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.

Roche agreed to develop a weight-loss drug with Danish biotech Zealand Pharma, pressuring Novo Nordisk and Eli Lilly.

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 start selling its obesity drug Wegovy directly to patients at a reduced price, following a similar move from Eli Lilly as the two drugmakers chase market share.

Novo’s share price fell 8 per cent on Monday, having previously dived in December after a late-stage trial of CagriSema in overweight or obese people without diabetes found they lost an average of 22.7 per cent of their body weight. That was only marginally ahead of results for Mounjaro, an existing rival treatment made by Eli Lilly.

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:

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

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.