FDA advisers recommend full approval of Pfizer Covid drug Paxlovid

The Food and Drug Administration’s independent advisory panel on Thursday recommended full approval of Pfizer Paxlovid’s Covid-19 antiviral pill for high-risk adults 16-1, but flagged potentially harmful drug interactions.

The treatment is advised for people over 50 or those with various medical conditions like high blood pressure or diabetes that put them at higher risk of ending up in hospital or dying from Covid.

The FDA first made Paxlovid available in December 2021 for emergency use in high-risk individuals ages 12 and older. Pfizer submitted a full drug approval application in June 2022, but the FDA extended its review period for the application to December 2022.

The agency generally follows the advice of its advisory committees, but is not required to do so. He is expected to make a final decision in May.

“I would say that in addition to oxygen, Paxlovid has probably been the most important treatment tool during this outbreak and continues to be,” said Richard Murphy, chief of infectious diseases at the Veterans Affairs Medical Center. from White River Junction.

The panel drew on three of Pfizer’s mid-to-late-stage clinical trials of Paxlovid that enrolled more than 6,000 patients in 21 countries.

A trial called EPIC-HR looked at high-risk adults who were unvaccinated and had no previous Covid infection. The trial found that Paxlovid reduced the risk of hospitalization or death by 86% in adults treated within five days of symptom onset and by 89% in those treated within three days of symptoms, according to a FDA review of company data.

“I thought the efficacy data was clear and compelling,” said Dr. Sankar Swaminathan, chief of the division of infectious diseases at the University of Utah School of Medicine.

But advisers agreed that serious adverse reactions due to drug interactions, or DDIs, with Paxlovid are a major safety concern.

“I would just like to emphasize that we emphasize the importance of risk mitigation for the prescriber, primary care, physician and other prescribers in terms of drug interactions,” said Dr. David Hardy, Assistant Clinical Professor of medicine at the University of Southern California. “That’s where I think we could get in trouble, should I say, where they would get in trouble with prescribing this drug without a good understanding of what ritonavir does to other drugs,” he said. he declares. Paxlovid is made up of two antiviral drugs, ritonavir and nirmatrelvir.

More than half of patients eligible for Paxlovid Medicare and Veterans Affairs are taking drugs that have drug interactions with Paxlovid, according to an FDA review of safety monitoring data. About 74% of Paxlovid prescriptions came from adult primary care practitioners who may not have experience managing potential adverse drug interactions, the FDA review added.

The FDA said its Office of Surveillance and Epidemiology had recorded 271 reports of serious adverse events potentially related to drug interactions with Paxlovid, including 147 hospitalizations, as of late January. The most common drugs causing problems were immunosuppressants, which are often used to treat HIV and organ transplant patients, the FDA said.

Paxlovid consists of two separate drugs packaged together which are intended to reduce the risk of hospitalization or death from Covid. Nirmatrelvir blocks a key enzyme the Covid virus needs to replicate, while ritonavir boosts the first drug’s ability to fight infection.

Patients take Paxlovid within five days of the onset of Covid symptoms to reduce their risk of hospitalization or death. To complete a full course of the drug, patients should take three tablets of Paxlovid twice a day for five days.

More than 12 million courses of Paxlovid have been delivered to pharmacies across the United States and 1.3 million doses are available nationwide, according to federal data. About 10 million patients in the United States and 14 million worldwide have been treated with the drug, according to Jim Rusnak, Pfizer’s director of development for internal medicine.

Sales of Paxlovid jumped to $18.9 billion in 2022, the first year of its availability, but Pfizer expects those revenues to drop 58% to $8 billion this year.