The FDA has accepted Moderna’s revised influenza vaccine filing days after controversially refusing to review the original submission, putting the biotech on track to win approval in time for the 2026-27 flu season.
Feb. 10, Moderna reported that the FDA issued a refusal-to-file (RTF) letter in response to a request for approval of its flu vaccine candidate, mRNA-1010. In the RTF, the FDA’s Vinay Prasad, M.D., said the agency wouldn’t review the submission because Moderna’s comparator didn’t reflect the best-available standard of care in the U.S. at the time of the study.
Moderna met with the FDA to discuss the situation and, just over one week after disclosing the RTF letter, said the agency has accepted an amended application for review. The FDA is scheduled to make a decision by Aug. 5.
The revised filing splits the regulatory pathway based on age. Moderna is seeking full approval for use in adults 50 to 64 years of age and accelerated approval for adults 65 and older. The accelerated approval proposal comes with a post-marketing commitment to run an additional study in older adults.
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Moderna’s two-track approach could address the concern that underpinned the RTF letter. In testing its shot, the company used a standard-dose inactivated influenza vaccine as the control in the first part of its phase 3 safety and immunogenicity trial dubbed P303, which enrolled adults ages 18 and older.
The U.S. Advisory Committee on Immunization Practices (ACIP) recommends people ages 65 and older receive a high-dose or adjuvanted inactivated—or recombinant—flu vaccine.
The biotech used a high-dose inactivated influenza vaccine as a comparator in seniors in another part of the trial. That cohort yielded favorable immunogenicity data on mRNA-1010 compared to one of the ACIP’s preferred vaccines for seniors.
In the separate P304 efficacy study in adults ages 50 and older, Moderna used a licensed standard-dose influenza vaccine in the control arm.
Moderna’s fast resolution of the impasse boosts the biotech’s prospects of achieving its 2028 break-even guidance. Type A meetings with the FDA are typically a 30-day process. By racing through the process, Moderna has positioned itself to launch mRNA-1010 before the next U.S. flu season, albeit with the caveat that the vaccine would only have accelerated approval in the key senior population.
Shares in Moderna rose 7% to $47 in premarket trading.
“Today’s course correction from the FDA reopens a meaningful opportunity for Moderna to capture a piece of the U.S. flu market near term,” analysts with William Blair wrote in a Feb. 18 note, adding that the pivotal data for the candidate “are worthy of approval.”
Editor’s note: This story was updated at 11:30 a.m. ET on Feb. 18 to include analyst commentary.
