Pfizer stock falls as Covid pill fails in preventive therapy trial

The trial failure, along with reports of rebounding coronavirus levels in some patients who have completed a course of Paxlovid, are unlikely to change the drug's sales potential

Pfizer Inc. slumped after Paxlovid, its pill for treating Covid-19, failed to show benefit as a preventive therapy in a trial. 

Paxlovid is poised to become one of the fastest-selling drugs of all time, with $24 billion in projected 2022 sales, according to analytics group Airfinity Ltd. Pfizer has also reaped billions in global sales from its Covid-19 vaccine.

The company said late Friday that the drug failed to hit its main goal of reducing the risk that adults exposed to the coronavirus through contact with a household member would become infected. Compared with those who took a placebo, people who received