Pfizer's oral COVID-19 antiviral fails to prevent infection, data shows

Photo: seksan MonKhonkhamsao/Getty Images

Paxlovid, an oral COVID-19 antiviral produced by pharmaceutical manufacturer Pfizer, proved ineffective at preventing coronavirus infection among people living in the same house as an infected person, according to new data published by the company.

Pfizer's own internal data showed that while there were risk reductions of 32% and 37% in adults who had received Paxlovid for five and 10 days, respectively, the results were not statistically significant. It's a disappointing finding for a drug that sought to prevent infection from a household contact.

While the finding is not what Pfizer had hoped, the company said the results don't impact the strong efficacy and safety data observed in an earlier trial that tested the drug's effect in preventing severe illness, and pointed out that use of Paxlovid is on the rise globally.

WHAT'S THE IMPACT

Medications such as Paxlovid have been developed to not only mitigate COVID-19 among patients, but to ease the burden on healthcare systems and facilities that have buckled under the weight of rising case counts at times during the pandemic.

While data still shows it can reduce the risk of severe disease, Paxlovid's goal of halting virus transmission altogether has failed, meaning hospitals won't be able to count on it putting the brakes on an illness that has sent volumes soaring and eroded profit margins and worker morale.

Paxlovid has not been officially approved, but has been authorized for emergency use by the Food and Drug Administration under an emergency use authorization, for the treatment of mild-to-moderate COVID-19 in adults and pediatric patients 12 years old and older who are at high risk of severe COVID-19.

The emergency use of Paxlovid is only authorized for the duration of the public health emergency, and is set to expire when the PHE lifts.

Paxlovid can only be prescribed by physicians, advanced practice registered nurses and physician assistants that are licensed or authorized under state law to prescribe anti-infectives. 

THE LARGER TREND

The Biden White House in November secured 10 million treatment courses of Paxlovid at a cost of about $5 billion, contingent on EUA or approval from the FDA. Through the purchase agreement, the U.S. government was set to receive 10 million treatment courses for $5.295 billion.

On Nov. 26, Merck said their molnupiravir offering, similar to Paxlovid in both makeup and intent, reduced the risk of hospitalization or death from 9.7% in the placebo group to 6.8% in the molnupiravir group, for an absolute risk reduction of 3%. Nine deaths were reported in the placebo group and one in the molnupiravir group.
 

Twitter: @JELagasse
Email the writer: jeff.lagasse@himssmedia.com