Pfizer COVID-19 Oral Antiviral Reduces Hospitalization Risk Further

Pfizer Inc. released final results from its Phase 2/3 EPIC-HR study of its novel oral antiviral candidate PAXLOVID™ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets) for COVID-19 in December 2021. The study confirmed that PAXLOVID significantly reduced the risk of hospitalization or death by 89% compared to placebo in non-hospitalized, high-risk adult patients treated within three days of symptom onset.

The final analysis of the primary endpoint involved 2,246 patients. Among those receiving PAXLOVID, 0.7% were hospitalized or died through Day 28, compared to 6.5% in the placebo group, which included nine subsequent deaths. This result showed a high statistical significance (p<0.0001).

A secondary endpoint showed an 88% reduction in hospitalization or death for any cause when treatment was initiated within five days of symptom onset. In this cohort, 0.8% of patients on PAXLOVID were hospitalized or died by Day 28, versus 6.3% of patients on placebo.

Pfizer has submitted these final data to the U.S. Food and Drug Administration (FDA) as part of its rolling submission for Emergency Use Authorization (EUA). The company also noted interim results from a separate EPIC-SR study in standard-risk adults, which indicated a 70% reduction in hospitalizations.