Pfizer Inc. begins human trials for a drug that could treat COVID-19

Pfizer Inc. says 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 York-based company said the phase one trial of the drug is being conducted in the United States. If it succeeds in trials, the pill could be prescribed early in an infection to block viral replication before patients get very sick. The drug binds to an enzyme called a protease to keep the virus from replicating. Protease-inhibiting medicines have been successful in treating other types of viruses, include HIV and Hepatitis C.