The Food and Drug Administration on Thursday granted full agreement from Pfizer Covid an antiviral pill, Paxlovidfor adults who are on high risk get seriously ill with a virus.
Paxlovid is specifically recommended for the treatment of mild to moderate Covid disease in adults over 50 and people who have certain medical conditions which puts them at higher risk of ending up in hospital or dying from Covid.
This includes those with diabetes, heart disease, cancer or a weak immune system.
As much as three quarters of adults in the US are at risk of severe Covid disease.
“Today’s approval demonstrates that Paxlovid has met the agency’s stringent standards for safety and efficacy and that it remains an important treatment option for people at high risk of progression to severe COVID-19, including those with prior immunity,” Dr. Patrizia Cavazzoni, Dr. director of the FDA’s Center for Drug Evaluation and Research, said in a press release.
The FDA first approved Paxlovid in December 2021 under emergency use permit for high-risk persons aged 12 and over. Under this designation, the FDA quickly approved the treatment based on data from preliminary clinical trials.
The latest FDA decision means that there is now extensive clinical data showing that Paxlovid is safe and effective.
The treatment consists of two drugs: nirmatrelvir, which blocks a key enzyme that the Covid virus needs to replicate, and ritonavir, which increases the first drug’s ability to fight infection.
Both Pfizer and the FDA see the treatment as an important complementary tool to vaccination that can help high-risk Americans manage their Covid infections and ultimately save lives.
Based on January’s Covid rates, FDA researchers estimated that Paxlovid could “lead to 1,500 lives saved and 13,000 hospitalizations averted each week” in the US.
But it is not clear how many people will undergo the treatment later this year.
About 4 million doses of Paxlovid are available at pharmacies and health care providers across the country for free, according to the Department of Health and Human Services. In addition, the US government has 9.6 million doses in stock.
Once those supplies run out, the government expects to shift the distribution of Paxlovid to the commercial market.
That means Pfizer will sell Paxlovid directly to health care providers for a price the company did not disclose. Paxlovid is priced around $530 per course Now.
Pfizer, which saw a jump in sales of Paxlovid nearly $19 billion in 2022expects drug revenue to drop 58% in 2023.
In March, an independent panel of FDA advisors recommended treatment based on three Pfizer clinical trials.
One study looked at high-risk adults who were unvaccinated and had no previous Covid infection.
That study found that Paxlovid reduced the risk of hospitalization or death by 86% in adults treated within five days of the first symptoms and by 89% in those treated within three days, according to an FDA review of the data.
No major safety concerns were identified in the study, the report said, although the agency has flagged 137 drugs that can lead to serious adverse reactions if they interact with Paxovid.
The FDA said the most common drugs that cause safety issues are immunosuppressants, which are often used to treat HIV patients and organ transplant patients.
As of the end of January, the FDA’s Office of Surveillance and Epidemiology had 271 reports of serious adverse events potentially related to drug interactions with Paxlovide, including 147 hospitalizations and six deaths.
FDA staff said these events could potentially be prevented by adjusting the dosage of certain drugs, increasing patient monitoring and ensuring product labeling informs prescribers and patients of potential drug interactions.
For some doctors, another area of concern with Paxlovid is “rebound cases”. This is when patients taking the treatment see their Covid symptoms return or test positive shortly after they initially recovered.
Reports of these cases emerged not long after Paxlovid first entered the market.
Both president Joe Biden and his former chief medical advisor, Dr. Anthony Fauci seemingly recovered from Covid after taking an antiviral cocktail but tested positive again soon after recovery.
A Pfizer FDA review of clinical trials found that overall rebound rates ranged from 10% to 16%, “with no evidence of a higher rebound rate or mean rebound symptom” in patients who received Paxlovid compared to patients who received placebo .
These results also hold true regardless of the risk of patients with severe disease or whether the omicron variant or an earlier strain of the virus was dominant, according to the FDA review.
Correction: The US has about 4 million doses of Paxlovid available in pharmacies and health care providers across the country. A previous version of this story misstated that number.
