Novo Nordisk stock was dropping on Wednesday after Roche said it had licensed a promising obesity drug in a deal that could cost it up to $5.3 billion.U.S.-listed shares of Novo Nordisk were down 5.2%.

Novo Nordisk on Monday revealed weaker-than-expected data from a second late-stage trial of its obesity drug candidate CagriSema, knocking shares and stoking worries that rival Eli Lilly may be gaining an edge over the company in the weight-loss drugs market.

The setback comes at a crucial time for Novo Nordisk, which had positioned CagriSema as its next-generation weight-loss treatment. The current generation, made up of blockbuster drugs like Wegovy and Ozempic, have been cash cows for Novo.

New trial data showed the drug helped obese or overweight type 2 diabetics lose an average 15.7% of their weight, when an earlier study recorded 22.7%.

Novo Nordisk will explore how GLP-1 drugs could help patients struggling with addiction, its head of development Martin Holst Lange told an online press conference on Thursday.

Novo Nordisk reported results on its next-generation obesity drug in diabetes patients, including data on weight loss that fell short of investors’ expectations.

Novo Nordisk stock tumbled Monday morning after disappointing trial results for its CagriSema weight-loss drug. Shares in rival Eli Lilly also sold off. Find out more:

Key Takeaways Roche moved to enter the booming weight-loss drug market now dominated by Novo Nordisk and Eli Lilly.The Swiss pharmaceutical firm signed an exclusive agreement with Zealand Pharma to produce treatments using Zealand's experimental petrelintide injectable.