Adolescent ObesityPhase 4NCT03922945

A Phase IV Safety and Efficacy Study of VI-0521 in Adolescents With Obesity

A Phase 4 study testing VI-0521 oral capsule and Lifestyle Modification in people with Adolescent Obesity and Obesity in Adolescence, run by VIVUS LLC at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

This study is being conducted to assess weight loss efficacy, as determined by changes in body mass index (BMI), and safety of VI-0521 (Qsymia®) or placebo, taken for 56 weeks accompanied by a lifestyle modification program in obese adolescents age 12-16 years. Read more about this study

Who is it for?: Ages 12 to 16 years
Conditions the study is for: Adolescent Obesity, Obesity in Adolescence, Adolescent Overweight
What is being tested?: VI-0521 oral capsule and Lifestyle Modification
Type of treatment: Pill or oral medicine, Lifestyle or therapy programme
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 223 participants
Where: 1 siteUnited States
Study dates: 2 May 2019to 16 Apr 2021
Phase: Phase 4
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 16 years
All sexes
No healthy volunteers
Child

Who may be able to join

Aged ≥ 12 years and < 17 years;
BMI ≥ the 95th percentile, with documented history of failure to lose sufficient weight or failure to maintain weight loss in a lifestyle modification program;
If female, must be using adequate contraception, defined as double barrier methods, stable hormonal contraception plus single barrier method, tubal ligation, or abstinence.

Who cannot join

Type 1 diabetes;
Congenital heart disease; clinically significant ECG abnormality;
Clinically significant physical exam, vital signs, or laboratory abnormality; clinically significant hepatic or renal disease;
Estimated Glomerular Filtration Rate (GFR; Schwartz formula) < 60 mL/minute;
Clinically significant thyroid dysfunction as evidenced by signs, symptoms, or thyroid stimulating hormone (TSH) > 1.5 x Upper Limit of Normal;
Obesity of known genetic or endocrine origin;

Show all 18Show fewer

History of bipolar disorder or psychosis, depression of moderate or greater severity, or presence or history of suicidal behavior or active suicidal ideation;
Recent weight instability, or prior bariatric surgery;
History of glaucoma or increased intraocular pressure;
Current smoker or smoking cessation within 3 months of screening;
Currently taking or plan on taking any of following medications during the study:
Anticonvulsants used for treatment of seizure disorder, including barbiturates, benzodiazepines, gamma-aminobutyric acid (GABA) analogues, hydantoins, phenyltriazines, succinimides, and other agents (valproic acid and its derivatives, carbamazepine and its derivatives, zonisamide, and felbamate);
Tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), lithium, levodopa, and dopamine receptor agonists;
Carbonic anhydrase inhibitors;
Insulin, Sulfonylureas (SFUs), glucagon-like peptide -1 (GLP-1) agonists, sodium glucose transporter-1 (SGLT-1), and SGLT-2 inhibitors;
Chronic systemic steroids (i.e. glucocorticoids, anabolic steroids) other than oral contraceptives;
Treatment for hyperactivity disorder; or
Over the counter, prescription medications, herbal agents and dietary supplements used with the intention to lose body weight.

Trial locations and contacts

1 site in 1 country.

United States1 site

Intend Research, LLC
Norman, Oklahoma, 73069

Other trials in United States

About this study

Official title: A Phase IV, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Parallel-Design Study to Determine the Safety and Efficacy of VI-0521 in Obese Adolescents

Conditions: Adolescent Obesity, Obesity in Adolescence, Adolescent Overweight
Being tested: VI-0521 oral capsule, Placebo oral capsule, Lifestyle Modification
Keywords: weight loss, obesity, weight control
Medical subject headings: Pediatric Obesity, Weight Loss, Obesity

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

VI-0521 oral capsuleDrug
Also called Qsymia, Phentermine and topiramate
Phentermine/Topiramate
Placebo oral capsuleDrug
Inactive drug
Lifestyle ModificationBehavioural
The lifestyle modification includes physical activity, behavior change, reduced calorie diet advice, and family support. This intervention is applied to all treatment groups.

Study groups in NCT03922945
Study group	Role	What they receive
VI-0521 Mid Dose (Phentermine 7.5 mg +Topiramate 46 mg)	Experimental	Weeks 1-2: VI-0521 (Phentermine 3.75 mg + Topiramate 23 mg) oral capsule, once daily; Weeks 3-56: VI-0521 (Phentermine 7.5 mg + Topiramate 46 mg) oral capsule, once daily Receives: Drug: VI-0521 oral capsule; Behavioral: Lifestyle Modification
VI-0521 Top Dose (Phentermine 15 mg + Topiramate 92 mg)	Experimental	Weeks 1-2: VI-0521 (Phentermine 3.75 mg + Topiramate 23 mg) oral capsule, once daily; Weeks 3-12: VI-0521 (Phentermine 7.5 mg + Topiramate 46 mg) oral capsule, once daily; Weeks 13-14: VI-0521 (Phentermine 11.25 mg + Topiramate 69 mg) oral capsule, once daily; Weeks 15-56: VI-0521 (Phentermine 15 mg + Topiramate 92 mg) oral capsule, once daily Receives: Drug: VI-0521 oral capsule; Behavioral: Lifestyle Modification
Placebo	Placebo comparator	Subjects will receive placebo oral capsule, once daily for up to 56 weeks Receives: Drug: Placebo oral capsule; Behavioral: Lifestyle Modification

What is being measured

The primary outcome is the main question the study is designed to answer.

Mean % Change in Body Mass Index (BMI)
Mean % change in BMI from Baseline to Week 56
Measured: Baseline to Week 56

Secondary outcomes (10)

Percentage of Subjects Achieving at Least 5% BMI Reduction at Week 56
Measured: Baseline to Week 56
Percentage of Subjects Achieving at Least 10% BMI Reduction at Week 56
Measured: Baseline to Week 56
Percentage of Subjects Achieving at Least 15% BMI Reduction at Week 56
Measured: Baseline to Week 56
Change in Waist Circumference at Week 56
Change in waist circumference from Baseline to Week 56
Measured: Baseline, Week 56
Change in Whole Body Insulin Sensitivity Index (WBISI) (Matsuda) at Week 56
Mean changes in glycemic parameters [Whole Body Insulin Sensitivity Index (WBISI) (Matsuda)] from baseline to Week 56. The Oral Glucose Tolerance Test (OGTT) were performed at Baseline and Week 56 using 75 g oral glucose load; blood samples were obtained at baseline and at 2 hours post glucose load for evaluation of both glucose and insulin levels. Insulin Sensitivity was measured by obtaining glucose and insulin levels in a fasting state and at 2 hours after administration of oral glucose load. Matsuda index = 10,000/SQRT [glucose concentration (mg/dL) (fasting)*insulin concentration (uIU/mL) (fasting)*glucose concentration (mg/dL) (2 hours after glucose load)*insulin concentration (uIU/mL) (2 hours after glucose load)], with higher numbers indicating better insulin sensitivity.
Measured: Baseline, Week 56
Change in Fasting Insulin at Week 56
Change in fasting insulin from Baseline to Week 56
Measured: Baseline, Week 56
Percent Change in Triglycerides From Baseline to Week 56
Measured: Baseline, Week 56
Percent Change in HDL-C From Baseline to Week 56
Measured: Baseline, Week 56
Change From Baseline in Systolic Blood Pressure at Week 56
Measured: Baseline, Week 56
Change From Baseline in Diastolic Blood Pressure at Week 56
Measured: Baseline, Week 56

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

2 May 201916 Apr 2021

First posted22 Apr 2019
Study start2 May 2019
Primary completion16 Apr 2021
Study completion16 Apr 2021

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.
Publications (2)Papers the sponsor has linked to this study.
Other trials for Adolescent ObesityStudies of the same condition, open and under way.
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: Phase 4
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 223 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03922945
Sponsor's protocol ID: OB-403
Status last verified: Aug 2022
First submitted: 16 Apr 2019
Last updated: 10 Sep 2022
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Publications

Bensignor MO, Freese RL, Rudser KD, Kelly AS, Kunin-Batson A, Gross AC, Bramante C, Shih W, Peterson C, Fox CK. Predictors of BMI reduction with phentermine/topiramate in adolescents with obesity. Int J Obes (Lond). 2025 Sep;49(9):1777-1780. doi: 10.1038/s41366-025-01821-6. Epub 2025 Jun 15.
PubMed 40518455
Kelly AS, Bensignor MO, Hsia DS, Shoemaker AH, Shih W, Peterson C, Varghese ST. Phentermine/Topiramate for the Treatment of Adolescent Obesity. NEJM Evid. 2022 Jun;1(6):10.1056/evidoa2200014. doi: 10.1056/evidoa2200014. Epub 2022 Apr 30.
PubMed 36968652

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Adolescent Obesity trials

Study at a glance

From the registry record, last updated by the sponsor on 10 Sep 2022. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase IV, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Parallel-Design Study to Determine the Safety and Efficacy of VI-0521 in Obese Adolescents
ClinicalTrials.gov ID: NCT03922945
Acronym / sponsor ID: OB-403
Conditions: Adolescent Obesity, Obesity in Adolescence, Adolescent Overweight
Keywords: weight loss, obesity, weight control
Phase: Phase 4
Study type: Interventional
Recruitment status: Completed
Enrolment: 223 participants (actual)
Lead sponsor: VIVUS LLCIndustry (pharma, biotech, devices)
Study start: 2 May 2019 (actual)
Primary completion: 16 Apr 2021 (actual)
Study completion: 16 Apr 2021 (actual)
First posted: 22 Apr 2019 (actual)
Results: Posted 10 Sep 2022

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 3

Arm	Type	Receives
VI-0521 Mid Dose (Phentermine 7.5 mg +Topiramate 46 mg)	Experimental	Drug: VI-0521 oral capsule, Behavioral: Lifestyle ModificationWeeks 1-2: VI-0521 (Phentermine 3.75 mg + Topiramate 23 mg) oral capsule, once daily; Weeks 3-56: VI-0521 (Phentermine 7.5 mg + Topiramate 46 mg) oral capsule, once daily
VI-0521 Top Dose (Phentermine 15 mg + Topiramate 92 mg)	Experimental	Drug: VI-0521 oral capsule, Behavioral: Lifestyle ModificationWeeks 1-2: VI-0521 (Phentermine 3.75 mg + Topiramate 23 mg) oral capsule, once daily; Weeks 3-12: VI-0521 (Phentermine 7.5 mg + Topiramate 46 mg) oral capsule, once daily; Weeks 13-14: VI-0521 (Phentermine 11.25 mg + Topiramate 69 mg) oral capsule, once daily; Weeks 15-56: VI-0521 (Phentermine 15 mg + Topiramate 92 mg) oral capsule, once daily
Placebo	Placebo comparator	Drug: Placebo oral capsule, Behavioral: Lifestyle ModificationSubjects will receive placebo oral capsule, once daily for up to 56 weeks

Who may qualify

Ages: 12 to 16 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Child

Key inclusion criteria (3 listed)

Aged ≥ 12 years and < 17 years;
BMI ≥ the 95th percentile, with documented history of failure to lose sufficient weight or failure to maintain weight loss in a lifestyle modification program;
If female, must be using adequate contraception, defined as double barrier methods, stable hormonal contraception plus single barrier method, tubal ligation, or abstinence.

Key exclusion criteria (18 listed)

Type 1 diabetes;
Congenital heart disease; clinically significant ECG abnormality;
Clinically significant physical exam, vital signs, or laboratory abnormality; clinically significant hepatic or renal disease;
Estimated Glomerular Filtration Rate (GFR; Schwartz formula) < 60 mL/minute;
Clinically significant thyroid dysfunction as evidenced by signs, symptoms, or thyroid stimulating hormone (TSH) > 1.5 x Upper Limit of Normal;

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
VI-0521 oral capsuleAlso: Qsymia, Phentermine and topiramatePhentermine/Topiramate	Drug	VI-0521 Mid Dose (Phentermine 7.5 mg +Topiramate 46 mg), VI-0521 Top Dose (Phentermine 15 mg + Topiramate 92 mg)
Placebo oral capsuleInactive drug	Drug	Placebo
Lifestyle ModificationThe lifestyle modification includes physical activity, behavior change, reduced calorie diet advice, and family support. This intervention is applied to all treatment groups.	Behavioural	Placebo, VI-0521 Mid Dose (Phentermine 7.5 mg +Topiramate 46 mg), VI-0521 Top Dose (Phentermine 15 mg + Topiramate 92 mg)

Primary outcome

Mean % Change in Body Mass Index (BMI)
Time frame: Baseline to Week 56
Mean % change in BMI from Baseline to Week 56

10 secondary outcomes

Percentage of Subjects Achieving at Least 5% BMI Reduction at Week 56
Time frame: Baseline to Week 56
Percentage of Subjects Achieving at Least 10% BMI Reduction at Week 56
Time frame: Baseline to Week 56
Percentage of Subjects Achieving at Least 15% BMI Reduction at Week 56
Time frame: Baseline to Week 56
Change in Waist Circumference at Week 56
Time frame: Baseline, Week 56
Change in Whole Body Insulin Sensitivity Index (WBISI) (Matsuda) at Week 56
Time frame: Baseline, Week 56
Change in Fasting Insulin at Week 56
Time frame: Baseline, Week 56
Percent Change in Triglycerides From Baseline to Week 56
Time frame: Baseline, Week 56
Percent Change in HDL-C From Baseline to Week 56
Time frame: Baseline, Week 56
Change From Baseline in Systolic Blood Pressure at Week 56
Time frame: Baseline, Week 56
Change From Baseline in Diastolic Blood Pressure at Week 56
Time frame: Baseline, Week 56

Results and safety

Results posted to the registry on 10 Sep 2022, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Placebo	56	29
VI-0521 Mid Dose	54	37
VI-0521 Top Dose	113	73

Primary outcome: Mean % Change in Body Mass Index (BMI)

Time frame: Baseline to Week 56. Least squares mean (Standard Error). Unit: Percentage Change

Measure	Placebo n = 56	VI-0521 Mid Dose n = 54	VI-0521 Top Dose n = 113
Value	3.34 (1.441)	-4.78 (1.302)	-7.11 (1.011)

Placebo vs VI-0521 Mid Dose vs VI-0521 Top Dose: p <0.0001, Mixed Models Analysis

10 secondary outcomes are reported in the full results.

Adverse events

Time frame: About 1 year (from the time when the subject provides written informed consent and extends until 28 calendar days after the last dose of the investigational product is administered).. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Placebo	0 of 56 (0%)	20 of 56 (35.7%)	0 of 56
VI-0521 Mid Dose	0 of 54 (0%)	11 of 54 (20.4%)	0 of 54
VI-0521 Top Dose	2 of 113 (1.8%)	18 of 113 (15.9%)	0 of 113

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 10 Sep 2022.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 40518455Bensignor MO, Freese RL, Rudser KD, Kelly AS, Kunin-Batson A, Gross AC, Bramante C, Shih W, Peterson C, Fox CK. Predictors of BMI reduction with phentermine/topiramate in adolescents with obesity. Int J Obes (Lond). 2025 Sep;49(9):1777-1780. doi: 10.1038/s41366-025-01821-6. Epub 2025 Jun 15.
Derived from this study: PubMed 36968652Kelly AS, Bensignor MO, Hsia DS, Shoemaker AH, Shih W, Peterson C, Varghese ST. Phentermine/Topiramate for the Treatment of Adolescent Obesity. NEJM Evid. 2022 Jun;1(6):10.1056/evidoa2200014. doi: 10.1056/evidoa2200014. Epub 2022 Apr 30.
Individual participant dataSharing planned: No

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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.

The record lists no contact. Use the official record to reach the sponsor.

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing VI-0521 oral capsule and Lifestyle Modification in people with Adolescent Obesity and Obesity in Adolescence, run by VIVUS LLC 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 18 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 10 Sep 2022. 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. Some participants in this study may receive a placebo. 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?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

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 10 Sep 2022). 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?

Mean % Change in Body Mass Index (BMI) (time frame: Baseline to Week 56). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03922945, which also lists 2 linked publications.

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 10 Sep 2022.