TLDR
- Moderna (MRNA) stock dropped 9% in premarket trading after FDA issued refusal-to-file letter for flu vaccine mRNA-1010
- FDA rejected application due to trial design issues, specifically objecting to use of standard flu shot as comparator instead of “best available care”
- FDA found no safety or efficacy concerns with the vaccine itself, only problems with study methodology
- Moderna’s September 2025 trial showed mRNA-1010 was 26.6% more effective than FDA-approved annual flu shot in 40,000+ participants
- Company disputes FDA decision, claiming it contradicts previous agency guidance and plans to request meeting
Moderna (MRNA) stock opened down 14% in Frankfurt trading and fell 9% in U.S. premarket trading Wednesday after the FDA refused to review its seasonal flu vaccine application. The rejection came as a surprise to investors and company executives alike.
The FDA issued a refusal-to-file letter for Moderna’s mRNA flu vaccine, mRNA-1010. This means the agency won’t review the application because it lacks necessary elements for proper evaluation.
The FDA vaccine director, Dr. Vinay Prasad, objected to Moderna’s trial design. The agency said comparing the new vaccine to a standard approved flu shot doesn’t reflect “best available care.”
Moderna used Fluarix as the comparator in a trial involving more than 40,000 participants. The company announced in September 2025 that mRNA-1010 proved 26.6% more effective than the FDA-approved annual flu shot.
The FDA emphasized it found no safety or efficacy concerns with the vaccine itself. The rejection focused solely on the trial methodology.
Company Disputes FDA Decision
Moderna CEO Stéphane Bancel expressed frustration with the decision. He stated that FDA rules don’t require using the most advanced or highest-dose vaccine as a comparator in trials.
The company claims the FDA’s rejection contradicts feedback it received in 2024 and 2025. Moderna has requested a meeting to understand the path forward.
Bancel said the decision doesn’t help America lead in innovative medicines. He questioned why it should be controversial to review a flu vaccine study that used an FDA-approved comparator agreed upon with the agency beforehand.
The rejection adds pressure to Moderna’s efforts to diversify beyond COVID-19 vaccines. Flu vaccines represent a key growth area for the company.
Regulatory Environment Changes
The FDA decision comes during a period of shifting U.S. immunization policy under HHS Secretary Robert F. Kennedy Jr. FDA officials have scaled back COVID-19 recommendations and added warnings to mRNA vaccines.
The agency has removed critics of the current administration from advisory panels. HHS plans to cancel over $500 million in mRNA vaccine contracts and funding.
Historically, the FDA allowed annual flu vaccine updates via immune-response data rather than lengthy efficacy studies. A 2025 internal memo from Prasad proposed blocking this streamlined method, which drew criticism from over a dozen former FDA commissioners.
Moderna may need to revise its trial design or pursue alternative approval paths. The company’s stock remains up 42% year-to-date despite Wednesday’s drop.
Moderna shares closed up 0.1% on Tuesday before the news broke. The Frankfurt opening showed 14% losses in low volume trading.
Analysts on TipRanks give Moderna a Hold consensus rating with one Buy, 16 Holds, and three Sell ratings. The average price target of $32.67 implies 22.2% downside from current levels.




