Pfizer has begun early-stage human trials of a pill to treat the first signs of Covid infection, the company announced today.
The US pharmaceuticals giant said the oral treatment had “demonstrated potent” activity against Sars-Cov-2 in previous trials.
If it succeeds in human trials, the pill could be prescribed to those recently infected with coronavirus to block viral replication before patients get sick.
The drug, described as a “potential game-changer”, binds to an enzyme called a protease to prevent the virus from replicating within a cell.
Protease-inhibiting medicines have been successful in treating other types of viruses, include HIV and Hepatitis C.
The pill will likely be given to patients to be taken twice a day for five days if human trial results prove fruitful.
“Given the way that Sars-Cov-2 is mutating and the continued global impact of Covid-19, it appears likely that it will be critical to have access to therapeutic options both now and beyond the pandemic,” said Mikael Dolsten, chief scientific officer at Pfizer.
In an interview, Dolsten said no unexpected problems had been seen in the study so far and that trial results could be published within weeks.
Pfizer is also trialing a separate antiviral drug to treat Covid that will be administered intravenously if it proves successful.
Together, the treatments have “the potential to create an end to end treatment paradigm that complements vaccination in cases where disease still occurs”, Dolsten said.
It comes as the global vaccine race continues at pace as a third coronavirus wave sweeps across Europe.
More than 461m vaccine doses have been administered across the world so far, according to Bloomberg’s Covid vaccine tracker.
In the US, more Americans have received at least one dose of a Covid jab than have tested positive for the virus since the pandemic began, with more than 128m vaccine doses administered to date.
Upwards of 28m Brits have received their first injection so far, including all top four priority groups.
Prime Minister Boris Johnson said this evening that there was “no doubt” that a third wave of coronavirus spreading across the continent would “wash onto our shores”, but that Britain’s best defence lay in the “strength of the fortifications we’ve built against it via the vaccine programme”.