FDA Accepts Moderna's Flu Vaccine for Review After Revised Regulatory Strategy
Moderna's mRNA-1010 seasonal influenza vaccine enters FDA review following a revised approach that splits approval pathways by age group, with a decision expected by August 2026.
The FDA's Center for Biologics Evaluation and Research has accepted Moderna's seasonal influenza vaccine candidate mRNA-1010 for formal review following a Type A meeting where the company revised its regulatory strategy. The acceptance came days after CBER issued a Refusal-to-File letter to the company.
According to Moderna, the refusal letter identified that the company's choice of a licensed standard-dose seasonal influenza vaccine as the comparator in its Phase III study was the sole reason the agency refused to file the application. The FDA cited Moderna was lacking an "adequate and well-controlled" study, due to the company using a comparator that "does not reflect the best-available standard of care."
Under the revised proposed approach, Moderna is seeking full approval for adults aged 50 to 64 and accelerated approval for adults 65 and older, alongside a post-marketing commitment to conduct an additional study in the older population. The regulatory path splits by age: traditional approval targeted to 50–64 years, while ≥65 years relies on accelerated approval with a postmarketing study commitment.
The FDA assigned a Prescription Drug User Fee Act (PDUFA) goal date of August 5, 2026. If approved, mRNA-1010 could be available for U.S. adults aged 50 and older in time for the 2026–2027 influenza season.
The vaccine is being evaluated in a Phase III study known as the Glow trial, which enrolled 22,502 adults aged 50 and older between September 2022 and January 2024. The randomized study is assessing the safety and efficacy of the mRNA-based candidate compared with a currently approved seasonal influenza vaccine. Participants received a single injection and were followed for approximately 13 months, including in-person visits and remote safety check-ins.
CBER moved the BLA into filing review centered on disagreement that a standard-dose licensed comparator represented contemporary best-available influenza vaccination. The decision by CBER did not identify any safety or efficacy concerns with the product.
mRNA-1010 has also been accepted for regulatory review in Europe, Canada and Australia, with additional submissions planned in 2026. The company expects potential approvals to begin in 2026 and will be subject to ongoing reviews.
Seasonal influenza is estimated to cause between 3 million and 5 million cases of severe illness globally each year and up to 650,000 deaths. Effectiveness of currently available flu vaccines varies by season but has typically remained below 60% overall.