Overview
- Moderna disclosed it received a Feb. 3 refusal‑to‑file letter stating its Phase 3 trial was not "adequate and well‑controlled" because the control arm did not represent the best available standard of care.
- Company officials say FDA feedback in 2024 allowed a standard‑dose comparator (Fluarix) and that supplemental data versus a high‑dose shot in older adults were included; the letter raised no specific safety or efficacy concerns.
- HHS spokesperson Andrew Nixon said the application was rejected because Moderna did not follow clear 2024 guidance to test against a CDC‑recommended high‑dose vaccine for seniors, a claim Moderna rejects.
- Reports say CBER Director Vinay Prasad signed the refusal over objections from some FDA career staff, including vaccine office head David Kaslow; the FDA called the internal debate "healthy" but rare refusals occur in about 4% of applications.
- Moderna’s Phase 3 program enrolled more than 40,000 adults and company analyses showed roughly 27% higher efficacy versus a standard flu shot, and the vaccine is under review in the EU, Canada and Australia while the firm seeks an FDA meeting on next steps.