Novo Nordisk Shares Fall as Weight Loss Drug Fails to Beat Eli Lilly

Nordisk Shares fell as much as 15% on Monday after it said its next-generation weight-loss drug failed to meet its key goal of proving it was non-inferior to Eli Lillys rival drug, in the latest blow to the Danish drugmaker, whose shares are trading at a multi-year low after a series of disappointing announcements.

The experimental drug, CagriSema, failed to meet its primary goal of demonstrating non-inferiority in weight loss compared to Eli Lilly's rival drug, tirzepatide, after 84 weeks, Novo said in a statement Monday morning.

Tirzepatide is the active ingredient in Lilly's blockbuster drugs Mounjaro and Zepbound, which have surpassed Novo Nordisk's semaglutide, sold as Ozempic and Wegovy, in U.S. prescriptions.

Copenhagen-listed Novo shares last fell 14% to 259 Danish crowns, hitting their lowest level since June 2021.

Eli LillyShares rose 3.1% in premarket trading.

Patients taking a 2.4 mg dose of CagriSema achieved 23% weight loss after 84 weeks, compared to 25.5% with a 15 mg dose of tirzepatide, Novo said.

The trial was an open trial, meaning participants knew what treatment they were receiving. Such a design can introduce a bias in favor of a well-known product when compared to an investigational therapy, Novo chief scientific officer Martin Holst Lange said, adding that he was “surprised” by the 25% weight loss seen with tirzepatide.

Lilly's own studies have shown that tirzepatide produces a 20.2% weight loss over 72 weeks in people living with obesity or overweight.

Eli Lilly did not immediately respond to a request for comment from CNBC.

Novo submitted CagriSema for approval by the U.S. Food and Drug Administration late last year, with a decision expected by the end of 2026. It has high hopes for the drug, which combines semaglutide and cagrilintide, another hormone released in the pancreas that affects appetite.

Despite Monday's disappointing results, Novo CEO Mike Doustdar remained optimistic about CagriSema's potential.

“We firmly believe that CagriSema has, at this time, the best anti-weight effectiveness of any product currently on the market,” he said.

Novo is exploring additional trials to test CagriSema, including higher dose combinations, the company said.

“CagriSema has the potential to be the first GLP-1/amylin combination product to come to market for people living with obesity, documenting that cagrilintide adds to the existing benefits of semaglutide and offers clinically significant additive weight loss effects superior to those seen with GLP-1 biology alone,” Lange de Novo said, adding that further trials would “evaluate the full weight loss potential of CagriSema.”

However, CagiSema's failure to meet non-inferiority to Zepbound adds further uncertainty, and the drug's commercial positioning is increasingly unclear, said Jefferies analyst Michael Leuchten.

CagriSema could account for 15% to 25% of Novo's revenue by 2030, “highlighting the urgent need for mergers and acquisitions,” Leuchten said, predicting that Novo could spend up to $35 billion on M&A this year.

Monday's trial outcome is another blow for the Danish drugmaker as it fell short of a drug already on the market, and comes after shares fell nearly 50% in 2025.

Earlier this month, Novo predicted that its sales and profit growth would decline between 5% and 13% in 2026, as the company navigates competition, lower prices in the US, and the loss of exclusivity for Wegovy and Ozempic in certain markets.

“People should expect it to go down before it goes up again,” Doustdar de Novo told CNBC at the time.

Meanwhile, Lilly predicted sales would grow by about 25% in 2026.

Novo started the year with a strong launch of the first GLP-1 weight-loss pill in the U.S., the Wegovy pill, but Doustdar said it was not enough to offset challenges in other parts of its business. Eli Lilly is expected to launch a rival pill in the second quarter of 2026.

In addition to competition from Lilly, Novo's sales have been hit due to competition from compounding pharmacies that sell copycat versions of semaglutide at a lower price, in what Novo has called “massive illegal compounding that poses a significant risk to patient safety.”

The FDA said earlier this month that it planned to take legal action against the telehealth company. him and herincluding restricting access to ingredients and referring it to the Department of Justice, after Hims offered a copy of the Wegovy pill at a price significantly cheaper than the price Novo sells for the brand-name pill. Hims quickly took the pill after the backlash.