The FDA authorized
Policy analysts say that while the Food and Drug Administration isn’t required to convene an advisory committee meeting before it makes decisions on new products, these public discussions have helped educate Americans on the regulatory process throughout the pandemic. Skipping this step for the Pfizer pill could affect the public’s level of confidence in the potentially lifesaving Covid-19 treatment and in the agency at large.
“There is quite a bit of urgency right now that many of us are feeling about the way that omicron is moving so rapidly into dominance,” Lynn Goldman, dean of the George Washington University’s Milken Institute School of Public Health, said. The FDA may be trying “to move these pills on the market as soon as possible,” but there is “always a cost when you do that in terms of transparency.”
The FDA’s Wednesday emergency use authorization makes Pfizer’s Paxlovid the first at-home medication cleared for Covid-19. The drug is intended to help prevent hospitalization and death among higher-risk people who test positive for the virus.
Officials familiar with the plans say U.S. regulators could authorize a second pill for Covid-19,
The FDA’s Antimicrobial Drugs Advisory Committee (AMDAC) met late last month to consider safety and efficacy data from trials with Merck’s drug. The committee narrowly recommended the pill in a 13-10 vote, with some members of the panel citing safety concerns—including for pregnant people and the potential for the treatment to spur genetic mutations.
Clinical trial data on Pfizer’s pill showed an 88% reduction in hospitalization for high-risk patients within five days of symptoms starting. Approximately 0.8% of those who received Paxlovid were hospitalized or died during 28 days of follow-up, compared with 6% of patients who received a placebo. The Merck drug reduced the relative risk of hospitalization or death among adults with mild to moderate disease by 30%.
Despite the differences in efficacy and questions on the Merck drug’s safety, public health analysts say a meeting for Pfizer’s treatment may still have been effective to quell fears that outside pressure is influencing the agency’s decisions. The FDA has faced questions over the past two years on whether the White House and other outside actors are influencing the pace of agency authorizations and approvals.
“The FDA does not always convene an advisory committee meeting in connection with EUA reviews, but may do so under certain circumstances when discussion with the advisory committee will help inform agency decision making,” the agency said in an emailed statement. “We’re committed to transparency and post materials related to EUAs, including scientific review documents, on our public website.”
FDA advisory panels are made up of researchers knowledgeable in infectious disease and other relevant subjects, as well as consumer and industry representatives. The agency may convene a committee meeting for its members to conduct an in-depth analysis of the evidence, and make their own recommendation on whether a treatment should be authorized.
Meetings of expert panels, while not required, have become a common practice in the FDA’s authorization process amid the ever-changing conditions of the pandemic.
“The FDA has smart people—but as smart people they also realize that they can’t always think of everything,” said Peter Weina, a current AMDAC member and an expert in infectious diseases. “That’s when they ask for outside opinions.”
Advisory committee meetings are most common “when something is controversial” or when “it’s not absolutely clear that it should be rejected, and it’s not absolutely clear that it should be approved or authorized,” said Diana Zuckerman, founder and president of the National Center for Health Research.
“Sometimes, it seems that the FDA has advisory committee meetings when they really want to reject something that they want other people to tell them to do it,” she added. “And then sometimes, it’s because they really want to approve or authorize something and they can pick their advisory committee to be the kind of people who are going to give them the answer that they want.”
While the FDA convened a meeting for the Merck drug, the Pfizer pill’s higher efficacy rate and the fact that the two treatments target Covid-19 differently may have influenced the FDA’s decision to authorize Paxlovid without first hearing from outside experts, analysts say.
“The mechanisms of action of the two drugs are different, so that may affect the FDA’s perspective on the risk in pregnancy,"said Joshua Sharfstein, Johns Hopkins University’s vice dean for public health practice and community engagement.
Paxlovid is a protease inhibitor, meaning it is designed to block an enzyme that Covid-19 needs to multiply. Molnupiravir, on the other hand, is designed to introduce errors in the virus’s genetic code, which has prompted concerns from some committee members that the treatment could do genetic damage.
“The Pfizer and the Merck pill are apples and oranges,” Weina said. “Different mechanisms of action which completely shift the risk/benefit ratio. He added that the “mutagenicity mechanism of action for the Merck pill is very concerning in an evolving organism that has shown us time and again in new variants.”
“If I worked at the FDA, given what data I have seen, I probably would have come to the same conclusion” to authorize the Pfizer drug, Weina added.
Analysts say that advisers could have discussed the drug in a meeting similar to the one held for Merck’s pill to ensure the highest level of transparency possible, despite the vast data in favor of the Pfizer pill’s safety and effectiveness.
“Given all the politicization of anything related to Covid, it’s in the public’s best interest to have as much information as possible publicly available,” Zuckerman said. “Having a public meeting where people can ask questions, and people have to answer those questions in front of reporters and other media people, is really the better way to go.”
The FDA released some research findings on the Pfizer pill Wednesday, but “it is still true that the FDA didn’t make the data available at a public FDA meeting where independent scientists could scrutinize the data and ask questions about the implications of the research findings,” she said.
Pfizer has made the clinical data from the Paxlovid trial publicly available online, and the FDA released fact sheets Wednesday to give health-care providers and patients detailed information on dosing instructions, potential side effects, drug interactions, and information on who is eligible to receive the drug.
The FDA also put in place conditions on the Pfizer pill’s authorization, Goldman noted. In its authorization letter to Pfizer, the FDA said that Pfizer, among other things, must report to the agency adverse events and all medication errors associated with use of the drug. The agency also requested that Pfizer provide additional information in the coming months from follow-up studies measuring factors like the drug’s effectiveness against Covid-19 variants, including omicron, and the pill’s safety among patients with chronic kidney disease.
Another action the FDA could take is to release a presentation that the FDA normally gives at the start of committee meetings outlining the key findings of clinical trial data, Goldman said.
“That would be really helpful in terms of disclosing to the scientific and medical community exactly what their thoughts are,” she said. “I think it helps with clinicians being able to make their own judgments about benefit and risk in terms of who gets the treatment.”
A committee meeting, however, is “an opportunity to release and discuss key data, which can help build public trust,” Sharfstein said.