Moderna Inc. shares rose 9.5%, trading above $57 in afternoon action on Tuesday, after U.S. Food and Drug Administration staff published briefing documents that presented a positive view of the company’s seasonal influenza vaccine candidate.
The FDA staff evaluation notes that immunogenicity data for mFlusiva show a robust immune response in adults 65 years and older, which the staff said could support an inference of vaccine effectiveness in that population. Those documents were posted in advance of a regulator advisory committee meeting scheduled for June 18.
According to the FDA staff summary, Moderna’s vaccine demonstrated superior relative vaccine efficacy compared with a standard-dose influenza vaccine in adults aged 50 to 64 years. The briefing materials emphasize that finding as part of the overall assessment presented to the advisory committee.
The agency’s advisory panel will convene on June 18 to vote on whether the benefits of mFlusiva outweigh its risks for adults 50 years and older. The committee will also separately consider the balance of benefits and risks specifically for older adults, as noted in the briefing materials.
FDA staff pointed out that Moderna’s regulatory submission for the 65-and-older age group depends largely on immunogenicity comparisons against a standard-dose vaccine. The documents state that the application does not primarily rely on data comparing mFlusiva to the Centers for Disease Control and Prevention-preferred high-dose influenza vaccines for older adults.
The staff assessment and the timing of its release appear to have influenced investor reaction, with Moderna shares recording a notable intraday gain on Tuesday. Market participants will be watching the June 18 advisory committee vote for the next regulatory milestone in the review process.
The briefing documents and the upcoming advisory committee meeting frame the immediate regulatory considerations for mFlusiva. The FDA staff conclusions emphasize immunogenicity and comparative efficacy findings for specified age groups while also noting the nature of the evidence submitted for older adults.