NCT06821126

Study Comparing Safety and Immunogenicity of Intranasal COVID-19 Vaccine and mRNA Booster in Healthy Adults

Randomized, Controlled, Multicenter Phase I/II Study Comparing the Safety and Immunogenicity of a Booster Dose of an Intranasal COVID-19 Vaccine Expressing SARS-CoV-2 N/S Recombinant Proteins With a Booster Dose of COVID-19 mRNA Vaccine in Healthy Adults (MUCOBOOST)

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 238 (estimated)
• Sponsor: ANRS, Emerging Infectious Diseases · Other Government
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

This Phase I/II trial in France evaluates safety and immunogenicity of a booster dose of an intranasal COVID-19 vaccine (LVT-001) versus a booster dose of a COVID-19 mRNA vaccine (Pfizer-BioNTech) in healthy adult volunteers. As a first-in-human trial, Phase I will assess the safety and immunogenicity of three escalating doses of the LVT-001 vaccine across 3 cohorts of 12 volunteers per dose level. Based on cumulative data collected up to Day 28 visit from the last included participant in the Phase I, the go/no-go decision for Phase II and selection of the optimal dose will be performed. Phase II will then evaluate the immunogenicity of the selected intranasal dose of LVT-001 vaccine, compared to the standard of care of intramuscular COVID-19 mRNA Pfizer-BioNTech booster.

Detailed description

This is a randomized, comparative, multicenter, open-label, phase I/II trial in France evaluating the safety and immunogenicity of a booster dose of an intranasal COVID-19 vaccine (LVt-001) versus a booster dose of a COVID-19 mRNA vaccine (Pfizer-BioNTech) in healthy adult volunteers. Phase I dose escalating - Primary Objective: To evaluate the safety of three escalating doses of a boost of an intranasal COVID-19 vaccine (LVT-001) expressing SARS-CoV-2 N/S recombinant protein in healthy volunteers. Phase II superiority trial - Primary Objective: To evaluate, using nasal swabs, the superiority of a booster dose of the selected intranasal COVID-19 vaccine (LVT-001) expressing SARS-COV-2 N/S recombinant protein versus a booster dose of the intramuscular COVID-19 mRNA vaccine (Pfizer-BioNTech) in healthy adult volunteers in term of mucosal humoral immune response at Day 28. Trial population: A total of 36 and 202 healthy volunteers will be enrolled in Phase I and Phase II, respectively. Interventions: Phase I: The investigational medicinal product is the intranasal recombinant protein vaccine LVT-001 administered at Day 0 in each nostril: * Cohort A (12 participants): 20 µg * Cohort B (12 participants): 60 µg * Cohort C (12 participants): 120 µg Phase II: Two investigational medicinal products will be compared: * The selected dose of the intranasal recombinant protein vaccine LVT-001, administered at Day 0 in each nostril. * The intramuscular COVID-19 mRNA vaccine (Pfizer-BioNTech), administered as the standard of care booster. Expected Outcomes and Safety Considerations: In Phase I, healthy participants are not expected to benefit directly from the trial aside from the potential theoretical benefit of a mucosal immune response against SARS-CoV-2. Currently, no clinical trial data exist for a nasal protein vaccine in humans. The anticipated risks primarily include local nasal reactions and systemic reactions similar to those observed with other vaccines. Any adverse events following vaccination are expected to be manageable with routine care, as determined by investigators. Given that this is the first human trial of a nasal protein vaccine, the dose-escalation design ensures a safety margin, allowing for careful monitoring before progressing to the next cohort.

Conditions

• Healthy

Interventions

Type	Name	Description
BIOLOGICAL	LVT-001	Intranasal administration
BIOLOGICAL	Cormirnaty	Intramuscular administration

Timeline

• Start date: 2025-05-09
• Primary completion: 2026-10-01
• Completion: 2028-03-01
• First posted: 2025-02-11
• Last updated: 2025-12-18

Locations

5 sites across 1 country: France