Wegovy trial result gives boost to Novo Nordisk amid U.S. market woes

New trial data suggests Novo Nordisk’s weight loss drug Wegovy edges out rival treatments on heart condition risk reduction, in good news for the Danish pharma giant as it battles a spate of challenges in the key U.S. market.

The company on Sunday said that continued use of its weight management drug semaglutide, sold to consumers as Wegovy, led to a 57% greater reduction in the risk of heart attack, stroke or death in people with obesity and cardiovascular disease or who were overweight, compared with users of tirzepatide.

Tirzepatide is the active ingredient in Zepbound and Mounjaro, the drugs manufactured by U.S. firm Eli Lilly — Novo Nordisk’s main rival in the battle to produce market-leading weight management treatments.

The company noted the results came from a real-world study as opposed to a randomized control trial, which is the “gold standard” for evaluating treatment efficacy. The number of patients recording such events was also very low, reaching 0.1% for those using Wegovy and 0.4% for those on tirzepatide.

However, the company said the study added to “growing evidence suggesting that the heart-protective benefits seen with Wegovy are specific to the semaglutide molecule and therefore cannot be extended to other GLP-1 or GIP/GLP-1-based treatments.”

GLP-1s, or glucagon-like peptide-1 receptor agonists, refers to the range of medications used to treat type-2 diabetes and obesity by mimicking hormones produced in the gut to suppress a person’s appetite and regulate blood sugar. That includes Novo Nordisk’s well-known semaglutide-based Ozempic, designed as a treatment for type-2 diabetes.

The huge growth of weight loss drug usage in recent years has lured in investors in the ongoing hunt for both leading medications and potential new challengers.

Trial data into different drugs’ impact on weight loss and on a range of other conditions — from heart conditions, liver and Alzheimer’s disease to sleep apnea and alcohol addiction — has frequently been a catalyst for share price moves. Traders have recently been assessing efforts by Eli Lilly and Novo Nordisk to develop oral pills for obesity, removing the need for injections.

Novo Nordisk shares were around 3% higher on Monday.

Michael Field, chief equity strategist at Morningstar, said that a significant reduction in the risk of heart attacks provided by Wegovy could be a potential “game changer” for Novo Nordisk, but that the Monday reaction indicated the market was “encouraged, but not getting carried away.”

“It’s important to remember that this is just trial data and rivals have a long history of overtaking each other again, and again. That said, the healthcare sector is one of the cheapest in Europe, with investors particularly dis-enthused by the large traditional pharma giants. This announcement just goes to show you should never underestimate the ability of these firms to innovate,” Field told CNBC by email.

Sheena Berry, healthcare analyst at Quilter Cheviot, said the latest heart disease data could be a “positive development” for Novo Nordisk, but that it was not possible to “draw any firm conclusions about the comparison of Wegovy versus tirzepatide in the battle between Novo Nordisk and Eli Lilly.”

“Following a tough period, it does, however, help Novo Nordisk in terms of promotion. Consequently, shares are up today after the difficult period, and investors will be watching closely to see if such events can act as a catalyst for improvement,” Berry said by email.

The huge success of Wegovy and Ozempic propelled Novo Nordisk to the top of Europe’s largest listed companies in late 2023, with much of the momentum driven by the company’s expansion in the U.S.

It has since lost that title, following share price declines of 10.6% in 2024 and 40% in 2025 to date. Denmark last week more than halved its annual economic growth forecast, in part citing Novo’s declining U.S. market share and expectations for lower pharmaceutical exports.

Novo Nordisk has been swept up in sector uncertainty around White House tariffs and U.S. President Donald Trump’s push to get firms to lower drug prices and move manufacturing stateside. Global competition in the weight loss space continues to grow, with companies also facing the challenge of copycat compounding treatments.

Novo last month reported huge annual sales growth in its second quarter earnings, but nonetheless flagged weaker second-half U.S. sales growth forecasts and said it would focus on direct-to-consumer sales to combat the challenge of copycats.

Denmark last week more than halved its annual economic growth forecast, in part citing reduced growth expectations for Novo Nordisk. The country’s economic ministry said that, while companies such as Novo Nordisk now had more clarity on tariff rates following the EU-U.S. trade deal, there remained a “significant degree of unpredictability linked to the U.S. administration’s policy.”

Analysts told CNBC last month that European pharmaceutical stocks failed to rally on the trade deal news because investors remained wary about the White House’s ongoing Section 232 investigation into the impact of various imports on U.S. national security, including pharmaceuticals.

In a note last week, UBS analysts said that, following the move in May by U.S. drugstore chain CVS to expand access to Wegovy, they were “beginning to see growth potentially plateau” for the drug. That was in-line with previous expectations “given the continued presence of compounders and relatively strong performance of Zepbound,” they added.

– CNBC’s Karen Gilchrist contributed to this story.