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, compared with once a week for other obesity drugs like Wegovy and Zepbound that are already on the market.

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

A highly anticipated obesity-drug candidate from biotech Amgen helped patients shed a significant amount of weight in a midstage study, but fell short of the loftier expectations of some investors. Subjects taking Amgen’s MariTide lost 20% of their ...