Tirzepatide superior to semaglutide in weight loss for adults with obesity

Tirzepatide provided a 47% greater relative weight loss compared to semaglutide in adults living with obesity or overweight, according to topline results from a head-to-head clinical trial.

 

The SURMOUNT-5 phase IIIb open-label randomised clinical trial compared tirzepatide 10mg or 15mg, a dual GIP and GLP-1 receptor agonist, to semaglutide 1.7mg or 2.4mg, a GLP-1 receptor agonist in adults living with obesity without diabetes.

 

On average, tirzepatide led to a superior weight loss of 20.2% compared to 13.7% with semaglutide. At 72 weeks, tirzepatide was superior to semaglutide on both the primary endpoint and all five key secondary endpoints of this trial. In a key secondary endpoint, 31.6% of people taking tirzepatide achieved at least 25% body weight loss compared to 16.1% of those taking semaglutide.

 

The overall safety profile of tirzepatide in SURMOUNT-5 was similar to previously reported SURMOUNT trials. The most commonly reported adverse events in SURMOUNT-5 for both tirzepatide and semaglutide were GI-related and were generally mild to moderate. Lilly is continuing to evaluate the SURMOUNT-5 results, which will be published in a peer-reviewed journal and presented at a medical meeting in 2025. 

 

SURMOUNT-5 was a multi-centre, randomised, open-label, phase IIIb trial evaluating the efficacy and safety of tirzepatide 10mg or 15mg compared with semaglutide 1.7mg or 2.4mg in adults with obesity, or overweight with at least one of the following comorbidities: hypertension, dyslipidaemia, obstructive sleep apnoea (OSA) or cardiovascular disease, who did not have diabetes.

 

The trial randomised 751 participants across the US and Puerto Rico in a 1:1 ratio to receive maximum tolerated dose of tirzepatide (10mg or 15mg) or semaglutide (1.7mg or 2.4mg). The primary objective of the study was to demonstrate tirzepatide’s superiority in percent change from baseline in body weight at 72 weeks compared to semaglutide.  

 

Tirzepatide is a once-weekly dual GIP (glucose-dependent insulinotropic polypeptide) receptor and GLP-1 (glucagon-like peptide-1) receptor agonist. Tirzepatide is a single molecule that activates the body’s receptors for GIP and GLP-1, which are natural incretin hormones.