On Dec. 14, 2021, Pfizer announced final results from an analysis of all 2,246 adults enrolled in its Phase 2/3 EPIC-HR (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients) trial of its novel COVID-19 oral antiviral candidate PAXLOVIDﾙ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets).

These results were consistent with the interim analysis announced in November 2021, showing PAXLOVID significantly reduced the risk of hospitalization or death for any cause by 89% compared to placebo in non-hospitalized, high-risk adult patients with COVID-19 treated within three days of symptom onset. In a secondary endpoint, PAXLOVID reduced the risk of hospitalization or death for any cause by 88% compared to placebo in patients treated within five days of symptom onset, an increase from the 85% observed in the interim analysis.