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’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.

Swiss drugmaker Roche on Wednesday announced a major deal in the weight-loss category, agreeing to pay up to $5.3 billion to Zealand Pharma in a licensing and development deal.