Novo Nordisk’s CagriSema trial deals blow in obesity drug battle with Eli Lilly

By Stine Jacobsen and Maggie Fick

COPENHAGEN, Feb 23 (Reuters) – Novo Nordisk’s next-generation obesity drug CagriSema underperformed Eli Lilly’s Zepbound in a head-to-head trial, the Danish drugmaker said on Monday, as it suffered a setback in its fight to regain leadership of the weight loss market.

Few analysts had predicted CagriSema would be found to be less effective than Lilly’s drug that sells as Zepbound in the U.S. and Mounjaro in Europe.

Novo’s shares fell 15% to lows not seen since 2021.

The company positions CagriSema as a more potent successor to its current weight loss drug Wegovy that faces patent expiries after 2030. 

It hoped it would be a powerful contender to Zepbound as it seeks to regain its market leadership, but the data released on Monday left some analysts and investors doubting that.

“This is a worst-case scenario for Novo, now it is clinically proven that Mounjaro is better than CagriSema,” Markus Manns at Novo and Lilly shareholder Union Investment told Reuters, adding Novo faced an “uphill battle” with the drug.

“The base case was that Mounjaro and CagriSema are similar… Upside was superiority, but nobody had on the agenda, that Cagri would be worse than Mounjaro.”

‘TO INVESTORS IT’S VERY SIGNIFICANT’

The trial was designed to show CagriSema was at least as effective as tirzepatide in reducing weight. Tirzepatide is sold in the United States under the brand name Zepbound for weight loss and Mounjaro for diabetes, as well as being marketed as Mounjaro in Europe as a treatment for both.

Instead the trial showed CagriSema achieved a 23% reduction in body weight over 84 weeks, compared to 25.5% for Eli Lilly’s tirzepatide in the trial, Novo’s statement said.

“Weight loss of 23% versus 25.5% after 84 weeks may seem like a minor difference, but to investors it’s very significant,” said Nordnet’s Per Hansen. “In a winner-takes-all world Eli Lilly has cemented its strong momentum.”

Lilly’s shares rose in pre-market trading.

Henrik Hallengreen Laustsen, analyst at Jyske Bank, called the news a “fairly big setback” for Novo.

“When we look at long-term estimates for Novo, CagriSema makes up a fairly large part of Novo Nordisk’s growth,” he said, adding that, according to consensus, 60% of Novo’s growth will come from CagriSema.

The share price slide has reduced Novo’s market capitalisation by more than $400 billion since a peak in 2024 and erased the gains after Wegovy’s launch in 2021 that made Novo temporarily Europe’s most valuable listed firm.

Monday’s share price fall is not the first time that Novo shares have plunged on CagriSema trial data. In December 2024, Novo shares lost $125 billion in a day when results from the first trial of CagriSema were published.

NOVO NORDISK PLANS A HIGH-DOSE TRIAL

CagriSema is a weekly injection combining cagrilintide, which mimics pancreatic hormone amylin, and semaglutide, the active ingredient in Wegovy that mimics the gut hormone GLP-1.

In the study involving around 800 patients mainly in the U.S., Novo tested a fixed-dose combination of cagrilintide 2.4 milligrams and semaglutide 2.4 mg, while patients on tirzepatide received a 15-milligram dose.

Novo executives sought to strike an optimistic tone in calls with investors and journalists. They said CagriSema still has the potential to deliver the highest weight loss of any drug on the market after its expected approval by the U.S. FDA by the end of this year and launch next year.

Chief Scientific Officer Martin Holst Lange said Novo was a “little bit surprised” at Zepbound’s performance in the trial and expected that other trials would establish the drug’s potential.

The company plans to start a high-dose trial for CagriSema in the second half of this year.

“For better or worse, we need to be a bit patient,” he said.

Lange said the “open-label” trial design – both the administrators and the participants knew which drug was being given – likely introduced bias in favour of Zepbound, given the drug is well-known and commercially established.

Analysts from Barclays wrote in a note they were unconvinced by that explanation, while Jefferies analysts were more broadly sceptical.

“Without the level of superiority over current high-volume GLP-1s, we believe it is difficult to command a premium positioning for the drug,” Jefferies analyst Michael Leuchten wrote in a note.

While Novo’s study published on Monday included data for both the drugs over a period of 84 weeks, previous studies have focused on the effects of treatment over fewer weeks.

(Reporting by Stine Jacobsen, Maggie Fick, Bhanvi Satija and Jacob Gronholt-Pedersen; Editing by Terje Solsvik, Adam Jourdan and Barbara Lewis)