June 21 (Reuters) - Eli Lilly ( LLY ) on Friday said its

popular weight-loss drug Zepbound helped resolve moderate to

severe obstructive sleep apnea in up to 52% of patients in two

late-stage trials.

U.S.-based Lilly and Danish rival Novo Nordisk

are in a race to get their obesity drugs approved to

treat other ailments. Novo's Wegovy was approved as a treatment

for heart disease in March, while Lilly's own heart-disease

trial for Zepbound is expected to conclude this year.

Lilly in April said Zepbound, known chemically as

tirzepatide, helped reduce episodes of irregular breathing in

patients with obstructive sleep apnea by 55% in the first study

and by 62.8% in the second.

Patients in the first study received tirzepatide, while

patients in the second tested the drug in combination with

continuous positive airway pressure (PAP) therapy, in which air

is pumped into the lungs to keep the airway open during sleep.

Full results from the trials, presented Friday at the

American Diabetes Association's scientific meeting in Orlando,

Florida, showed Zepbound helped resolve sleep apnea in 43% of

patients taking the drug alone and in 51.5% of those also using

PAP.

The criteria for disease resolution was patients

experiencing fewer than five episodes of shallow or no breathing

per hour during sleep, or five to 14 episodes and not being

excessively sleepy during the day, according to Lilly.

Lilly said 14.9% of patients on a placebo also achieved

disease resolution in the first study, along with 6.4% in the

second.

Friday's data showed Zepbound helped lower biomarkers

related to sleep apnea, including oxygen desaturation, blood

pressure, and C-reactive proteins - signs of inflammation that

can indicate heart disease - Lilly said.

The drugmaker said it had submitted its application to the

U.S. Food and Drug Administration to have Zepbound approved as a

treatment for obstructive sleep apnea and would submit to other

regulatory agencies globally in the coming weeks.

Lilly said the overall safety of tirzepatide in these trials

was similar to past studies, with the most frequent side effects

being diarrhea, nausea, vomiting and constipation.

The Indianapolis-based drugmaker presented data earlier this

month showing Zepbound helped treat liver scarring in patients

with a difficult-to-treat fatty liver disease called metabolic

dysfunction-associated steatohepatitis, or MASH.