Study to Learn About a Respiratory Syncytial Virus Vaccine in Children at High Risk of RSV Disease

NCT07839871
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Phase
Phase 3
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Recruitment status
Not yet recruiting
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Participants
920
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Lead sponsor
Pfizer
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Start date
2026-09-28
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Number of sites
2
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Summary
The purpose of the study is to evaluate the safety, tolerability, and immunogenicity of RSVpreF in children 5 to \<18 years of age at high risk for RSV disease, including those who are immunocompromised.
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Short title
Study to Learn About a Respiratory Syncytial Virus Vaccine in Children at High Risk of RSV Disease
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Official title
A PHASE 3 STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A RESPIRATORY SYNCYTIAL VIRUS VACCINE IN CHILDREN AT HIGH RISK OF RSV DISEASE
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Control arm
Placebo
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Registry reports results
No
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Listing at source
Listed
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Recruitment status
Not yet recruiting
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Phase
Phase 3
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Study type
Interventional
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Completion date
2031-04-01
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First posted
2026-09-24
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Registry last updated
2026-09-24
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Primary completion date
2031-04-01
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Start date
2026-09-28
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Participants
920
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Participant count basis
Estimated
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Planned participants
920
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Number of sites
2
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Data monitoring committee
Yes
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Registry sponsor category
Industry
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Lead sponsor
Pfizer
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Source registry
ClinicalTrials.gov
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Registry ID
NCT07839871
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ClinicalTrials.gov ID
NCT07839871
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Registry record
Open registry record
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Allocation
Randomised
Model
Parallel groups
Purpose
Prevention
Masking
Double masking
Masking description
Double-blinded, placebo-controlled
Masked roles
Participants, Investigators
Sources for study design
clinicaltrials.gov

  1. Cohort 1: Proportion of participants reporting pre-specified local reactions within 7 days following investigational product administration

    Timeframe: Within 7 days

    Describe pre-specified local reactions in children 5 to \<18 years of age with chronic medical conditions

  2. Cohort 2: Proportion of participants reporting pre-specified local reactions within 7 days following each investigational product administration

    Timeframe: Within 7 days

    Describe pre-specified local reactions in children 5 to \<18 years of age with immunocompromising conditions

  3. Cohort 1: Proportion of participants reporting pre-specified systemic events within 7 days following investigational product administration

    Timeframe: Within 7 days

    Describe pre-specified systemic events in children 5 to \<18 years of age with chronic medical conditions

  4. Cohort 2: Proportion of participants reporting pre-specified systemic events within 7 days following each investigational product administration

    Timeframe: Within 7 days

    Describe pre-specified systemic events in children 5 to \<18 years of age with immunocompromising conditions

  5. Cohort 1: Proportion of participants reporting adverse events (AEs) through 1 month following investigational product administration

    Timeframe: From vaccination through 1 month after vaccination

    Describe AEs in children 5 to \<18 years of age with chronic medical conditions

  6. Cohort 2: Proportion of participants reporting adverse events (AEs) through 1 month following last investigational product administration

    Timeframe: From vaccination through 1 month after last vaccination

    Describe AEs in children 5 to \<18 years of age with immunocompromising conditions

  7. Cohort 1: Proportion of participants reporting serious adverse events (SAEs) throughout the study

    Timeframe: From vaccination through 24 months after vaccination

    Describe SAEs in children 5 to \<18 years of age with chronic medical conditions

  8. Cohort 2: Proportion of participants reporting serious adverse events (SAEs) throughout the study

    Timeframe: From vaccination through 12 months after last vaccination

    Describe SAEs in children 5 to \<18 years of age with immunocompromising conditions

  9. Cohort 1: Proportion of participants reporting newly diagnosed chronic medical conditions (NDCMCs) throughout the study

    Timeframe: From vaccination through 24 months after vaccination

    Describe NDCMCs in children 5 to \<18 years of age with chronic medical conditions

  10. Cohort 2: Proportion of participants reporting newly diagnosed chronic medical conditions (NDCMCs) throughout the study

    Timeframe: From vaccination through 12 months after last vaccination

    Describe NDCMCs in children 5 to \<18 years of age with immunocompromising conditions

  11. Cohort 1: Geometric mean ratio (GMR), estimated by the ratio of the geometric mean titers (GMTs) for RSV A and RSV B serum neutralizing titers (NTs) 1 month after vaccination in participants in Study C3671017 Cohort 1 compared to those in Study C3671013

    Timeframe: 1 month after vaccination

    Demonstrate that the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions are noninferior to the immune responses in adults ≥60 years of age

  12. Cohort 1: Seroresponse rate of RSV A and RSV B serum NTs at 1 month after vaccination

    Timeframe: 1 month after vaccination

    Demonstrate that the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions are noninferior to the immune responses in adults ≥60 years of age. Seroresponse is defined as a postvaccination NT ≥4 times the lower limit of quantitation (LLOQ) if the prevaccination titer is below the LLOQ; or a ≥4-fold rise from prevaccination if the prevaccination titer is ≥ LLOQ

  13. Cohort 2: Neutralizing Titers (NTs) for RSV A and RSV B expressed as Geometric Mean Titers (GMT)

    Timeframe: Before each vaccination, 1 month after each vaccination, 12 months after last vaccination

    Describe the immune responses elicited by 1 or 2 doses of RSVpreF in children 5 to \<18 years of age with immunocompromising conditions

  14. Cohort 2: NTs for RSV A and RSV B expressed as Geometric Mean Fold Rise (GMFR)

    Timeframe: 1 month after each vaccination, 12 months after last vaccination

    Describe the immune responses elicited by 1 or 2 doses of RSVpreF in children 5 to \<18 years of age with immunocompromising conditions

  15. Cohort 2: NTs for RSV A and RSV B expressed as seroresponse rate

    Timeframe: 1 month after each vaccination, 12 months after last vaccination

    Describe the immune responses elicited by 1 or 2 doses of RSVpreF in children 5 to \<18 years of age with immunocompromising conditions

  1. Cohort 1: NTs for RSV A and RSV B expressed as Geometric Mean Titers (GMT)

    Timeframe: Before vaccination, 1 month after vaccination, 12 months after vaccination, 24 months after vaccination

    Describe the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions

  2. Cohort 1: NTs for RSV A and RSV B expressed as GMFR

    Timeframe: 1 month after vaccination, 12 months after vaccination, 24 months after vaccination

    Describe the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions

  3. Cohort 1: NTs for RSV A and RSV B expressed as seroresponse rate

    Timeframe: 1 month after vaccination, 12 months after vaccination, 24 months after vaccination

    Describe the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions. Seroresponse is defined as a postvaccination NT ≥4 times the lower limit of quantitation (LLOQ) if the prevaccination titer is below the LLOQ; or a ≥4-fold rise from prevaccination if the prevaccination titer is ≥ LLOQ

Sources for outcomes
clinicaltrials.gov

Sex
All
Age groups
Children
Minimum age
5 Years
Maximum age
17 Years
Healthy volunteers
Yes

Key Inclusion Criteria:

  • Participants' age requirements for each study cohort at enrollment, respectively Cohort 1a (chronic medical conditions) 12 to <18 years of age Cohort 1b (chronic medical conditions) 5 to <12 years of age Cohort 2a (immunocompromising conditions) 12 to <18 years of age Cohort 2b (immunocompromising conditions) 5 to <12 years of age
  • Participants depending on the study cohort requirements, will be considered by the investigator to be at high risk of LRTI-RSV based on the following disease characteristics and definitions:

Chronic medical conditions:

  • Cystic fibrosis
  • Medically treated asthma
  • Other chronic respiratory diseases and malformations of the lung
  • Trisomy 21 (Down syndrome)
  • Neuromuscular disease
  • Cerebral palsy
  • Hemodynamically significant or symptomatic congenital heart disease
  • Sickle cell disease
  • Confirmed stable HIV disease defined as documented viral load <50 copies/mL and CD4 count >200 cells/mm3 within 6 months before enrollment, and on stable antiretroviral therapy for at least 6 months

Immunocompromising conditions:

  • Immunomodulatory therapy: Is on an active immunosuppressive (including cytotoxic) or immunomodulatory therapy at a stable dose. Patients taking steroids as monotherapy must be on a dose of at least 2 mg/kg/day or 20 mg/day or greater OR
  • Primary immune deficiency: Has a diagnosed primary immunodeficiency disease OR
  • Cellular therapy: Has received a bone marrow or stem cell transplant at least 6 months (180 days) prior to enrollment with adequate immune reconstitution for immunization in the investigator's opinion or has received chimeric antigen receptor T cell (CAR-T) therapy more than 90 days prior to enrollment OR
  • Solid organ transplant: Has received a solid organ transplant at least 3 months prior and with no acute rejection episodes within 90 days prior to enrollment and is on ongoing immunosuppressive therapy OR
  • End-stage renal disease: Has end-stage renal disease (ESRD) on hemodialysis (HD)
  • Participants' weight must be:

Cohort 1a: ≥30.0 kg at enrollment Cohort 1b: ≥14.5 kg at enrollment Cohort 2a : ≥30 kg at enrollment Cohort 2b: ≥14.5 kg at enrollment

•The participant's parent(s)/legal guardian is capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICD and in the protocol. Depending on the age of the participant and according to local requirements, participants will also be asked to provide assent as appropriate (verbal or written)

Key Exclusion Criteria:

  • Applicable to Cohort 1 (a and b) participants only: Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination
  • Applicable to Cohort 1 (a and b) participants only: Individuals with a history of autoimmune disease, past or present, requiring therapeutic intervention including, but not limited to, systemic lupus erythematosus. Note: Stable type 1 diabetes and hypothyroidism are permitted
  • History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s)
  • Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection
  • Individuals with epilepsy or other seizure disorders that is uncontrolled/unstable, or a history of seizures and/or other neurological complications following vaccination
  • History of Guillain-Barré syndrome and/or acute polyneuropathy without an underlying etiology.
  • Individuals who are pregnant
  • Any medical or psychiatric condition, including any active suicidal ideation in the past year or suicidal behavior in the past 5 years or laboratory abnormality, that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study
Sources for eligibility
clinicaltrials.gov

  • Senders PediatricsSouth Euclid, United States
  • Fukuwa ClinicChuo-ku, Japan
Sources for sites
clinicaltrials.gov

Other registry identifiers

  • 2026-525797-19-00
Sources for references
clinicaltrials.gov

Related records

Drugs (1)

Lead sponsors (1)

Conditions (1)