NIRSEVIMAB for Respiratory syncytial virus (RSV) infection

Inclusion criteria

• {"criterion_text":"- Nirsevimab group: Infants and newborns born before or at the beginning of the RSV season and are 0-4 months of age by immunization"}
• {"criterion_text":"- Control group: Children around 12-15 months of age at the start of the RSV season (September/October)"}
• {"criterion_text":"- Nirsevimab group: Infants eligible for the nirsevimab immunization and the parents/ legal representatives decided that the infants will receive the nirsevimab immunization"}
• {"criterion_text":"- Children have to be healthy according to the same health criteria applied in the well baby clinic when a child is immunized, e.g. also infants with small increases in body temperature or a cold are seen as children with normal health"}
• {"criterion_text":"- The parents/ legal representatives accept participation of their (unborn) child in the study according to the described procedures"}
• {"criterion_text":"- Presence of a signed informed consent (the parents/legal representatives have given written informed consent after receiving oral and written information)"}

Exclusion criteria

• {"criterion_text":"- Nirsevimab group: Having received nirsevimab immunization before study entry"}
• {"criterion_text":"- Known or suspected serious underlying medical condition that can interfere with the results of the study. Such as, but not limited to, certain chromosomal abnormalities or craniofacial abnormalities (like Trisomy 21 or schisis), known or suspected immunodeficiency disease, seizure disorder or cancer."}
• {"criterion_text":"- Control group: Having received nirsevimab immunization"}
• {"criterion_text":"- Control group: Being hospitalized due to a confirmed RSV infection"}
• {"criterion_text":"- The biological mother received an RSV vaccination during pregnancy"}
• {"criterion_text":"- Nirsevimab group: Confirmed RSV infection before study entry"}
• {"criterion_text":"- Active or past immunosuppressive or immune modulating medication. However, for steroid treatment the exclusion criteria are: receipt of any high-dose (≥ 20 mg of prednisone daily or equivalent) steroid treatment; daily corticosteroids (locally, incl. inhaled steroids, are acceptable) within 2 weeks before study entry or repeated use of any high dose of corticosteroids (a dose of > 30 mg of prednisone or equivalent per day for multiple days) within 2 weeks before study entry. The use of hydrocortisone as a substitution therapy in case a subject does not produce sufficient amounts is allowed."}
• {"criterion_text":"- Known or suspected immunological disorder"}
• {"criterion_text":"- Known or suspected bleeding disorder"}
• {"criterion_text":"- Premature infants born before 37 weeks gestational age"}

Primary endpoints

• {"endpoint_text":"- RSV-specific antibody levels at 12 months post-nirsevimab immunization in the nirsevimab group and the control group (at 12-15 months of age)","definition_or_measurement_approach":"Measurement of RSV-specific antibody levels at 12 months post-immunization in both the nirsevimab group and the control group (assay-based measurement of RSV-specific antibodies at the 12-month timepoint)."}

Secondary endpoints

• {"endpoint_text":"- RSV-specific serum IgA levels pre- and 2, 4, 6, 12 months post-nirsevimab immunization and in the control group","definition_or_measurement_approach":"Measurement of RSV-specific serum IgA at baseline (pre-) and at 2, 4, 6 and 12 months post-immunization; comparison with control group."}
• {"endpoint_text":"- RSV-specific serum antibody levels pre- and 2, 4, 6 and 12 months post-nirsevimab immunization","definition_or_measurement_approach":"Measurement of RSV-specific serum antibody levels at baseline and at 2, 4, 6 and 12 months post-immunization."}
• {"endpoint_text":"- RSV-specific serum antibody concentration pre- and 2, 4, 6 and 12 months postnirsevimab immunization / Questionnaire data such as age and weight of immunization","definition_or_measurement_approach":"Quantification of RSV-specific serum antibody concentrations at baseline and at 2, 4, 6 and 12 months; collection of questionnaire data (age, weight at immunization) for covariate analyses."}
• {"endpoint_text":"- RSV-specific antibody neutralization and Fc-functionality at 12 months post immunization in the nirsevimab group and the control group","definition_or_measurement_approach":"Assessment of antibody neutralization and Fc-mediated functionality at 12 months post-immunization in both groups using functional assays."}
• {"endpoint_text":"- RSV-specific monoclonal and maternal antibody levels pre- and 2, 4, 6 and 12 months post-nirsevimab immunization","definition_or_measurement_approach":"Measurement of levels distinguishing monoclonal (nirsevimab) and maternal RSV-specific antibodies at baseline and 2, 4, 6 and 12 months post-immunization."}

Methods

• Recruitment via flyers targeted to parents/legal representatives (documents: wervingsflyer Nirsevimab groep and controlegroep).
• Website text recruitment (document: websitetekst_Redacted) targeted to parents/legal representatives.
• Recruitment via well-baby clinics/consultation bureaus (study population defined according to well baby clinic immunization criteria).

Netherlands

Earliest CTIS Part Ii Submission Date

10-07-2025

Latest Decision Or Authorization Date

07-11-2025

Processing Time Days

120

Number Of Sites

1

Number Of Participants

250

Primary sponsor

Full Name

Rijksinstituut voor Volksgezondheid en Milieu (RIVM)

Organisation Type

Hospital/Clinic/Other health care facility

Country Of Registered Address

Netherlands