ZURICH: Swiss drugmaker Novartis said on Tuesday that a large British study of its cholesterol-lowering drug Leqvio is now not expected to be completed until 2026, a year later than expected, as COVID-19 infections made participant recruitment difficult.

In January 2020, Novartis struck a deal with the National Health Service to use its data to find patients at risk of heart disease for whom conventional treatment had failed. They are due to get Leqvio, which targets "bad cholesterol" that can cause heart attacks and strokes.

Novartis, which said rising UK vaccinations are now helping the study to again accelerate recruitment, hopes to gather data about the efficacy of Leqvio, which it bought two years ago for nearly $10 billion and which it expects will eventually reach billions of dollars in annual sales.

Britain, meanwhile, is seeking to compile safety and efficacy data as it seeks to manage heart disease, one of the country's leading killers. It sees the study with Novartis and Oxford University as a precursor to other, similar trials.

"With the impact of COVID in the UK, recruitment has been challenging," said John Tsai, Novartis's head of drug development, adding that recruitment is now "starting to get back on track".

Tsai made the delay public in a call with analysts after Novartis reported first-quarter results that missed expectations, with the pandemic weighing on drug sales as people skipped going to the doctor for other illnesses.

As COVID-19 infections have surged, waned and then surged again, they have disrupted other companies' trials, too, including Roche's study of an experimental pill against the coronavirus. Roche was forced to find another location after rising vaccinations in Britain suddenly left it with too few patients there.