Merck and Ridgeback Biotherapeutics announced Friday they’ve developed a drug that reduces the risk of hospitalization or death by around 50% for patients with mild or moderate cases of Covid. Molnupiravir could be the first oral antiviral medicine for Covid. It works by inhibiting the replication of the coronavirus inside the body. No deaths were reported in patients who were given molnupiravir within a 29-day period, in the actual study with 775 trial participants. Every participant was unvaccinated and had at least one underlying factor that put them at greater risk of developing a more severe case of the virus. The trial was conducted at more than 170 sites, in countries including the U.S., Brazil, Italy, Japan, South Africa, Taiwan and Guatemala. Just 1.3% of the molnupiravir group discontinued therapy due to an adverse event. “The news of the efficacy of this particular antiviral is obviously very good news,” White House chief medical advisor Dr. Anthony Fauci said at a Covid briefing Friday.

Robert M. Davis, CEO and president of Merck, said in a press release Friday that the company would do everything it can to bring molnupiravir to patients as quickly as possible. Ridgeback Biotherapeutics CEO Wendy Holman added: “With the virus continuing to circulate widely, and because therapeutic options currently available are infused or require access to a healthcare facility, antiviral treatments that can be taken at home to keep people with Covid-19 out of the hospital are critically needed.”The FDA must previously approve the molnupiravir. An emergency use authorization is expected. Merck has already begun producing molnupiravir.