Eli Lilly and Company announced that its tirzepatide has demonstrated significant and superior weight loss compared to placebo in two Phase 3 studies of adults with obesity or overweight with weight-related comorbidities, excluding type 2 diabetes.
Tirzepatide is a once-weekly GIP (glucose-dependent insulinotropic polypeptide) receptor and GLP-1 (glucagon-like peptide-1) receptor agonist.
In the SURMOUNT-3 and SURMOUNT-4 studies, tirzepatide met all primary and key secondary objectives compared to placebo.
For the efficacy estimand, participants in SURMOUNT-3 and SURMOUNT-4 who started taking GIP receptor after an intensive lifestyle intervention or who maintained taking tirzepatide saw a mean weight loss of up to 26.6%.
SURMOUNT-3 evaluated the efficacy and safety of the GIP receptor against a placebo.
In the study, Tirzepatide achieved both co-primary endpoints showing superiority to placebo during the 72-week double-blind treatment period.
For the efficacy estimand, patients receiving GIP receptor lost an additional 21.1% of their body weight from randomisation compared to those taking a placebo.
In addition, tirzepatide demonstrated a total mean weight loss of 26.6% from study entry over 84 weeks.
SURMOUNT-4 assessed the efficacy and safety of the drug against a placebo for 52 weeks after a 36-week open-label tirzepatide lead-in period.
In the trial, the GIP receptor met the primary endpoint of superior mean percentage change in body weight compared to the placebo from 36 weeks to 88 weeks, showing sustained weight loss.
Additionally, patients receiving tirzepatide lost an additional 6.7% of their body weight during a 52-week continued treatment period, for a total mean weight loss of 26.0% over 88 weeks.
Lilly product development SVP Jeff Emmick said: “The results of SURMOUNT-3 and -4 showed the highest level of weight loss observed in the SURMOUNT program to date.
“Whether taking tirzepatide for 88 weeks in SURMOUNT-4 or taking tirzepatide for 72 weeks following intensive caloric restriction in SURMOUNT-3, participants achieved similar mean weight reduction — about 26%.”
The overall safety profile of the drug was similar in both studies to previously reported SURMOUNT and SURPASS trials. It was also like the results of incretin-based therapies cleared for the treatment of obesity and overweight.
SURMOUNT-3 is a multi-centre, randomised, double-blind, parallel, placebo-controlled trial that enrolled 806 participants whereas the SURMOUNT-4 trial recruited 783 participants.
In April, Lilly announced that tirzepatide showed superior weight loss compared to placebo at 72 weeks of treatment of adults with obesity or overweight and type 2 diabetes in the Phase 3 SURMOUNT-2 trial.
