FDA Counters Pfizer’s CEO on Second Paxlovid Course After Rebound

One day after Pfizer CEO Albert Bourla said physicians could prescribe a second course of the company’s oral COVID-19 treatment Paxlovid to patients who suffer a rebound, the FDA refuted the executive’s statement.

The agency quickly released an update on Paxlovid (nirmatrelvir and ritonavir) for healthcare providers, saying the efficacy of a second five-day course of the pill is not yet backed up by science.

“There is no evidence of benefit at this time for a longer course of treatment (e.g., 10 days rather than the five days recommended in the Provider Fact Sheet for Paxlovid) or repeating a treatment course of Paxlovid in patients with recurrent COVID-19 symptoms following completion of a treatment course,” wrote John Farley, director of the FDA’s Office of Infectious Diseases.

The update was in direct response to what Bourla had said publicly on Tuesday after patients began reporting that, after their five-day course of Paxlovid, their COVID-19 symptoms returned and some even had a positive polymerase chain-reaction (PCR) test.

“Paxlovid does what it has to do: It reduces the viral load. Then your body is supposed to do the job,” Bourla said in published reports, adding that in the rare case that virus levels rebound, “then you give a second course, like you do with antibiotics, and that’s it.”

The FDA granted Emergency Use Authorization (EUA) to Paxlovid in December for adult and pediatric patients 12 years and older who have tested positive for COVID-19 and are at risk of progression to severe forms of the disease. Under the EUA, though, it’s not authorized for more than five days.

In its update, the FDA said that in light of recent reports, it conducted additional analyses of the Paxlovid clinical trial data and found that 1 to 2 percent of patients had one or more positive SARS-CoV-2 PCR tests after testing negative or an increase in the amount of SARS-CoV-2 detected by PCR after completing their treatment course.

But, said Farley in the FDA’s Paxlovid update, this finding was observed in patients treated with the drug as well as patients who received placebo, “so it is unclear at this point that this is related to drug treatment.”

Additional analyses, he said, show that most of the patients did not have symptoms at the time of a positive PCR test after testing negative and, “most importantly, there was no increased occurrence of hospitalization or death or development of drug resistance.”

He reiterated that the FDA is fully behind Paxlovid.

The new reports of some patients experiencing rebound “do not change the conclusions from the Paxlovid clinical trial, which demonstrated a marked reduction in hospitalization and death,” said Farley.

In a comment to FDAnews, a Pfizer spokesperson said the Paxlovid label says it is not authorized for use for longer than 5 consecutive days, but “ there are no limitations within the authorized label around use for subsequent COVID-19 infections if the patient is at high risk of progression to severe illness.”

Read the FDA update here: bit.ly/3kPwLzC. — Suz Redfearn