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

Sanofi logo


Status and phase

Active, not recruiting
Phase 3


Healthy Volunteer
RSV Immunization


Biological: Nirsevimab

Study type


Funder types



2022-000099-20 (EudraCT Number)
U1111-1272-2514 (Registry Identifier)

Details and patient eligibility


The purpose of this study is 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 are not eligible to receive palivizumab. The visit frequency will be 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 will also include a 12-month (Day 366) follow-up telephone call. The D366 follow-up telephone call will be the final follow-up telephone call for France, Germany and UK non-reconsented participants. The study will include an 18-month (D546) and a 24-month (D731, final telephone call) follow-up telephone call for UK reconsented participants.

Full description

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


8,058 patients




Under 12 months old


Accepts Healthy Volunteers

Inclusion criteria

  • Born at ≥ 29 weeks gestational age and aged 0 to 12 months (calendar age), who are entering their first RSV season on the day of inclusion in the study (D01)
  • Informed consent form has been 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 are able to attend the scheduled visit and to comply with all study procedures

Exclusion criteria

Participants are 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 should not be 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 was not intended to contain all considerations relevant to a participant's potential participation in a clinical trial.

Trial design

Primary purpose




Interventional model

Parallel Assignment


None (Open label)

8,058 participants in 2 patient groups

Experimental group
1 intramuscular injection at Day 01
Biological: Nirsevimab
No preventive intervention for RSV
No Intervention group
No intervention

Trial contacts and locations



Central trial contact

Trial Transparency email recommended (Toll free for US & Canada)

Data sourced from

Clinical trials

Find clinical trialsTrials by location
© Copyright 2024 Veeva Systems