(Bloomberg) -- Pfizer Inc. said it has begun human safety testing of a new pill to treat the coronavirus that could be used at the first sign of illness. The new protease inhibitor is the second such medicine Pfizer has brought into human trials to treat Covid-19. Among major drugmakers, Merck & Co. has one of the few coronavirus pills that is far along in human testing. Its experimental antiviral drug molnupiravir works by a different mechanism than the Pfizer drug and is in late-stage human trials. Additionally, the coronavirus protease doesn’t mutate much, which means the therapy is likely to work equally well against numerous variant strains, he said.
