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.

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%.

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.