NCT05829356

Substudy 01 - Safety and Immunogenicity of One Monovalent Modified mRNA Vaccine Encoding Influenza Hemagglutinin With LNP, in Adult Participants Aged 18 to 49 Years and 60 Years and Above

A Phase I, Parallel, Randomized, Active-controlled, Multi-center, Dose-escalation Study With Early Safety Data Reviews to Assess Safety and Immunogenicity of One Monovalent Modified Influenza mRNA Vaccine Encapsulated in LNP, in Adults Aged 18 to 49 Years and 60 Years and Above.

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 159 (actual)
• Sponsor: Sanofi Pasteur, a Sanofi Company · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

This is a Phase 1, parallel, randomized, active-controlled, multi-center, dose-esclation study with a Master Protocol design which will include several substudies that are developed to evaluate the safety and immunogenicity of different dose levels of modified messenger ribonucleic acid (mRNA) vaccines encoding full length hemagglutinin (HA) sequence of influenza virus encapsulated in lipid nanoparticles (LNPs) (hereafter referred to as HA mRNA vaccines) compared to control(s). The HA mRNA vaccine candidates and control(s) are presented in the substudy protocols. The aim is to generate clinical data across different substudies to provide learnings regarding the mRNA technology to support optimization of the mRNA platform including mRNA and LNP design and to support the decision of LNP and dose selection for future projects using mRNA technology. The purpose of this Substudy 01 is to evaluate the safety and immunogenicity of a single IM injection of up to 5 dose levels of a monovalent modified mRNA encoding the full-length HA sequence of A/Tasmania/503/2020 (H3N2) influenza virus encapsulated in LNP (hereafter referred to as H3 mRNA /LNP) administered as a single intramuscular (IM) injection in adults 18 to 49 years of age and 60 years of age and above, compared to the following active control: a quadrivalent recombinant influenza vaccine (RIV4).

Detailed description

The study duration per participant will be approximately 6 months with 1 injection of one of the different HA mRNA vaccines or control for each substudy and a dose-escalation with sequential enrollment (sentinel cohort followed by main cohort).

Conditions

• Influenza Immunization

Interventions

Type	Name	Description
BIOLOGICAL	H3 mRNA / LNP Vaccine	Pharmaceutical Form: Suspension for injection Route of Administration: Intra-Muscular
BIOLOGICAL	Quadrivalent recombinant influenza Vaccine (RIV4)	Pharmaceutical Form: Solution for injection in a pre-filled syringe Route of Administration: Intra-Muscular

Timeline

• Start date: 2023-04-12
• Primary completion: 2024-03-14
• Completion: 2024-03-14
• First posted: 2023-04-25
• Last updated: 2025-09-12

Locations

8 sites across 2 countries: Australia, United Kingdom