Moderna received a refusal-to-file (RTF) letter from the FDA on February 3, 2026, for its mRNA-1010 flu vaccine due to the Phase 3 trial's control arm using a standard-dose flu vaccine, which the FDA deemed not reflective of the 'best-available standard of care'.123
Moderna claims the FDA previously agreed to the trial protocol without objection and that neither regulations nor guidance require a 'best-available' comparator; the company released the RTF letter publicly and requested a meeting.123
CEO Stéphane Bancel criticized the decision as hindering U.S. innovation leadership, noting no safety or efficacy issues were raised.123
The vaccine is under review in the EU, Canada, and Australia; Moderna expects no financial impact and has another Phase 3 trial with a high-dose comparator.12
Context includes Trump administration scrutiny of mRNA vaccines, HHS actions under Robert F. Kennedy Jr., such as ending mRNA funding and altering COVID vaccine policies.123
Sources:
1. https://www.fiercebiotech.com/biotech/moderna-hit-fda-refusal-file-letter-mrna-flu-shot-issues-sharp-rebuke-agencys-rationale
2. https://www.biopharmadive.com/news/moderna-fda-influenza-mrna-refuse-to-file/811909/
3. https://www.foxnews.com/health/fda-refuses-review-modernas-mrna-flu-vaccine-application