is a letter sent to an applicant during an application review to request further 

information or clarification that is needed or would be helpful to allow completion of the 

discipline review. FDA does not consider IR letters to be action letters because they do not 

represent a complete review of the submission and therefore do not stop the user fee review 

clock. As with DR letters, an IR letter does not necessarily reflect input from upper 

supervisory levels. However, IR letters are not like DR letters in that FDA issues IR letters 

while the discipline review continues. Information requested in IR letters should be 

information that would assist in the completion of the review and, as such, would usually be 

reviewed during the review cycle in which the IR letter was issued.

The user fee review clock measures the time elapsed during which an application is under 

review by CBER or CDER (i.e., a review cycle). The review clock starts at Agency receipt of 

an NDA or BLA that is subsequently filed, or a complete resubmission and stops when the 

agency issues an action letter to the applicant.

IV. ISSUANCE AND USE OF INFORMATION REQUEST AND DISCIPLINE 

 REVIEW LETTERS

A. General

CBER and CDER will use IR letters to obtain clarifying information to assist in 

completing a review. Because the Agency issues IRs to obtain clarification, it is normally 

expected that the applicant will respond as quickly as possible. FDA reviews such 

responses (if they are of a clarifying nature) as part of the current review cycle of the 

application. However, if the response is of a significant nature, the response could 

constitute a major amendment. Major amendments to an original application received in 

the last three months of the review cycle may extend the Action Due date by three months. 

Only one such extension is permitted. FDA may defer the review of a response to the 

next review cycle, if the review team believes that the new information cannot be fully 

reviewed in the time remaining in the current review cycle or is ready to issue an action 

letter.

To help expedite the development of drug and biologic products, under PDUFA 2, CBER 

and CDER will generally convey early thoughts on possible deficiencies to applicants in 

the form of a DR letter as each discipline finishes its review of its section of the pending 

application, unless the discipline review completes the review of the application. FDA 

will not issue a DR letter if its issuance would delay or coincide with the issuance of an 
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action letter. You should not construe the absence of a DR letter for a particular discipline 

to mean that the action letter will not contain any deficiencies for that discipline. 

Comments in a DR letter will usually reflect the input of the review team but not that of 

the review division director or office director.

The DR letter will allow applicants to know as soon as possible the review team's early 

thoughts on possible deficiencies that have been identified within specific sections of the 

application. With this information they can begin to assemble the needed data to address 

these deficiencies. DR letters will only contain items that the review team believes require 

resolution prior to approval of the product. A DR letter intended to convey deficiencies 

found during a discipline review will be clearly distinguishable from IR letters, which are 

requests for clarifications needed to proceed with the on-going review.

Applicants should be aware that because the DR letter will originate at the review team 

level, supervisors may add or delete items in the course of their evaluation, resulting in 

more or fewer deficiencies in the subsequent action letter. In addition, as reviews from 

different disciplines are integrated, additional concerns might arise or previously stated 

concerns may be resolved. Therefore, applicants could spend time gathering information 

that in the end may not be necessary for responding to the action letter. This possibility 

was raised during PDUFA 2 discussions with industry representatives, and it was agreed 

during those discussions that the DR letter program should be evaluated to determine if it 

truly helps achieve the goal of reducing the time it takes to make products available to the 

consumer (i.e. if the benefit of early notification of possible deficiencies outweighs the 

possibility of unnecessary extra work on the part of industry).

B. Applicant Response and Effect on the User Fee Clock

The IR letters and DR letters will not affect the user fee review clock for a given review 

cycle. The review team will review responses to IR letters and DR letters during the 

current review cycle at the discretion of the review team. Normally, unless the amount 

and type of information is substantive or voluminous, FDA will review a clarifying IR 

letter response during the current review cycle. We may or may not consider a response 

to a DR letter conveying deficiencies identified in a discipline review of an original 

application a major amendment, which would extend the review time for the current 

review cycle. At the Division's discretion, it may review the response if the review can be 

completed in the current review cycle. The Agency is not obligated to review the 

response before the issuance of an action letter. If the Agency determines that it cannot 

review the newly submitted data before the user fee action due date, it may defer review 

of the response. If the review team is ready to issue an action letter, review of the 

response could also be deferred. When FDA defer the review of a response it will be 

reviewed during the next review cycle for the application as part of the complete 

resubmission if the applicant references such response in the resubmission.

Deficiencies addressed in a response to an IR letter or a DR letter may appear in an action 

letter if the review of the response has been deferred or if concerns remain after review of 
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the response. The action letter will include all deficiencies that must be answered in order 

to place the application in condition for approval.

If the applicant has already submitted a complete response to all of the outstanding 

deficiencies, the applicant may simply refer to such responses in the complete 

resubmission that responds to the action letter; further reiteration of previously submitted 

information is not necessary. However, the applicant should clearly identify in the 

resubmission all such responses that are required to complete the resubmission as such.