Merck & Co Inc and partner Ridgeback Biotherapeutics said six lab studies showed their experimental oral Covid-19 drug Molnupiravir was active against the fast-spreading Omicron variant.

The data evaluated the antiviral activity of Molnupiravir and other Covid-19 antiviral agents against variants of concern. Molnupiravir is yet to be studied against Omicron in human studies, the companies said.

Molnupiravir and a rival oral pill from Pfizer Inc were authorised in the United States in December and are considered as important tools against Omicron, Reuters reports.