Pfizer’s antiviral Covid-19 pill reduced the risk of hospitalization or death by 89 percent in high-risk patients who’d been experiencing symptoms for three days or less, according to final results from a trial of 2,246 adults the company released Tuesday.
The results tracked with interim findings the company reported last month, which prompted it to petition the Food and Drug Administration for emergency use authorization of the pill, called Paxlovid.
A second analysis of unvaccinated people at standard risk of developing Covid-19 symptoms found the drug reduced hospitalizations by 70 percent but didn’t meet the target goal, the company said.
“This news provides further corroboration that our oral antiviral candidate, if authorized or approved, could have a meaningful impact on the lives of many,” Pfizer CEO Albert Bourla said in a statement. “Emerging variants of concern, like Omicron, have exacerbated the need for accessible treatment options for those who contract the virus, and we are confident that, if authorized or approved, this potential treatment could be a critical tool to help quell the pandemic.”
The results were shared with the FDA as part of the company’s application but have not been reviewed by outside scientists.
Pfizer said results showed its treatment appears to work against the Omicron by targeting a protein associated with the strain called 3CL and inhibiting viral replication. “This indicates nirmatrelvir’s [Paxlovid’s chemical name] potential to maintain robust antiviral activity against Omicron,” the company said, adding more studies with the variant are underway.
The availability of an oral medication that can treat Covid symptoms and keep most patients out of the hospital could be a game changer for the course of the pandemic. Pills are easier to manufacture and distribute than therapies like monoclonal antibodies, which are administered in health care settings.
Pfizer’s treatment consists of three pills taken twice a day over five days. Two of the pills are Paxlovid while the third pill is an HIV drug called ritonavir.
FDA is also considering an EUA application from Merck and Ridgeback Biotherapeutics for an antiviral drug, molnupiravir, creating the prospect of two at-home coronavirus treatments being available. Independent advisers to the agency narrowly endorsed the that pill last month for adults at high risk of developing severe Covid-19 after some of the experts voiced concern about the treatment’s efficacy and risks to pregnant people.
The Merck-Ridgeback pill is aimed at adults who have been experiencing Covid-19 symptoms for five days or less.