FDA Reverses Rejection of Moderna Flu Vaccine After Company Modifies Application
The FDA agreed to review Moderna's mRNA flu vaccine application after initially rejecting it, reversing course within a week. The agency will now consider full approval for adults 50-64 and accelerated approval for those 65 and above, with a decision expected by August 5.
Moderna said on Wednesday the U.S. Food and Drug Administration has agreed to review its influenza vaccine, reversing an earlier decision to reject the application, after the company made modifications.
The reversal, which comes just a week after the FDA's surprise decision to not review the company's experimental flu vaccine application, lifted shares of the vaccine maker more than 3% before the bell.
The FDA has accepted Moderna's revised approach seeking full approval for the shot for adults aged between 50 and 64, and accelerated approval for those 65 and above, the company said, adding that it will also conduct a post-marketing study in older adults. The regulator is expected to make a decision on the candidate by August 5.
On Feb. 3 the FDA issued a so-called Refuse-to-File letter to the biotech company over a flu vaccine the company developed using its mRNA technology, which was the core of its COVID-19 vaccine and is at the center of Moderna's pipeline of developmental vaccines against cancer, HIV, Lyme disease, respiratory syncytial virus (RSV) and many other conditions. The letter was more than merely a rejection of Moderna's clinical testing of the vaccine; it was a refusal even to examine Moderna's data, which the company says was derived from tests on nearly 44,000 subjects.
The FDA rejected Moderna's application "because the company refused to follow very clear FDA guidance from 2024" on how the clinical trial should proceed, according to HHS. The company disputed that. It says it consulted with the FDA in designing its clinical trial and received the agency's approval for its protocol, in writing. The agency "did not raise any objections ... at any time before the initiation of the study in September 2024," Moderna said in a news release after the rejection.
The regulator had defended its initial decision, saying the company should have given a higher-strength vaccine to older patients in the control arm of its trial. The reversal only underscored the chaotic decision-making at the agency.
Healthcare professionals say that the FDA's original refusal was way out of line and a shocking departure from the standard for refuse-to-file decisions. According to a 2021 study of RTF letters published in the Journal of the American Medical Assn., only about 4% of all drug applications resulted in such a letter. In most cases, the problem was that the submitted data were incomplete and in about 26% the problem was that the applicant didn't follow FDA advice, including advice about the design of their clinical trials. According to Moderna, that wasn't the case with its flu vaccine.
Normally, recipients of RTF letters keep them secret, generally out of embarrassment at being called out by the FDA for incomplete or suspect data; that Moderna made this one public suggests that it feels the problem lies elsewhere.
The mRNA technology used in Moderna's and most other COVID-19 shots, credited with saving millions of lives, comes with a shift in the national health policy under U.S. Health Secretary Robert F. Kennedy Jr., a long-time anti-vaccine activist who has been particularly critical of mRNA vaccines.
"Pending FDA approval, we look forward to making our flu vaccine available later this year so that America's seniors have access to a new option to protect themselves against flu," the CEO stated.