A large phase 3 clinical trial involving a new anti-obesity drug has offered particularly promising results. Tirzepatide helped overweight and obese participants lose up to 22.5% of their total body weight.
A “double action” molecule
Last year, theUS Food and Drug Administration (FDA) had approved the use of semaglutide to treat overweight and obesity. Originally formulated to treat type 1 diabetes, this compound mimics the action of a natural hormone called glucagon-like peptide-1 (GLP-1), produced by intestinal cells and playing a number of metabolic roles, from regulating blood sugar levels to suppressing appetite.
The operation of tirzepatide turns out to be significantly different. Mimicking a hormone called gastric inhibitory polypeptide (GIP), the new molecule acts simultaneously on the receptors GLP-1 et GIPleading to a greater decrease in food intake and higher energy expenditure.
Led by the pharmaceutical company Eli Lillythe phase 3 trial SURMOUNT-1 involved 2,539 subjects from 9 countries with an average body weight of 105 kg. These were divided into four groups (5 mg of tirzepatide, 10 mg, 15 mg and placebo) and received a weekly subcutaneous injection of the compound or a saline solution.
Spectacular results
At the end of the 72-week program, people who received the lowest dose of tirzepatide had seen an average drop in body weight of 16%, compared to 22.5% (or 24 kilos) for those who received the highest dose. In comparison, the reduction seen in subjects in the placebo group was only 2.4%.
If this trial assessed the effect of the drug as an adjunct to a low-calorie diet and exercise program, the significant differences in weight loss between members of the placebo group (who also followed such a routine) and those who received injections of tirzepatide underline its effectiveness.
« Tirzepatide is the first investigational drug to show greater than 20% weight loss in a Phase 3 trial, boosting our confidence in its potential to help people with obesity “, said Eli Lilly in a press release.
