Effectiveness of molnupiravir for the treatment of COVID-19: a systematic literature review of real-world observational studies.

Objective: Molnupiravir (MOV), an oral antiviral, is prescribed to treat adult patients with mild-to-moderate COVID-19 at risk of progressing to severe disease. Previous systematic literature reviews (SLRs) have evaluated the effectiveness of MOV in the general population; however, evidence on high-risk population is lacking. This SLR assessed the real-world effectiveness of MOV for reducing the progression to severe COVID-19 outcomes in clinical settings, including high-risk or special populations (such as patients with type 2 diabetes, chronic respiratory diseases, immunocompromised conditions, older adults, and nursing home residents) who have limited alternative COVID-19 treatment options.

Methods: We searched EMBASE and PubMed databases for studies published between 1 January 2021 and 24 May 2024, using predefined search terms related to MOV. Studies comparing MOV-treated with untreated groups of non-hospitalized adults at risk of progression to severe COVID-19 outcomes (hospitalization, death, and the composite of hospitalization/death) were included. Risk of bias of the included studies was assessed using the ROBINS-I tool.

Results: Twenty-one general and special population studies were included. General population studies (n = 16) showed that MOV reduced the risk of death, hospitalization, and hospitalization/death. Special population studies (n = 10; five additional and five general population articles with subgroups of interest) also showed that MOV reduced the risk of the same outcomes, with a more pronounced effect in older adults (≥60 years). The wide range of risk reduction observed might be attributed to variability in COVID-19 hospitalization guidelines and vaccination status.

Conclusions: Findings from this SLR suggest that MOV may reduce the risk of hospitalization, death, and hospitalization/death compared with untreated groups, including high-risk adults with underlying comorbidities. Further studies are needed to confirm the effectiveness of MOV in high-risk or special populations.