Results came in this week from a Phase 2/3 trial of Pfizer Inc.’s COVID-19 oral antiviral treatment, and the data showed a drug capable of cutting risks of hospitalization or death by 89 percent among high-risk adults, when given within a few days of their first symptoms.
The final data from the EPIC-HR study, which studied 2,246 participants, confirmed prior efficacy of the Paxlovid treatment, noting that risk reduction to hold when given within three days of symptom onset, followed by a slight reduction to 88 percent when given within five days. In total, five hospitalizations emerged among those treated with Paxlovid pills over the course of 28 days, and no one died. Comparatively, nine of those given placebo in the study died, while 44 were hospitalized.
All participants were unvaccinated.
As a result, Pfizer has shared its findings with the U.S. Food and Drug Administration (FDA) and continued its ongoing, rolling submission of Paxlovid for Emergency Use Authorization.
“This news provides further corroboration that our oral antiviral candidate, if authorized or approved, could have a meaningful impact on the lives of many, as the data further support the efficacy of PAXLOVID in reducing hospitalization and death and show a substantial decrease in viral load,” Albert Bourla, chairman and CEO of Pfizer, said. “This underscores the treatment candidate’s potential to save the lives of patients around the world. 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.”
If approved, a formulation like Paxlovid could even expand options for those at home.
Notably, the pills also provided a 10-fold decrease in viral load on the fifth day of treatment, relative to placebo. It is the strongest viral load reduction reported to date for a COVID-19 oral antiviral agent, and was determined after accounting for baseline viral load, geographic region, and serology status. Most side effects were mild, although 2.1 percent of patients dosed with Paxlovid did have to discontinue participation in the study due to adverse effects.