Study of a Single Intramuscular Dose of Nirsevimab in the Prevention of Hospitalizations Due to Respiratory Syncytial Virus (RSV) Infection in Healthy Term and Preterm Infants During the First Year of Life

Study on RSV Hospitalization Prevention in Infants with Investigational Medication

Not Recruiting
12 months or below
All
Phase 3
8057 participants needed

Study Overview

The purpose of this study was to determine the efficacy and safety of a single intramuscular (IM) dose of nirsevimab, compared to no intervention, for the prevention of hospitalizations due to lower respiratory tract infection (LRTI) caused by confirmed RSV infection (henceforth referred to as RSV LRTI hospitalizations) in all infants under 12 months of age who were not eligible to receive palivizumab.

The visit frequency was 1 in-person dosing/randomization visit, with monthly safety follow-up electronic contacts through the first 6 months post dosing/randomization for all participants. The study also included a 12-month (Day 366) follow-up telephone call. The D366 follow-up telephone call was the final follow-up telephone call for France, Germany and UK non-reconsented participants. The study included an 18-month (D546) and a 24-month (D731, final telephone call) follow-up telephone call for UK reconsented participants.

Study Details

12 months post-dosing/randomization for France, Germany and UK non-reconsented participants, 24 months post-dosing/randomization for UK reconsented participants. D01 was the day of randomization (both study groups) and immunization (nirsevimab group).

Eligibility Criteria

You may be eligible for this study if you meet the following criteria:

  • Conditions: RSV Immunization, Healthy Volunteer
  • Age: 12 months or below
  • Gender: All

Inclusion Criteria:

  • Born at ≥ 29 weeks gestational age and aged 0 to 12 months (calendar age), who entered their first RSV season on the day of inclusion in the study (D01)
  • Informed consent form was signed and dated by the parent(s) or other LAR(s) (and by an independent witness if required by local regulations)
  • Participant and parent/LAR were able to attend the scheduled visit and to comply with all study procedures

Exclusion Criteria:

  • Participants were not eligible for the study if any of the following criteria are
    met
  • 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)

  • Active confirmed RSV infection at the time of dosing/randomization
  • Active LRTI at the time of dosing/randomization
  • 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
  • Laboratory confirmed thrombocytopenia, or known thrombocytopenia, as reported by the parent/LAR, contraindicating intramuscular injection
  • Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection
  • Any condition that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion
  • Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 38.0°C [≥ 100.4°F]) on the day of study intervention administration.
  • A prospective participant was not included in the study until the condition has resolved or the febrile event has subsided
  • Mother of the infant participant was administered an RSV vaccine during her pregnancy with the infant participant
  • Receipt of any monoclonal antibody by the infant participant
  • Receipt of immune globulins, blood or blood-derived products in the past 3 months by the infant participant
  • Participation at the time of study enrollment or planned participation during the present study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure
  • Eligible to receive palivizumab at time of inclusion (as per local guidelines)
  • In an emergency setting or hospitalized involuntarily
  • Identified as a natural or adopted child of the Investigator or employee with direct involvement in the proposed study

The above information were not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.

Updated on 08 May 2025. Study ID: NCT05437510

This study investigates the prevention of hospitalizations due to lower respiratory tract infections (LRTI) caused by Respiratory Syncytial Virus (RSV) in infants under 12 months. RSV is a virus that can cause serious lung infections. The study compares a single dose of an investigational medication given by injection into a muscle to no intervention in infants who are not eligible for another treatment called palivizumab.

Participants will receive one injection of the investigational medication or no treatment. The study includes monthly safety follow-up contacts for the first six months after the injection. There will also be follow-up phone calls at 12, 18, and 24 months, depending on the location and consent status of the participants.

  • Who can participate: Infants born at 29 weeks or later and aged 0 to 12 months who are entering their first RSV season can participate. Parents must provide consent and be able to comply with study procedures. Infants should not have certain medical conditions or be eligible for palivizumab.
  • Study details: Participants will receive either an investigational medication or no treatment. Parents will need to ensure their infants attend follow-up appointments and phone calls. The investigational medication is compared to no intervention to see if it prevents RSV hospitalizations.
  • Study Timelines and Visits: The study will last 12 months. The study requires 1 visits.