The preclinical discovery and development of molnupiravir for the treatment of SARS-CoV-2 (COVID-19)

ABSTRACT Introduction Molnupiravir (MOV) is a broad-spectrum oral antiviral agent approved for the treatment of COVID-19. The results from in vitro and in vivo studies suggested MOV activity against many RNA viruses such as influenza virus and some alphaviruses agents of epidemic encephalitis. MOV is a prodrug metabolized into the ribonucleoside analog β-D-N4-hydroxycytidine. It is incorporated into the viral RNA chain causing mutations impairing coding activity of the virus, thereby inhibiting viral replication. Areas covered This review analyzes the in vitro and in vivo studies that have highlighted the efficacy of MOV and the main pre-authorization randomized controlled trials evaluating its safety, tolerability, and pharmacokinetics, as well as its antiviral efficacy against SARS-COV-2 infection. Expert opinion MOV is an antiviral agent with an excellent tolerability profile with few drug–drug interactions. Treatment of mild-to-moderate COVID-19 can benefit from MOV administration in the precocious phases of the disease, prior to the trigger of an aberrant immune response responsible for the parenchymal damage to pulmonary and extrapulmonary tissues. However, its suspected mutagenic effect can be a factor limiting its use at least in selected populations and studies on its teratogen effects should be planned before it is authorized for use in the pediatric population or in pregnant women.