Pfizer's COVID-19 Oral Antiviral Prepares to Launch

New York-based Pfizer Inc. today announced its investigational novel COVID-19 oral antiviral candidate, PAXLOVID™, significantly reduced hospitalization and death, based on an interim analysis of the Phase 2/3 EPIC-HR 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, the study's primary endpoint.

And 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 placebo and were hospitalized or died (27/385 hospitalized with seven subsequent deaths).

The statistical significance of these results was high (p<0.0001).

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 ten subsequent deaths), with high statistical significance (p<0.0001).

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 placebo.

Furthermore, at the recommendation of an independent Data Monitoring Committee and consultation with the U.S. FDA, Pfizer stated it would cease further enrollment into the study due to the overwhelming efficacy demonstrated in these results.

Moreover, Pfizer plans to submit the data as part of its ongoing rolling submission to the U.S. FDA for Emergency Use Authorization as soon as possible.

If approved or authorized, PAXLOVID™, which originated in Pfizer's laboratories, would be the first oral antiviral of its kind, a specifically designed SARS-CoV-2-3CL protease inhibitor.

And subject to approval or authorization, it could be prescribed more broadly as an at-home treatment to help reduce illness severity, hospitalizations, and deaths and reduce the probability of infection following exposure among adults.

"Today's news is a real game-changer in the global efforts to halt the devastation of this pandemic. 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," commented Albert Bourla, Chairman and Chief Executive Officer, Pfizer, in a press statement.

It has demonstrated potent antiviral in vitro activity against circulating variants of concern and other known coronaviruses, suggesting its potential as a therapeutic for multiple types of coronavirus infections.

PAXLOVID is an investigational SARS-CoV-2 protease inhibitor antiviral therapy, specifically designed to be administered orally to be prescribed at the first sign of infection or at first awareness of exposure, potentially helping patients avoid severe illness, which can lead to hospitalization and death.

It is designed to block the activity of the SARS-CoV-2-3CL protease, an enzyme that the coronavirus needs to replicate.

Co-administration with a low dose of ritonavir helps slow the metabolism, or breakdown, of PF-07321332 to remain active in the body for longer periods of time at higher concentrations to help combat the virus.

PAXLOVID inhibits viral replication at a stage known as proteolysis, which occurs before viral RNA replication.

In preclinical studies, PAXLOVID (PF-07321332) did not demonstrate evidence of mutagenic DNA interactions. For more information on the EPIC Phase 2/3 clinical trials for PAXLOVID, visit clinicaltrials.gov.

Pfizer confirmed it 'is committed to working toward equitable access to PAXLOVID for all people, aiming to deliver safe and effective antiviral therapeutics as soon as possible and at an affordable price.'