NCT07282340

Phentermine's Impact on Treatment in Teens

Phentermine's Impact on Treatment in Teens (PhITT): A Randomized Placebo-Controlled Trial of Phentermine for Adolescents With Obesity

• Status: Not Yet Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 240 (estimated)
• Sponsor: Russell McCulloh, MD · Network
• Sex: All
• Age: 12 Years – 17 Years
• Healthy volunteers: Not accepted

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

Interventions

Type	Name	Description
DRUG	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.
DRUG	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.

Timeline

• Start date: 2025-12-01
• Primary completion: 2028-01-01
• Completion: 2028-01-01
• First posted: 2025-12-15
• Last updated: 2025-12-15

Regulatory

• FDA-regulated drug study