Pfizer’s COVID-19 Drug Paxlovid Fails in Postexposure Clinical Trial

Pfizer’s oral COVID-19 treatment Paxlovid (nirmatrelvir and ritonavir) failed to show meaningful improvements in people who took it after exposure to COVID-19.

The company conducted a study of 2,957 participants who tested negative for COVID-19 and who were then exposed within four days to symptomatic individuals with COVID-19 infections. Compared with placebo, the reduction in risk from the Paxlovid treatment was “not statistically significant,” the company said.

“While we are disappointed in the outcome of this particular study, these results do not impact the strong efficacy and safety data we’ve observed in our earlier trial for the treatment of COVID-19 patients at high risk of developing severe illness,” said Pfizer CEO Albert Bourla.

The FDA granted Emergency Use Authorization to Paxlovid in December for adult and pediatric patients 12 years and older who have tested positive for COVID-19 and are at risk of progression to severe forms of the disease.