In a phase 3 clinical trial, Merck's experimental antiviral pill molnupiravir reduced the risk of hospitalization or death by about 50% in patients with mild-to-moderate COVID-19. These preliminary findings, published in Nature Structural & Molecular Biology, await peer review.
Our arsenal against COVID-19 includes vaccines, masks, and social distancing. Now, a new oral antiviral from Merck and Ridgeback Biotherapeutics shows strong potential. The drug halved hospitalization or death rates in high-risk patients during late-stage trials.
If approved, molnupiravir could become the first oral therapy specifically for COVID-19. Note: trial data is not yet peer-reviewed.
This broad-spectrum antiviral targets the virus's RNA. By mimicking a building block of viral genetic material, it introduces errors during replication, halting the virus's spread.
The trial enrolled 1,433 adults with mild-to-moderate COVID-19 and at least one risk factor, like diabetes or heart disease. Within five days of symptoms, participants received either molnupiravir (800 mg twice daily for five days) or placebo.
After 29 days, 14.1% (53 patients) in the placebo group were hospitalized or died, compared to 7.3% (28 patients) in the molnupiravir group—with zero deaths reported.
Side effects were similar: about 35% in the molnupiravir group and 40% in placebo. Only 1.3% discontinued molnupiravir due to adverse events, versus 3.4% on placebo. Specific effects weren't detailed and may relate to COVID-19 symptoms.
An independent data monitoring committee and the FDA recommended halting placebo enrollment, citing the drug's clear benefits—continuing placebo would be unethical.
Merck and Ridgeback plan to submit Emergency Use Authorization requests to the FDA and other regulators soon. Merck aims to produce 10 million doses by end-2021 if approved.
