A new study published in The New England Journal of Medicine evaluated the efficacy and safety of molnupiravir therapy—started within 5 days after the onset of signs or symptoms––in non-hospitalized, unvaccinated adults with mild-to-moderate, laboratory-confirmed COVID-19 and at least one risk factor for severe COVID -19 illness.

In this phase 3, double-blinded, randomized, placebo-controlled trial 1,433 participants were randomized to receive 800 mg of molnupiravir or placebo twice daily for 5 days. The primary efficacy end point was the incidence hospitalization or death on day-29.

The results revealed superiority of molnupiravir at the interim analysis. The risk of hospitalization for any cause or death through day-29 was lower with molnupiravir (7.3%) than with placebo (14.1%). In addition, the percentage of participants (among all) who were hospitalized or died through day-29 was lower in the molnupiravir group than in the placebo group (6.8% versus 9.7%).

Meanwhile, the results of subgroup analyses were largely consistent. In patients with prior SARS-CoV-2 infection and in those with low baseline viral load, the outcomes with this agent were similar to that of placebo. Adverse events were reported in 30.4% of participants in the molnupiravir group and 33.0% in the placebo group.

Thus, it was inferred that early treatment with molnupiravir reduced the risk of hospitalization and death in at-risk, unvaccinated adults with COVID-19.

Source: The New England Journal of Medicine. 2021 Dec 16;NEJMoa2116044. doi: 10.1056/NEJMoa2116044.