The results came from a multi-national clinical trial with over 700 subjects across the world, mostly from the United States, recruited during April-December, 2021, who were given either proxalutamide or a placebo, the company said in a filing.

It remains unclear how many patients contracted the Omicron variant.

Among trial subjects with more than seven days of treatment, six in the placebo group were hospitalized, including one death, versus no death or hospitalisation in the group taking proxalutamide, according to the filing, without providing detailed data.

For all subjects who took at least one day of treatment, Proxalutamide reduced the risk of hospitalization or death by 50%. For subjects with more than one day of treatment, the risk was reduced by 71%, Kintor said.

China has approved Pfizer Inc's Paxlovid and Brii Biosciences Ltd's antibody-based medicine for mild and moderate COVID patients with high risk of progressing to severe conditions.

Kintor chairman Tong Youzhi said a separate trial of the treatment for use in severe cases is facing some challenges, as the number of such cases remain low in China, and the trial in Ukraine has been affected by the ongoing war with Russia.

Kintor is arranging sites in countries including southeastern Asia nations to push forward the trial, he said.

(Reporting by Roxanne Liu and Ryan Woo)