Moderna Inc has revealed that its Phase 3 trial of mRNA-1083, an investigational combination vaccine targeting influenza and COVID-19, has successfully met its primary endpoints.
Superior immune response
The vaccine demonstrated a superior immune response compared to the licensed comparator vaccines used in the trial.
CEO Stéphane Bancel underscored the significance of combination vaccines in reducing the burden of respiratory viruses on healthcare systems and improving vaccination convenience and compliance.
"Moderna is the only company with a positive Phase 3 flu and COVID combination vaccine," said Bancel. "We continue to address significant unmet medical needs and advance public health."
The mRNA-1083 vaccine integrates components from mRNA-1010, Moderna's seasonal influenza vaccine candidate, and mRNA-1283, its next-generation COVID-19 vaccine candidate. Both components have independently shown positive results in Phase 3 clinical trials.
The ongoing Phase 3 clinical trial is a randomised, observer-blind, active control study assessing the safety, reactogenicity and immunogenicity of mRNA-1083.
Two comparative cohorts
It involves two age cohorts of around 4,000 adults each. With one cohort, consisting of adults 65 years and older, investigators compared mRNA-1083 to co-administered Fluzone HD®, an enhanced influenza vaccine, and Spikevax®, Moderna's licensed COVID-19 vaccine.
Investigators used the other cohort, consisting of adults aged 50 to 64, to compare mRNA-1083 to co-administered Fluarix®, a standard-dose influenza vaccine, and Spikevax.
Results indicated that a single dose of mRNA-1083 produced non-inferior immune responses compared to the co-administered licensed comparator vaccines.
In both age cohorts, mRNA-1083 elicited significantly higher immune responses against three influenza virus strains (H1N1, H3N2 and B/Victoria) and SARS-CoV-2.
Notably, in the 65 years and older cohort, the Geometric Mean Ratios (GMRs) for influenza strains were 1.155 for A/H1N1, 1.063 for A/H3N2 and 1.118 for B/Victoria.
The GMR for the Omicron XBB.1.5 SARS-CoV-2 variant was 1.641.
Similarly, in the 50 to 64 years cohort, the GMRs were 1.414 for A/H1N1, 1.380 for A/H3N2 and 1.216 for B/Victoria, with a GMR of 1.308 for the Omicron variant.
Immunogenicity against the B/Yamagata strain of influenza also met non-inferiority criteria in both age cohorts.
Due to the B/Yamagata lineage's disappearance, the World Health Organization has recommended a trivalent influenza vaccine composition for the 2024-2025 season, excluding B/Yamagata.
Tolerability and safety ‘acceptable’
The tolerability and safety profile of mRNA-1083 were deemed acceptable, with most adverse reactions being grade 1 or 2 in severity and consistent with those of the licensed vaccines used in the trial.
Common adverse reactions included injection site pain, fatigue, myalgia and headache.
Moderna plans to present the Phase 3 clinical data for mRNA-1083 at an upcoming medical conference and submit the data for publication.
The company will then engage with regulators to discuss the next steps.