The experimental drug remdesivir could cut the time to recovery among severely ill patients with COVID-19 by one-third compared with placebo, US researchers say.

Top US health official Dr Anthony Fauci announced preliminary data from the randomised controlled trial from the White House overnight (Australian time) ahead of publication in a peer-reviewed journal.

Dr Fauci’s press briefing coincided with the publication of findings from a Chinese clinical trial investigating the same antiviral, that found no benefit.

“The [US] data shows that remdesivir has a clear-cut, significant, positive effect in diminishing the time to recovery,” Dr Fauci told reporters.