SURMOUNT trial programme (revision 13)
Old revision·04:06, 27 Jan 2025·CiteBot
| SURMOUNT trial programmePhase 3 programme | |
|---|---|
Weight change by dose in the principal obesity trial. | |
| Drug | Tirzepatide 5, 10 and 15 mg weekly |
| Indication | Chronic weight management |
| Principal duration | 72 weeks |
| Topic infobox · conventions | |
The SURMOUNT trial programme is the phase 3 series that established tirzepatide for chronic weight management. SURMOUNT-1 randomised 2,539 adults with obesity and without diabetes to tirzepatide 5, 10 or 15 mg weekly or placebo for 72 weeks.[1]
Mean weight change was −15.0%, −19.5% and −20.9% at the three doses against −3.1% on placebo. Both arms received lifestyle counselling, so the placebo figure is not a no-treatment baseline; see Placebo-adjusted effect.[1]
SURMOUNT-2 studied participants with obesity and type 2 diabetes and reported smaller reductions — −12.8% and −14.7% at 10 and 15 mg against −3.2% — reproducing the attenuation of weight response in diabetes seen across this field.[2]
Constituent trials
[edit]| Trial | Population | Duration | Result at highest dose |
|---|---|---|---|
| SURMOUNT-1 | Obesity, no diabetes | 72 weeks | −20.9% vs −3.1% |
| SURMOUNT-2 | Obesity with type 2 diabetes | 72 weeks | −14.7% vs −3.2% |
| SURMOUNT-3 | After intensive lifestyle lead-in | 72 weeks | Further loss after lead-in |
| SURMOUNT-4 | Randomised withdrawal after lead-in | 88 weeks total | Regain on withdrawal |
SURMOUNT-4 is the counterpart of STEP 4 and addresses the same question: what happens when treatment stops. Participants randomised to placebo after a lead-in regained a substantial proportion of the weight lost. See Weight regain after discontinuation.[2]
SURMOUNT-3 shows that a lifestyle lead-in does not exhaust the available effect: participants who had already lost weight on intensive lifestyle intervention lost further weight on active treatment.[1]
Reading the figures
[edit]The 72-week duration includes a 20-week escalation, so as in STEP a substantial part of the trial was spent below the maintenance dose.[1]
Weight-change curves at the higher doses were still declining at 72 weeks rather than plateauing, which limits what the endpoint figure says about the eventual effect and is one reason the programme's later trials run longer.
See also
References
- ^ a b c d Jastreboff AM, Aronne LJ, Ahmad NN, et al. "Tirzepatide once weekly for the treatment of obesity." New England Journal of Medicine 387(3):205–216 (2022). DOI:10.1056/NEJMoa2206038. PMID 35658024.
- ^ a b Garvey WT, Frias JP, Jastreboff AM, et al. "Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2)." The Lancet 402(10402):613–626 (2023). PMID 37385275.