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.

Amgen's experimental drug MariTide helped overweight or obese patients shed up to 20% weight on average in a year-long mid-stage trial, although its shares tumbled 12% on Tuesday after the data failed to meet lofty investor expectations.

The company reported a Phase 2 study of its injectable MariTide medicine showed an approximately 20% average weight loss over one year for patients who were obese or overweight without diabetes. In addition, Amgen noted the results were without a plateau, suggesting that even more pounds could be lost with additional use.