Efficacy of Molnupiravir in Reducing the Risk of Severe Outcomes in Patients with SARS-CoV-2 Infection: A Real-Life Full-Matched Case–Control Study (SAVALO Study)

We conducted a real-life case–control study among outpatients with Omicron SARS-CoV-2 infection to assess the effectiveness of molnupiravir (MNP) in reducing hospital admission, admission to the intensive care unit, and death at day 28. Cases were SARS-CoV-2-positive patients seeking medical care within five days of symptom onset from 1 January to 31 December 2022, who received MNP. Controls were selected from a regional database among positive subjects who did not receive antiviral treatment for SARS-CoV-2. A total of 1382 patients were included (146 cases, 1236 controls). Vaccinated patients had a lower risk of mortality and of the composite outcome (hospital admission, ICU admission, or all-cause death) than unvaccinated ones (0.6% vs. 7.8%, p < 0.001 and 2% vs. 7.8%, p = 0.001, respectively). After full-matching propensity score analysis, MNP-treated subjects had a lower incidence of the composite outcome, although no effect was observed on individual outcomes. In subgroup analyses by vaccination status, MNP was effective in preventing all outcomes among unvaccinated patients and reduced the risk of ICU admission in both vaccinated and unvaccinated patients. Molnupiravir treatment effectively reduced the composite outcome risk in outpatients with SARS-CoV-2 infection, with a more pronounced benefit in unvaccinated patients. These findings highlight MNP’s potential to help prevent disease progression in high-risk patients, thereby supporting its role as an outpatient therapeutic option for COVID-19.