Moderna has withdrawn its application for FDA approval of its combination flu and COVID-19 vaccine, mRNA-1083, for adults aged 50 and older. The company plans to resubmit the application later this year, incorporating efficacy data from an ongoing Phase 3 trial of its standalone seasonal influenza vaccine, mRNA-10102. Interim results from this trial are expected to be available by summer.

The decision follows discussions with the FDA, which recently introduced stricter guidelines for COVID-19 vaccine approvals. The agency now requires placebo-controlled studies for any new COVID-19 vaccine seeking approval for healthy adults under 65 years old. Moderna had initially filed for approval last year, aiming for a November 2025 authorization, but the FDA’s request for additional efficacy data pushed the expected approval date to 20262.

Moderna’s flu/COVID combination vaccine had previously demonstrated promising results, showing comparable or superior antibody responses against flu strains and the Omicron XBB.1.5 COVID-19 variant compared to existing flu and COVID vaccines. Despite this, the FDA’s requirement for further efficacy data led Moderna to voluntarily withdraw its application rather than amend the existing submission1.

The withdrawal is a setback for Moderna, which has been facing declining revenue from its COVID-19 and RSV vaccines. Following the announcement, Moderna’s stock initially rose by more than 6% but later lost those gains1. The company remains optimistic about its resubmission later this year, once the necessary efficacy data is available.