Pfizer Submits COVID-19 Oral Antiviral Candidate to FDA for Emergency Use Authorization

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Pfizer’s PAXLOVID oral solid-dosage treatment is designed to combat SARS-CoV-2 in high-risk patients at the first sign of infection.

Pifzer is seeking FDA 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 hospitalization or death, the company announced in a Nov. 16, 2021 press release. Rolling submission of non-clinical data for PAXLOVID was initiated with FDA in October 2021, and the November submission includes clinical data from the Phase II/III EPIC-HR [Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients] interim analysis. PAXLOVID oral antiviral is a 3CL protease inhibitor 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.

“With more than 5 million deaths and countless lives impacted by this devastating disease globally, there is an urgent need for life-saving treatment options,” said Albert Bourla, Chairman and CEO, Pfizer, in the press release. “The overwhelming efficacy achieved in our recent clinical study of PAXLOVID, and its potential to help save lives and keep people out of the hospital if authorized, underscores the critical role that oral antiviral therapies could play in the battle against COVID-19.”

The EPIC-HR trial enrolled non-hospitalized adults aged 18 and older with confirmed COVID-19 who are at increased risk of progressing to severe illness. According to the press release, the data showed 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. Enrollment in the study was ended because demonstrated efficacy was high. Pfizer has submitted for rolling review to several countries, including in the United Kingdom, Australia, New Zealand, and South Korea, with planned submissions to other regulatory agencies around the world to follow.

According to the press release, Pfizer has signed a voluntary licensing agreement with the Medicines Patent Pool to help expand access, pending regulatory authorization or approval, in 95 low- and middle-income countries that account for approximately 53% of the world’s population.


Merck, known as MSD outside the United States and Canada, and Ridgeback Biotherapeutics submitted an EUA application to FDA for molnupiravir, an investigational oral antiviral medicine for the treatment of mild-to-moderate COVID-19 in adults who are at risk for progressing to severe COVID-19 and/or hospitalization, the companies announced in an Oct. 11, 2021 press release. FDA’s Advisory Committee is set to meet on Nov. 30, 2021 to discuss this application. FDA said in an Oct. 14, 2021 press release that this meeting was scheduled as soon as possible following the submission of the EUA request by Merck and Ridgeback.

Source: Pfizer, FDA, Merck