Pfizer develops COVID-19 pill

An interim analysis of the company’s clinical trial on an oral pill ended early after Pfizer reported 89 percent effectiveness at preventing hospitalization and death from COVID-19 infection. Pfizer plans to submit data and an emergency authorization request to the Food and Drug Administration and international regulators soon. Of the study participants who took the oral drug with another common antiviral pill, none died and fewer than 1 percent needed to be hospitalized. Participants who took a placebo had a 7 percent hospitalization rate, and seven died. The data has not yet been submitted to a scientific journal for peer review.

What does the drug do? Paxlovid, or PF-07321332, blocks an enzyme the novel coronavirus needs to replicate. The study group combined it with a low dose of the antiretroviral drug ritonavir within five days of patients exhibiting COVID-19 symptoms. The 775 adults took six pills every day for five days. Each participant was unvaccinated and considered high risk for serious infection. Pfizer reported 19 percent had negative side effects compared to 21 percent in the placebo group, but the company did not reveal what the effects were.

Dig deeper: Read my report in The Sift about molnupiravir, Merck’s drug that is under review.