A pill form of remdesivir, an antiviral drug currently administered intravenously, may be able to treat COVID-19 in mice. The corresponding research was conducted by a team of scientists at the University of North Carolina at Chapel Hill and published in the journal Science Translational Medicine.
While remdesivir is already used to treat COVID-19 it is currently only given intravenously, which limits its use outside of hospital settings. The current study examines whether a pill version of remdesivir could also treat the disease, and allow for more widespread use of the drug.
In the study, the researchers tested a prodrug- an inactive compound that converts into an active compound inside the body- named GS-621763 that is metabolized into remdesivir when ingested. They gave the compound to mice with COVID-19 and compared their lungs to those of untreated mice 24 hours later.
They found that mice treated within 24 hours of infection had reduced lung damage and viral load in comparison to untreated controls, alongside improved lung function. This, they say, implies that remdesivir in pill form may have a protective effect on the lungs.
The pill form of remdesivir likely works similarly to its intravenous counterpart by interfering with how the virus replicates in the body, and thus stopping its spread. The researchers noted that as this mechanism has remained stable among different COVID variants virus, remdesivir may be effective in treating COVID-19 as it continues to mutate.
The researchers noted some limitations to their study. They found that GS-621763 had to be administered within 12 to 24 hours after infection to be effective. However, this may be explained by the different physiologies between humans and mice; whereas viral load in mice peaks 24-48 hours after infection, it remains high in humans for up to 24 days.
These different timelines mean that researchers are uncertain about when the drug should be administered to humans. They also do not know when the compound stops improving disease outcomes.
Nonetheless, this research has set the ground for human trials. Future studies will also determine the timeline in which oral remdesivir is most effective, as well as its potential for treating other coronaviruses.