None listed
Conditions
Brief summary
This study aims to determine whether using clinical and genetic calorie-to-satiation scores can help select the most effective weight loss medication for people with obesity. Participants will undergo detailed assessments and be randomly assigned to receive either phentermine–topiramate or a GLP-1–based medication (semaglutide or tirzepatide). The study will compare how much weight participants lose after reaching a stable treatment dose. We hypothesise that individuals with different calorie-to-satiation scores will respond better to specific medications, allowing more personalised treatment. The findings may help improve weight loss outcomes and reduce trial-and-error prescribing in obesity care.
Interventions
Arm 1:
- Phentermine + Topiramate
- Dose: Phentermine 15 mg orally once daily; Topiramate commencing at a dose of 25mg daily and then up-titrating by 25mg every 2 weeks, if tolerated until a dose of 100mg daily is reached (Week 1 and 2: Phentermine 15 mg mane + Topiramate 25 mg nocte; Week 3 and 4: Phentermine 15 mg mane + Topiramate 50 mg nocte; Week 5 and 6: Phentermine 15 mg mane + Topiramate 25 mg mane and 50 mg nocte; Week 7-30: Phentermine 15 mg mane + Topiramate 50 mg mane and 50 mg noct
Arm 1: - Phentermine + Topiramate - Dose: Phentermine 15 mg orally once daily; Topiramate commencing at a dose of 25mg daily and then up-titrating by 25mg every 2 weeks, if tolerated until a dose of 100mg daily is reached (Week 1 and 2: Phentermine 15 mg mane + Topiramate 25 mg nocte; Week 3 and 4: Phentermine 15 mg mane + Topiramate 50 mg nocte; Week 5 and 6: Phentermine 15 mg mane + Topiramate 25 mg mane and 50 mg nocte; Week 7-30: Phentermine 15 mg mane + Topiramate 50 mg mane and 50 mg nocte). Maintenance dose is maximum tolerated dose or maximum dose defined in the protocol. - Duration: up to 30 weeks (24weeks on maintenance dose) - Mode: Phentermine oral capsule; Topiramate oral tablets. - Adherence: Regular phone follow-ups Arm 2: GLP-1 based therapy (Semaglutide or Tirzepatide allocated using randomisation stratified by CTS) Arm 2, Stratum B: - Tirzepatide - Dose: 2.5 mg -> 15 mg weekly. Tirzepatide commencing at a dose of 2.5mg weekly and then up-titrating every 4 weeks, if tolerated until a dose of 15mg weekly is reached (Week 1-4: Tirzepatide 2.5mg weekly; Week 5-8: Tirzepatide 5mg weekly; Week 9-12: Tirzepatide 7.5mg weekly; Week 13-16: Tirzepatide 10mg weekly; Week 17-20: Tirzepatide 12.5mg weekly; Week 21-44: Tirzepatide 15mg weekly). Maintenance dose is maximum tolerated dose or maximum dose defined in the protocol. - Duration: up to 44 weeks (24eeks on maintenance dose) - Mode: Subcutaneous injection delivered by pre-filled multi-dose pens - Adherence: Regular phone follow-ups
Sponsors
MetroSouth Health, Queensland Health
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
- Patients 18-65 years old with obesity BMI >=30kg/m2 or BMI >=27kg/m2 and at least one obesity-related chronic disease such as type 2 diabetes mellitus, hypertension, obstructive sleep apnoea, amongst others. - Individuals undergoing an evaluation for weight loss interventions (e.g., diet, medication, bariatric procedures, or weight loss surgery). - Ability and willingness to comply with the study protocol including completion of all procedures, study visits, questionnaires, assessments for the duration of the study. - Ability and willingness to self-administer the injectables. - Agreement to adhere to the contraception requirements.
Exclusion criteria
- No indication for weight loss medications - Already on weight loss medications or within 3months of enrolment into the study. - History of chronic gastrointestinal diseases - Prior weight loss surgery and/or GI surgery - Pregnancy or women planning pregnancy - Uncontrolled systemic disease/mental health illness - Uncontrolled hypertension - Medications that can affect GI motility and appetite - H/O acute or chronic pancreatitis or clinically significant gall bladder diseases. - Known personal or family H/O MEN-2 syndrome or medullary thyroid cancer. - Hypersensitivity to any of the study medications - Food intolerances to the meals involved in the study
Outcome results
None listed