Obesity, ChildhoodEarly Phase 1PHARMATOPNCT04986631
Pharmacokinetics and Pharmacodynamics of Topiramate for Weight Loss in Youth: PHARMATOP
A Early Phase 1 study testing Topiramate Tablets in people with Obesity, Childhood, run by University of Minnesota at 1 site in United States.
Trial summary
Pediatric severe obesity is the fastest growing obesity category in the United States, and anti-obesity pharmacotherapies are promising adjuncts to lifestyle modification (LSM) for the treatment of this disease. Read more about this study
- Who is it for?
- Ages 12 to 18 years
- Conditions the study is for
- Obesity, Childhood
- What is being tested?
- Topiramate Tablets
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 65 participants
- Where
- 1 siteUnited States
- Study dates
- 4 Apr 2022to 26 Sep 2024
- Phase
- Early Phase 1
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Body mass index (BMI) </= 1.2 times the 95th percentile (age and sex-adjusted) and/or BMI >/= 35 kg/m2
- Ages 12 to < 18 years old
- Deemed appropriate candidates to receive topiramate (without contraindications) for weight loss by an obesity medicine specialist at the University of Minnesota
Who cannot join
- History of metabolic/bariatric surgery
- Obesity associated with a diagnosed genetic disorder (i.e. monogenic obesity, Prader-Willi, Bardet-Biedl syndrome)
- Clinically diagnosed hyperthyroidism or uncontrolled hypothyroidism as determined by local medical monitor (who is a board certified endocrinologist)
- History of acute angle closure glaucoma. Individuals with other types of glaucoma will need approval from the participant's ophthalmologist to be enrolled.
- History of nephrolithiasis
- History of seizures (aside from febrile seizures)
Show all 16Show fewer
- Major psychiatric disorder as determined by local medical monitor
- History of bulimia nervosa or anorexia nervosa
- History of suicide attempt within the last year
- History of active suicidal ideation or self-harm within the past 30 days
- Current or recent (< 6 months prior to enrollment) use of anti-obesity medication(s) defined as orlistat, phentermine, topiramate, combination phentermine/topiramate, liraglutide (or other glucagon-like peptide (GLP1-RA)), and/or combination naltrexone/bupropion (monotherapy use of naltrexone or bupropion is not an exclusion), unless participant has been on stable doses for >/= 6 months. Of note, if phentermine was increased from 15 mg daily to 18.75 mg daily during this period, it is not considered a dose increase.
- Current or recent (< 6 months prior to enrollment) use of medication(s) associated with weight gain (e.g. oral steroids, anti-psychotics), unless participant has been on stable doses of such medication(s) for ≥ 6 months
- Current or recent (< 6 months prior to enrollment) use of long-acting stimulant medications, unless participant has been on stable doses of such medication for ≥ 6 months. In terms of short-acting ADHD stimulant medications, the PI will determine eligibility based on weight and dose (no studies have shown this contributes to weight outcomes)
- Baseline bicarbonate < 18 mmol/L
- Baseline creatinine > 1.2 mg/dL
- Females: pregnant, planning to become pregnant, or, if sexually active, unwilling to use 2+ acceptable contraceptive methods during the study period
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Minnesota
Minneapolis, Minnesota, 55455
About this study
Pediatric severe obesity is the fastest growing obesity category in the United States, and anti-obesity pharmacotherapies are promising adjuncts to lifestyle modification (LSM) for the treatment of this disease. While anti-obesity pharmacotherapies have overall been associated with mean weight loss, there is substantial variability in their individual-level effectiveness. While some patients lose a significant amount of weight with anti-obesity pharmacotherapies, others lose little or even gain weight.
Due to this well-recognized variability in individual-level response, the National Institutes of Health (NIH) has recognized the importance of using precision medicine approaches in order to optimize treatments for pediatric severe obesity. Pharmacometrics, which uses mathematical models to study medication dose-exposure (i.e. blood drug concentrations)-response relationships, is an emerging science that can help determine optimal dosing regimens based upon patient-specific characteristics. Pharmacometrics quantitates the interplay between pharmacokinetics (PK; drug dose-exposure associations) and pharmacodynamics (PD; drug exposure-response associations). Population PK (popPK), a type of PK, can be used to quantitate variability in drug exposure among individuals in order to help inform recommendations on therapeutic individualization (e.g. through tailored dosing). In this study, investigators will use popPK/PD modeling to characterize associations between anti-obesity pharmacotherapy dose, exposure, and changes in weight and weight-related outcomes in youth with severe obesity.
This study will focus on topiramate because this medication is commonly prescribed for weight loss in youth with severe obesity and has been associated with highly variable individual-level effectiveness.
Read the detailed description
The weight loss achieved with topiramate occurs through several purported mechanisms including reductions in appetite, food cravings, and binge eating, and adverse alterations in taste for carbonated beverages. It is hypothesized that some of the individual-level effectiveness of this medication on weight loss response is secondary to patient-specific differences in these factors. In a 3.5-month pragmatic-based prospective cohort study (n=65), the investigators will develop a popPK model using sparse sampling by drawing a series of topiramate concentration measures over time in order to begin determining patient-specific factors that contribute to topiramate exposure variability. The investigators will also identity associations between topiramate exposure, changes in eating behaviors, and weight loss outcomes through PD models using regression techniques. It is hypothesized that patient-specific characteristics (i.e. age, body mass index (BMI), and sex) will explain some variability in topiramate exposure in youth, and that higher topiramate exposure will be associated with greater improvements in weight loss response and eating behaviors among youth prescribed this medicine for the treatment of pediatric severe obesity.
- Conditions
- Obesity, Childhood
- Being tested
- Topiramate Tablets
- Medical subject headings
- Pediatric Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Topiramate TabletsDrug
Topiramate intervention
| Study group | Role | What they receive |
|---|---|---|
| Topiramate | Experimental | Individuals will receive 75 mg of topiramate daily. The dose will start at 25 mg daily for the first week. The second week participants will receive 50 mg daily. Starting at week 3 participants will take 75 mg daily. Receives: Drug: Topiramate Tablets |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percent BMI Change
Percent change in body mass index (BMI) from baseline to 14 weeks (mean change from baseline to 14 weeks of follow up, analysis using paired t-tests)
Measured: 14 Weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Aug 2021
- Study start4 Apr 2022
- Primary completion26 Sep 2024
- Study completion26 Sep 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Obesity, ChildhoodStudies of the same condition, open and under way.
- More trials run by University of MinnesotaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Individuals in this pilot study will be 12-\<18 years of age at enrollment. All participants will receive topiramate for 3.5 months.
- Masking
- None (open label)
- Enrolment
- 65 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Eric Bomberg, MD, Principal investigator, University of Minnesota
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04986631
- Sponsor's protocol ID
- PEDS-2021-29920
- Other IDs
- 5K23DK125668-03
- Acronym
- PHARMATOP
- Status last verified
- Aug 2026
- First submitted
- 16 Jul 2021
- Last updated
- 24 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Summary data that has been de-identified will be made available to other researchers
Study at a glance
From the registry record, last updated by the sponsor on 24 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pharmacokinetics and Pharmacodynamics of Topiramate for Weight Loss in Youth: PHARMATOP
- ClinicalTrials.gov ID
- NCT04986631
- Acronym / sponsor ID
- PHARMATOP / PEDS-2021-29920
- Conditions
- Obesity, Childhood
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 65 participants (actual)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 4 Apr 2022 (actual)
- Primary completion
- 26 Sep 2024 (actual)
- Study completion
- 26 Sep 2024 (actual)
- First posted
- 3 Aug 2021 (actual)
- Results
- Posted 24 Aug 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Pediatric severe obesity is the fastest growing obesity category in the United States, and anti-obesity pharmacotherapies are promising adjuncts to lifestyle modification (LSM) for the treatment of this disease. While anti-obesity pharmacotherapies have overall been associated with mean weight loss, there is substantial variability in their individual-level effectiveness. While some patients lose a significant amount of weight with anti-obesity pharmacotherapies, others lose little or even gain weight.
Due to this well-recognized variability in individual-level response, the National Institutes of Health (NIH) has recognized the importance of using precision medicine approaches in order to optimize treatments for pediatric severe obesity. Pharmacometrics, which uses mathematical models to study medication dose-exposure (i.e. blood drug concentrations)-response relationships, is an emerging science that can help determine optimal dosing regimens based upon patient-specific characteristics. Pharmacometrics quantitates the interplay between pharmacokinetics (PK; drug dose-exposure associations) and pharmacodynamics (PD; drug exposure-response associations). Population PK (popPK), a type of PK, can be used to quantitate variability in drug exposure among individuals in order to help inform recommendations on therapeutic individualization (e.g. through tailored dosing). In this study, investigators will use popPK/PD modeling to characterize associations between anti-obesity pharmacotherapy dose, exposure, and changes in weight and weight-related outcomes in youth with severe obesity.
This study will focus on topiramate because this medication is commonly prescribed for weight loss in youth with severe obesity and has been associated with highly variable individual-level effectiveness.
Detailed description
The weight loss achieved with topiramate occurs through several purported mechanisms including reductions in appetite, food cravings, and binge eating, and adverse alterations in taste for carbonated beverages. It is hypothesized that some of the individual-level effectiveness of this medication on weight loss response is secondary to patient-specific differences in these factors. In a 3.5-month pragmatic-based prospective cohort study (n=65), the investigators will develop a popPK model using sparse sampling by drawing a series of topiramate concentration measures over time in order to begin determining patient-specific factors that contribute to topiramate exposure variability. The investigators will also identity associations between topiramate exposure, changes in eating behaviors, and weight loss outcomes through PD models using regression techniques. It is hypothesized that patient-specific characteristics (i.e. age, body mass index (BMI), and sex) will explain some variability in topiramate exposure in youth, and that higher topiramate exposure will be associated with greater improvements in weight loss response and eating behaviors among youth prescribed this medicine for the treatment of pediatric severe obesity.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Individuals in this pilot study will be 12-<18 years of age at enrollment. All participants will receive topiramate for 3.5 months.
| Arm | Type | Receives |
|---|---|---|
| Topiramate | Experimental | Drug: Topiramate TabletsIndividuals will receive 75 mg of topiramate daily. The dose will start at 25 mg daily for the first week. The second week participants will receive 50 mg daily. Starting at week 3 participants will take 75 mg daily. |
Who may qualify
- Ages
- 12 to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (3 listed)
- Body mass index (BMI) </= 1.2 times the 95th percentile (age and sex-adjusted) and/or BMI >/= 35 kg/m2
- Ages 12 to < 18 years old
- Deemed appropriate candidates to receive topiramate (without contraindications) for weight loss by an obesity medicine specialist at the University of Minnesota
Key exclusion criteria (16 listed)
- History of metabolic/bariatric surgery
- Obesity associated with a diagnosed genetic disorder (i.e. monogenic obesity, Prader-Willi, Bardet-Biedl syndrome)
- Clinically diagnosed hyperthyroidism or uncontrolled hypothyroidism as determined by local medical monitor (who is a board certified endocrinologist)
- History of acute angle closure glaucoma. Individuals with other types of glaucoma will need approval from the participant's ophthalmologist to be enrolled.
- History of nephrolithiasis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Topiramate TabletsTopiramate intervention | Drug | Topiramate |
Primary outcome
Percent BMI Change
Time frame: 14 Weeks
Percent change in body mass index (BMI) from baseline to 14 weeks (mean change from baseline to 14 weeks of follow up, analysis using paired t-tests)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. Summary data that has been de-identified will be made available to other researchers
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Eric Bomberg, MD principal investigator
University of Minnesota
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Topiramate Tablets in people with Obesity, Childhood, run by University of Minnesota at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 24 Aug 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Percent BMI Change (time frame: 14 Weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Aug 2026.