Is Molnupiravir the miracle treatment we’ve been waiting for?

• A study published in the journal “Nature Microbiology” demonstrates the effectiveness of an experimental antiviral drug against Covid-19 tested on ferrets.
• This drug, Molnupiravir, would have the capacity to block the transmission of the coronavirus in one day, but would also have the capacity to limit the risks of progression to a severe form of the disease.
• Very promising results, which must however be confirmed in humans.

–

The year 2020 will have been rotten by the pandemic of coronavirus, but the light begins to dawn at the end of the tunnel. While the United Kingdom
just starting their vaccination campaign against the
Covid-19 and that France will follow suit
in the next few weeks, another major piece of news looks very promising in the field of therapeutic research against this disease, which was unknown a year ago. Hope could be in five syllables: Molnupiravir.

Kezako? It is an investigational antiviral drug, originally developed to fight seasonal flu. Tested on ferrets, it would have shown formidable efficiency, blocking the transmission of the virus in 24 to 36 hours, according to a scientific study conducted by researchers at the Institute of Biomedical Sciences at the University of Georgia (United States) published on December 3 in the journal Nature Microbiology. If the efficacy and safety of this treatment were demonstrated in humans, Molnupiravir may well be the
anti-Covid treatment that the planet was waiting for.

A drug potentially capable of blocking the transmission of the virus

To test the effectiveness of MK-4482 / EIDD-2801, or Molnupiravir, the researchers therefore opted for the ferret, because of the similarity of their coronavirus receptors to those of humans. “We believe ferrets are a relevant transmission model because they easily spread SARS-CoV-2, but generally do not develop a severe form of the disease, which closely resembles the spread of SARS-CoV-2 in young adults, ”said Dr. Robert Cox, co-director of this study, in a statement relayed by the University of Georgia. The ferret is also the cousin of the mink, an animal very sensitive to coronavirus and including several farms,
in France in particular, were contaminated with Covid-19.

In practice, researchers infected six ferrets with SARS-CoV-2 and treated three of them with Molnupiravir. The team distributed twelve uninfected ferrets, either in cages with the sick animals treated or with the ferrets that did not receive the drug. Scientists tested ferrets daily for eight days. As a result, none of the ferrets sharing the cages of the treated animals contracted the coronavirus. In contrast, after four days, all healthy ferrets caged with their sick fellows who had not received Molnupiravir were infected with SARS-CoV2.

In short: this antiviral treatment, administered orally, made it possible to block virus transmission. “Therapeutic treatment of animals infected with MK-4482 / EIDD-2801 twice daily significantly reduced the burden of SARS-CoV-2 in the upper respiratory tract. This completely suppressed the spread to untreated contact ferrets, comments Dr Richard Plemper, who led the work. This is the first demonstration that an oral drug can rapidly block the transmission of SARS-CoV-2 ”.

A drug potentially capable of reducing the progression of the disease to a severe form

“If the data from the transmission of SARS-CoV-2 on the ferret are predictive of the effect in humans, patients infected with Covid-19 could become non-infectious within 24 to 36 hours of starting treatment. administered orally “, project the authors of the study, acknowledging however that” the antiviral effectiveness “of Molnupiravir” in humans is still unknown “.

And this is not the only promise of Molnupiravir: “Treatment with MK-4482 / EIDD-2801, in particular when it is started very soon after infection”, would have three advantages, assure the researchers: “it can reduce the risk of the disease progressing to a severe form and accelerate recovery ”, which would represent a major therapeutic advance, in particular for the elderly or those with co-morbidities. Molnupiravir would also “relieve the emotional and socio-economic impact of the pandemic by avoiding isolation and confinements, and quickly put an end to the appearance of clusters ”, or epidemic foci, by drastically shortening the duration of contagiousness.

Ongoing clinical trials on Covid patients

But after conclusive trials on ferrets, it remains to be seen whether Molnupiravir will be as effective in humans. A few months ago it is remdesivir, another antiviral drug, which caused runaway. Administered to Covid patients, this drug has not shown conclusive effects against the disease, and would even expose patients to serious side effects. On November 20, the World Health Organization (WHO) therefore recommended not to administer this antiviral drug to patients with Covid-19: “The antiviral drug
remdesivir is not recommended for patients admitted to hospital for Covid-19, regardless of the degree of severity of their disease, as there is currently no evidence that it improves survival or prevents d ‘be placed under artificial ventilation’. And in early October, the European Medicines Agency said it would investigate reports of “acute kidney problems” that could be linked to taking remdesivir.

No question, therefore, of letting a new fiasco occur. To date, phase II / III clinical trials of Molnupiravir are underway and conducted by the Ridgeback Biotherapeutics laboratory: this experimental antiviral is being tested in patients with Covid-19. The researchers tested three different dosages of the treatment on them, given every 12 hours for five days. The data of these clinical tests however, should not be available until May 2021.

Ridgeback Biotherapeutics is already working with the pharmaceutical firm Merck to develop this treatment. But before we rejoice prematurely, more work needs to be done on Molnupiravir. Previous versions of Molnupiravir have had mutagenic effects which may lead to birth defects. The two firms will therefore have to demonstrate that this formulation is not only effective, but exhibits no serious toxic or undesirable effects.

–