Individuals with co-occurring AUD and overweight or obesity (AUD-OOB) are an underserved population with high relapse rates and elevated cardiometabolic risk. Recent evidence suggests that Tirzepatide can simultaneously reduce alcohol intake in animal models and craving, drinks per day and heaving drinking days over a 9-week period in non-treatment seeking individuals with AUD. Tirzepatide's dual incretin mechanism offers the potential to simultaneously reduce alcohol use and improve metabolic health in this group, with a favourable safety profile and weekly dosing that supports adherence. As rates of AUD and obesity continue to rise, identifying pharmacological strategies that can address both conditions concurrently is a high public health priority.
This is a phase II, randomised, double-blind, placebo-controlled clinical trial of 46 individuals designed to evaluate the effects of Tirzepatide on alcohol consumption, craving and cardiometabolic outcomes in adults with alcohol used disorder and overweight/obesity (AUD-OOB), to receive either a sub-cutaneous injection of tirzepatide (n=23) or a visually matched placebo (n=23).
The trial will be conducted at a single clinical site in New South Wales, Australia. The Edith Collins Centre (ECC) will serve as the coordinating centre.
In summary participants will:
- Be randomized in a double-blind fashion to receive either tirzepatide or a visually matched placebo
- Receive subcutaneous injections of tirzepatide (2.5mg for 4 weeks followed by 5mg for 4 weeks) or a matching placebo over an eight-week treatment period.
- Visit the clinic weekly (for 8 weeks) for medication administration, clinical monitoring and brief behavioural support (delivered by the "Take Control" computerised CBT program).
- Receive clinical assessments including alcohol use, cardiometabolic biomarkers (HbA1c, lipids, ASCVD) and alcohol biomarkers (PEth) at baseline (week 0), end of treatment (week 9) and follow-up (week 12).
- Undergo neuroimaging (fMRI) and psychophysiology assessmenrts as a substudy at 2 timepoints: baseline (week 0) and between week 7-9. These tasks will assess neural and autonomic reactivity to alcohol and food-related cues, and will support a mechanistic understanding of tirzepatide's impact on reward sensitivity and stress responsivity-key predictors of relapse and treatment outcome
The primary aim of this clinical trial is to examine the effects of weekly tirzepatide (2.5 mg for 4 weeks followed by 5 mg for 4 weeks) versus placebo injections, in combination with a structured behavioural intervention (Take Control) on alcohol consumption in adults with alcohol use disorder and overweight/obesity (AUD-OOB). The main question[s] it aims to answer are:
- Main outcome: To determine the efficacy of Tirzepatide on alcohol related outcomes, the change in the number of heavy drinking days during the final four weeks of treatment (week 5 - 8, with a final assessment at week 9) will be assessed by comparison with baseline (28 days prior to baseline visit). Researchers will compare tirzepatide to placebo injections (a look-alike substance that contains no drug) to see if weekly tirzepatide administration can reduce the number of heavy drinking days.
- Secondary Outcomes:
i) To evaluate changes in additional alcohol-related outcomes:
- Number of drinks per drinking day measured using the Timeline Follow Back
- Number of abstinent days measured using the Timeline Follow Back
- WHO drinking risk level
- Weekly alcohol craving
- Proportion of participants with zero heavy drinking days (Weeks 5-8)
ii) To evaluate changes in cardiometabolic indices from baseline to Week 9:
- Body weight
- Waist circumference
- Blood pressure
- HbA1c
- Total cholesterol
- Triglycerides
- 10-year ASCVD risk score
iii) To assess safety outcomes associated the delivery of Tirzepatide, investigators will measure the:
- Frequency and severity of side effects (graded using CTCAE V5.0 and monitored continuously throughout the intervention).
- Number of serious adverse events (SAEs)
- Treatment-related discontinuation
Participants will complete additional neurobiological assessments including functional magnetic resonance imaging (fMRI) and laboratory-based psychophysiology at two timepoints: baseline (pre-treatment) and the final treatment visit (Week 8), which coincides with the final tirzepatide/placebo dose and final Take Control session. These measures will assess changes in brain activity and autonomic responses to alcohol and food cues.