Pfizer’s Covid Drug Fails to Show Benefit as Preventive Therapy

(Bloomberg) -- Pfizer Inc. slid in extended trading after its Covid-19 treatment failed a late-stage study testing it as a way to prevent infections.

The drug, Paxlovid, failed to meet its primary goal of significantly reducing the risk of Covid-19 infection in adults exposed to the virus through a household contact, Pfizer said in a statement Friday. The drug reduced risks by about a third compared with a placebo, which didn’t meet the threshold for statistical significance.

Chief Executive Officer Albert Bourla said he was “disappointed” by the study results. Expanding Paxlovid’s use to people who hadn’t yet tested positive for Covid-19 but have had close contact with an infected person would have opened up a large potential new market for the drug. Paxlovid is already one of the fastest sellers of all-time in the pharmaceutical industry, with projected sales of almost $24 billion in 2022, according to a forecast from analytics group Airfinity Ltd. 

Shares of New York-based Pfizer fell as much as 3.9% in extended trading before paring declines.

If it had succeeded, Paxlovid would have competed with AstraZeneca Plc’s Evusheld, a pre-exposure prevention treatment for the immunocompromised and other people who respond poorly to vaccines.

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