FDA releases EUA guidelines that may extend review time for COVID-19 vaccines

The FDA on Tuesday published briefing documents related to an upcoming advisory committee (AdCom) meeting on COVID-19 vaccines, as well as guidance for industry, in which it outlines anticipated stricter criteria that need to be met in order to support an emergency-use authorisation (EUA) request. The briefing documents, which outlined some of the tougher criteria, came earlier in the day amid reports the White House wanted to block the FDA from releasing its updated industry guidance. However, people familiar with the matter later said the Trump administration had in fact endorsed the FDA's plans, with the agency issuing the guidance on Tuesday afternoon, saying it hopes their release "helps the public understand our science-based decision-making process that assures vaccine quality, safety and efficacy."

Controversy about the updated guideline centred on the requirement that companies will have to monitor patients enrolled in their late-stage studies for at least two months after the final vaccination before seeking an EUA. According to sources cited in a report in The New York Times, that provision would almost certainly guarantee that no vaccine could be authorised before the US election on November 3.

Prior to the White House signing off on the FDA guidance, an unnamed senior administration official was quoted as saying the White House believed there was "no clinical or medical reason" for the additional requirement. President Donald Trump has also recently indicated that the White House could potentially overrule the tougher EUA standards, casting the FDA move as being politically motivated to hurt his chances of re-election.

EUA unlikely before election

The updated FDA guidance recommends that an EUA request should contain "data from Phase III studies that include a median follow-up duration of at least two months after completion of the full vaccination regimen to help provide adequate information to assess a vaccine's benefit-risk profile, including adverse events, cases of severe COVID-19 disease among study subjects, and cases of COVID-19 occurring during the timeframe when adaptive (rather than innate) and memory immune responses to the vaccine would be responsible for a protective effect." It also reaffirmed that a coronavirus vaccine needs to be at least 50% effective in order for the agency to consider granting approval.

Raymond James analyst Steven Seedhouse said the two-month timeline "likely assures no COVID-19 vaccine EUA consideration is possible until around November 24-25 for Pfizer/Moderna at the earliest." Moderna has said it expects to generate enough Phase III data by November to be able to tell if its mRNA-1273 vaccine is effective at preventing SARS-CoV-2 infection, while Pfizer indicated that it could get conclusive data on its BNT162b2 candidate, which is being co-developed with BioNTech, by the end of October.

AdCom meetings for specific EUA requests

The upcoming advisory committee meeting, scheduled for October 22, was called to discuss general issues surrounding COVID-19 vaccines, with no plans to focus on any individual filing. However, the FDA said it also expects to convene an additional, follow-up meeting of its Vaccine and Related Biological Products Advisory Committee (VRBPAC) to look at specific applications by drugmakers. "This discussion will be specific to the particular vaccine that is the subject of the EUA request and will be separate from, and in addition to, any general discussion by the VRBPAC regarding the development, authorisation and/or licensure of vaccines to prevent COVID-19," the FDA noted in its AdCom briefing document.

Agency spokesman Michael Felberbaum pointed out that the FDA had "already communicated with individual manufacturers about its expectations, data the agency intends to consider," and what it expects "to see in a request for an [EUA] to demonstrate safety and efficacy." Peter Marks, head of the FDA's vaccine division, last week said "the companies know what we're expecting," adding that releasing the guidelines was "an attempt to help the public see what we're requiring of COVID-19 vaccines."

Meanwhile, Pfizer CEO Albert Bourla, who has decried the "amplified political rhetoric" surrounding the approval of an eventual COVID-19 vaccine, said his company would never discuss the FDA's guidelines on coronavirus vaccines with the White House as it could undermine the agency's independence. "We believe FDA's independence is today more important than ever as public trust in COVID-19 vaccine development has been eroded by the politicisation of the process," Bourla said via Twitter.


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