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

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

Status
Not yet recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07839871
Enrollment
920
Registered
2026-09-24
Start date
2026-09-28
Completion date
2031-04-01
Last updated
2026-09-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Respiratory Syncytial Virus (RSV)

Keywords

RSV, Vaccine, Pediatric

Brief 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.

Detailed description

The study will first enroll immunocompetent, RSV-experienced participants before enrolling immunocompromised participants to allow for safety data review. Both Cohorts 1 (chronic conditions) and 2 (immunocompromising conditions) will be stratified into 2 age strata. Cohort 1a will enroll participants 12 to \<18 years of age with chronic medical conditions and Cohort 1b will enroll participants 5 to \<12 years of age with chronic medical conditions. Cohort 2a will enroll immunocompromised participants 12 to \<18 years of age and Cohort 2b will enroll immunocompromised participants 5 to \<12 years of age.

Interventions

BIOLOGICALRSVpreF

RSVpreF Vaccine

BIOLOGICALPlacebo

Placebo

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)

Masking description

Double-blinded, placebo-controlled

Eligibility

Sex/Gender
ALL
Age
5 Years to 17 Years
Healthy volunteers
Yes

Inclusion criteria

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

Design outcomes

Primary

MeasureTime frameDescription
Cohort 1: Proportion of participants reporting pre-specified local reactions within 7 days following investigational product administrationWithin 7 daysDescribe pre-specified local reactions in children 5 to \<18 years of age with chronic medical conditions
Cohort 2: Proportion of participants reporting pre-specified local reactions within 7 days following each investigational product administrationWithin 7 daysDescribe pre-specified local reactions in children 5 to \<18 years of age with immunocompromising conditions
Cohort 1: Proportion of participants reporting pre-specified systemic events within 7 days following investigational product administrationWithin 7 daysDescribe pre-specified systemic events in children 5 to \<18 years of age with chronic medical conditions
Cohort 2: Proportion of participants reporting pre-specified systemic events within 7 days following each investigational product administrationWithin 7 daysDescribe pre-specified systemic events in children 5 to \<18 years of age with immunocompromising conditions
Cohort 1: Proportion of participants reporting adverse events (AEs) through 1 month following investigational product administrationFrom vaccination through 1 month after vaccinationDescribe AEs in children 5 to \<18 years of age with chronic medical conditions
Cohort 2: Proportion of participants reporting adverse events (AEs) through 1 month following last investigational product administrationFrom vaccination through 1 month after last vaccinationDescribe AEs in children 5 to \<18 years of age with immunocompromising conditions
Cohort 1: Proportion of participants reporting serious adverse events (SAEs) throughout the studyFrom vaccination through 24 months after vaccinationDescribe SAEs in children 5 to \<18 years of age with chronic medical conditions
Cohort 2: Proportion of participants reporting serious adverse events (SAEs) throughout the studyFrom vaccination through 12 months after last vaccinationDescribe SAEs in children 5 to \<18 years of age with immunocompromising conditions
Cohort 1: Proportion of participants reporting newly diagnosed chronic medical conditions (NDCMCs) throughout the studyFrom vaccination through 24 months after vaccinationDescribe NDCMCs in children 5 to \<18 years of age with chronic medical conditions
Cohort 2: Proportion of participants reporting newly diagnosed chronic medical conditions (NDCMCs) throughout the studyFrom vaccination through 12 months after last vaccinationDescribe NDCMCs in children 5 to \<18 years of age with immunocompromising conditions
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 C36710131 month after vaccinationDemonstrate 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
Cohort 1: Seroresponse rate of RSV A and RSV B serum NTs at 1 month after vaccination1 month after vaccinationDemonstrate 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
Cohort 2: Neutralizing Titers (NTs) for RSV A and RSV B expressed as Geometric Mean Titers (GMT)Before each vaccination, 1 month after each vaccination, 12 months after last vaccinationDescribe the immune responses elicited by 1 or 2 doses of RSVpreF in children 5 to \<18 years of age with immunocompromising conditions
Cohort 2: NTs for RSV A and RSV B expressed as Geometric Mean Fold Rise (GMFR)1 month after each vaccination, 12 months after last vaccinationDescribe the immune responses elicited by 1 or 2 doses of RSVpreF in children 5 to \<18 years of age with immunocompromising conditions
Cohort 2: NTs for RSV A and RSV B expressed as seroresponse rate1 month after each vaccination, 12 months after last vaccinationDescribe the immune responses elicited by 1 or 2 doses of RSVpreF in children 5 to \<18 years of age with immunocompromising conditions

Secondary

MeasureTime frameDescription
Cohort 1: NTs for RSV A and RSV B expressed as Geometric Mean Titers (GMT)Before vaccination, 1 month after vaccination, 12 months after vaccination, 24 months after vaccinationDescribe the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions
Cohort 1: NTs for RSV A and RSV B expressed as GMFR1 month after vaccination, 12 months after vaccination, 24 months after vaccinationDescribe the immune responses elicited by RSVpreF in children 5 to \<18 years of age with chronic medical conditions
Cohort 1: NTs for RSV A and RSV B expressed as seroresponse rate1 month after vaccination, 12 months after vaccination, 24 months after vaccinationDescribe 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

Countries

Japan, United States

Contacts

CONTACTPfizer CT.gov Call Center
ClinicalTrials.gov_Inquiries@pfizer.com1-800-718-1021
STUDY_DIRECTORPfizer CT.gov Call Center

Pfizer

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 25, 2026