FDA staff concluded in briefing documents published ahead of an advisory meeting that Moderna’s mFlusiva generated a robust immune response that could support its effectiveness in adults 65 years and older. The documents also note that mFlusiva demonstrated superior relative vaccine efficacy when compared with a standard-dose influenza vaccine in the 50 to 64 age group.
The regulator’s advisory committee is scheduled to meet on June 18 to consider whether the benefits of mFlusiva outweigh its risks for adults 50 to 64 and for adults 65 and older. Following publication of the briefing materials, Moderna’s shares rose roughly 2% in morning trading.
What the FDA staff highlighted
- For adults 65 and older, the staff said the company’s application relies primarily on immunogenicity data comparing mFlusiva to a standard-dose vaccine rather than to the higher-dose formulations that the Centers for Disease Control and Prevention prefer for this age group.
- Staff called attention to additional limitations including data derived from a single influenza season, a higher incidence of short-term side effects, and the need for postmarket studies specifically in adults 65 and older.
Despite these caveats, at least one former agency official described the staff assessment as reasonable and said the existing data support approval for both age cohorts under consideration.
Regulatory pathway and company strategy
Moderna is pursuing traditional approval for mFlusiva in adults aged 50 to 64 and an accelerated approval for the 65-and-older population. If the product receives authorization, it would become the first mRNA-based seasonal influenza vaccine approved for use in the United States. A final regulatory decision is expected by August 5.
History of the submission
The FDA previously rejected Moderna’s initial application in February under the leadership of the agency’s former commissioner, citing concerns that the trial’s control arm for older adults did not use the preferred higher-dose influenza vaccine. The agency later accepted an amended filing after Moderna committed to conducting a post-approval study in the 65-plus population.
Market and analyst reaction
Jefferies analyst Andrew Tsai characterized the staff assessment as favorable and projected U.S. sales of $750 million by 2030 for Moderna’s flu and COVID-flu combination vaccines, according to the briefing materials. Observers noted the stock uptick following release of the documents. Moderna did not immediately respond to a request for comment.
Next steps and context
The advisory committee’s vote will inform the FDA’s decision on whether benefits outweigh risks for both the 50-64 and 65-plus age groups. The staff documents underline both promising immunogenicity and specific evidence gaps that regulators expect to be addressed through additional study and postmarket commitments if the vaccine is authorized.