Molnupiravir for Oral Treatment of Covid-19 in Nonhospitalized Patients

Background:New treatments are needed to reduce the risk of progression of coronavirus disease 2019(Covid-19).Molnupiravir is an oral,small-molecule antiviral prodrug that is active against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Methods:We conducted a phase 3,double-blind,randomized,placebo-controlled trial to evaluate the efficacy and safety of treatment with molnupiravir started within 5 days after the onset of signs or symptoms in nonhospitalized,unvaccinated adults with mild-to-moderate,laboratory-confirmed Covid-19 and at least one risk factor for severe Covid-19 illness.Participants in the trial were randomly assigned to receive 800 mg of molnupiravir or placebo twice daily for 5 days.The primary efficacy end point was the incidence hospitalization or death at day 29;the incidence of adverse events was the primary safety end point.A planned interim analysis was performed when 50%of 1550 participants(target enrollment)had been followed through day 29.