By Patrick Wingrove

(Reuters) – Eli Lilly 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.

(Reporting by Patrick Wingrove; editing by Caroline Humer and Rod Nickel)