The World Health Organization (WHO) says it welcomes early results of a human trial of the drug dexamethasone to treat COVID-19 disease. Researchers in Britain announced Tuesday that their study shows dexamethasone cut death rates by around a third among patients with the most severe cases of COVID-19. Dexamethasone has been in use since the 1960s to reduce swelling caused by diseases such as arthritis. This is the first treatment to be shown to reduce mortality in patients with COVID-19 requiring oxygen or ventilator support, WHO Director-General Tedros Adhanom Ghebreyesus said in a statement on Tuesday. The United Nations health agency also said it was looking forward to the full findings of the British trial. The WHO said the additional information could lead it to change its COVID-19 treatment guidelines.