WASHINGTON
Moderna announced Tuesday that the U.S. Food and Drug Administration has refused to review its application for a new mRNA flu vaccine, citing issues with its clinical trial design.
The FDA issued a “refusal-to-file” letter stating that Moderna’s 40,000-person trial did not constitute an “adequate and well-controlled” study.
While the trial showed the mRNA vaccine was somewhat more effective than a standard flu shot in adults 50 and older, regulators said it failed to compare the new vaccine to the “best-available standard of care in the United States at the time of the study.”
The decision is the latest sign of heightened FDA scrutiny of vaccines under Health Secretary Robert F. Kennedy Jr., who has publicly criticized mRNA technology.
In the letter, FDA vaccine director Dr. Vinay Prasad noted that the agency had offered Moderna related advice in 2024 under the previous administration, which the company did not follow.
Moderna’s mRNA platform, which won a Nobel Prize and was successfully used in COVID-19 vaccines, has faced significant regulatory and political hurdles in its expansion to other diseases.
The company must now decide whether to address the FDA’s concerns and resubmit its application.
By James Kisoo
