Moderna, Inc. announced that its Phase 3 trial of mRNA-1083, an investigational combination vaccine against influenza and COVID-19, has met its primary endpoints, eliciting a higher immune response than the licensed comparator vaccines used in the trial. mRNA-1083 comprises components of mRNA-1010, Moderna's vaccine candidate for seasonal influenza, and mRNA-1283, Moderna's next-generation COVID-19 vaccine candidate. Each investigational vaccine has independentlydemonstrated positive Phase 3 clinical trial results. The ongoing Phase 3 clinical trial (ClinicalTrials.gov Identifier:NCT06097273) is a randomized, observer-blind, active control study evaluating the safety, reactogenicity and immunogenicity of mRNA-1083 in two independent age group cohorts of approximately 4,000 adults each. One cohort, consisting of adults 65 years and older, compared mRNA-1083 to co-administered Fluzone HD®, an enhanced influenza vaccine, and Spikevax®, Moderna's currently licensed COVID-19 vaccine. The other cohort of adults 50 to 64 years of age compared mRNA-1083 to co-administered, Fluarix®, a standard dose influenza vaccine, and Spikevax. The immune responses from a single dose of mRNA-1083 were found to be non-inferior versus the co-administered, routinely recommended, licensed comparators. In both age cohorts, mRNA-1083 also elicited statistically significantly higher immune responses against three influenza virus strains (H1N1, H3N2, and B/Victoria) and against SARS-CoV-2. In the 65 years and older cohort, overall Geometric Mean Ratios (GMRs) of the mRNA-1083 group compared to the Fluzone HD group for the influenza strains were 1.155 (95% CI: 1.094, 1.220) for A/H1N1, 1.063 (95% CI: 1.007, 1.122) for A/H3N2 and 1.118 (95% CI: 1.070, 1.167) for B/Victoria. The GMR of mRNA-1083 compared to Spikevax for the SARS-CoV-2 variant Omicron XBB.1.5 was 1.641 (95% CI: 1.526, 1.765). In the 50 to 64 years of age cohort the GMRs of the mRNA-1083 group compared to the Fluarix group for the influenza virus strains were 1.414 (95% CI: 1.333, 1.500) for A/H1N1, 1.380 (95% CI: 1.310, 1.454) for A/H3N2, and 1.216 (95% CI: 1.163, 1.270) for B/Victoria. The GMR of mRNA-1083 compared to Spikevax for the SARS-CoV-2 variant Omicron XBB.1.5 was 1.308 (95% CI: 1.219, 1.404). Immunogenicity was also tested against the B/Yamagata strain of influenza and mRNA-1083 met non-inferiority criteria in both age cohorts. Due to the disappearance of the B/Yamagata lineage from circulation, WHO has recommended a trivalent influenza vaccine composition without B/Yamagata for 2024/2025 vaccines.mRNA-1083 showed an acceptable tolerability and safety profile. The majority of solicited adverse reactions were grade 1 or 2 in severity and consistent with the licensed vaccines used in the trial. The most commonly solicited adverse reactions were injection site pain, fatigue, myalgia and headache.

Moderna plans to present the Phase 3 clinical data for mRNA-1083 at an upcoming medical conference as well as submit it for publication. The Company will engage with regulators on next steps.