Phase 3
N=1,900
A Study to Evaluate the Safety and Immune Response of mRNA-1345, a Vaccine Targeting Respiratory Syncytial Virus (RSV), When Co-administered With a Fluzone HD, in Adults ≥65 Years of Age
Respiratory Syncytial Virus
Bottom Line
View on ClinicalTrials.gov: NCT06060457 ↗Enrolled (actual)
1,900
Serious AEs
3.0%
Results posted
Jul 2025
Primary outcome: Primary: Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs) Within 7 Days After Day 1 Injection — 689; 547 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- Placebo (Biological); mRNA-1345 (Biological); Fluzone HD (Biological)
- Age
- Older Adult · 65+ yrs
- Sex
- All
- Sponsor
- ModernaTX, Inc.
- Primary completion
- Jun 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs) Within 7 Days After Day 1 Injection |
689; 547 | — |
| PRIMARY Number of Participants With Solicited Local and Systemic ARs Within 7 Days After Day 22 Injection |
251; 557 | — |
| PRIMARY Number of Participants With Unsolicited Adverse Events (AEs) Up to 21 Days After Day 1 Injection |
72; 72 | — |
| PRIMARY Number of Participants With Unsolicited AEs Up to 21 Days After Day 22 Injection |
60; 71 | — |
| PRIMARY Number of Participants With Medically Attended Adverse Events (MAAEs), Adverse Events of Special Interest (AESIs), Serious Adverse Events (SAEs), and AEs Leading to Discontinuation |
194; 191; 0; 1; 23; 33 | — |
| PRIMARY Geometric Mean Titer (GMT) of Serum Respiratory Syncytial Virus Subtype A (RSV-A) and Respiratory Syncytial Virus Subtype B (RSV-B) Neutralizing Antibodies (nAbs) |
11800.26; 18874.12; 4197.74; 6579.15 | — |
| PRIMARY GMT of Serum Anti-Hemagglutination (HA) Ab Level, as Measured by Hemagglutination Inhibition (HAI) Assay |
108.11; 124.15; 198.53; 228.83; 105.32; 118.27 | — |
| SECONDARY Percentage of Participants With Seroresponse for RSV-A and RSV-B nAbs, as Measured by HAI Assay |
64.7; 78.2; 48.7; 61.9 | — |
| SECONDARY Geometric Mean Fold-Rise (GMFR) of Postinjection RSV-A and RSV-B nAbs Antibodies for Influenza, as Measured by HAI Assay |
6.49; 10.00; 4.08; 5.92 | — |
| SECONDARY Percentage of Participants With ≥2-fold Increase in RSV-A and RSV-B nAbs |
85.4; 93.2; 75.4; 83.5 | — |
| SECONDARY Percentage of Participants With Seroconversion, as Measured by HAI Assay |
56.0; 59.0; 60.3; 65.8; 55.5; 59.1 | — |
| SECONDARY GMFR of Serum Ab Level, as Measured by HAI Assay |
5.21; 5.78; 6.20; 7.16; 4.87; 5.64 | — |
Summary
The main purpose of this study is to evaluate the safety and immunogenicity of mRNA-1345 RSV vaccine when coadministered with a high dose (HD) quadrivalent seasonal influenza vaccine (Fluzone HD) in adults ≥65 years of age. The study will examine the impact of Fluzone HD on the immune response to mRNA-1345 against RSV-A and RSV-B, as well as the impact of mRNA-1345 on the immune response to Fluzone HD against 4 vaccine-matched Influenza A and B strains.
Eligibility Criteria
Key Inclusion Criteria
- Participants may have one or more chronic medical diagnoses, but should be medically stable as assessed by:
- Absence of changes in medical therapy within 60 days of Day 1 due to treatment failure or toxicity,
- Absence of serious or significant medical events within 30 days of Day 1, and
- Absence of known, current, and life-limiting diagnoses which, in the opinion of the Investigator, would make completion of the protocol unlikely.
- A participant assigned female at birth is eligible to participate if they are postmenopausal or not a person of childbearing potential.
Key Exclusion Criteria
- Close contact with someone with laboratory-confirmed influenza and/or RSV infection or with someone who has been treated with antiviral therapies for influenza (for example, Tamiflu®) within the past 5 days prior to Day 1.
- Reported history of congenital or acquired immunodeficiency, immunosuppressive condition or immune-mediated disease, asplenia, or recurrent severe infections.
- Participant has tested positive for influenza or RSV by local health authority-approved testing methods ≤6 months prior to Day 1.
- Participant has received or plans to receive any vaccine authorized or approved by a local health agency ≤28 days prior to study injections (Day 1 and Day 22) or plans to receive a vaccine authorized or approved by a local health agency within 28 days after study injections.
- Participant has received a seasonal influenza vaccine or any other investigational influenza vaccine ≤6 months prior to Day 1.
- Participant has received any RSV vaccine (authorized/approved by local health agency or investigational) prior to Day 1.
Note: Other protocol-defined inclusion and/or exclusion criteria may apply.
Data sourced from ClinicalTrials.gov (NCT06060457). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.