Any coronavirus vaccine that could be authorized for emergency use by the U.S. Food and Drug Administration (FDA) faces several additional hurdles after completing the final stage of clinical trials.
That was the theme of key issues addressed today by the FDA’s vaccine advisory committee — which includes a group of health and science experts who advise the regulatory agency on the best way to approach the path forward for a COVID-19 vaccine.
Among the more immediate hurdles, the path to receive an emergency use authorization remains somewhat murky for the pharmaceutical industry, as the agency has not nailed down specifics for things such as labeling and what qualifies as sufficient monitoring of individuals who have enrolled in clinical trials.
In separate letters to the committee, Pfizer (PFE), Johnson & Johnson’s (JNJ) Janssen and trade group BIO all asked for more clarity on the follow-up period for participants following the final dose of the vaccine.
J&J wrote that the current guidelines ask for 50% of the trial population to be monitored for two months following the final dosing. With J&J enrolling 60,000 participants, and other competitors only enrolling 30,000, that provides an uneven playing field.
“Specifying a minimum required follow-up in terms of subjects and months … would ensure consistency across all studies,” the company wrote.
Another concern is what happens to trial participants — especially in a placebo group — after an emergency use authorization is awarded. The FDA’s guidelines require that the placebo group is maintained so that collection of data for safety and efficacy continues on through until the vaccine can be fully approved — especially since the vaccine would still be considered “investigational” at the point.
Pfizer had said it anticipates offering the vaccine to the placebo participants once it receives an emergency use authorization (EUA) — which is an ethical obligation, according to BIO.
“Additional discussion is needed to determine how placebo-controlled trials can be maintained after an EUA is granted. As an industry, we have an ethical obligation to make our trial participants aware that a vaccine may be available,” wrote BIO’s senior director of infectious disease policy Gregory Frank.
FDA’s deputy director of vaccines, Doran Fink, said the trial has to remain blinded because that isn’t a step that can be walked back and it could jeopardize the integrity of the massive trials.
When asked what can be done to ensure that participants don’t simply then drop out of the trial or choose to take the vaccine, Fink said the FDA had no idea and is asking the companies to figure it out and describe their plan in any emergency use authorization filings.
Distribution and administration
What happens after an EUA is also of concern, as the distribution process for two frontrunners — Moderna (MRNA) and Pfizer — requires extra cold temperatures. While Moderna has