Will pharmacies soon have boxes of anti-Covid drugs on their shelves?
After vaccines, pharmaceutical companies are in line to develop a treatment to be swallowed simply at home, with a full glass of water, if symptoms appear.
Because even if prevention is better than cure, as the saying goes, knowing how to heal remains crucial.
Prevent the virus from replicating.
Antivirals already exist against other viruses, for example HIV responsible for AIDS, or that of influenza (prescriptions of Tamiflu).
How do they work?
“They introduce a mutation into the virus, and when this happens multiple times, these mutations decrease the virus's ability to replicate,” says Daria Hazuda, biochemist.
The disease thus slowed down, severe cases, hospitalizations and deaths can be avoided.
Two relatively advanced projects.
Both have already been tested on more than a thousand people (“phase 3” clinical trials).
The first is that of the American pharmaceutical company Merck, in partnership with the biotechnology company Ridgeback Biotherapeutics.
The product is called
Molnupiravir
. First developed against the flu, it has been modified to be able to be put in the form of a pill. This should be taken twice a day for five days. The treatment was very well tolerated by the few hundred people who have already received it. Analyzes on several dozen of them showed that the virus was no longer detectable after 5 days for all those treated with Molnupiravir, but it was still so in 26% of the placebo group. Results from trials in 1,450 additional adults are expected in the fall.
The second project is that of the Swiss pharmaceutical company Roche, in partnership with the American Atea Pharmaceuticals.
Called
AT-527
, the treatment is being tested in around 1,400 participants in Europe and Japan, this time as young as 12 years old.
"We expect to seek authorization from regulators by the end of the year and launch the drug in 2022," said Jean-Pierre Sommadossi, CEO of Atea.
A third,
less advanced
project
is being developed by Pfizer.
Unlike the others, the treatment called
PF-07321332
has not been
readapted
but developed specifically against SARS-CoV-2, the virus causing Covid-19.
It is being tested in around 60 adults, with results expected by the end of June.
Medicines to take at the first symptoms
.
At both Merck and Roche, the medicine should be taken no more than five days after the onset of symptoms.
Indeed, virus replication is maximal during the first week.
"The sooner you treat with an antiviral, the better the outcome," says Daria Hazuda, who leads research for the drug at Merck.
In order to speed up the process, "home tests will become more and more important," predicts Jean-Pierre Sommadossi.
This explains the relative failure of Remdesivir, the only antiviral against Covid-19 authorized so far.
Produced by the US laboratory Gilead Sciences, it must be administered intravenously in hospital.
Patients are thus too advanced in the disease to derive any real benefit from it.
Effective in prevention.
But these antivirals should also be able to be used in prevention: for example, when a member of a family is infected, the others can take the treatment in order to avoid developing the disease in their turn. Against the flu, scientists know that this use of Tamiflu is very effective.
Treat multiple variants and infections.
Experts are confident in the ability of antivirals to remain effective against variants, as well as against other coronaviruses including, potentially, some as yet unknown. This is a significant advantage compared to another existing treatment, synthetic antibodies. Promising advances, according to Daria Hazuda: “One can imagine a future where (an antiviral) could be used widely, regardless of the diagnosis, to treat and prevent multiple respiratory infections. "