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 pharmaceutical company's MariTide treatment performed well in a Phase 2 study but not as well as Wall Street expected.

Shares of Amgen (NASDAQ: AMGN) recently ticked lower despite a very positive-sounding press release regarding its weight management candidate. According to the giant drugmaker, treatment with an anti-obesity candidate called MariTide helped patients reduce their weight by up to 20% after 52 weeks.

Amgen's experimental drug MariTide led to an average weight loss of up to 20% in a year-long mid-stage trial of nearly 600 people who were overweight or obese, the company said on Tuesday.

An Amgen obesity drug helped participants lose a substantial amount of weight, but questions about how competitive it could be remain

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.

Amgen's latest once-monthly weight loss drug data looks "OK," analysts say, as its path to approval still remains murky.

Upcoming data from a mid-stage study of Amgen's experimental weight-loss drug MariTide will shed light on how well it might measure up against the popular GLP-1 drugs sold by Eli Lilly and Novo Nordisk .

Analysts were expecting the treatment to achieve an average weight loss of about 20% to 25% after one year of treatment, making it competitive with Eli Lilly & Co. Inc.’s Zepbound.