Paxlovid not linked to Covid-19 rebound, FDA says ahead of meeting to consider drug's full approval

The US Food and Drug Administration's independent advisers are set to discuss the full approval of Pfizer's Covid-19 antiviral, Paxlovid, on Thursday. Agency experts say that clinical trial data shows that it is safe and effective for treatment of mild to moderate illness in high-risk adults.

Paxlovid not linked to Covid-19 rebound, FDA says ahead of meeting to consider drug's full approval


The US Food and Drug Administration's independent advisors are set to discuss Thursday's full approval of Pfizer’s Covid-19 antiviral drug, Paxlovid. Agency experts stated this week that the clinical trial data proves that the drug is safe and effective in treating mild to moderate illnesses in high-risk adults.

Also, the agency concluded that Paxlovid was not associated with Covid-19 Rebound. This is when people are either positive for the drug or have their symptoms return after completing the five-day course.

Paxlovid has been administered to more than 8 million Americans since December 2021, when it was made available for emergency use. The FDA's Antimicrobial Drugs Advisory Committee will meet on Thursday to discuss and vote in favor of full approval of mild-to-moderate Covid-19 for adults at high risk of severe illness.

FDA is expected to finish its review for approval in May, as it follows the recommendations of the committee.

The FDA states that data from the phase 2 and 3 clinical trials support the efficacy Paxlovid regardless if there has been any prior infection or Covid vaccination. The FDA stated that it was reasonable to conclude that Paxlovid, despite the lack of data, is likely to maintain clinical efficacy in high-risk adults with Covid infection due to the Omicron coronavirus variant, just like earlier variants.

FDA stated that it had reviewed data concerning Covid-19 rebound. This was something some users reported since Paxlovid's approval in 2021. Both President Biden, and Dr. Anthony Fauci, his former chief medical advisor, reported rebound symptoms last year after taking Paxlovid.

The FDA stated that it did not find any association between Paxlovid treatment, Covid-19 rebound, and clinical trial data.

The Covid rebound rates varied from 10% to 16% for people who received Paxlovid, while there was no difference between those who received a placebo. According to FDA clinical trial data, this was regardless of the person's risk for severe disease from the Omicron variant.

The agency stated that the findings suggest that Covid-19 rebound could occur in a small number of infections as part the natural progression of the disease and resolution.

According to the FDA, no major safety issues were found in the clinical trial data. The FDA has identified several drugs with drug-drug interactions with Paxlovid (DDIs), which could cause serious adverse reactions.

According to the FDA Emergency Use Authorization Fact sheet, Paxlovid can prevent your body from metabolizing some drugs. This could lead to higher drug concentrations which can cause serious or life-threatening reactions. Paxlovid should not be used with medications that treat conditions like gout, migraines, irregular heartbeat, benign prostatic hyperplasia, and gout.

FDA states that in order to safely prescribe Paxlovid all prescribers must consider the possibility of DDIs. This is to both take steps to manage DDIs as well as to decide whether Paxlovid would be a suitable treatment option for each patient, taking into account the risk of serious adverse reactions from DDIs.