An antiviral medication could soon be available for treating COVID-19. Molnupiravir, an antiviral medication that is currently in clinical trials, may soon be added to the currently available tools to treat COVID-19.
Molnupiravir is an antiviral that is different from the currently used remdesivir because unlike remdesivir, which is given via IV, molnupiravir can be taken orally. This means it will be much easier for doctors to prescribe to patients who are not hospitalized with COVID-19, and could be used in a similar fashion as the antiviral, Tamiflu.
Molnupiravir is considered a broad-spectrum antiviral – meaning it can target multiple different viruses – that blocks the replication of RNA viruses – such as SARS-CoV-2 (the virus that causes COVID-19).
This antiviral was initially being tested as a treatment for the flu, but was repurposed and tested as a treatment that had the potential to be used against the SARS-CoV-2 virus.
Molnupiravir was tested in ferrets to see whether treatment could stop the spread of the SARS-CoV-2 virus. The study1 reported that treating ferrets twice a day with the antiviral reduced the amount of virus (viral load) in the respiratory tract of these animals. Importantly, the study reported that transmission of the virus to uninfected ferrets was totally stopped when infected ferrets were given the antiviral.1 Given these results, the researchers suggest that Molnupiravir is a “promising antiviral countermeasure to break SARS-CoV-2 community transmission chains”.1
The first human clinical trial of the drug2 – a randomized, double-blind, controlled clinical trial – was completed, testing the safety and effectiveness of this antiviral at multiple doses. The trial included 64 participants between the ages of 19 and 60.
The study reported that the antiviral was well tolerated and that there were no serious adverse events in people taking the medication. They also reported that the medication was able to be detected in the plasma of participants.
The drug is now in phase II and phase III clinical trials to test whether it is effective in patients who are hospitalized or not hospitalized with COVID-19. The trials will determine the effectiveness of molnupiravir in reducing the viral load of SARS-CoV-2 in participants – this will give an indication of whether it might be effective in reducing the spread of the virus from person to person. In addition, the trials will assess whether there will be an impact on hospitalizations and deaths from COVID-19 in those who receive molnupiravir antiviral treatment.
- Cox, R.M., Wolf, J.D. & Plemper, R.K. Therapeutically administered ribonucleoside analogue MK-4482/EIDD-2801 blocks SARS-CoV-2 transmission in ferrets. Nat Microbiol 6, 11–18 (2021). https://doi.org/10.1038/s41564-020-00835-2
- Painter WP, Holman W, Bush JA, Almazedi F, Malik H, Eraut NCJE, Morin MJ, Szewczyk LJ, Painter GR. Human Safety, Tolerability, and Pharmacokinetics of Molnupiravir, a Novel Broad-Spectrum Oral Antiviral Agent with Activity Against SARS-CoV-2. Antimicrob Agents Chemother. 2021 Mar 1:AAC.02428-20. doi: 10.1128/AAC.02428-20. Epub ahead of print. PMID: 33649113.
- Image by Thor Deichmann from Pixabay