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 pharmaceutical giant released fresh trial data showing the drug helped obese or overweight type 2 diabetics lose an average 15.7% of their weight.

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