A Study on the Immunogenicity and Safety of 3 Different Dose Concentrations of a Respiratory Syncytial Virus Vaccine in Infants and Toddlers

NCT06705140 | Terminated Phase 3 DMC FDA Drug

• 3 other identifiers: VAD000152023-509536-26U1111-1298-7338
• Study Type: interventional
• Target: 947
• Locations: 2 countries
• Sites: 4

Brief Summary

This study is a Phase III, parallel group, randomized, observer blind, placebo controlled, multi-national, multi-center, multi-arm study to be conducted in 947 healthy children enrolled at 6 months to \<22 months of age. The purpose of the study is to evaluate the non-inferiority of the immune response of the lower dose (LD) when compared to the standard dose (SD) respiratory syncytial virus infant and toddler (RSVt) vaccine and the safety of the LD, SD and high dose (HD) vaccine in preterm born children and of the HD vaccine in full term born children administered by intranasal route and compared to placebo.

Conditions

RSV Immunisation

Keywords

RSV; RSVt (RSV toddler and Infant) Vaccine

Outcome Measures

Primary Outcomes (9)

• RSV A serum neutralizing antibody titers at 28 days post dose 2 (D85)

  Antibody titers are expressed as GMT at Day 85

  Day 85

• RSV B serum neutralizing antibody titers at 28 days post dose 2 (D85)

  Antibody titers are expressed as GMT at Day 85

  Day 85

• Presence of unsolicited systemic adverse events (AEs) reported in the 30 minutes after each vaccination

  Number of participants experiencing immediate unsolicited systemic AEs

  Within 30 minutes after each vaccination

• Presence of solicited administration site reactions within 21 days after each vaccination

  Number of participants experiencing solicited site reactions

  Within 21 days after each vaccination

• Presence of solicited systemic reactions within 21 days after each vaccination

  Number of participants experiencing solicited systemic reactions

  Within 21 days after each vaccination

• Presence of unsolicited AEs within 28 days after each vaccination

  Number of participants experiencing unsolicited AEs

  Within 28 days after each vaccination

• Presence of medically attended adverse events MAAEs throughout the study

  Number of participants experiencing MAAEs

  Throughout the study (approximately 8 months)

• Presence of serious adverse events (SAEs) throughout the study

  Number of participants experiencing SAEs

  Throughout the study (approximately 8 months)

• Presence of adverse events of special interest (AESIs) throughout the study

  Number of participants experiencing AESIs

  Throughout the study (approximately 8 months)

Secondary Outcomes (6)

• RSV A serum neutralizing antibody titers at baseline (D01) and D85

  At baseline through Day 85

• RSV B serum neutralizing antibody titers at baseline (D01) and D85

  At baseline through Day 85

• RSV serum anti-F Immunoglobulin A (IgA) at baseline (Day01) and D85

  At baseline through Day 85

• RSV serum anti-F Immunoglobulin G (IgG) at baseline (Day01) and D85

  At baseline through Day 85

• Presence of RSVt vaccine virus viral shedding in D08 and D64 nasal samples

  Day 08 through Day 64

Study Arms (8)

Cohort 1: Group 1- (SD RSVt vaccine)

EXPERIMENTAL

Participants will receive 2 intranasal administrations of SD RSVt vaccine

Biological: Standard Dose (SD) RSVt vaccine

Cohort 1: Group 2-Control

PLACEBO COMPARATOR

Participants will receive 2 intranasal administrations of placebo

Biological: Placebo

Cohort 1: Group 3- (HD RSVt vaccine)

EXPERIMENTAL

Participants will receive 2 intranasal administrations of HD RSVt vaccine

Biological: High Dose (HD) RSVt vaccine

Cohort 1: Group 4-Control

PLACEBO COMPARATOR

Participants will receive 2 intranasal administrations of placebo

Biological: Placebo

Cohort 2: Group 1- (LD RSVt vaccine)

EXPERIMENTAL

Participants will receive 2 intranasal administrations of LD RSVt vaccine

Biological: Low Dose (LD) RSVt vaccine

Cohort 2: Group 2- (SD RSVt vaccine)

EXPERIMENTAL

Participants will receive 2 intranasal administrations of SD RSVt vaccine

Biological: Standard Dose (SD) RSVt vaccine

Cohort 2: Group 3- (HD RSVt vaccine

EXPERIMENTAL

Participants will receive 2 intranasal administrations of HD RSVt vaccine

Biological: High Dose (HD) RSVt vaccine

Cohort 2: Group 4-Control

PLACEBO COMPARATOR

Participants will receive 2 intranasal administrations of placebo

Biological: Placebo

Interventions

Placebo BIOLOGICAL

Pharmaceutical form:Liquid for nasal spray-Route of administration:Intranasal

Cohort 1: Group 2-Control; Cohort 1: Group 4-Control; Cohort 2: Group 4-Control

Low Dose (LD) RSVt vaccine BIOLOGICAL

Pharmaceutical form: Liquid for nasal spray Route of administration: Intranasal

Also known as: 534

Cohort 2: Group 1- (LD RSVt vaccine)

Standard Dose (SD) RSVt vaccine BIOLOGICAL

Pharmaceutical form:Liquid for nasal spray-Route of administration:Intranasal

Also known as: 534

Cohort 1: Group 1- (SD RSVt vaccine); Cohort 2: Group 2- (SD RSVt vaccine)

High Dose (HD) RSVt vaccine BIOLOGICAL

Pharmaceutical form:Liquid for nasal spray-Route of administration:Intranasal

Also known as: 534

Cohort 1: Group 3- (HD RSVt vaccine); Cohort 2: Group 3- (HD RSVt vaccine

Eligibility Criteria

• Age: 6 Months - 21 Months
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• Participants who are healthy as determined by medical evaluation including medical history.
• For Cohort 1 and Cohort 2 (contingent upon satisfactory safety profile of the RSVt vaccine in Cohort 1):
• Participant born 28 through 36 weeks of gestation and medically stable as assessed by the investigator, based on the following definition: "Medically stable" refers to the condition of premature infants who do not require significant medical support or ongoing management for debilitating disease and who have demonstrated a clinical course of sustained recovery by the time they receive the first dose of study intervention.
• For Cohort 2:

You may not qualify if:

• Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).
• Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study intervention used in the study or to a product containing any of the same substances.
• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion.
• History of medically diagnosed wheezing. Children with a history of recurrent wheezing will be excluded. Children with a previous single episode of wheezing may be included if that episode of wheezing was not associated with hospitalization or if does not have a family history of wheezing.
• Any acute febrile illness in the past 48 hours that according to investigator judgment is significant enough to interfere with successful inoculation on the day of vaccination. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
• Probable or confirmed ongoing case of viral respiratory infection (including COVID-19, influenza, rhinovirus, etc.) at the time of enrollment. A prospective participant should not be included in the study until the respiratory infection has resolved.
• Member of a household that contains an immunocompromised individual, including, but not limited to:
• a person who is HIV infected
• a person who has received chemotherapy within the 12 months prior to study enrollment
• a person who has received (within the past 6 months) or is receiving (at the time of enrollment) immunosuppressant agents
• a person living with a solid organ or bone marrow transplant
• Potential close contact with other immunocompromised individual within 30 days after each vaccination as per investigator's discretion.
• Participant's biological mother's previous receipt or planned administration of an investigational RSV vaccine during pregnancy and/or breastfeeding.
• Receipt or planned receipt of any of the following vaccines prior to enrollment or after the first study intervention administration:
• Any other intranasal live attenuated vaccine within the 28 days prior to and after Dose 1 study administration

Sponsors & Collaborators

• Sanofi Pasteur, a Sanofi Company: lead

Study Sites (4)

Investigational Site Number : 2140002

Santo Domingo, 10201, Dominican Republic

Location

Investigational Site Number : 3400002

San Pedro Sula, Honduras

Location

Investigational Site Number : 3400001

Tegucigalpa, 11101, Honduras

Location

Investigational Site Number : 3400003

Tegucigalpa, 11101, Honduras

Location

Related Links

• VAD00015 Plain Language Results Summary

MeSH Terms

Interventions

YM 534

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: * Blinding for vaccine group assignment: participants, parents or legally acceptable representatives (LARs), outcome assessors, investigators, laboratory personnel, Sponsor study staff * No blinding for study staff who prepare and administer the study interventions
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 22, 2024
• First Posted: November 26, 2024
• Study Start: November 25, 2024
• Primary Completion: June 11, 2025
• Study Completion: June 11, 2025
• Last Updated: February 3, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share

Locations

DO (1); HO (3)