Pfizer is seeking Emergency Use Authorization (EUA) of its investigational oral antiviral candidate, PAXLOVID (PF-07321332; ritonavir), for the treatment of mild to moderate COVID-19 in patients at increased risk of hospitalizations or death. This submission to the U.S. FDA includes clinical data from the Phase 2/3 EPIC-HR (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients) interim analysis. Rolling submission of non-clinical data for PAXLOVID was initiated with the FDA in October 2021.
 
If authorized or approved, PAXLOVID would be the first oral antiviral of its kind, a 3CL protease inhibitor specifically designed to combat SARS-CoV-2 that could be prescribed as an at-home treatment to high-risk patients at the first sign of infection, potentially helping patients avoid severe illness which can lead to hospitalization and death.
 
Pfizer is seeking EUA for PAXLOVID based on positive results from the EPIC-HR interim analysis. The data demonstrated an 89% reduction in risk of COVID-19-related hospitalization or death from any cause in patients treated with PAXLOVID compared to placebo within three days of symptom onset, with no deaths in the treatment group. Similar results were seen with within five days of symptom onset. Treatment-emergent adverse events were comparable between PAXLOVID (19%) and placebo (21%), most of which were mild in intensity.
 
PF-07321332 inhibits viral replication at a stage known as proteolysis, which occurs before viral RNA replication. In preclinical studies, PF-07321332 did not demonstrate evidence of mutagenic DNA interactions.
 
At the recommendation of an independent Data Monitoring Committee, and in consultation with the FDA, Pfizer ceased further enrollment into the study due to the overwhelming efficacy.
 
Rolling submissions began in several countries including in the UK, Australia, New Zealand and South Korea, with planned submissions to other regulatory agencies to follow.
 
Pfizer has begun and will continue to invest up to approximately $1 billion of its own funds to support the manufacturing and distribution of this investigational treatment candidate.