Amgen's experimental drug MariTide helped overweight or obese patients shed up to 20% of their body weight in a mid-stage trial, but the results failed to meet lofty investor expectations and shares of the biotech company tumbled about 12% on Tuesday.

Amgen also tested MariTide in a population with Type 2 diabetes, a group that tends to lose less weight with the new obesity drugs. On average they lost up to 17 percent of their initial weight.

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