Efficacy and Safety of Phentermine/Topiramate in Youth With Hypothalamic Obesity

Trial statusRecruiting
Trial phasePhase 2
Trial typeInterventional
Biological sexAll
Age6-28
SponsorSeattle Children's Hospital

About this trial

Hypothalamic obesity (HO) refers to the substantial weight gain that often complicates hypothalamic brain tumors. Children with this treatment-recalcitrant form of obesity have excess rates of metabolic sequelae compared to otherwise healthy children with similar obesity, and later experience excess mortality related to cardiometabolic disease. In this pilot trial, our objective is to gather key preliminary data about phentermine/topiramate (Ph/T) that is FDA-approved for "common" obesity but has never been tested in HO. The subset of individuals with HO who experience hyperphagia or excess daytime sleepiness may benefit from the Ph/T-induced decrease in appetite and increase in alertness.

Preliminary assessments of safety, adverse events, dosing (Aim 1), as well as of efficacy (% BMI loss, Aim 2) will be made in a 28-week parallel-arm double-blinded Phase 2 placebo-controlled clinical trial in 6-28-year-old individuals with HO.

Eligibility criteria

Qualifiers

Males and Females; Ages 6-28 years (inclusive)

History of rapid weight gain related to tumor onset or treatment, as assessed by an experienced endocrinologist (for example, change in BMI z-score > 0.2 and/or BMI +5% during the first 6 months following tumor treatment)

Obesity (BMI > 95th%ile for age/sex using CDC 2000 reference for under 18; BMI > 30 kg/m2 for 18+ years)

Recent evidence of hypothalamic injury by brain MRI with central review; >6 months status-post definitive therapy (surgery, chemotherapy, or radiation); no major operations/surgeries planned during the study period.

Disqualifiers

Contraindication to Phentermine, Topiramate, or Qsymia as assessed using current package inserts. Including: History of glaucoma and known hyperthyroidism.

Known history of nephrolithiasis (kidney stones).

Current clinical diagnosis of anorexia nervosa or bulimia nervosa in the medical record.

Known history of metabolic acidosis, low bicarbonate on screening laboratory assessment (below lower limit of normal), or clinically significant bone disease requiring medication (beyond calcium and/or vitamin D).

Trial design

Treatments tested in this trial

  • Phentermine / Topiramate Extended Release Oral Capsule [Qsymia]
  • Placebo

Treatment groups

24 Participants
are divided into 2 treatment groups

Sponsors and collaborators

Seattle Children's Hospital

Lead sponsor

Children's Hospital of Philadelphia

Collaborator