Lilly’s Zepbound Tops Wegovy for Weight Loss in Head-to-head Trial

(Reuters) -Eli Lilly said on Wednesday patients on obesity drug Zepbound lost 47% more weight than those who were given Novo Nordisk’s Wegovy in the first large, head-to-head trial of the highly in-demand rival medicines.

The drugmaker’s shares rose marginally in premarket trading, while Novo Nordisk’s Copenhagen-listed shares slipped about 1%.

In the 751-person trial sponsored by Lilly, Zepbound helped patients lose an average of 20.2% of their weight after 72 weeks compared to 13.7% for the group treated with Wegovy, Lilly said.

The data comparing the wildly popular medicines shows for the first time that when trial parameters are the same, Lilly’s drug is more effective for weight loss.

Participants were either obese or overweight and had an additional related health issue such as obstructive sleep apnea or heart disease. None of the trial subjects had diabetes.

Before the data was published, BMO Capital Markets analyst Evan Seigerman said in a note the market expects Lilly’s drug to show superior efficacy.

A confirmation, however, “could be a differentiator when the market matures in the long-term and physicians are not capacity constrained, but can select…(a drug) more easily by efficacy alone – not availability”, he wrote.

U.S. approvals for the medicines were based on separate trials in which Zepbound helped patients lose more than 22% of their weight after 72 weeks, while Wegovy led to a 15% weight loss after 68 weeks.

Lilly said it would publish the results in a peer-reviewed journal and present it at a medical meeting next year.

Novo Nordisk said it will wait for the complete data, including the distribution of treatment doses in the two groups, after the trial is peer-reviewed and published.

It said Wegovy is the only obesity drug to reduce the risk of heart attack or stroke. The companies have been racing to get the drugs approved to treat other ailments to help improve acceptance by insurers and governments.

The U.S. approved Wegovy as a treatment for heart disease in March, while Zepbound is expected to get the green light as a treatment for obstructive sleep apnea.

Doctors had been prescribing the obesity drugs based on whichever was available to patients at the pharmacy given intermittent supply shortages.

The results may persuade insurers in the U.S. and cost-conscious health authorities in Europe to give preferential coverage to Zepbound over Wegovy.

An analysis of health records and other data published by the medical journal JAMA Internal Medicine earlier this year showed Zepbound led to faster and greater weight loss than Wegovy.

Both drugs are sold in the U.S. under different brand names – Novo’s Ozempic and Lilly’s Mounjaro – to treat type 2 diabetes.

Novo Nordisk, meanwhile, is banking on a novel drug with a dual mode of action, CagriSema, to regain an edge on efficacy over Lilly. Its late-stage trial results, which Novo projected could likely result in 25% weight loss, are expected this year.

(Reporting by Patrick Wingrove in New York and additional reporting by Manas Mishra in Bengaluru; Editing by Bill Berkrot and Arun Koyyur)