The UK government has announced deals to purchase two investigational Covid-19 antiviral drugs as coronavirus cases rise and the country approaches an uncertain winter.
The UK has secured 480,000 courses of Merck’s molnupiravir and 250,000 courses of Pfizer’s PF-07321332/ritonavir. The oral antivirals are yet to be approved by the country’s medicines regulator; Pfizer’s candidate is in late-stage clinical trials, while Merck is seeking emergency use authorisation for molnupiravir in the US.
The government said the pills are expected to be given to those most at risk from Covid-19 to help “reduce the severity of symptoms and ease pressure on the NHS over winter”. Pending regulatory approval, Merck’s antiviral could be available to patients before the end of the year.
Health experts have called for the return of some Covid-19 restrictions amid concerns that hospitals could once again be overwhelmed by hospitalisations this winter. The UK is currently seeing between 40,000 and 50,000 new Covid-19 cases a day, with the number of hospitalisations rising slowly but steadily.
Deputy chief medical officer Professor Jonathan Van-Tam commented: “The Covid-19 vaccines and therapeutics that have been rolled out to tens of millions of UK patients have had a critical impact on this pandemic, and antivirals bring another key intervention to the table.
“They will be particularly vital in protecting those who may not get the same antibody response to the vaccines as the majority of the population.”
The government is now working with the NHS to conduct a national study of the antiviral pills, which it says will “allow medical experts to gather further data on the potential benefits these treatments bring to vaccinated patients”. Further details on the study are to be announced in due course.
Merck’s molnupiravir, developed in collaboration with Ridgeback Biotherapeutics, has been touted as a potential game-changer when it comes to tackling the pandemic. Trial data on molunpiravir is promising; the drug reduced the risk of Covid-related hospitalisation or death by almost 50% in a Phase III study.
Pfizer’s Covid-19 pill is a combination of the company’s investigational antiviral PF-07321332 and a lower dose of ritonavir, an antiretroviral commonly used to treat HIV and AIDS. The drug – which is designed to be prescribed at the first sign of infection or knowledge of exposure, without requiring patients to be hospitalised – is currently in Phase II/III trials.