A Phase 3, Randomized, Placebo-Controlled, Double-Blind Clinical Study to Evaluate the Efficacy and Safety of Molnupiravir (MK-4482) in Non-Hospitalized Adults With COVID-19 at High Risk for Disease Progression

Researchers are looking for other ways to prevent severe illness from COVID-19. COVID-19 is a virus that often causes mild flu or cold-like symptoms. However, people with certain health conditions or other factors have a high chance of getting severely ill from COVID-19, which can require a hospital stay or lead to death.Some people who are high risk for severe illness may be unable to take certain treatments for COVID-19 because they are not available to them, or they take other medicines that may react with a treatment and cause an unwanted effect. Molnupiravir is a study medicine designed to stop the COVID-19 virus from copying itself in the body. Researchers want to know if molnupiravir can prevent severe illness in people who are high risk. The goals of this study are to learn: • If molnupiravir prevents severe illness from COVID-19 more than placebo in people who are high risk. A placebo looks like the study medicine but has no study medicine in it. • About the safety of molnupiravir and if people who are high risk tolerate it compared to placebo About 3,082 people aged ?18 years, with COVID-19 will be in this study that: •Have COVID-19 symptoms for 4 days or less •Have one or more of the following that makes them high risk for severe illness from COVID-19: -Being 75 years old or older -Having a weakened immune system due to certain health conditions or treatments -Having at least 3 certain health conditions (e.g. as diabetes, asthma, and high blood pressure) •Are not staying in the hospital or will need a hospital stay due to COVID-19 before joining the study People will be assigned by equal chance, to one of these treatments by mouth as a tablet twice a day for 5 days: • Molnupiravir • Placebo Neither the people in the study nor the researchers will know which study treatment a person is taking. During the study, people will give blood samples, have physical examinations and COVID-19 tests. A person may be in this study for 6 months.