Will pharmacies soon have covid-19 drugs on their shelves? After vaccines, drug companies are now in the race to develop a treatment that can be taken at home with a glass of water as soon as symptoms appear.
Because although prevention is better than cure, as the saying goes, knowing how to cure is still crucial.
What is an antiviral?
There are already antivirals for other viruses, such as HIV, which causes AIDS, and the flu. At the beginning of the pandemic, funding and research focused on the development of vaccines, which partly explains the delay in the development of antivirals against the coronavirus.
“Viruses are small machines that need certain components to replicate,” explains Daria Hazuda, a biochemist who has been working on these treatments for years.
“Antivirals are usually small chemical molecules, developed to interfere with this machinery,” she says. “They introduce a mutation into the virus, and when this happens multiple times, these mutations reduce the virus’s ability to replicate,” she adds.
By curbing the disease, severe cases, hospitalizations, and deaths can be avoided.
The ongoing projects
There are currently two relatively advanced projects, tested on more than 1,000 people.
The first is that of the American pharmaceutical company Merck, in association with the biotechnology company Ridgeback Biotherapeutics. The product is called Molnupiravir.
Developed initially to treat the flu, it has been modified so that it can be taken in pill form, to be taken twice a day for five days.
The treatment has been very well tolerated by the few hundred people who have already received it. Analyzes of several dozen of them showed that the virus was no longer detectable after five days for all those treated with Molnupiravir, but it was still detectable in 26% of the placebo group (test product with no medicinal value).
Results of trials in another 1,450 adults are expected in October.
The second project is from the Swiss pharmaceutical company Roche, in collaboration with the American company Atea Pharmaceuticals.
Called AT-527, the treatment is being tested in about 1,400 participants in Europe and Japan, this time starting at the age of 12.
“We hope to seek regulatory approval by the end of the year and launch the drug in 2022,” said Atea CEO Jean-Pierre Sommadossi.
A third, less advanced project is being developed by Pfizer. Unlike the others, the treatment called PF-07321332 was developed specifically against SARS-CoV-2, the virus that causes covid-19. It is being tested in about 60 adults, with results expected by the end of June.
A challenge: take it quickly
Both Merck and Roche require that the drug be taken within five days of the onset of symptoms.
This is because the virus replicates more during the first week.
“The sooner you treat with an antiviral, the better the outcome,” says Daria Hazuda, who leads Merck’s drug research.
This explains the relative failure of Remdesivir, the only antiviral against COVID-19 approved so far. Produced by the American laboratory Gilead Sciences, it must be administered intravenously in the hospital.
This means that patients are too advanced in the disease to get any real benefit from it.
Once the pills are available, the main challenge will be to diagnose patients very early.
Benefits: prevention and variants
But these antivirals should also be able to be used for prevention: for example, when one member of a family becomes infected, the others can take treatment to avoid developing the disease.
Finally, experts are confident in the ability of antivirals to remain effective against variants, as well as against other coronaviruses, including some still unknown.