Pfizer COVID antiviral comes up big in late-stage study

Nov. 5, 2021

Pfizer reported that its experimental oral antiviral pill for COVID-19 cut rates of hospitalization and death by 89% in high-risk adults.

In a scheduled interim analysis of the Phase 2/3 EPIC-HR randomized, double-blind study of non-hospitalized, unvaccinated patients with COVID-19 who are at high risk of progressing to severe illness, Paxlovid significantly reduced hospitalization and death. In the overall study population through day 28, no deaths were reported in patients who received the drug as compared to 10 deaths in patients who received placebo. The primary analysis of the interim data set evaluated data from 1219 adults who were enrolled by September 29, 2021.

Paxlovid is a SARS-CoV-2 protease inhibitor antiviral therapy, specifically designed to be administered orally so that it can be prescribed at the first sign of infection or first awareness of exposure, potentially helping patients avoid severe illness.

Pfizer competitor Merck (MSD) and partner Ridgeback Biotherapeutics announced last month that Merck has submitted an EUA application to the U.S. FDA for an investigational oral antiviral, molnupiravir. The submission was based on positive results from a planned interim analysis from the MOVe-OUT clinical trial, which found that molnupiravir reduced the risk of hospitalization or death by approximately 50% in at-risk, non-hospitalized adult patients with mild-to-moderate COVID. The UK has already given the drug the green light.

Pfizer says that at the recommendation of an independent Data Monitoring Committee, it will cease further enrollment in the Paxlovid study due to the overwhelming efficacy demonstrated. The drugmaker plans to submit the data as part of its ongoing rolling submission to the U.S. FDA for EUA as soon as possible.