Efficacy and Safety of Phentermine/Topiramate in Youth With Hypothalamic Obesity
Eligible age
6–28 yrs
Accepts
All genders
Locations
2 states
Healthy volunteers
No
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About this study
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.
Sponsor: Seattle Children's Hospital
You may qualify if…
- ✓ 1. Males and Females; Ages 6-28 years (inclusive)
- ✓ 2. 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)
- ✓ 3. Obesity (BMI \> 95th%ile for age/sex using CDC 2000 reference for under 18; BMI \> 30 kg/m2 for 18+ years)
- ✓ 4. 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.
- ✓ 5. Stable on pituitary replacement\* and/or appetite-modulating medications (including stimulants) for at least 2 months. \*Adjustments of less than 25% (\<25%) are permitted to hydrocortisone, growth hormone or thyroid hormone. Sex steroids and DDAVP are exempt.
- ✓ 6. Post-menarchal females must use a highly effective form of contraception, unless hypogonadotropic hypogonadism is documented. All participating females of child-bearing potential will have pregnancy testing as outlined in the protocol.
- ✓ 7. Participants must be able to communicate well with the investigative team, must comply with requirements of the study, and be able to provide written informed consent and/or assent for individuals less than 18y with consent of a parent/legal guardian.
You may not qualify if…
- ✕ 1. Contraindication to Phentermine, Topiramate, or Qsymia as assessed using current package inserts. Including: History of glaucoma and known hyperthyroidism.
- ✕ 2. Known history of nephrolithiasis (kidney stones).
- ✕ 3. Current clinical diagnosis of anorexia nervosa or bulimia nervosa in the medical record.
- ✕ 4. 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).
- ✕ 5. Current or recent (\<14 days) use of monoamine oxidase inhibitor.
- ✕ 6. Known hypersensitivity to sympathomimetic amines.
- ✕ 7. Clinically significant cardiovascular conditions, as defined as any of the following: i) abnormal blood pressure, defined as: under 13y, 95th%ile +12 mm Hg or \> 140/90, whichever is lower; 13y and older, \> 140/90 ; ii) history of cardiac arrhythmia or arrhythmia detected on screening ECG; iii) history of heart failure and/or cardiomyopathy; iv) prolonged QTc interval (QTc \> 460 msec), and/or long QT syndrome phenotype and/or positive genotype for long QT syndrome pathogenic; v) history of cardiac disease including coronary artery disease.
- ✕ 8. Females who are pregnant, breastfeeding, or planning to become pregnant during the trial.
Where it's recruiting
Philadelphia
Seattle
Source: ClinicalTrials.gov · NCT06299891 · last updated 2025-07-28