Pfizer Inc. announced in a press release, the submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for approval of PAXLOVID (nirmatrelvir [PF-07321332] tablets and ritonavir tablets) for patients who are at high risk for progression to severe illness from COVID-19.
PAXLOVID is currently authorized for emergency use for the treatment of mild-to-moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least 40 kg [88 lbs]) with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death. The submission provides the longer-term follow-up data necessary for acceptance and potential approval.
According to the U.S. Centers for Disease Control and Prevention (CDC), 50-60% of the U.S. population is estimated to have one or more risk factors for progressing to severe COVID-19 illness. These risk factors include any of the following: being aged 65 and older, obesity, diabetes, hypertension, smoking, physical inactivity, chronic kidney or liver disease, and immunocompromised conditions such as cancer, among others2
The NDA submission is supported by non-clinical and clinical data for PAXLOVID. It includes results from the Phase 2/3 EPIC-HR study (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients), which found that, compared to placebo, treatment with PAXLOVID reduced the risk of hospitalization or death from any cause by 88% in non-hospitalized, high-risk adult patients treated within five days of symptom onset; results from the final Clinical Study Report showed an 86% reduction in relative risk. The submission is also comprised of the most recent analyses from the Phase 2/3 EPIC-SR study (Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients), which included data from both vaccinated patients with, and unvaccinated patients without, risk factors for severe COVID-19.
While the novel primary endpoint of self-reported, sustained alleviation of all symptoms for four consecutive days was not met, the data were supportive of the efficacy and safety data observed in EPIC-HR for use in patients at increased risk of progression to severe COVID-19 illness. The NDA submission also includes:
An integrated analysis of data across the EPIC-HR and EPIC-SR studies, which showed an 84% reduction in hospitalizations or death, compared to placebo and regardless of vaccination status, in patients with at least one risk factor for progression to severe COVID-19 illness who were treated with PAXLOVID-treated patients versus within five days of symptom onset.
In EPIC-HR, there was an 86% relative risk reduction in hospitalizations or death through Day 28 in PAXLOVID-treated patients with no deaths, compared to placebo which included twelve deaths.
In EPIC-SR, there was a 57% relative risk reduction in hospitalizations or death through Day 28 in PAXLOVID-treated patients with no deaths, compared to placebo which included one death.
Available safety data for PAXLOVID, which have been generally consistent in more than 3,500 PAXLOVID-treated participants across the EPIC clinical development program, including EPIC-HR, EPIC-SR, and EPIC-PEP3 studies, as well as in reported post-authorization safety experience.
Data from the EPIC-HR, EPIC-SR and EPIC-PEP studies which showed a consistent reduction in viral load with PAXLOVID, including across both the Delta and Omicron variants.
Data which show that the frequency of return of detectable nasal viral RNA following PAXLOVID treatment was low and generally similar among PAXLOVID and placebo recipients.
PAXLOVID is currently approved or authorized for conditional or emergency use in more than 65 countries across the globe to treat COVID-19 patients who are at increased risk for progressing to severe illness. As of the end of May 2022, Pfizer had shipped more than 12 million treatment courses of PAXLOVID to nearly 40 countries around the world.
