Novo Nordisk's hopes of heralding a new era of obesity treatment with its next-generation CagriSema drug may be in doubt after a series of trial results have left investors feeling unsatisfied.

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's U.S.-listed shares fell Monday morning following the release of data for a new phase 3 clinical trial of its in-development weight loss drug CagriSema.