FDA Declines Moderna's Application for mRNA Flu Vaccine
Moderna announced on Tuesday that the U.S. Food and Drug Administration has refused to consider its application for a novel flu vaccine utilizing Nobel Prize-winning mRNA technology. This decision marks a significant setback for the company and highlights the FDA's intensified oversight under Health Secretary Robert F. Kennedy Jr., who has previously criticized mRNA-based vaccines.
Clinical Trial Concerns Lead to Refusal
The FDA issued a "refusal-to-file" letter to Moderna, objecting to the design of a 40,000-person clinical trial that compared the new vaccine to a standard flu shot. While the trial concluded the mRNA vaccine was somewhat more effective in adults aged 50 and older, FDA vaccine director Dr. Vinay Prasad stated the application lacked an "adequate and well-controlled trial." The agency argued it did not compare the new shot to "the best-available standard of care in the United States at the time of the study." Prasad's letter referenced advice given to Moderna in 2024 under the Biden administration, which the company did not follow, though Moderna claims the FDA initially agreed to proceed with the study as planned.
Moderna's Response and Additional Data
Moderna has shared additional data from a separate trial comparing the vaccine against a licensed high-dose shot for seniors. In a statement, Moderna CEO Stephane Bancel emphasized that the FDA "did not identify any safety or efficacy concerns with our product" and criticized the decision as not advancing "our shared goal of enhancing America's leadership in developing innovative medicines." The company has requested an urgent meeting with the FDA and noted it has also applied for approval in Europe, Canada, and Australia.
Broader Implications Under Kennedy's Leadership
This refusal is rare for the FDA, particularly for new vaccines, which typically involve extensive discussions between companies and agency staff. Under Kennedy's tenure, the FDA has rolled back recommendations for COVID-19 shots, added extra warnings to leading mRNA COVID vaccines, and removed critics from advisory panels. Kennedy also announced the cancellation of over $500 million in contracts for mRNA vaccine development last year. Additionally, an internal memo from Prasad indicated that streamlined methods for updating flu vaccines, long permitted by the FDA, would no longer be allowed, prompting criticism from more than a dozen former FDA commissioners.
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