The pharmaceutical manufacturer Amgen announced on Tuesday that an experimental obesity drug helped patients lose up to 20 percent of their weight in a year. The drug, MariTide, is given by injection once a month,

Shares in Amgen fell by double digits Tuesday on results for the company’s MariTide shot, which is viewed as a potential rival to Wegovy and Zepbound.

The results shed light on how MariTide may measure up to weight loss injections from Novo Nordisk and Eli Lilly and other experimental treatments.