Gilead criticised a WHO study that raised doubts about its Covid-19 treatment, insisting that the overnight blockbuster drug does improve survival rates for a large group of hospitalised patients. The company mounted the defence of remdesivir as it revealed that the drug, which had not even been approved by the US FDA at the start of the year, generated $873 million in revenue in the third quarter. The WHO study published this month found remdesivir, now known by its brand name Veklury, had little effect on mortality, reducing time in hospital or whether a patient ends up on a ventilator.