Pfizer announced that its investigational COVID-19 oral antiviral candidate, PAXLOVID, significantly reduced hospitalization and death, based on an interim analysis of a Phase 2/3 randomized, double-blind study of non-hospitalized adult patients with COVID-19 who are at high risk of progressing to severe illness.
The scheduled interim analysis showed an 89% reduction in risk of COVID-19-related hospitalization or death from any cause compared to placebo in patients treated within three days of symptom onset (primary endpoint); 0.8% of patients who received PAXLOVID were hospitalized through Day 28 following randomization (3/389 hospitalized with no deaths), compared to 7.0% of patients who received the placebo and were hospitalized or died (27/385 hospitalized with 7 subsequent deaths).
Similar reductions in COVID-19-related hospitalization or death were observed in patients treated within five days of symptom onset; 1.0% of patients who received PAXLOVID were hospitalized through Day 28 following randomization (6/607 hospitalized with no deaths), compared to 6.7% of patients who received a placebo (41/612 hospitalized with 10 subsequent deaths), with high statistical significance.
In the overall study population through Day 28, no deaths were reported in patients who received PAXLOVID, compared to 10 (1.6%) deaths in patients who received the placebo.
At the recommendation of an independent data monitoring committee and in consultation with the U.S. Food and Drug Administration (FDA), Pfizer said it will cease further enrollment into the study and plans to submit the data as part of its ongoing rolling submission to the FDA for emergency use authorization (EUA).
If approved or authorized, PAXLOVID, which originated in Pfizer’s laboratories, would be the first SARS-CoV-2-3CL protease inhibitor antiviral therapy, the company said.
The Phase 2/3 EPIC-HR study began enrollment in July 2021.
The Phase 2/3 EPIC-SR (Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients) and EPIC-PEP (Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Prophylaxis) studies, which began in August and September 2021 respectively, were not included in this interim analysis and are ongoing, Pfizer said.
