SURMOUNT-1 Results Tout Tirzepatide's Weight Loss Benefits

Tirzepatide met both coprimary endpoints in SURMOUNT-1, with use contributing to reductions in body weight of up to 22.5% during the 72-week trial and more than 60% of those receiving the 15 mg dose achieving body weight reductions of 20% or more.

Use of tirzepatide was associated with weight loss of up to 22.5% of a patient’s body weight in the SURMOUNT-1 trial, according to a release from Eli Lilly and Company.

A phase 3 trial assessing tirzepatide in 5, 10, and 15 mg formulations for weight loss, Eli Lilly and Company announced the trial had met both its coprimary endpoints of superior mean percent change in body weight from baseline and greater percentage of participants achieving weight reductions of at least 5% against placebo therapy, with the trial also achieving all key secondary endpoints.

"Obesity is a chronic disease that often does not receive the same standard of care as other conditions, despite its impact on physical, psychological and metabolic health, which can include increased risk of hypertension, heart disease, cancer and decreased survival," said Louis J. Aronne, MD, FACP, DABOM, director of the Comprehensive Weight Control Center and the Sanford I. Weill Professor of Metabolic Research at Weill Cornell Medicine, obesity expert at New York-Presbyterian/Weill Cornell Medical Center and investigator of SURMOUNT-1, in the release from Eli Lilly and Company. "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."

A novel, once-weekly GIP/GLP-1 receptor agonist, the effects of tirzepatide seen in the SURPASS trials have led to SURMOUNT-1 becoming one of the most anticipated trials in the obesity space in recent years. A multicenter, randomized, double-blind, parallel, placebo-controlled trial comparing the efficacy and safety of tirzepatide 5 mg, 10 mg, and 15 mg to placebo as an adjunct to diet and physical activity, SURMOUNT-1 enrolled 2,539 adult patients without type 2 diabetes who have obesity or overweight with hypertension, dyslipidemia, obstructive sleep apnea, or cardiovascular disease.

In their release, Eli Lilly and Company reported those using tirzepatide achieved mean weight reductions of 16% (16 kg), 21.4% (22 kg), and 22.5% (24 kg) with the 5 mg, 10 mg, and 15 mg formulations, respectively, compared to placebo therapy. Bodyweight reductions of 5% or more were achieved by 89% and 96% of the tirzepatide 5 mg and 10 mg arms, respectively. Among the placebo arm, only 28% achieved bodyweight reductions of 5% or more. The release also pointed out 55% of the tirzepatide 10 mg arm and 63% of the tirzepatide 15 mg arm achieved body weight reductions of 20% or more compared to 1.3% of those receiving placebo therapy.

When assessing safety of tirzepatide, results indicated the most commonly reported adverse events were gastrointestinal-related and generally mild to moderate in severity, with most occurring during the dose-escalation period of the trial. Events more common among the tirzepatide arms than placebo included nausea, diarrhea, committing, and constipation.The overall treatment discontinuation rates were 14.3%with tirzepatide 5 mg, 16.4% for tirzepatide 10 mg, 15.1% for tirzepatide 15 mg, and 26.4% for 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 at Eli Lilly and Company. "Obesity is a chronic disease that requires effective treatment options, and Lilly is working relentlessly to support people with obesity and modernize how this disease is approached

The release from Eli Lilly and Company pointed out those with prediabetes at the start of the study will remain enrolled in SURMOUNT-1 for an additional 104 weeks to assess the impact win bodyweight and differences in progression to diabetes after 3 years of treatment with tirzepatide compared to placebo therapy. Eli Lilly and Company expect to present the results of SURMOUNT-1 at an upcoming medical meeting and submit them to a peer-reviewed journal.