Summarised by Centrist
The US Food and Drug Administration has refused to review Moderna’s mRNA flu vaccine application, issuing a rare “refuse-to-file” letter and deeming it “inadequate for review” for lacking an “adequate and well-controlled” study.
Refuse-to-file letters are uncommon. A study in JAMA Internal Medicine found that over a decade, only 4 per cent of nearly 2,500 applications received such letters.
The filing included results from two Phase 3 trials in adults aged 50 and older. In one, the shot was compared with Fluarix, a standard-dose flu vaccine.
The FDA had previously suggested the company compare its product to a higher-dose flu shot for older adults, who are most at risk from influenza.
The regulator did not publicly cite safety or efficacy concerns. Instead, it focused on the structure of the evidence submitted.
Moderna said the agency had earlier indicated its trial design was “acceptable,” making the refusal unexpected.
FDA vaccine chief Vinay Prasad has urged the agency to “rethink its framework for annual flu shots.”
The current administration has also pulled back funding from several mRNA projects, with Health Secretary Robert F. Kennedy Jr. saying the government was “moving beyond the limitations of mRNA and investing in better solutions.”
Moderna’s application has been accepted for review in the European Union, Canada and Australia. The company has requested a formal meeting with the FDA to clarify what additional evidence would be required.
