Moderna announced Tuesday morning that its flu vaccine, mRNA-1010, “did not accrue  sufficient cases” at the interim efficacy analysis to declare early success in its Phase 3 trial.

As part of the company’s fourth annual vaccines day, Moderna stated that mRNA-1010 demonstrated titers “consistent with superiority” against influenza A strains as well as non-inferiority against influenza B strains compared to a licensed flu vaccine.

The biotech added that the Data and Safety Monitoring Board (DSMB) recommended a continuation of efficacy follow up for mRNA-1010. DSMB said the shot demonstrated an acceptable safety and tolerability profile in the Phase 3 trial and did not result in any identifiable safety concerns.

Another Phase 3 trial for mRNA-1010 is also being conducted. 

The flu vaccine data announced Tuesday came nearly two months after Moderna released mixed results from a safety and immunogenicity study of the shot. The company said the vaccine triggered an immune response to A strains of the influenza virus but didn’t demonstrate the same level of efficacy against the B strains.

News of the flu vaccine’s disappointing performance in the Phase 3 trial sent Moderna’s stock down more than 5% during the early morning trading session. Despite the setback, Moderna said it has five flu vaccines in clinical development, including mRNA-1011/1012 and mRNA-1020/1030 in addition to mRNA-1010.

Nevertheless, Moderna remains bullish on its prospects going forward.

“With mRNA-1010, our first investigational vaccine against seasonal flu, we are encouraged by the consistently strong immunogenicity results against influenza A, and titers consistent with non-inferiority against influenza B strains in the most recent Phase 3 trial,” Moderna CEO Stéphane Bancel said in a statement. “With our mRNA platform and technology, as well as our agile manufacturing capabilities, we are confident that we can quickly develop safe and effective vaccines to address critical unmet needs.”

Beyond the flu vaccine, the company announced that it has dosed its first patient in a Phase 3 trial for its next-gen COVID-19 vaccine candidate and that it is developing vaccines for Lyme disease and norovirus.

The company has also made significant progress in the respiratory syncytial virus (RSV) space, receiving a Breakthrough Therapy Designation for mRNA-1345. In Phase 3 trial data released in January, mRNA-1345 was found to have an efficacy of 84% against RSV. 

Going forward, Moderna said it plans to file a license application for regulatory approval during the first half of 2023.