Image of different colored pills spilled onto a flat surface

The experimental antiviral pill Paxlovid reduced the rate of hospitalization and death from COVID-19 by nearly 90% in clinical trials, drugmaker Pfizer has announced.

The news follows the clinical trial success of molnupiravir, a COVID-19 antiviral pill developed by Merck and Ridgeback Therapeutics, which is up for emergency use authorization in the United States. Pfizer is aiming for an EUA as well, and said it plans to submit its new data to the Food and Drug Administration as soon as possible.

Either one of these drugs could become the first orally-administered COVID-19 preventive on the market if given the green light.

Antivirals block the ability of a virus to replicate and spread further throughout the body. An oral drug could offer unprecedented convenience when compared to the other COVID-19 treatment options currently available in the United States. These include monoclonal antibodies, which are administered intravenously, or in the case of REGEN-COV in a series of four injections.

To date, remdesivir (Veklury) is the only antiviral drug that has been approved in the United States for the treatment of COVID-19. In contrast with Merck’s and Pfizer’s orally-delivered drugs, it is recommended for use in severely ill, hospitalized patients and must be delivered intravenously. 

Pfizer’s trial data involved non-hospitalized adult patients with COVID-19 who were at high risk of progressing to severe illness. At day 28, there were no deaths reported in patients who received Paxlovid, compared to 10 deaths in patients who received placebo, the company said.  

“These data suggest that our oral antiviral candidate, if approved or authorized by regulatory authorities, has the potential to save patients’ lives, reduce the severity of COVID-19 infections, and eliminate up to nine out of ten hospitalizations,” said Albert Bourla, chairman and chief executive officer, Pfizer.