FDA Comparator Ruling Elevates Sanofi’s Fluzone HD in Flu Vaccine Review
FDA refused to review Moderna’s influenza shot application, citing the use of a standard-dose comparator rather than an ACIP-recommended vaccine such as Sanofi’s Fluzone HD. This highlights Sanofi’s high-dose influenza vaccine as the “best-available standard-of-care,” potentially strengthening its competitive position.
1. FDA Comparator Requirement Spurs Regulatory Rejection
The FDA’s Center for Biologics Evaluation and Research refused to file Moderna’s biologics license application for its mRNA-1010 influenza vaccine, citing the choice of a standard-dose seasonal flu vaccine as the sole reason. The letter raised no safety or efficacy concerns but emphasized the need for a comparator reflecting the best-available standard of care.
2. Sanofi’s Fluzone HD Gains Spotlight
In a 2024 pre-Phase 3 consultation, CBER had agreed that a licensed standard-dose vaccine was acceptable but recommended using one preferentially recommended for adults over 65, specifically Sanofi’s Fluzone HD. The FDA’s reversal underscores regulatory preference for high-dose and adjuvanted vaccines in older populations.
3. Strategic Implications for Sanofi’s Vaccine Business
The FDA’s emphasis on best-available comparators could drive greater adoption of Sanofi’s high-dose influenza franchise, potentially lifting US market share ahead of the 2026–2027 flu season. Sanofi may leverage this to secure inclusion of Fluzone HD in future clinical trials and strengthen its positioning against novel vaccine entrants.