FDA advisors recommend full approval of Pfizer’s Covid drug Paxlovid

Paxlovid tablets for the treatment of coronavirus disease (COVID-19) are seen in boxes at the Misericordia hospital in Grosseto, Italy February 8, 2022.

Jennifer Lorenzini | Reuters

An independent panel of consultants from the Food and Drug Administration recommended Pfizer’s full approval. COVID-19 Paxlovid adult antiviral pills with a high risk of 16-1 on Thursday, but potentially dangerous drug interactions noted.

Treatment is recommended for people over 50 years of age or those suffering from various medical conditions for example, high blood pressure or diabetes, which puts them at a higher risk of being hospitalized or dying from Covid.

The FDA first made Paxlovid available in December 2021 for emergency use in high-risk individuals aged 12 years and older. pfizer applied for full drug approval in June 2022, but the FDA expanded his review The application deadline is December 2022.

The agency usually follows the advice of its advisory committees, but is not required to do so. The final decision is expected to be made in May.

“Apart from oxygen, I would argue that Paxlovid has probably been the most important treatment during this epidemic and continues to be,” said Richard Murphy, director of infectious diseases at White River Junction Medical Center for Veterans Affairs.

The panel relied on the results of three mid-to-late-stage clinical trials of Paxlovid conducted by Pfizer, which included more than 6,000 patients in 21 countries.

86% efficiency

One trial, called EPIC-HR, looked at high-risk adults who had not been vaccinated and had no prior Covid infection. A study 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 symptom onset, according to an FDA review of company data. .

“I thought the efficacy data was clear and compelling,” said Dr. Sankar Swaminathan, Chief of the Department of Infectious Diseases, University of Utah School of Medicine.

But the consultants agree that serious adverse reactions due to drug-drug interactions or DDIs with Paxlovid are a key safety concern.

This photograph, taken on July 31, 2022, shows a health worker taking a swab sample from a woman to be tested for the Covid-19 coronavirus at a swab collection site in Guangzhou, south China’s Guangdong province. About a third of people with Covid will recur with symptoms, regardless of whether they were treated with the antiviral drug Paxlovid, according to a study published online Tuesday.

st. Afp | Getty Images

“I would just like to emphasize that we highlight the importance of risk reduction for prescribers, primary health care providers, physicians and other prescribers in terms of drug-drug interactions,” the doctor said. David Hardy is Associate Professor of Clinical Medicine at the University of Southern California.

“I think that’s where we might have problems, I would say when they have problems prescribing this drug without a good knowledge of how ritonavir works on other drugs,” he said. Paxlovid consists of two antiviral drugs, ritonavir and nirmatrelvir.

Drug Interactions

According to an FDA review of safety surveillance data, more than half of Medicare and Veterans Affairs eligible patients for Paxlovid are taking medications that interact with Paxlovid. The FDA review added that approximately 74% of Paxlovid prescriptions were written by adult primary care practitioners who may not have experience in managing possible adverse drug interactions.

The Food and Drug Administration (FDA) reported that 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 the end of January. According to the FDA, the most common drugs causing problems were immunosuppressants, which are often used to treat patients with HIV and organ transplants.

But Swaminathan noted that drug interactions should be “avoidable and kept to a minimum.” FDA officials said earlier in the meeting that they could potentially be controlled by adjusting the dose of certain drugs, increasing patient monitoring and ensuring that product labeling informs prescribers and patients of potential drug interactions.

Paxlovid consists of two separate medicines packaged together that are designed to reduce the risk of hospitalization or death from Covid. Nirmatrelvir blocks a key enzyme needed for the Covid virus 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 the risk of hospitalization or death. To complete the 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 US pharmacies and 1.3 million doses available throughout the country according to federal date About 10 million patients in the US and 14 million worldwide have been treated with the drug, according to Jim Rusnak, chief development officer for internal medicine at Pfizer.

Sales of Paxlovid jumped to $18.9 billion in 2022.in the first year it was available, but Pfizer expects revenue to fall 58% to $8 billion this year.

ricochet cases

The only vote against Paxlovid was from Terry Gillespie, a patient representative from Plainfield, Illinois. Gillespie expressed concern that doctors do not know when to prescribe the drug, noting that they have had a Covid infection four to five times “but never” have been offered Paxlovid.

“I don’t think doctors really know how to use it,” Gillespie said.

After the vote, Swaminathan also noted that he had a “disappointingly large number of patients” whose doctors discouraged them from taking Paxlovid due to fears of a recurrence of Covid cases. That is when patients see their Covid symptoms or positive test result return after initial recovery.

“I am concerned about the lack of good understanding in the medical community and the actual dissuasion of patients from taking an effective drug that could save their lives,” he said.

These cases were reported shortly after Paxlovid entered the market in 2021. Joe Biden and his former chief medical adviser Dr. Anthony Fauci appeared to have recovered from Covid after taking an antiviral cocktail before testing positive again.

Swaminathan said there is “dramatic acknowledgment” in the media that Paxlovid causes relapses and is “potentially worse” than what you were taking before taking the drug, despite the lack of data to support this notion.

Dr. Lindsey Baden, chair of the panel and director of Brigham and Women’s Hospital, added that the new findings indicate that Paxlovid-induced rebound incidents “are not the biology of what’s going on.”

“Up until recently, and even some of the data provided today, helped me understand what this means. So we see real-time data that is systematic and informative,” said Baden.

A US Food and Drug Administration (FDA) review of Pfizer clinical trials found that the overall rate of symptom recovery ranged from 10% to 16%, “with no evidence of a higher rate of symptom recovery or moderate recovery.” symptoms” in patients treated with Paxlovid compared with placebo. This was also independent of patients’ risk of severe illness or whether the dominant omicron variant or an earlier strain was dominant, the agency said.