June 23 (Reuters) - People started on a low dose of

Amgen's ( AMGN ) long-acting experimental obesity drug MariTide lost as

much weight as those given high doses but with milder side

effects, according to full results of a mid-stage trial

presented at a medical meeting on Monday.

As a result, Amgen ( AMGN ) said its recently launched

72-week Phase 3 trial will randomize obese or overweight adults

to three different doses, with each group started at a much

lower dose that will be increased over an eight-week period.

"MariTide is a long-acting drug, but side effects are

short-lived, which is a great learning and gives us confidence

to go into Phase 3," Jay Bradner, executive vice president of

research and development at Amgen ( AMGN ), told Reuters.

The company previously announced top-line results from the

year-long Phase 2 trial showing that MariTide, injected monthly

or every other month, helped overweight or obese patients shed

up to 20% of their body weight.

The full results were presented at the American Diabetes

Association meeting in Chicago and published in the New England

Journal of Medicine.

The data show that for people with type 2 diabetes, MariTide

lowered blood sugar by up to 2.2 percentage points. Amgen ( AMGN ) said

weight loss with MariTide also improved pre-specified

cardiometabolic measures, including waist circumference, blood

pressure, inflammation markers and blood lipids.

MariTide is an antibody linked to a pair of peptides that

activates receptors for the appetite- and blood sugar-reducing

hormone GLP-1 while simultaneously blocking a second gut hormone

called GIP.

Amgen ( AMGN ) said no new safety signals were identified in the

study and tolerability was consistent with the GLP-1 class,

which is associated with gastrointestinal side effects such as

nausea.

In late-stage trials, Novo Nordisk's GLP-1

obesity drug Wegovy had a vomiting rate of 24%, while Eli

Lilly's ( LLY ) Zepbound, which is designed to activate both

GLP-1 and GIP, had a rate of 13%. Each of those drugs are given

as weekly injections.

In the mid-stage MariTide study, vomiting was reported by

nearly 90% of patients started at the highest tested dose,

compared with 50% of patients ramped up to a full dose in one

step and 22% of those brought to their target dose over eight

weeks.

Amgen ( AMGN ) said trial discontinuation rates due to

gastrointestinal issues of up to 7.8% were lower for groups

treated with escalating doses.

The company said it plans to start additional Phase 3

studies this year for MariTide in patients with a variety of

serious health issues, including cardiovascular disease caused

by clogging arteries, heart failure, and obstructive sleep

apnea.