Pharmaceutical company Merck will apply for emergency use authorization for a pill that may be the first to treat COVID-19, according to experiment results released by the company on Friday.

Merck and its partner Ridgeback Biotherapeutics tracked 775 adults with mild to moderate COVID-19 symptoms who were considered to be at higher risk for severe disease due to health problems. The adults who took Merck’s molnupiravir pill within five days of showing COVID-19 symptoms experienced about half the rate of hospitalization and death compared to patients who received a placebo, according to the company’s research.