Eli Lilly announced on Friday that 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. In April, Lilly reported that 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, where 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 were patients experiencing fewer than five episodes of shallow or no breathing per hour during sleep, or five to 14 episodes without being excessively sleepy during the day, according to the study. Placebo results showed that 14.9% of patients achieved disease resolution in the first study, along with 6.4% in the second. Friday's data indicated that Zepbound helped lower biomarkers related to sleep apnea, including oxygen desaturation, blood pressure, and C-reactive proteins, which are signs of inflammation that can indicate heart disease. The drugmaker submitted its application to the U.S. Food and Drug Administration for Zepbound to be approved as a treatment for obstructive sleep apnea and plans to submit to other regulatory agencies globally in the coming weeks. 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. Earlier this month, Lilly presented data showing Zepbound helped treat liver scarring in patients with a difficult-to-treat fatty liver disease called metabolic dysfunction-associated steatohepatitis (MASH).