Paxlovid is a combination of the 3CL protease inhibitor nirmatrelvir and low-dose ritonavir, which is effective against the Omicron variant.
On December 22, 2021, Pfizer announced that the U.S. Food and Drug Administration (FDA) had granted approval for PAXLOVID™ (nirmatrelvir tablets). [PF-07321332] and ritonavir tablets) Emergency Use Authorization for the treatment of adult and pediatric patients (12 years and older and at least 40 kilograms [88 pounds]) with mild to moderate COVID-19 who have a positive direct test for SARS-CoV-2 virus and are at higher risk of developing severe COVID-19, including hospitalization or death. Treatments include nirmatrelvir, a new master protease (Mpro) inhibitor developed by Pfizer Laboratories and designed to block the activity of SARS-CoV-2 Mpro, the enzyme the coronavirus needs to replicate.
Pfizer CEO Albert "Granting PAXLOVID an emergency use authorization represents a step closer to defeating this pandemic that, two years after its ravage, continues to kill people," said Dr. Bourla. "This breakthrough therapy has been shown to significantly reduce hospitalizations and deaths and can be taken at home. It will transform the way we treat COVID-19 and has the potential to relieve significant pressure on health care and hospital systems. Pfizer stands ready to produce PAXLOVID in the United States to help get PAXLOVID into the hands of the right patients as quickly as possible."
The decision was based on clinical data from the Phase 2/3 EPIC-HR trial, which enrolled non-hospitalized adult patients 18 years and older with confirmed COVID-19 who are at increased risk of developing severe disease. Study data showed that compared with placebo, PAXLOVID reduced the risk of hospitalization or death from any cause by 89% within 3 days of symptom onset, reaching the trial's primary endpoint; on day 28, there were no deaths in the PAXLOVID group, compared with 9 cases in the placebo group. Similar results were observed among patients treated within 5 days of symptom onset, with an 88% risk reduction in the PAXLOVID group and no deaths observed. Treatment-emergent adverse events were comparable in the PAXLOVID group (23%) and the placebo group (24%), with the majority being mild. Although clinical trials of PAXLOVID do not include patients under the age of 18, this dosing regimen is expected to achieve plasma concentrations of PAXLOVID equivalent to those in adults in pediatric patients 12 years of age and older and weighing at least 40 kilograms. Additional Phase 2/3 clinical trials are ongoing in groups of adults at standard risk of developing severe disease (i.e., lower risk of hospitalization or death), as well as in groups exposed to the virus through household contacts.
With emergency use approval for PAXLOVID, Pfizer is ready to begin deliveries in the United States immediately. In November 2021, Pfizer announced an agreement with the US government to provide 10 million courses of PAXLOVID, which is expected to be delivered in 2022.
References:
https://www.pfizer.com/news/press-release/press-release-detail/pfizer-receives-us-fda-emergency-use-authorization-novel
.jpeg)
