An experimental drug from Amgen helped people who are obese lose up to 15% of their body weight in a short study, a finding that has prompted executives to accelerate its development, the company said Monday.

The data, revealed at a medical meeting on Monday, come from a small Phase 1 trial primarily designed to test safety and find the best dose of the drug to move into further testing. Amgen has only provided summary results. Full details will be presented at a conference next month.

Yet the results suggest the treatment, known as AMG 133, could compete with treatments from Novo Nordisk and Eli Lilly because of its fast-acting effect and less frequent dosing.

Amgen enrolled 110 volunteers in the trial, testing low and high doses of the drug against a placebo. After 85 days, patients given three low doses of AMG 133 spaced four weeks apart lost 7% of their body weight, while those given three high doses lost 15%. By comparison, placebo recipients gained just over 1% in additional body weight.

Researchers haven’t observed any major safety issues and most side effects were “mild and transient,” Amgen said.

Based on those results, Amgen plans to “rapidly initiate” a Phase 2 program early next year that will recruit several hundred patients, including those with diabetes and other metabolic disorders, the company said.

Although AMG 133 hasn’t been tested extensively or for a long duration, the early findings suggest it could compare favorably to Novo’s Saxenda and Wegovy as well as Lilly’s diabetes drug Mounjaro, which is in late-stage testing as a weight-loss treatment.

Though comparing drugs across trials can be difficult, daily treatment with Saxenda resulted in average weight loss of around 5% to 7% after 56 weeks in Phase 3 testing, while weekly Wegovy treatment led to 10% to 16% reduction, on average, after 68 weeks. Patients who received Mounjaro in its one completed Phase 3 trial in obesity lost 16% to 23% of their body weight in 72 weeks.

On an earnings call last week, Amgen executives were optimistic AMG 133 could stand out despite the competition.

“There are many potential avenues to differentiation here,” such as how fast AMG 133 can help patients lose weight, how long its effects last and its tolerability, said David Reese, Amgen’s head of research and development.

Novo had combined obesity drug sales of 8.4 billion Danish kroner, or about $1.3 billion, in 2021. Through the first nine months of 2022, the Danish company recorded sales of $1.6 billion, a number that could have been higher except the company has had trouble producing sufficient supplies of Wegovy.

Mounjaro, meanwhile, is off to a fast start, earning $187 million in global revenue in its first full quarter on the market as a diabetes treatment.

Wegovy, Mounjaro and AMG 133 all act on hormones that help control insulin production. Each does so differently, however. AMG 133 modulates a hormone called GLP-1, as well as another metabolic hormone called gastric inhibitory polypeptide, or GIP.