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Eyes on Moderna
- Jana Chisholm
- 1 hour ago
- 2 min read
Moderna received a refusal-to-file (RTF) letter for its next-generation mRNA flu vaccine, the FDA citing concerns over the trial’s control arm design. Analysts warn the decision may complicate Moderna’s flu-COVID combination strategy, with policy shifts suggesting increased scrutiny of mRNA platforms in the U.S.
FDA Raises the Bar on Trial Design
Moderna received a refusal-to-file (RTF) letter from the FDA for its phase 3 mRNA flu vaccine, mRNA-1010.
T
he FDA criticized the trial’s control arm, which used a licensed standard-dose influenza vaccine rather than what the agency described as the “best available standard of care.”
Moderna argues that neither FDA guidance nor federal regulations require use of a best-available comparator, and that this concern was not flagged during phase 3 protocol development.
The company responded sharply, stating that the RTF does not advance shared goals of innovation leadership.
Implications for Moderna's Combination Vaccines
Analysts quickly focused on broader consequences. Moderna’s combined flu-COVID vaccine relies heavily on the standalone flu data package.
Market observers had projected approximately $750 million in 2028 revenue from the combined vaccine platform. The RTF letter now introduces regulatory uncertainty around that forecast.
The decision complicates Moderna’s plan to reach cash break-even by 2028, which relies partly on seasonal respiratory vaccine revenue.
Regulatory and Political Backdrop
The RTF occurs against a shifting policy environment:
HHS discontinued certain mRNA vaccine initiatives supported by BARDA.
HHS leadership has publicly criticized mRNA COVID-19 vaccine distribution.
Recent commentary suggests some policymakers are questioning COVID-19 vaccine market presence.
Moderna has stated that the flu vaccine remains under review in the EU, Canada, and Australia, and additional filings are expected.
Meanwhile, the company is pivoting R&D emphasis toward oncology, where most future investigational new drug filings are now expected.
Outlook: Platform Risk or Temporary Setback?
The key question is whether this RTF represents:
A procedural disagreement on trial design
Or a broader recalibration of regulatory expectations for mRNA platforms
For now, Moderna maintains financial guidance. But the episode reinforces that regulatory risk has become a more prominent variable in vaccine development strategy.
