Notice2026-08521
Obesity and Drug Dosing: Clinical Pharmacology Considerations; Request for Comments
Primary source
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Published
May 1, 2026
Issuing agencies
Health and Human Services DepartmentFood and Drug Administration
Abstract
The Food and Drug Administration (FDA) is establishing a public docket entitled "Obesity and Drug Dosing: Clinical Pharmacology Considerations." The Agency is soliciting input from interested persons on assessing the effect of obesity on drug pharmacokinetics and pharmacodynamics during drug (including biological product) development. These assessments could potentially inform whether obesity impacts the safety and effectiveness of the drug and dosing recommendations for obese patients.
Full Text
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<title>Federal Register, Volume 91 Issue 84 (Friday, May 1, 2026)</title>
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[Federal Register Volume 91, Number 84 (Friday, May 1, 2026)]
[Notices]
[Pages 23424-23426]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-08521]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
[Docket No. FDA-2026-N-3499]
Obesity and Drug Dosing: Clinical Pharmacology Considerations;
Request for Comments
AGENCY: Food and Drug Administration, HHS.
ACTION: Notice; establishment of a public docket; request for comments.
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SUMMARY: The Food and Drug Administration (FDA) is establishing a
public docket entitled ``Obesity and Drug Dosing: Clinical Pharmacology
Considerations.'' The Agency is soliciting input from interested
persons on assessing the effect of obesity on drug pharmacokinetics and
[[Page 23425]]
pharmacodynamics during drug (including biological product)
development. These assessments could potentially inform whether obesity
impacts the safety and effectiveness of the drug and dosing
recommendations for obese patients.
DATES: Submit either electronic or written comments by June 30, 2026.
ADDRESSES: FDA is establishing a docket for public comment on this
notice. The docket number is FDA-2026-N-3499. The docket will close on
June 30, 2026. Submit either electronic or written comments by June 30,
2026. Please note that late, untimely filed comments will not be
considered. Electronic comments must be submitted on or before June 30,
2026. The <a href="https://www.regulations.gov">https://www.regulations.gov</a> electronic filing system will
accept comments until 11:59 p.m. Eastern Time at the end of June 30,
2026. Comments received by mail/hand delivery/courier (for written/
paper submissions) will be considered timely if they are postmarked or
the delivery service acceptance receipt is on or before that date.
You may submit comments as follows:
Electronic Submissions
Submit electronic comments in the following way:
<bullet> Federal eRulemaking Portal: <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Follow the instructions for submitting comments. Comments submitted
electronically, including attachments, to <a href="https://www.regulations.gov">https://www.regulations.gov</a>
will be posted to the docket unchanged. Because your comment will be
made public, you are solely responsible for ensuring that your comment
does not include any confidential information that you or a third party
may not wish to be posted, such as medical information, your or anyone
else's Social Security number, or confidential business information,
such as a manufacturing process. Please note that if you include your
name, contact information, or other information that identifies you in
the body of your comments, that information will be posted on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
<bullet> If you want to submit a comment with confidential
information that you do not wish to be made available to the public,
submit the comment as a written/paper submission and in the manner
detailed (see ``Written/Paper Submissions'' and ``Instructions'').
Written/Paper Submissions
Submit written/paper submissions as follows:
<bullet> Mail/Hand delivery/Courier (for written/paper
submissions): Dockets Management Staff (HFA-305), Food and Drug
Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852.
<bullet> For written/paper comments submitted to the Dockets
Management Staff, FDA will post your comment, as well as any
attachments, except for information submitted, marked and identified,
as confidential, if submitted as detailed in ``Instructions.''
Instructions: All submissions received must include the Docket No.
FDA-2026-N-3499 for ``Obesity and Drug Dosing: Clinical Pharmacology
Considerations; Request for Comments.'' Received comments will be
placed in the docket and, except for those submitted as ``Confidential
Submissions,'' publicly viewable at <a href="https://www.regulations.gov">https://www.regulations.gov</a> or at
the Dockets Management Staff between 9 a.m. and 4 p.m., Monday through
Friday, 240-402-7500.
<bullet> Confidential Submissions--To submit a comment with
confidential information that you do not wish to be made publicly
available, submit your comments only as a written/paper submission. You
should submit two copies total. One copy will include the information
you claim to be confidential with a heading or cover note that states
``THIS DOCUMENT CONTAINS CONFIDENTIAL INFORMATION.'' The Agency will
review this copy, including the claimed confidential information, in
its consideration of comments. The second copy, which will have the
claimed confidential information redacted/blacked out, will be
available for public viewing and posted on <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Submit both copies to the Dockets Management Staff. If you do not wish
your name and contact information to be made publicly available, you
can provide this information on the cover sheet and not in the body of
your comments and you must identify this information as
``confidential.'' Any information marked as ``confidential'' will not
be disclosed except in accordance with 21 CFR 10.20 and other
applicable disclosure law. For more information about FDA's posting of
comments to public dockets, see 80 FR 56469, September 18, 2015, or
access the information at: <a href="https://www.govinfo.gov/content/pkg/FR-2015-09-18/pdf/2015-23389.pdf">https://www.govinfo.gov/content/pkg/FR-2015-09-18/pdf/2015-23389.pdf</a>.
Docket: For access to the docket to read background documents or
the electronic and written/paper comments received, go to <a href="https://www.regulations.gov">https://www.regulations.gov</a> and insert the docket number, found in brackets in
the heading of this document, into the ``Search'' box and follow the
prompts and/or go to the Dockets Management Staff, 5630 Fishers Lane,
Rm. 1061, Rockville, MD 20852, 240-402-7500.
FOR FURTHER INFORMATION CONTACT: Martina Sahre, Center for Drug
Evaluation and Research, Food and Drug Administration, 10903 New
Hampshire Ave., Silver Spring, MD 20993-0002, 301-796-9659.
SUPPLEMENTARY INFORMATION:
I. Background
Obesity is a critical and increasingly prevalent public health
concern in the United States affecting approximately 20% of children
\1\ and approximately 40% of adults.\2\ It is linked to a variety of
comorbidities such as diabetes and heart disease. The U.S. Centers for
Disease Control and Prevention (CDC) defines obesity as having a body
mass index of >=30 kg/m\2\ for adults and a body mass index at or above
the 95th percentile (based on age and sex) for children.\1,2\ Despite
its high prevalence, the effect of obesity on drug pharmacokinetics,
pharmacodynamics, effectiveness, and safety is not consistently
assessed in clinical trials, except in certain therapeutic areas (e.g.,
obesity, Type 2 diabetes mellitus, sleep apnea). Furthermore, obesity-
related information on these aspects is often absent in drug product
labels.
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\1\ U.S. Centers for Disease Control and Prevention (CDC), 2024,
Childhood Obesity Facts, CDC, accessed May 8, 2025, <a href="https://www.cdc.gov/obesity/childhood-obesity-facts/childhood-obesity-facts.html">https://www.cdc.gov/obesity/childhood-obesity-facts/childhood-obesity-facts.html</a>.
\2\ CDC, 2024, Adult Obesity Facts, CDC, accessed May 8, 2025,
<a href="https://www.cdc.gov/obesity/adult-obesity-facts/index.html">https://www.cdc.gov/obesity/adult-obesity-facts/index.html</a>.
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Obesity is reported to affect the pharmacokinetics and
pharmacodynamics of drugs in several ways: (1) lipophilic drugs can
show increased distribution into fat tissues; (2) absorption can be
altered due to changes in gastric transit times and gastrointestinal pH
values; (3) metabolism and excretion could be altered due to an impact
on drug-metabolizing enzymes, transporters, or changes in renal
clearance; and (4) the sensitivity of drug targets could be altered.
The impact of body size (usually total body weight) is typically
considered as part of population pharmacokinetic analysis. If
identified as a significant covariate in population pharmacokinetic
analysis, the need for dosing based on body weight, body mass index, or
body surface area is routinely assessed. However, limited enrollment of
obese patients in clinical trials--particularly patients with morbid
obesity--limits pharmacokinetic and pharmacodynamic assessments across
a full range of body sizes.
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II. Request for Information and Comments
FDA invites interested persons to provide detailed information and
comments on relevant considerations for evaluating the impact of
obesity on drug pharmacokinetics and pharmacodynamics and the need for
specific dosage recommendations. Please provide the rationale for your
suggestions and include supporting data if available.
FDA is particularly interested in responses to the following
overarching questions:
1. Body mass index is often used to identify and classify the
degree of obesity. Is the categorization of body mass index sufficient
for evaluating the impact of obesity on drug pharmacokinetics or
pharmacodynamics and to inform recommendations for use in the obese
population? If not, what other pragmatic measures (e.g.,
anthropometric, biochemical, clinical) can be used in drug development
to assess the impact of obesity on drug pharmacokinetics or
pharmacodynamics and develop appropriate dosing recommendations for
adults and pediatric patients? Please also discuss the applicability of
body mass index or other measures in pediatric patients with obesity.
2. What drug-specific characteristics or therapeutic-area/disease-
related considerations are important when assessing the impact of
obesity on pharmacokinetics or pharmacodynamics?
3. How should the impact of obesity on pharmacokinetics or
pharmacodynamics, and potentially safety and effectiveness, be assessed
throughout drug development (e.g., standalone phase 1 studies, using
model-informed drug development approaches to evaluate data from late
phase trials that can also incorporate available data from other phases
of drug development)? Please also comment on any specific study design
considerations for the different approaches proposed and the timing of
such assessments.
III. Electronic Access
Persons with access to the internet may obtain relevant clinical
pharmacology guidances at <a href="https://www.fda.gov/regulatory-information/search-fda-guidance-documents">https://www.fda.gov/regulatory-information/search-fda-guidance-documents</a>.
Citation Authority: 21 CFR 312, 21 CFR 314, and 21 CFR 601.
Grace R. Graham,
Deputy Commissioner for Policy, Legislation, and International Affairs.
[FR Doc. 2026-08521 Filed 4-30-26; 8:45 am]
BILLING CODE 4164-01-P
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