Pfizer on Thursday announced it had submitted an application to receive full approval from the Food and Drug Administration (FDA) for its COVID-19 antiviral Paxlovid for use in high-risk individuals.
The FDA in December issued an emergency use authorization for Paxlovid to be used as treatment of mild-to-moderate COVID-19 in adults and children over the age of 12 who are at a high risk of developing cases that progress in severity.
“As the COVID-19 pandemic continues to evolve and be highly unpredictable, we must remain vigilant in protecting those who are at greatest risk of getting very sick from COVID-19, as they remain vulnerable to potential hospitalization or even death,” Pfizer CEO Albert Bourla said in a statement.
According to Bourla, recently gathered data had “reinforced” Paxlovid’s importance as an oral treatment for the coronavirus. Data from Pfizer’s Phase 2/3 studies indicated that Paxlovid reduced the risk of hospitalization and death by 88 percent when compared to placebos among non-hospitalized, high-risk patients.
Paxlovid is administered as a round of oral medications — a combination of nirmatrelvir and ritonavir tablets — taken twice daily over the course five days. It is one of two oral COVID-19 antiviral treatments available in the U.S. along with Merck and Ridgeback’s molnupiravir.
The oral treatment must be started within five days of symptom onset per FDA’s guidance on the medication. This timeline has presented a challenge for many people who test positive for COVID-19.
Despite the Biden administration’s “Test to Treat” initiative, many people have encountered difficulties in obtaining the medication, which still requires a prescription. While most pharmacies have coronavirus testing capabilities, not all locations have medical providers who can issue prescriptions.
This has resulted in many people having to wait until they can meet with a provider before starting a round of antivirals, pushing some of them out of the window of time in which they would reap the benefits of the medications.
Another issue that has recently been noted among patients who complete a round of Paxlovid is an apparent “rebound” effect, in which symptoms of COVID-19 reemerge after having initially attenuated.
Chief White House medical adviser Anthony Fauci also experienced this effect after going through a round of Paxlovid. During a health summit this week, Fauci said he had tested negative for COVID-19 for three consecutive days following the completion of a round of Paxlovid, but tested positive once again on the fourth day.
Fauci said he has started on a second round of Paxlovid.
The Centers for Disease Control and Prevention has warned healthcare providers to be on the lookout for this rebound effect, while health experts have said that testing positive after taking Paxlvoid does not necessarily mean a person has been reinfected.