Merck & Co Inc's experimental oral drug for Covid-19, molnupiravir, reduced by around 50 percent the chance of hospitalisation for patients at risk of severe disease, according to interim clinical trial results announced on Friday.

Merck and partner Ridgeback Biotherapeutics plan to seek US emergency use authorisation for the pill as soon as possible and to submit applications to regulatory agencies worldwide. Due to the positive results, the Phase 3 trial is being stopped early at the recommendation of outside monitors.

"This is going to...