Using Phentermine and Topiramate to Treat Obesity in Teens with Type 2 Diabetes

Phentermine/Topiramate in Adolescents With Type 2 Diabetes and Obesity

Early Phase 1 Interventional University of Minnesota · NCT04881799

This study is testing if a combination of two medications can help teens with type 2 diabetes and obesity lose weight and better manage their diabetes.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment30 (estimated)
Ages12 Years to 20 Years
SexAll
SponsorUniversity of Minnesota Academic / other
Locations1 site (Minneapolis, Minnesota)
Trial IDNCT04881799 on ClinicalTrials.gov

What this trial studies

This pilot trial investigates the effects of the combination medication phentermine/topiramate on body mass index (BMI), insulin sensitivity, and glycemic control in adolescents aged 12 to 20 with type 2 diabetes and obesity. The study includes a 6-month placebo-controlled phase followed by a 6-month open-label extension, comparing the medication's effects against a placebo plus standard treatment. The goal is to determine if this treatment can effectively reduce obesity and improve diabetes management in this population.

Who should consider this trial

Good fit: Ideal candidates are adolescents aged 12 to 20 with obesity and type 2 diabetes, specifically those with a BMI at or above the 95th percentile for their age and sex.

Not a fit: Patients who are pregnant, lactating, or have recently changed their weight-altering medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new effective option for managing obesity and type 2 diabetes in adolescents.

How similar studies have performed: While the use of phentermine/topiramate has been approved for adults, this specific application in adolescents with type 2 diabetes is novel and has not been extensively tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Ages 12 to \</= 20 years at study entry
* Obesity (BMI \>/= the 95th percentile for age and sex)
* HgbA1c \>/= 6.5% at type 2 diabetes diagnosis
* Negative diabetes auto-antibodies
* English-speaking and Spanish speaking
* For participants of child-bearing potential: when sexually active, agreement to use two forms of highly effective contraception (oral contraceptive pill, IUD, implant, and/or condoms) during study participation

Exclusion Criteria:

* Pregnancy or lactation
* Newly-initiated or change in dose of weight altering medication within past 6 months, including SGLT-2 inhibitors and DPP-IV inhibitors, liraglutide 1.8 mg and exenatide ER.
* Current or recent (\< six months prior to enrollment) use of anti-obesity medication(s) defined as orlistat, phentermine, topiramate, combination PHN/TPM, semaglutide, and/or combination naltrexone/bupropion (monotherapy use of naltrexone or bupropion is not an exclusion)
* Current use of sulfonylureas
* Previous metabolic/bariatric surgery
* Current use of a stimulant medication
* History of glaucoma
* Current or recent (\< 14 days) use of monoamine oxidase inhibitor or carbonic anhydrase inhibitors
* Known hypersensitivity to sympathomimetic amines
* Any history of treatment with growth hormone
* any history of bulimia nervosa
* Major psychiatric disorder as determined by the local medical monitor
* Unstable and clinically-diagnosed (defined as documented in the medical record, if available) depression or PHQ-9 score of \>/= 15
* Any history of active suicide attempt, a "yes" answer to Question 4 (Active Suicidal Ideation with Some Intent to Act, Without Specific Plan) on the "Suicidal Ideation" portion of the C-SSR, or a "yes" to answer to Question 5 (Active Suicidal Ideation with Specific Plan and Intent) on the "Suicidal Ideation" portion of the C-SSRS
* History of suicidal ideation or self-harm within the previous 30 days or a "yes" answer to any of the suicide-related behaviors (actual attempt, interrupted attempt, aborted attempt, preparatory act, or behavior) on the "Suicidal Behavior" portion of the C-SSRS and the ideation or behavior occurred within the past month.
* Current pregnancy or plans to become pregnant during study participation
* Current tobacco use
* ALT or AST \>/= 3 times the upper limit of normal
* Moderate (Child-Pugh score 7-9) or severe (Child-Pugh score 10-15)
* Bicarbonate \<18 mmol/L
* Moderate (creatinine clearance \[CrCl\] greater than or equal to 30 and less than 50 mL/min) or severe (CrCl less than 30 mL/min) renal impairment
* Any history of seizures

  • BP for ages 13 and older of \> 130/80 on 3 separate measurements and for age 12 \> 95th percentile on 3 separate measurements
* HR ≥120 bpm on 3 separate measurements
* History of structural heart defect or clinically significant arrhythmia
* Diagnosed monogenic obesity
* Any history of cholelithiasis
* Any history of nephrolithiasis
* Clinically diagnosed hyperthyroidism
* Untreated thyroid disorder or TSH below the lower laboratory limit of normal
* Any disorder, unwillingness, or inability, not covered by any other exclusion criteria, which in the investigator's opinion may put the participant at risk

Where this trial is running

Minneapolis, Minnesota

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Pediatric Obesity
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.