Pfizer begins early-stage study of oral COVID-19 drug

Pfizer Inc has started an early-stage U.S. trial of an oral COVID-19 antiviral therapy that could be prescribed to patients at the first sign of infection, the company said on Tuesday.

The drugmaker, which developed the first authorized COVID-19 vaccine in the U.S. with Germany's BioNTech SA, said the antiviral candidate showed potent activity against SARS-CoV-2, the virus that causes COVID-19, in lab studies. Pfizer's candidate, named PF-07321332, is a protease inhibitor that prevents the virus from replicating in cells.