Molnupiravir Use Among Patients with COVID-19 in Real-World Settings: A Systematic Literature Review

Introduction Molnupiravir (MOV) is an oral antiviral for the treatment of individuals with mild-to-moderate COVID-19 and at high risk of progression to severe disease. Our objective was to conduct a systematic literature review (SLR) of evidence on the effectiveness of MOV in reducing the risk of severe COVID-19 outcomes in real-world outpatient settings.Methods The SLR was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines and using pre-determined population, intervention, comparison, outcome, time, and study design inclusion criteria. Eligible studies were published between January 1, 2021, and March 10, 2023, and evaluated the real-world effectiveness of MOV compared to no treatment in reducing the risk of severe COVID-19 outcomes among outpatients >= 18 years of age with a laboratory-confirmed diagnosis of SARS-CoV-2 infection.Results Nine studies from five countries were included in the review. The size of the MOV-treated group ranged from 359 to 7818 individuals. Omicron variants of SARS-CoV-2 were dominant in all study periods. Most studies noted differences in the baseline characteristics of the MOV-treated and untreated control groups, with the treated groups generally being older and with more comorbidities. Eight studies reported that treatment with MOV was associated with a significantly reduced risk of at least one severe COVID-19 outcome in at least one age group, with greater benefits consistently observed among older age groups.Conclusions In this SLR study, treatment with MOV was effective in reducing the risk of severe outcomes from COVID-19 caused by Omicron variants, especially for older individuals. Differences in the ages and baseline comorbidities of the MOV-treated and control groups may have led to underestimation of the effectiveness of MOV in many observational studies. Real-world studies published to date thus provide additional evidence supporting the continued benefits of MOV in non-hospitalized adults with COVID-19. COVID-19 continues to be a major source of morbidity and mortality. Throughout the pandemic, many countries authorized various therapies for the treatment of individuals presenting with mild-to-moderate COVID-19 and at high risk of progression to severe disease. Some of these therapies have since been rendered ineffective due to the emergence of Omicron variants in late 2021. The objective of the current study was to conduct a systematic literature review to assess real-world evidence on the effectiveness of molnupiravir, including effectiveness against COVID-19 caused by Omicron variants, to supplement the findings of the MOVe-OUT clinical trial and further inform on the potential clinical benefit and utility of this antiviral agent. Nine studies were included in the systematic literature review. We found that treatment with molnupiravir was effective in reducing the risk of severe outcomes from COVID-19 caused by Omicron variants, especially for older individuals. Differences in the ages and baseline comorbidities of the molnupiravir-treated and control groups may have led to underestimation of the effectiveness of molnupiravir in many observational studies. In summary, real-world effectiveness studies provide additional evidence supporting the continued benefits of molnupiravir in non-hospitalized adults with COVID-19.