Clinical Trials Arena

Lilly’s Zepbound wins the weight loss duel with Novo’s Wegovy

An open- label Phase III trial showed that participants using Zepbound saw 47% greater relative weight loss compared to Wegovy.

Eli Lilly has scored a win in the ongoing competition with Novo Nordisk in the obesity space, as a Phase III study showed trial participants experienced 47% more relative weight loss using the former’s weight loss therapy Zepbound (tirzepatide) compared to Novo’s Wegovy (semaglutide).

The market for weight loss management drugs has been booming, with GlobalData expecting the obesity market to be worth $37.1bn in 2031. Novo Nordisk and Lilly have dominated the obesity market, with the former enjoying the first-to-market advantage with its semaglutide versions.

GlobalData is the parent company of Clinical Trials Arena.

Zepbound raked in more than $3bn in sales in the first three quarters this year, compared to DKK 43.7bn ($6.17bn) that Novo generated from its obesity portfolio, consisting of Wegovy and Saxenda (liraglutide), during the same period, as per the companies’ financials. Lilly’s tirzepatide brand Mounjaro, which is indicated for the treatment of type 2 diabetes, also earned $8.01bn in the first three quarters of 2024.

Following the news, Lilly’s stock was up by about 2.5% in trading today (4 December). Lilly’s market cap currently stands at $750.9bn.

The head-to-head open-label Phase IIIb SURMOUNT-5 trial (NCT05822830) enrolled 751 obese or overweight participants with at least one of the comorbidities such as hypertension, dyslipidemia, obstructive sleep apnea, or cardiovascular disease. At 72 weeks, the participants receiving Zepbound lost an average of 22.8 kg compared to a mean weight loss of 15kg seen in the Wegovy group.

At least 25% body weight loss was seen in 31.6% of participants in the Zepbound group compared to 16.1% in the Wegovy group. The reported adverse events were similar for both groups, mainly mild to moderate gastrointestinal-related events. Lilly did not disclose the detailed results from the trial choosing to reserve those for presentation at a scientific conference.

Multiple companies are developing o besity treatments, and a majority of these have a similar mechanism of action as Wegovy and Zepbound. Last month, Amgen reported an average 20% weight loss in a Phase II trial with its weight loss therapy, MariTide (maridebart cafraglutide). In May, Roche released positive data from a Phase Ib trial of its investigational obesity and type 2 diabetes therapy, CT-388.