Preliminary results suggest that the GIP/GLP-1 agonist tirazeptide reduced weight by 24 kg in overweight and obese people in the 72-week Phase III SURMOUNT-1 study. There were four arms in the randomized, double-blind, placebo-controlled study: 5 mg, 10 mg, or 15 mg tirzepetide or placebo. The 2,539 overweight or obese subjects were evenly distributed among the groups. In addition, they received a calorie-restricted diet and were encouraged to exercise. They had at least one comorbidity, such as hypertension or dyslipidemia, but did not have type 2 diabetes.

In all verum groups, tirzepatide was initially given in a dose of 2.5 mg once a week. Thereafter, the dose was increased by 2.5 mg every four weeks until the respective dose, depending on the treatment arm. The estimated mean weight loss was 16.0 percent for tirazeptide 5 mg, 21.4 percent for 10 mg, and 22.5 percent for tirazeptide 15 mg and 24 kg, respectively, compared to 2.4 percent for placebo. Tirazeptide is also known as “twincretin” because of its action on two incretin receptors (GIP and GLP-1).