Pfizer Inc said on Monday it has started a large study testing its investigational oral antiviral drug for the prevention of Covid-19 infection among those who have been exposed to the virus.
The drugmaker and its rivals, including US-based Merck & Co Inc and Swiss pharmaceutical Roche Holding AG , have been racing to develop an easy-to-administer antiviral pill for Covid-19.
The mid-to-late-stage study will test Pfizer's drug, PF-07321332, in up to 2,660 healthy adult participants aged 18 and older who live in the same household as an individual with a confirmed symptomatic Covid-19 infection.
In the trial, PF-07321332, designed to block the activity of a key enzyme needed for the coronavirus to multiply, will be administered along with a low dose of ritonavir, an older medication widely used in combination treatments for HIV infection.