Amgen’s Weight-Loss Drug Candidate Shows Promise in Early Data

Amgen HQ sign_iStock, JHVEPhoto

Pictured: Sign at entrance to Amgen's headquarters in Thousand Oaks, California/iStock, JHVEPhoto

Phase I data for Amgen’s experimental weight-loss drug MariTide suggest the candidate may produce longer-lasting effects than popular glucagon-like peptide-1 medicines currently on the market such as Novo Nordisk’s Wegovy and Eli Lilly’s Zepbound, according to results published Monday in the journal Nature Metabolism

In the study enrolling obese patients without diabetes, the highest dose of the monoclonal antibody MariTide resulted in a body weight loss of 14.5% by day 85, compared to the placebo group who had gained 1.5% body weight. Even on the lowest dose, patients lost 7.4% of their body weight after just three doses. By comparison, Wegovy and Zepbound showed 15% to 21% weight loss in trials conducted over a year. 

MariTide is a bispecific molecule combining a glucose-dependent insulinotropic polypeptide (GIP) receptor antagonist and glucagon-like peptide-1 (GLP-1) receptor agonist. It works by both activating the GLP-1 receptors while blocking receptors of the GIP hormone.  

A promising component of Amgen’s candidate is durability. Blockbuster drugs like Wegovy and Zepbound, which are dosed weekly, must be taken continuously once started to maintain efficacy. Effectively, patients need to keep taking them to keep benefiting from them. However, the early data published Monday suggest MariTide could be effective with tapered-down dosing that can be taken less frequently over time. 

In the Phase I study, overall weight loss was sustained for up to 150 days after the last dose, whilemaximum weight loss was maintained for two months after the last dose. A Phase II trial is now underway to validate the theory of lowered dosing. After being titrated up to the full dose, patients in the study will then be transitioned to a less intensive dosing regimen, an Amgen executive told STAT News.  

Still, it’s not yet clear if patients will be able to stop the drug altogether. Results for Amgen’s Phase II trial of MariTide are expected late this year. 

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at and on LinkedIn.   

Back to news