KEY POINTS
- U.S. regulator FDA declined to review Moderna’s new influenza vaccine application.
- FDA said Moderna’s trial lacked appropriate comparison against high-dose flu shots for seniors.
- Company stock fell sharply as broader regulatory caution raises concerns across vaccine sector.
Moderna Inc said U.S. regulators refused to review its application for an experimental influenza vaccine. The Food and Drug Administration sent a refusal-to-file letter on Tuesday, halting any formal evaluation.
Shares of Moderna fell significantly following the announcement. The FDA said the company did not include an “adequate and well-controlled” comparator in its Phase 3 trials.
Moderna compared its mRNA vaccine to a standard influenza shot, not the high-dose version recommended for older adults. FDA officials said this trial design did not reflect the best-available standard of care.
The agency’s refusal letter did not raise safety or efficacy concerns about the vaccine itself. Moderna argued the decision was inconsistent with prior regulatory guidance.
The company’s CEO said the letter did not point to any specific safety issues. Moderna conducted two large late-stage studies to support its application.
Those trials showed the new shot was more effective than a traditional vaccine for adults over 50. The FDA’s vaccine division cited the lack of comparison against the best-available care for seniors.
Experts say the refusal reflects evolving regulatory expectations. Investors feared broader pressure on respiratory vaccine approvals.
Some analysts described the regulator’s move as part of heightened scrutiny toward mRNA technologies. Health officials under the current U.S. administration have shifted vaccine review policies.
Last year, major mRNA vaccine development funding was scaled back by federal agencies. Moderna noted it plans to seek a meeting with the FDA to clarify next steps.
The company is also pursuing approval of the vaccine in other countries. Regulatory decisions abroad may follow different trial interpretation standards.
Investors will watch closely for signs of future filings or revisions to clinical data. Moderna’s stock performance this year had been benefiting from gains in its drug pipeline.
The FDA decision adds uncertainty to the company’s strategy to grow beyond COVID-19. Analysts say a revised submission could address regulator concerns.
Moderna must decide whether to redesign trials or narrow target age groups. The broader vaccine market reacted to the news with volatility.
Several other vaccine developers saw share movements after the FDA stance became clear. Moderna’s refusal to have its application reviewed marks a setback for mRNA influenza vaccine ambitions. The company and regulators now face choices on how to proceed.
