Recruiting

Phase 2

PhenterminePhentermine's Impact on Treatment in Teens

Sponsor:

Russell McCulloh, MD

Code:

NCT07282340

Conditions

Childhood Obesity

Eligibility Criteria

Sex: All

Age: 12 - 17

Healthy Volunteers: Not accepted

Interventions

Phentermine

Placebo

Study Details

Brief summary:

PhITT is a Phase IIb, multicenter, randomized, double-blind, placebo-controlled clinical trial evaluating the efficacy and safety of phentermine (16 mg daily) in adolescents aged 12 to <18 years with obesity. Conducted across approximately 10 sites within the IDeA States Pediatric Clinical Trials Network (ISPCTN), the study aims to enroll up to 240 participants and then randomize up to 198 who meet eligibility criteria, randomized in a 2:1 ratio to phentermine or placebo over a 52-week treatment period, followed by a 2-week withdrawal assessment.

Conditions

Childhood Obesity

Study ID

NCT07282340

Start date

Jun 3, 2026

Status verified date

Nov, 2025

Completion date

Jan, 2028

Anticipated

Primary completion date

Jan, 2028

Anticipated

Eligibility Criteria

Sex: All

Age: 12 - 17

Healthy Volunteers: Not accepted

Inclusion criteria\* include, but are not limited to:

Age ≥ 12 years and < 18 years at time of consent;
Tanner Staging ≥ 2 at the time of screening;
Obesity (BMI ≥ 95th age- and sex-specific CDC percentile or BMI ≥ 30 kg/m2);
Biological females must agree to use adequate contraception, defined as double barrier methods, stable hormonal contraception plus single barrier method, tubal ligation, or abstinence.

Exclusion criteria\* include, but are not limited to:

Contraindications to phentermine in adults such as:

A history of cardiovascular disease (e.g., coronary artery disease, stroke, clinically significant congenital heart disease, clinically significant cardiac arrhythmias, and congestive heart failure);
History of glaucoma;
Current or recent (within 14 days of screening) use of a monoamine oxidase (MAO) inhibitor;
Any previous history of drug dependency or current use of an illicit substance (positive urine drug screen);
Current pregnancy or breastfeeding;
Plans to become pregnant within the study duration;
Known hypersensitivity to sympathomimetic amines;
Current nicotine use or nicotine cessation within 3 months of screening;
Stage 2 hypertension (or greater) or taking any medication to treat hypertension;
Current type 1 or type 2 diabetes mellitus or taking any medication to treat diabetes or prediabetes;
Current or recent (within 3 months of screening) use of prescribed weight loss medication(s)/medically prescribed diets (e.g., low calorie, meal replacement/herbal agents/dietary supplements or weight loss program);
Current or recent (within 3 months of screening) use of other sympathomimetic amines such as stimulants to treat attention- deficit/hyperactive disorder;
Use of chronic systemic glucocorticoid therapy (consecutive use of 3 months or more) or other steroid hormone therapy other than oral contraceptives;
Use of tricyclic antidepressants, lithium, levodopa, or dopamine receptor agonists;
History of bariatric surgery;
History or current diagnosis of schizophrenia, psychosis, bipolar disorder, or mental illness requiring hospitalization within 12 months of screening;
History of suicide attempt within 2 years or self-harm within 3 months of screening;
Current Patient Health Questionnaire-9 (PHQ-9) score of ≥ 10;
Current suicidal ideation type 4 or 5 on Columbia Suicide Severity Rating Scale (C-SSRS);
Current Eating Attitudes Test-26 (EAT-26) score ≥ 20 or any history of anorexia or bulimia.
Current condition or disease interfering with metabolism, such as untreated hypo- or hyperthyroidism, Cushing's syndrome;
Current clinically significant hepatic aspartate transaminase (AST) or alanine transaminase (ALT) > 3x upper limit of age- and sex-specific normal range or renal disease (creatinine clearance < 60 mL/minute); hypertriglyceridemia (triglyceride ≥ 400 mg/dL) or syndromic or monogenic obesity;
Any clinically significant abnormalities on a standard 12-lead electrocardiogram at baseline;
Heart rate > 100 bpm at screening;
Current or recent use of any investigational medication or device or participation in an interventional clinical trial within 30 days of screening;
Any clinically significant medical or psychiatric condition or laboratory abnormality that may increase the risk associated with trial participation, investigational product administration, or interpretation of trial results.

Study Design

Enrollment

240 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Phentermine 16 mg Group

Participants in this arm will receive phentermine 16 mg daily, administered as two 8 mg tablets taken orally once

placebo comparator: Placebo Group

Participants in this arm will receive placebo tablets that are visually identical to the phentermine tablets but contain no active pharmaceutical ingredient. The placebo will be taken orally once daily in the morning for 52 weeks. All participants will also receive lifestyle education handouts at each study visit. This arm serves as the control group for evaluating the efficacy and safety of phentermine in adolescents with obesity.

Interventions

Phentermine

Phentermine 16 mg administered orally once daily in the morning for 52 weeks. The dose is provided as two 8 mg tablets. Participants also receive lifestyle education handouts at each study visit. The intervention is designed to evaluate the efficacy and safety of phentermine for weight loss in adolescents with obesity.

Placebo

Placebo tablets that are visually identical to phentermine tablets but contain no active pharmaceutical ingredient. Administered orally once daily in the morning for 52 weeks. Participants also receive lifestyle education handouts at each study visit. This control arm is used to evaluate the efficacy and safety of phentermine in adolescents with obesity.

Primary outcome measure

Percent Change in BMI from Baseline at Week 52 [ Time Frame: 52 weeks ]

Central Contacts and Locations

Central contacts

Aubrey VanStory

402-559-4815 aubrey.vanstory@unmc.edu

Locations

Pennington Biomedical Research Center

Recruiting

Baton Rouge, Louisiana, United States, 70808

Contacts

Lauren Harrington

225-763-2974 Lauren.Harrington@pbrc.edu

Principal Investigator:

Stephanie Waldrop, MD, MPH

Children's Mercy Hospital

Recruiting

Kansas City, Missouri, United States, 64108

Contacts

Pete Muenks

816-816-6840 epmuenks@cmh.edu

Principal Investigator:

Helena Laroche, MD

Dartmouth Hitchcock Medical Center

Recruiting

Lebanon, New Hampshire, United States, 03756

Contacts

Mary M McNally

603-653-6115 Mary.M.McNally@hitchcock.org

Principal Investigator:

Kimberly Dovin, MD

University of New Mexico Health Sciences Center

Recruiting

Albuquerque, New Mexico, United States, 87131

Contacts

Arielle Padilla, RN

(505) 272-1972 agartn01@salud.unm.edu

Principal Investigator:

Michele Hutchison, MD

The University of Oklahoma Health Sciences Children's Hospital

Recruiting

Oklahoma City, Oklahoma, United States, 73104

Contacts

Blair A Hill

405-271-8001 Blair-AppleHill@ou.edu

Gina Herbert

405-271-3480 Gina-Herbert@ou.edu

Principal Investigator:

Jeanie Tryggestad, MD

Prisma Health-Midlands Children's Hospital

Recruiting

Columbia, South Carolina, United States, 29203

Contacts

Page Wiggins

803-434-8977 mollie.wiggins@prismahealth.org

Principal Investigator:

Lisa Knight, MD

More Information

Sponsor

Russell McCulloh, MD

Last update posted

Aug 10, 2026

Last verified

Nov, 2025

Keywords

Adolescent Obesity
Pediatric Obesity
Weight Loss
BMI Reduction
Phentermine

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Russell McCulloh, MD on 2026-08-10.