(Bloomberg) -- Novo Nordisk A/S's shares fell by the most on record after patients using its experimental obesity shot CagriSema lost less weight than predicted in a study, throwing into question the drugmaker's ability to maintain its lead in the exploding weight-loss market.
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The shot helped patients lose an average of 20.4% of their weight over 68 weeks, short of the 25% weight loss that Novo had predicted for its next-generation product, which analysts had expected to launch in 2026.
The study results were roughly in line with the performance of Eli Lilly & Co..'s Zepbound shot, which is already on the market and competes with existing Novo treatment Wegovy. Lilly is also working on a next-generation medicine, called retatrutide, which helped people lose up to about 24% of their weight in a mid-sized study last year.
Novo's shares plunged as much as 27% in Copenhagen, and they're now down 13% for the year after a runup on the strength of Wegovy sales. Shares of Eli Lilly jumped 10% in premarket US trading. The share decline briefly knocked more than $120 billion from Novo's market value.
The study is one of the most anticipated this year in the field. Novo has been counting on CagriSema to help it ward off a growing roster of competitors, led by Eli Lilly, in a weight-loss market that's predicted to grow to nearly $130 billion by 2030.
The results suggest that side effects may have made it difficult for patients to remain on the treatment, Peter Welford, a London-based analyst for Jefferies, wrote in a note. Investors had expected 25% to 27% weight loss, Welford said.
Novo's existing blockbusters mimic the gut hormone GLP-1, and CagriSema adds a second mode of action. The extra compound, called cagrilintide, works in a similar way as another gut hormone called amylin. Both the old and the new medicines suppress the appetite, though taking amylin has been described as a gentler experience than a GLP-1 drug, helping people stay satisfied for longer instead of wiping away their drive to eat.
What Bloomberg Intelligence Says:
Novo Nordisk's results for its CagriSema drug (20.4-22.7% weight loss vs. targeted 25%) look on par with Eli Lilly's marketed Zepbound. Lilly also has retatrutide to follow, which may offer even greater potency. With the patent expiration of Wegovy in the early 2030s and potential IRA headwinds, the underwhelming result will likely pressure consensus, which sees the asset driving almost 20% of Novo's sales in 2030. There's now added onus on Novo's amycretin, though it's only in Phase 1 trials currently.