Tirzepatide may lead weight loss of up to 23 percent in obese people: SURMOUNT-1 trial
USA: Recent data from SURMOUNT-1 clinical trial showed that tirzepatide achieved superior weight loss compared to a placebo in obese/overweight individuals at 72 weeks of treatment. According to the findings, the individuals lost up to 22.2% of their body weight (52 lb.).
Tirzepatide is a novel once-weekly glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist. The results were reported by the pharmaceutical company Eli Lilly and Company.
In a statement, Louis J. Aronne, MD, director of the Comprehensive Weight Control Center and Sanford I. Weill Professor of Metabolic Research at Weill Cornell Medicine, said, "Tirzepatide delivered impressive body weight reductions in SURMOUNT-1, which could represent an important step forward for helping the patient and physician partnership treat this complex disease."
In the phase 3 trial, the researchers aimed to evaluate the safety and efficacy of tirzepatide in adults with obesity, or overweight with at least one comorbidity, who do not have diabetes. It enrolled a total of 2,539 participants.
Following were the key findings of the study:
- Tirzepatide met both co-primary endpoints of superior mean percent change in body weight from baseline and greater percentage of participants achieving body weight reductions of ≥5% compared to placebo for both estimands.
- For the efficacy estimand, individuals taking tirzepatide achieved average weight reductions of 16.0% (35 lb or 16 kg on 5 mg), 21.4% (49 lb or 22 kg on 10 mg) and 22.5% (52 lb or 24 kg on 15 mg) compared to placebo (2.4% 5lb. or 2 kg).
- 89% (5 mg) and 96% (10 mg and 15 mg) of people taking tirzepatide achieved ≥5% body weight reduction compared to 28% of those taking placebo.
- In a key secondary endpoint, 55% (10 mg) and 63% (15 mg) of people taking tirzepatide achieved at least 20% body weight reductions compared to 1.3% of those taking placebo. The mean baseline body weight of individuals was 231 lb.
- Regarding the treatment regimen estimand, findings showed the average body weight reductions were 15.0% (5 mg), 19.5% (10 mg), 20.9% (15 mg), and 3.1% (placebo). Further, the percentage of individuals achieving body weight reductions of ≥5% were reported as 85% (5mg), 89% (10 mg), 91% (15mg), and 35% (placebo).
- The data additionally show the percentage of patients achieving body weight reductions of ≥20%: 30% (5 mg, not controlled for type 1 error), 50% (10 mg), 57% (15 mg), and 3.1% (placebo).
- The overall safety and tolerability of the study agent was found similar to other incretin-based therapies approved for obesity treatment.
- For individuals treated with tirzepatide (5 mg, 10 mg and 15 mg, respectively), nausea (24.6%, 33.3%, 31.0%), diarrhea (18.7%, 21.2%, 23.0%), vomiting (8.3%, 10.7%, 12.2%) and constipation (16.8%, 17.1%, 11.7%) were more frequently experienced, compared to placebo.
- Treatment discontinuation rates due to adverse events were 4.3% (5 mg), 7.1% (10 mg), 6.2% (15 mg), and 2.6% (placebo).
"Tirzepatide is the first investigational medicine to deliver more than 20 percent weight loss on average in a phase 3 study, reinforcing our confidence in its potential to help people living with obesity," said Jeff Emmick, MD, PhD, vice president, product development, Lilly in an accompanying statement.
It will continue to evaluate findings from the SURMOUNT-1 trial and additional studies are ongoing for tirzepatide as a potential treatment for patients with obesity or overweight, Lilly noted.
