Eli Lilly’s weight-loss drug tirzepatide significantly reduced sleep apnoea problems in a late-stage clinical trial, the pharmaceutical group said on Wednesday, adding to evidence that could encourage more insurers to cover the drug.

The results from two year-long clinical studies showed that tirzepatide, which is marketed under brands including Zepbound for weight loss and Mounjaro for diabetes, helped to cut the severity of obstructive sleep apnoea in adults with obesity by up to nearly two-thirds, suggesting the treatment could help the estimated 20mn Americans affected by moderate to severe sleep apnoea.

The positive data will also be a boon to Eli Lilly’s efforts to push for more wide scale coverage of the drugs by private insurers and US federal health insurance programme Medicare, which were both initially reluctant to cover the treatment.