Clinical Trials & Research News

Eli Lilly’s Obesity Drug Elicits 22.5% of Weight Loss in Adults

The overall average body weight reductions in the obesity drug group were 15% in the 5 mg group, 19.5% in the 10 mg group, 20.9% in the 15 mg group, and 3.1% in the placebo group.

Obesity Drug

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By Samantha McGrail

- Eli Lilly and Company recently announced that patients in a Phase 3 trial who received its obesity drug, tirzepatide, lost up to 22.5% of their body weight.  

The SURMOUNT-1 clinical trial compared the safety and efficacy of 5, 10, and 15 mg of tirzepatide compared to placebo as an adjunct to a reduced-calorie diet and increased physical activity in 2,539 adults without type 2 diabetes who have obesity or are overweight. All patients had at least hypertension, dyslipidemia, obstructive sleep apnea, or cardiovascular disease. 

The average body weight reductions were 15% in the 5 mg group, 19.5% in the 10 mg group, 20.9% in the 15 mg group, and 3.1% in the placebo group. Overall, 85% of participants achieved body weight reductions in the 5 mg group, 89% in the 10 mg group, 91% in the 15 mg group, and 35% in the placebo.  

Specifically, patients in the tirzepatide study achieved weight reductions of 16%, 21.4%, and 22.5%, compared to placebo. And 89% and 96% of people taking the drug achieved at least 5% of body weight reductions compared to 28% of those taking a placebo.  

In a key secondary endpoint, 55% and 63% of people taking the drug achieved at least 20% body weight reductions compared to 1.3% of patients taking a placebo.  

Notably, the overall safety and tolerability profile of tirzepatide was similar to other incretin-based therapies approved to treat obesity.  

"Tirzepatide is the first investigational medicine to deliver more than 20% weight loss on average in a Phase 3 study, reinforcing our confidence in its potential to help people living with obesity," Jeff Emmick, MD, PhD, vice president of product development at Eli Lilly and Company, said in the announcement. 

"We're proud to research and develop potentially innovative treatments like tirzepatide, which helped nearly two-thirds of participants on the highest dose reduce their body weight by at least 20% in SURMOUNT-1," Emmick continued.  

Eli Lilly and Company will continue to evaluate the SURMOUNT-1 results, presented at an upcoming medical meeting and submitted to a peer-reviewed journal. And additional studies for tirzepatide as a potential treatment for obesity or overweight are ongoing.