Pfizer starts dosing trial for antiviral therapy for Covid

A person walks past a Pfizer logo amid the coronavirus disease (COVID-19) pandemic in the Manhattan borough of New York City, New York, U.S., April 1, 2021. REUTERS/Carlo Allegri/File Photo

Pfizer Inc said on Wednesday it had started dosing in a mid-to-late-stage trial of its oral antiviral therapy for COVID-19 in non-hospitalized, symptomatic adult patients.

The company and its rivals, including U.S.-based Merck & Co Inc and Swiss pharmaceutical Roche Holding AG, have been racing to develop the first antiviral pill to be taken on early signs of the illness.

Pfizer’s mid-to-late-stage trial in 1,140 participants would study the therapy, PF-07321332, in combination with a low dose of ritonavir, which has been used with other antivirals too, the company said. (https://bit.ly/3kJWzg9)

PF-07321332 is designed to block the activity of a key enzyme that is needed for the coronavirus to replicate.

To date, Gilead Sciences Inc’s remdesivir, administered intravenously, is the only approved antiviral treatment for COVID-19 in the United States.

Merck and partner Ridgeback Biotherapeutics’ molnupiravir is already being studied in a late-stage trial in non-hospitalized patients to see if it reduces the risk of hospitalization or death.

The companies said on Wednesday they had started a late-stage trial of molnupiravir for the prevention of COVID-19 infection.

Pfizer said in July if the PF-07321332 trial was successful, it would file for a potential emergency use authorization in the fourth quarter.