Hahn: COVID-19 vaccine decision will be "deliberative"

Regulatory NewsRegulatory News | 11 August 2020 |  By 

The commissioner of the US Food and Drug Administration assured physicians and other healthcare providers that vaccine and therapeutics approvals for the COVID-19 pandemic will be “based on good science and sound data.”
“Nothing else will be used to guide our decisions,” said Stephen Hahn, MD, speaking at a virtual meeting held by the Reagan-Udall Foundation on 10 August.
Hahn delivered prepared remarks along with American Medical Association president Patrice Harris, MD; Harris then fielded questions for Hahn from attendees. Much of Hahn’s presentation and Harris’ subsequent questions focused on FDA’s projected process to approve vaccines for SARS-CoV2, the virus that causes COVID-19.
Vaccine decisions will be “deliberative”
Hahn’s remarks frequently turned to reassurances about FDA’s plans to run a rigorous approval program despite the press of the pandemic. “Because of the speed with which we need to make decisions, there has been discussion about whether FDA will compromise any of our scientific principles in reviewing data and making decisions about new products,” said Hahn. “Let me assure you that we will not cut corners… All of our decisions will continue to be based on good science and the same careful, deliberative processes which we have always used when reviewing medical products.”
Hahn also announced a new initiative termed the Pandemic Recovery and Preparedness Plan (PREPP) that he said will “help systematically review FDA’s actions to date and identify lessons learned.”
The commissioner said that the US has made “significant progress” on many fronts during the pandemic. “Yet with cases continuing to rise, it is evident that further action is needed for our country to chart a course for recovery,” he said: “We all know in medicine that a look back on our actions can help us” in improving care and service delivery.  “This is the important part of the PREPP goal for FDA. Our goal is both to make needed adjustments to the ongoing COVID-19 response as well as improve our capacity to respond to public health emergencies in the future.”
Hahn’s discussion at the Reagan-Udall Foundation event followed a 7 August Viewpoint article in JAMA authored by Hahn, together with Anand Shah, MD, FDA’s deputy commissioner for medical and scientific affairs, and Peter Marks, MD, who heads the Center for Biologics Evaluation and Research (CBER). That editorial also promised “unwavering regulatory safeguards” for the FDA COVID-19 vaccine approval process in the face of “public anxiety about the safety and effectiveness of vaccines developed on expedited timelines.”
Hahn and his coauthors cited a recent poll showing that nearly a third of US adults were uncertain whether they would take a COVID-19 vaccine when it becomes available; one in five said they would not receive a vaccine.
The BLA path versus an EUA
They also noted that the most likely pathways through FDA for a vaccine would either be the traditional biologics license application (BLA) review or an emergency use authorization (EUA). Sponsors are still advised to file for review via traditional market authorization, however, “considering that any vaccine would be intended for widespread use.”
In anticipation of an influx of vaccine candidates, FDA is adding members to the Vaccines and Related Biological Products Advisory Committee, where Hahn and his colleagues said “transparent discussion” will be needed before any authorization or licensure, to make sure the public has a clear understanding of the evidence underpinning any recommendations.
During the Reagan-Udall event, Harris and attendees had several questions about the specifics of the vaccine approval process, including under what circumstances the agency might issue an emergency use authorization (EUA). Asked Harris, “What type of evidence would you have to have in a phase 3 trial to be able to make an EUA?”
“We would have to be very secure about the safety of a vaccine,” Hahn responded. “We would have to see the evidence of clinical efficacy. We’re not going to back away from what we’ve said with respect to these data. We’ve set a floor of 50% for efficacy,” he said, referencing the figure given in a June 2020 guidance. (RELATED:  FDA issues COVID-19 vaccine guidance, setting 50% effectiveness threshold, Regulatory Focus 30 June 2020)
Hahn noted that the streamlined nature of the EUA process means the timetable may be tightened up for coronavirus vaccine approval, “but we won’t stray” from the vaccine requirements delineated in the guidance.
Will an EUA carve out sub-populations?
The potential exists that EUAs might be carved out for sub-populations in a clinical trial in whom high efficacy is seen, said Hahn. “I can’t pre-judge the data,” he added, “but one could imagine a situation where we had very robust safety and efficacy data and could make an EUA determination.”
The threshold of 50% reduction in COVID-19 cases established in the guidance, he said, should be seen in every subgroup “in order to make this generalizable.” Whether decisions would be made for individual subgroups, he said, “is a complete unknown at this point, because we don’t have the data in front of us.”
Regarding safety, Hahn said that current and projected Phase 3 trials will fall within the usual practice of requiring a patient pool of 3,000-5,000 for determining vaccine safety, since FDA foresees these trials enrolling 30,000 patients or more, with about half that number receiving active vaccines.
However, Hahn and his colleagues noted in the JAMA piece that “FDA recognizes that there could be rare adverse events not detected in a trial of 15, 000 to 20,000 patients, so postmarketing surveillance will be critical.” The officials said that “a discussion will need to take place” prior to authorization or licensure of a vaccine about postmarket surveillance, with an eye to building the proper pharmacovigilance framework.
He emphasized that FDA is “asking for clinical endpoints, not immunological endpoints, from the vaccine trials,” since the presence of antibodies alone has not yet been shown to be protective of becoming ill with COVID-19.


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