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NCT05639894 · ClinicalTrials.gov registry record · Phase 1

Study of a Respiratory Syncytial Virus Candidate Encapsulated in a Lipid Nanoparticle Based Formulation in Adults Aged 18 to 50 Years and 60 Years and Older

A Phase 1 study, sponsored by Sanofi Pasteur, a Sanofi Company.

Completed
Registry status
Phase 1
Development phase
865
Enrollment target

NCT05639894: Completed Phase 1 study, sponsored by Sanofi Pasteur, a Sanofi Company.

NCT05639894 is a Phase 1 study that has completed, run by Sanofi Pasteur, a Sanofi Company. The registered enrollment target is 865 participants, above the 60-participant average among 29,502 other Phase 1 trials with a reported enrollment target (1342% higher). According to ClinicalTrials.gov, the official US trial registry.

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The verdict

NCT05639894, a Phase 1 study, has completed, sponsored by Sanofi Pasteur, a Sanofi Company.

COMPLETED
Registry status
Phase 1
Development phase
865 participants
Enrollment target

Study Summary

Brief Summary of Stage 1: The purpose Stage 1 (Phase I/IIa) is to assess the safety and immunogenicity of a single intramuscular (IM) injection of 3 dose-levels of an Respiratory Syncytial Virus (RSV) vaccine candidate formulated with 2 different lipid nanoparticles (LNPs) in healthy adult participants aged between 18 to 50 years, and 60 years and older. The primary objectives of this stage are to assess the safety and immunogenicity profiles across the dose-level groups (low, medium, and high doses) with 2 LNPs. This stage will evaluate the safety and immunogenicity of a booster vaccination administered 12 months after the primary vaccination in a subset of the study population. Brief Summary of Stage 2: The study also also incorporates a Stage 2 (Phase IIa, dose-ranging design) that includes adults aged 60 years and older to assess the safety and immunogenicity of different doses of RSV vaccine encapsulated in one of the LNPs. In the Phase IIa dose-ranging stage, eligible participants will be randomly assigned in a 1:1:1 ratio to receive a single IM administration of RSV vaccine candidate doses, or placebo. Multiple safety analyses will be performed, minimally at D07 and D28. Additional analyses may be performed as data are available.

Primary Outcome

An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. Immediate events were recorded to capture medically relevant unsolicited systemic AEs which occurred within the first 30 minutes after vaccination. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the case report form (CRF) in terms of diagnosis an

Interventions

  • OTHER Placebo
  • BIOLOGICAL RSV vaccine candiate formulation 1
  • BIOLOGICAL RSV vaccine candidate formulation 2

Trial Details

FieldValue
Enrollment Target 865 participants
Start Date 2022-11-17
Est. Completion 2025-05-02
Phase Phase 1
Sanofi Pasteur, a Sanofi Company

153 total trials

What the finished NCT05639894 record still lists

NCT05639894 is an interventional study that assigns participants to a tested intervention. The registered 865 participants enrollment target is mid-sized for trials with a published cap, above the 60-participant average among 29,502 other Phase 1 trials with a reported enrollment target (1342% higher).

The record links to 0 conditions, and to 3 interventions - of which Placebo is the first listed.

NCT05639894 does not publish any study locations in the registry export this page uses.

Frequently Asked Questions

What is clinical trial NCT05639894 about?

NCT05639894 is a clinical study titled "Study of a Respiratory Syncytial Virus Candidate Encapsulated in a Lipid Nanoparticle Based Formulation in Adults Aged 18 to 50 Years and 60 Years and Older". Brief Summary of Stage 1: The purpose Stage 1 (Phase I/IIa) is to assess the safety and immunogenicity of a single intramuscular (IM) injection of 3 dose-levels of an Respiratory Syncytial Virus (RSV) vaccine candidate formulated with 2 different lipid nanoparticles (LNPs) in healthy adult particip...

What is the current status of trial NCT05639894?

This trial is currently completed. It is a Phase 1 study. The enrollment target is 865 participants. The study started on 2022-11-17. Estimated completion is 2025-05-02.

What interventions are being tested in trial NCT05639894?

The interventions under investigation include: Placebo (OTHER), RSV vaccine candiate formulation 1 (BIOLOGICAL), RSV vaccine candidate formulation 2 (BIOLOGICAL).

Who is sponsoring clinical trial NCT05639894?

This trial is sponsored by Sanofi Pasteur, a Sanofi Company, which has 153 total clinical trials registered on ClinicalTrials.gov.

How this trial's enrollment target compares

Where NCT05639894's enrollment target sits among peer trials

865 11th of 2000 higher than 1,990 of 2,000 other Phase 1 trials

participants (enrollment target), bucketed by value

Each bar is a band; taller bars hold more other Phase 1 trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source ClinicalTrials.gov registry export · 2026-08-08

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Source: ClinicalTrials.gov NCT05639894, the US trial registry maintained by the National Library of Medicine. NCT05639894 (mid enrollment · none site footprint · completed) retrieved and formatted by PlainTrial, see methodology.